[gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs

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* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2022-10-25  2:51 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2022-10-25  2:51 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:bc2980c11d217e5febcd379656c20b1b66b86f8e

commit bc2980c11d217e5febcd379656c20b1b66b86f8e
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Wed Oct 19 20:36:28 2022 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 04af0584d82..bf11956c467 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4391,10 +4391,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index d2e751060ff..b90c85167dc 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -338,6 +338,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -346,6 +347,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 6474a663b30..16582e69804 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5879,6 +5879,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index ae079fcd20e..39f6a1b278d 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2099,6 +2099,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2023-06-23 20:56 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2023-06-23 20:56 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:e02b6f64b36ad02d20c8e24528e5832cc4a6734c

commit e02b6f64b36ad02d20c8e24528e5832cc4a6734c
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Fri Jun 23 17:10:21 2023 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 30 +++++++++++++++++++---
 gcc/flag-types.h                                   |  5 ++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 +++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 +++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++
 8 files changed, 103 insertions(+), 3 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 852f6b629be..739c40368f5 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4349,7 +4349,7 @@ through registers.
 In order to satisfy users with different security needs and control the
 run-time overhead at the same time, the @var{choice} parameter provides a
 flexible way to choose the subset of the call-used registers to be zeroed.
-The three basic values of @var{choice} are:
+The four basic values of @var{choice} are:
 
 @itemize @bullet
 @item
@@ -4362,10 +4362,16 @@ the function.
 
 @item
 @samp{all} zeros all call-used registers.
+
+@item
+@samp{leafy} behaves like @samp{used} in a leaf function, and like
+@samp{all} in a nonleaf function.  This makes for leaner zeroing in leaf
+functions, where the set of used registers is known, and that may be
+enough for some purposes of register zeroing.
 @end itemize
 
 In addition to these three basic choices, it is possible to modify
-@samp{used} or @samp{all} as follows:
+@samp{used}, @samp{all}, and @samp{leafy} as follows:
 
 @itemize @bullet
 @item
@@ -4412,10 +4418,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
 Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+@samp{all-gpr-arg}, @samp{leafy-arg}, and @samp{leafy-gpr-arg} are
+mainly used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index 2e650bf1c48..0d2dab1b99d 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 6a79a8290f6..dd2c1136e07 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5866,6 +5866,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index 3087bdac2c6..ac81d4e4294 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2115,6 +2115,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2023-06-23 20:13 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2023-06-23 20:13 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:b56e58d510f090bd70470dcb02b23253946883da

commit b56e58d510f090bd70470dcb02b23253946883da
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Fri Jun 23 17:10:21 2023 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 28 +++++++++++++++++++---
 gcc/flag-types.h                                   |  5 ++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 ++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 ++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 +++++++++++++
 8 files changed, 101 insertions(+), 3 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 852f6b629be..b30191b6850 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4349,7 +4349,7 @@ through registers.
 In order to satisfy users with different security needs and control the
 run-time overhead at the same time, the @var{choice} parameter provides a
 flexible way to choose the subset of the call-used registers to be zeroed.
-The three basic values of @var{choice} are:
+The four basic values of @var{choice} are:
 
 @itemize @bullet
 @item
@@ -4362,10 +4362,14 @@ the function.
 
 @item
 @samp{all} zeros all call-used registers.
+
+@item
+@samp{leafy} behaves like @samp{used} in a leaf function, and like
+@samp{all} in a nonleaf function.
 @end itemize
 
 In addition to these three basic choices, it is possible to modify
-@samp{used} or @samp{all} as follows:
+@samp{used}, @samp{all}, and @samp{leafy} as follows:
 
 @itemize @bullet
 @item
@@ -4412,10 +4416,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
 Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+@samp{all-gpr-arg}, @samp{leafy-arg}, and @samp{leafy-gpr-arg} are
+mainly used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index 2e650bf1c48..0d2dab1b99d 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 6a79a8290f6..dd2c1136e07 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5866,6 +5866,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index 3087bdac2c6..ac81d4e4294 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2115,6 +2115,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2023-06-09  8:07 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2023-06-09  8:07 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:b5bfd1a54dfd94f4e3854ea41e84172de59508eb

commit b5bfd1a54dfd94f4e3854ea41e84172de59508eb
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Thu Jun 8 01:34:48 2023 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index e6e1236e338..6f3338ed397 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4409,10 +4409,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index f83d165fbfe..6a2e1beb997 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index edf0b2ec6cf..ebca0628a26 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5894,6 +5894,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index fb2e5388ab1..9cc8998cfe1 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2114,6 +2114,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2023-06-09  6:25 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2023-06-09  6:25 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:8107c786ebc29b9f6b8b41b22f0b9acc1cc19faa

commit 8107c786ebc29b9f6b8b41b22f0b9acc1cc19faa
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Thu Jun 8 01:34:48 2023 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index e6e1236e338..6f3338ed397 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4409,10 +4409,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index f83d165fbfe..6a2e1beb997 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index edf0b2ec6cf..ebca0628a26 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5894,6 +5894,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index fb2e5388ab1..9cc8998cfe1 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2114,6 +2114,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2023-06-09  6:17 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2023-06-09  6:17 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:d6f494022996bdaf2c9e5e2310d5a5c5f5598c04

commit d6f494022996bdaf2c9e5e2310d5a5c5f5598c04
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Thu Jun 8 01:34:48 2023 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index e6e1236e338..6f3338ed397 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4409,10 +4409,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index f83d165fbfe..6a2e1beb997 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index edf0b2ec6cf..ebca0628a26 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5894,6 +5894,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index fb2e5388ab1..9cc8998cfe1 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2114,6 +2114,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2023-06-08 10:59 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2023-06-08 10:59 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:ede7847039a404d1ff8d3bf2143368cbb38247db

commit ede7847039a404d1ff8d3bf2143368cbb38247db
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Wed Oct 19 20:36:28 2022 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 7b559250273..f8b0bb53ef5 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4412,10 +4412,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index f83d165fbfe..6a2e1beb997 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 82102ed78d7..7b03f9e7441 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5868,6 +5868,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index 86b94d62b58..93c78be8b0d 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2114,6 +2114,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2023-06-08 10:43 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2023-06-08 10:43 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:3f2ba1decbee0c60d31df764555ba4fa1ae09970

commit 3f2ba1decbee0c60d31df764555ba4fa1ae09970
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Thu Jun 8 01:34:48 2023 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 7b559250273..f8b0bb53ef5 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4412,10 +4412,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index f83d165fbfe..6a2e1beb997 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 82102ed78d7..7b03f9e7441 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5868,6 +5868,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index 86b94d62b58..93c78be8b0d 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2114,6 +2114,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2023-06-08  9:18 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2023-06-08  9:18 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:ede7847039a404d1ff8d3bf2143368cbb38247db

commit ede7847039a404d1ff8d3bf2143368cbb38247db
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Wed Oct 19 20:36:28 2022 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 7b559250273..f8b0bb53ef5 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4412,10 +4412,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index f83d165fbfe..6a2e1beb997 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 82102ed78d7..7b03f9e7441 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5868,6 +5868,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index 86b94d62b58..93c78be8b0d 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2114,6 +2114,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2023-06-08  4:47 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2023-06-08  4:47 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:d707886095e92e560170820e55b3e1c97defc51a

commit d707886095e92e560170820e55b3e1c97defc51a
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Wed Oct 19 20:36:28 2022 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index cdbd4b34a35..56aa81c8c37 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4401,10 +4401,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index 78dbdbe90dd..36305de589e 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -338,6 +338,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -346,6 +347,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 82102ed78d7..7b03f9e7441 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5868,6 +5868,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index 86b94d62b58..93c78be8b0d 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2114,6 +2114,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2022-10-20 22:32 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2022-10-20 22:32 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:5b40f4909641fdcbca58c2997db2b4bd1c68127f

commit 5b40f4909641fdcbca58c2997db2b4bd1c68127f
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Wed Oct 19 20:36:28 2022 -0300

    Add leafy mode for zero-call-used-regs
    
    Introduce 'leafy' to auto-select between 'used' and 'all' for leaf and
    nonleaf functions, respectively.
    
    
    for  gcc/ChangeLog
    
            * doc/extend.texi (zero-call-used-regs): Document leafy and
            variants thereof.
            * flag-types.h (zero_regs_flags): Add LEAFY_MODE, as well as
            LEAFY and variants.
            * function.cc (gen_call_ued_regs_seq): Set only_used for leaf
            functions in leafy mode.
            * opts.cc (zero_call_used_regs_opts): Add leafy and variants.
    
    for  gcc/testsuite/ChangeLog
    
            * c-c++-common/zero-scratch-regs-leafy-1.c: New.
            * c-c++-common/zero-scratch-regs-leafy-2.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-1.c: New.
            * gcc.target/i386/zero-scratch-regs-leafy-2.c: New.

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 3532728aa1a..16f161ebf8a 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4402,10 +4402,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index d6d3b0e7800..268bf028ada 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 6474a663b30..16582e69804 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5879,6 +5879,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index ae079fcd20e..39f6a1b278d 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2099,6 +2099,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2022-10-20  5:45 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2022-10-20  5:45 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:f9b0e7992963ace4b3167f7bfdc822c80c2d3f63

commit f9b0e7992963ace4b3167f7bfdc822c80c2d3f63
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Wed Oct 19 20:36:28 2022 -0300

    Add leafy mode for zero-call-used-regs

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  3 +++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 3532728aa1a..16f161ebf8a 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4402,10 +4402,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index d6d3b0e7800..268bf028ada 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 6474a663b30..16582e69804 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5879,6 +5879,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index ae079fcd20e..39f6a1b278d 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2099,6 +2099,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

* [gcc(refs/users/aoliva/heads/testme)] Add leafy mode for zero-call-used-regs
@ 2022-10-20  4:09 Alexandre Oliva
  0 siblings, 0 replies; 13+ messages in thread
From: Alexandre Oliva @ 2022-10-20  4:09 UTC (permalink / raw)
  To: gcc-cvs

https://gcc.gnu.org/g:e7149e1c1eb60ddc7e0dac2b3b553ecf8db25823

commit e7149e1c1eb60ddc7e0dac2b3b553ecf8db25823
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Wed Oct 19 20:36:28 2022 -0300

    Add leafy mode for zero-call-used-regs

Diff:
---
 gcc/doc/extend.texi                                | 22 ++++++++++++++++++++--
 gcc/flag-types.h                                   |  5 +++++
 gcc/function.cc                                    |  4 ++++
 gcc/opts.cc                                        |  4 ++++
 .../c-c++-common/zero-scratch-regs-leafy-1.c       | 15 +++++++++++++++
 .../c-c++-common/zero-scratch-regs-leafy-2.c       | 21 +++++++++++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-1.c    | 12 ++++++++++++
 .../gcc.target/i386/zero-scratch-regs-leafy-2.c    | 16 ++++++++++++++++
 8 files changed, 97 insertions(+), 2 deletions(-)

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 3532728aa1a..16f161ebf8a 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -4402,10 +4402,28 @@ zeros all call-used registers that pass arguments.
 @item all-gpr-arg
 zeros all call-used general purpose registers that pass
 arguments.
+
+@item leafy
+Same as @samp{used} in a leaf function, and same as @samp{all} in a
+nonleaf function.
+
+@item leafy-gpr
+Same as @samp{used-gpr} in a leaf function, and same as @samp{all-gpr}
+in a nonleaf function.
+
+@item leafy-arg
+Same as @samp{used-arg} in a leaf function, and same as @samp{all-arg}
+in a nonleaf function.
+
+@item leafy-gpr-arg
+Same as @samp{used-gpr-arg} in a leaf function, and same as
+@samp{all-gpr-arg} in a nonleaf function.
+
 @end table
 
-Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{all-arg},
-and @samp{all-gpr-arg} are mainly used for ROP mitigation.
+Of this list, @samp{used-arg}, @samp{used-gpr-arg}, @samp{leafy-arg},
+@samp{leafy-gpr-arg}, @samp{all-arg}, and @samp{all-gpr-arg} are mainly
+used for ROP mitigation.
 
 The default for the attribute is controlled by @option{-fzero-call-used-regs}.
 @end table
diff --git a/gcc/flag-types.h b/gcc/flag-types.h
index d6d3b0e7800..268bf028ada 100644
--- a/gcc/flag-types.h
+++ b/gcc/flag-types.h
@@ -348,6 +348,7 @@ namespace zero_regs_flags {
   const unsigned int ONLY_GPR = 1UL << 2;
   const unsigned int ONLY_ARG = 1UL << 3;
   const unsigned int ENABLED = 1UL << 4;
+  const unsigned int LEAFY_MODE = 1UL << 5;
   const unsigned int USED_GPR_ARG = ENABLED | ONLY_USED | ONLY_GPR | ONLY_ARG;
   const unsigned int USED_GPR = ENABLED | ONLY_USED | ONLY_GPR;
   const unsigned int USED_ARG = ENABLED | ONLY_USED | ONLY_ARG;
@@ -356,6 +357,10 @@ namespace zero_regs_flags {
   const unsigned int ALL_GPR = ENABLED | ONLY_GPR;
   const unsigned int ALL_ARG = ENABLED | ONLY_ARG;
   const unsigned int ALL = ENABLED;
+  const unsigned int LEAFY_GPR_ARG = ENABLED | LEAFY_MODE | ONLY_GPR | ONLY_ARG;
+  const unsigned int LEAFY_GPR = ENABLED | LEAFY_MODE | ONLY_GPR;
+  const unsigned int LEAFY_ARG = ENABLED | LEAFY_MODE | ONLY_ARG;
+  const unsigned int LEAFY = ENABLED | LEAFY_MODE;
 }
 
 /* Settings of flag_incremental_link.  */
diff --git a/gcc/function.cc b/gcc/function.cc
index 6474a663b30..ad9b56c14ea 100644
--- a/gcc/function.cc
+++ b/gcc/function.cc
@@ -5857,6 +5857,7 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   bool only_gpr = true;
   bool only_used = true;
   bool only_arg = true;
+  bool leafy = true;
 
   /* No need to zero call-used-regs in main ().  */
   if (MAIN_NAME_P (DECL_NAME (current_function_decl)))
@@ -5879,6 +5880,9 @@ gen_call_used_regs_seq (rtx_insn *ret, unsigned int zero_regs_type)
   only_used = zero_regs_type & ONLY_USED;
   only_arg = zero_regs_type & ONLY_ARG;
 
+  if ((zero_regs_type & LEAFY_MODE) && leaf_function_p ())
+    only_used = true;
+
   /* For each of the hard registers, we should zero it if:
 	    1. it is a call-used register;
 	and 2. it is not a fixed register;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index ae079fcd20e..39f6a1b278d 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -2099,6 +2099,10 @@ const struct zero_call_used_regs_opts_s zero_call_used_regs_opts[] =
   ZERO_CALL_USED_REGS_OPT (all-gpr, zero_regs_flags::ALL_GPR),
   ZERO_CALL_USED_REGS_OPT (all-arg, zero_regs_flags::ALL_ARG),
   ZERO_CALL_USED_REGS_OPT (all, zero_regs_flags::ALL),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr-arg, zero_regs_flags::LEAFY_GPR_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy-gpr, zero_regs_flags::LEAFY_GPR),
+  ZERO_CALL_USED_REGS_OPT (leafy-arg, zero_regs_flags::LEAFY_ARG),
+  ZERO_CALL_USED_REGS_OPT (leafy, zero_regs_flags::LEAFY),
 #undef ZERO_CALL_USED_REGS_OPT
   {NULL, 0U}
 };
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..c1a0c31ba1c
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,15 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy" } */
+
+volatile int result = 0;
+int 
+__attribute__((noipa))
+foo (int x)
+{
+  return x;
+}
+int main()
+{
+  result = foo (2);
+  return 0;
+}
diff --git a/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..d450620c1fc
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+#include <assert.h>
+int result = 0;
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo1 (int x)
+{
+  return (x + 1);
+}
+
+int 
+__attribute__((noipa))
+__attribute__ ((zero_call_used_regs("leafy")))
+foo2 (int x)
+{
+  return foo1 (x + 2);
+}
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
new file mode 100644
index 00000000000..2277710c771
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy -fno-stack-protector -fno-PIC" } */
+
+void
+foo (void)
+{
+}
+
+/* { dg-final { scan-assembler-not "vzeroall" } } */
+/* { dg-final { scan-assembler-not "%xmm" } } */
+/* { dg-final { scan-assembler-not "xorl\[ \t\]+%" } } */
+/* { dg-final { scan-assembler-not "movl\[ \t\]+%" } } */
diff --git a/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
new file mode 100644
index 00000000000..24b85c3dbb7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/zero-scratch-regs-leafy-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fzero-call-used-regs=leafy-gpr -fno-stack-protector -fno-PIC" } */
+
+extern int bar (int);
+
+void
+foo (void)
+{
+  int x = bar (0);
+  if (x)
+    bar (1);
+}
+
+/* { dg-final { scan-assembler "xorl\[ \t\]+%eax, %eax" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%edx, %edx" } } */
+/* { dg-final { scan-assembler "xorl\[ \t\]+%ecx, %ecx" } } */

^ permalink raw reply	[flat|nested] 13+ messages in thread

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