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* [PATCH][AARCH64][PR target/84882] Add mno-strict-align
@ 2018-03-27 13:17 Sudakshina Das
  2018-05-10 10:31 ` Sudakshina Das
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Sudakshina Das @ 2018-03-27 13:17 UTC (permalink / raw)
  To: gcc-patches; +Cc: James Greenhalgh, Richard Earnshaw, Marcus Shawcroft, nd

[-- Attachment #1: Type: text/plain, Size: 1243 bytes --]

Hi

This patch adds the no variant to -mstrict-align and the corresponding
function attribute. To enable the function attribute, I have modified
aarch64_can_inline_p () to allow checks even when the callee function
has no attribute. The need for this is shown by the new test
target_attr_18.c.

Testing: Bootstrapped, regtested and added new tests that are copies
of earlier tests checking -mstrict-align with opposite scan directives.

Is this ok for trunk?

Sudi


*** gcc/ChangeLog ***

2018-03-27  Sudakshina Das  <sudi.das@arm.com>

	* common/config/aarch64/aarch64-common.c (aarch64_handle_option):
	Check val before adding MASK_STRICT_ALIGN to opts->x_target_flags.
	* config/aarch64/aarch64.opt (mstrict-align): Remove RejectNegative.
	* config/aarch64/aarch64.c (aarch64_attributes): Mark allow_neg
	as true for strict-align.
	(aarch64_can_inline_p): Perform checks even when callee has no
	attributes to check for strict alignment.
	* doc/extend.texi (AArch64 Function Attributes): Document
	no-strict-align.
	* doc/invoke.texi: (AArch64 Options): Likewise.

*** gcc/testsuite/ChangeLog ***

2018-03-27  Sudakshina Das  <sudi.das@arm.com>

	* gcc.target/aarch64/pr84882.c: New test.
	* gcc.target/aarch64/target_attr_18.c: Likewise.

[-- Attachment #2: strict-align.diff --]
[-- Type: text/x-patch, Size: 6137 bytes --]

diff --git a/gcc/common/config/aarch64/aarch64-common.c b/gcc/common/config/aarch64/aarch64-common.c
index 7fd9305..d5655a0 100644
--- a/gcc/common/config/aarch64/aarch64-common.c
+++ b/gcc/common/config/aarch64/aarch64-common.c
@@ -97,7 +97,10 @@ aarch64_handle_option (struct gcc_options *opts,
       return true;
 
     case OPT_mstrict_align:
-      opts->x_target_flags |= MASK_STRICT_ALIGN;
+      if (val)
+	opts->x_target_flags |= MASK_STRICT_ALIGN;
+      else
+	opts->x_target_flags &= ~MASK_STRICT_ALIGN;
       return true;
 
     case OPT_momit_leaf_frame_pointer:
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 4b5183b..4f35a6c 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -11277,7 +11277,7 @@ static const struct aarch64_attribute_info aarch64_attributes[] =
   { "fix-cortex-a53-843419", aarch64_attr_bool, true, NULL,
      OPT_mfix_cortex_a53_843419 },
   { "cmodel", aarch64_attr_enum, false, NULL, OPT_mcmodel_ },
-  { "strict-align", aarch64_attr_mask, false, NULL, OPT_mstrict_align },
+  { "strict-align", aarch64_attr_mask, true, NULL, OPT_mstrict_align },
   { "omit-leaf-frame-pointer", aarch64_attr_bool, true, NULL,
      OPT_momit_leaf_frame_pointer },
   { "tls-dialect", aarch64_attr_enum, false, NULL, OPT_mtls_dialect_ },
@@ -11640,16 +11640,13 @@ aarch64_can_inline_p (tree caller, tree callee)
   tree caller_tree = DECL_FUNCTION_SPECIFIC_TARGET (caller);
   tree callee_tree = DECL_FUNCTION_SPECIFIC_TARGET (callee);
 
-  /* If callee has no option attributes, then it is ok to inline.  */
-  if (!callee_tree)
-    return true;
-
   struct cl_target_option *caller_opts
 	= TREE_TARGET_OPTION (caller_tree ? caller_tree
 					   : target_option_default_node);
 
-  struct cl_target_option *callee_opts = TREE_TARGET_OPTION (callee_tree);
-
+  struct cl_target_option *callee_opts
+	= TREE_TARGET_OPTION (callee_tree ? callee_tree
+					   : target_option_default_node);
 
   /* Callee's ISA flags should be a subset of the caller's.  */
   if ((caller_opts->x_aarch64_isa_flags & callee_opts->x_aarch64_isa_flags)
diff --git a/gcc/config/aarch64/aarch64.opt b/gcc/config/aarch64/aarch64.opt
index 52eaf8c..1426b45 100644
--- a/gcc/config/aarch64/aarch64.opt
+++ b/gcc/config/aarch64/aarch64.opt
@@ -85,7 +85,7 @@ Target RejectNegative Joined Enum(cmodel) Var(aarch64_cmodel_var) Init(AARCH64_C
 Specify the code model.
 
 mstrict-align
-Target Report RejectNegative Mask(STRICT_ALIGN) Save
+Target Report Mask(STRICT_ALIGN) Save
 Don't assume that unaligned accesses are handled by the system.
 
 momit-leaf-frame-pointer
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 93a0ebc..dcda216 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -3605,8 +3605,10 @@ for the command line option @option{-mcmodel=}.
 @item strict-align
 @cindex @code{strict-align} function attribute, AArch64
 Indicates that the compiler should not assume that unaligned memory references
-are handled by the system.  The behavior is the same as for the command-line
-option @option{-mstrict-align}.
+are handled by the system.  To allow the compiler to assume that aligned memory
+references are handled by the system, the inverse attribute
+@code{no-strict-align} can be specified.  The behavior is the same as for the
+command-line option @option{-mstrict-align} and @option{-mno-strict-align}.
 
 @item omit-leaf-frame-pointer
 @cindex @code{omit-leaf-frame-pointer} function attribute, AArch64
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index feacd56..0574d21 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -596,7 +596,7 @@ Objective-C and Objective-C++ Dialects}.
 @gccoptlist{-mabi=@var{name}  -mbig-endian  -mlittle-endian @gol
 -mgeneral-regs-only @gol
 -mcmodel=tiny  -mcmodel=small  -mcmodel=large @gol
--mstrict-align @gol
+-mstrict-align -mno-strict-align @gol
 -momit-leaf-frame-pointer @gol
 -mtls-dialect=desc  -mtls-dialect=traditional @gol
 -mtls-size=@var{size} @gol
@@ -14601,9 +14601,11 @@ Generate code for the large code model.  This makes no assumptions about
 addresses and sizes of sections.  Programs can be statically linked only.
 
 @item -mstrict-align
+@itemx -mno-strict-align
 @opindex mstrict-align
-Avoid generating memory accesses that may not be aligned on a natural object
-boundary as described in the architecture specification.
+@opindex mno-strict-align
+Avoid or allow generating memory accesses that may not be aligned on a natural
+object boundary as described in the architecture specification.
 
 @item -momit-leaf-frame-pointer
 @itemx -mno-omit-leaf-frame-pointer
diff --git a/gcc/testsuite/gcc.target/aarch64/pr84882.c b/gcc/testsuite/gcc.target/aarch64/pr84882.c
new file mode 100644
index 0000000..ffc7d55
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr84882.c
@@ -0,0 +1,33 @@
+/* This is a copy of pr71727.c with scanning reversed.  */
+/* { dg-do compile } */
+/* { dg-options "-mstrict-align -O3 -mno-strict-align" } */
+
+struct test_struct_s
+{
+  long a;
+  long b;
+  long c;
+  long d;
+  unsigned long e;
+};
+
+
+char _a;
+struct test_struct_s xarray[128];
+
+void
+_start (void)
+{
+  struct test_struct_s *new_entry;
+
+  new_entry = &xarray[0];
+  new_entry->a = 1;
+  new_entry->b = 2;
+  new_entry->c = 3;
+  new_entry->d = 4;
+  new_entry->e = 5;
+
+  return;
+}
+
+/* { dg-final { scan-assembler "add\tx[0-9]+, x[0-9]+, :" {target lp64} } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/target_attr_18.c b/gcc/testsuite/gcc.target/aarch64/target_attr_18.c
new file mode 100644
index 0000000..33b1d44
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/target_attr_18.c
@@ -0,0 +1,21 @@
+/* This is a copy of target_attr_6.c to instead check no-strict-align.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -save-temps -mstrict-align" } */
+
+/* Inlining strict-align functions into non-strict align
+   functions is not allowed.  */
+
+int
+bar (int a)
+{
+  return a - 6;
+}
+
+__attribute__ ((target ("no-strict-align")))
+int
+bam (int a)
+{
+  return a - bar (a);
+}
+
+/* { dg-final { scan-assembler "bl.*bar" } } */

^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-05-23 11:36 UTC | newest]

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2018-03-27 13:17 [PATCH][AARCH64][PR target/84882] Add mno-strict-align Sudakshina Das
2018-05-10 10:31 ` Sudakshina Das
2018-05-17  9:52 ` Kyrill Tkachov
2018-05-18 14:51 ` Richard Earnshaw (lists)
2018-05-23 11:47   ` Sudakshina Das

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