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* [RFC/PATCH v2][PR89245] Check REG_CALL_DECL note during the tail-merging
@ 2019-07-09 21:00 Dragan Mladjenovic
  2019-07-09 21:21 ` Jeff Law
  0 siblings, 1 reply; 7+ messages in thread
From: Dragan Mladjenovic @ 2019-07-09 21:00 UTC (permalink / raw)
  To: gcc-patches
  Cc: Dragan Mladjenovic, Richard Sandiford, Jakub Jelinek, Jeff Law

This patch prevents merging of CALL instructions that that have different
REG_CALL_DECL notes attached to them.

On most architectures this is not an important distinction. Usually instruction patterns
for calls to different functions reference different SYMBOL_REF-s, so they won't match.
On MIPS PIC calls get split into an got_load/*call_internal pair where the latter represents
indirect register call w/o SYMBOL_REF attached (until machine_reorg pass). The bugzilla issue
had such two internal_call-s merged despite the fact that they had different register usage
information assigned by ipa-ra.

As per comment form Richard Sandiford, this version compares reg usage for both call
instruction instead of shallow comparing the notes. Tests updated accordingly.

gcc/ChangeLog:

2019-07-09  Dragan Mladjenovic  <dmladjenovic@wavecomp.com>

	* cfgcleanup.c (old_insns_match_p): Check if used hard regs set is equal
	for both call instructions.

gcc/testsuite/ChangeLog:

2019-07-09  Dragan Mladjenovic  <dmladjenovic@wavecomp.com>

	* gcc.target/mips/cfgcleanup-jalr1.c: New test.
	* gcc.target/mips/cfgcleanup-jalr2.c: New test.
	* gcc.target/mips/cfgcleanup-jalr3.c: New test.
---
 gcc/cfgcleanup.c                                 |  9 +++++++++
 gcc/testsuite/gcc.target/mips/cfgcleanup-jalr1.c | 19 +++++++++++++++++++
 gcc/testsuite/gcc.target/mips/cfgcleanup-jalr2.c | 23 +++++++++++++++++++++++
 gcc/testsuite/gcc.target/mips/cfgcleanup-jalr3.c | 23 +++++++++++++++++++++++
 4 files changed, 74 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/mips/cfgcleanup-jalr1.c
 create mode 100644 gcc/testsuite/gcc.target/mips/cfgcleanup-jalr2.c
 create mode 100644 gcc/testsuite/gcc.target/mips/cfgcleanup-jalr3.c

diff --git a/gcc/cfgcleanup.c b/gcc/cfgcleanup.c
index 992912c..fca3a08 100644
--- a/gcc/cfgcleanup.c
+++ b/gcc/cfgcleanup.c
@@ -53,6 +53,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "dce.h"
 #include "dbgcnt.h"
 #include "rtl-iter.h"
+#include "regs.h"
 
 #define FORWARDER_BLOCK_P(BB) ((BB)->flags & BB_FORWARDER_BLOCK)
 
@@ -1224,6 +1225,14 @@ old_insns_match_p (int mode ATTRIBUTE_UNUSED, rtx_insn *i1, rtx_insn *i2)
 		}
 	    }
 	}
+
+      HARD_REG_SET i1_used, i2_used;
+
+      get_call_reg_set_usage (i1, &i1_used, call_used_reg_set);
+      get_call_reg_set_usage (i2, &i2_used, call_used_reg_set);
+
+      if (!hard_reg_set_equal_p (i1_used, i2_used))
+        return dir_none;
     }
 
   /* If both i1 and i2 are frame related, verify all the CFA notes
diff --git a/gcc/testsuite/gcc.target/mips/cfgcleanup-jalr1.c b/gcc/testsuite/gcc.target/mips/cfgcleanup-jalr1.c
new file mode 100644
index 0000000..24c1826
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/cfgcleanup-jalr1.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-mabicalls -fpic -mno-mips16 -mno-micromips" } */
+/* { dg-skip-if "needs codesize optimization" { *-*-* } { "-O0" "-O1" "-O2" "-O3" } { "" } } */
+
+extern void foo (void*);
+
+extern void bar (void*);
+
+void
+test (void* p)
+{
+   if (!p)
+	foo(p);
+   else
+	bar(p);
+}
+
+/* { dg-final { scan-assembler-not "\\\.reloc\t1f,R_MIPS_JALR,foo" } } */
+/* { dg-final { scan-assembler-not "\\\.reloc\t1f,R_MIPS_JALR,bar" } } */
diff --git a/gcc/testsuite/gcc.target/mips/cfgcleanup-jalr2.c b/gcc/testsuite/gcc.target/mips/cfgcleanup-jalr2.c
new file mode 100644
index 0000000..9fd75c9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/cfgcleanup-jalr2.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-mabicalls -fpic -mno-mips16 -mno-micromips" } */
+/* { dg-additional-options "-fno-inline -fipa-ra -mcompact-branches=never" } */
+/* { dg-skip-if "needs codesize optimization" { *-*-* } { "-O0" "-O1" "-O2" "-O3" } { "" } } */
+
+static int foo (void* p) { __asm__ (""::"r"(p):"$t0"); return 0; }
+
+static int bar (void* p) { return 1; }
+
+int
+test (void* p)
+{
+  int res = !p ? foo(p) : bar(p);
+
+  register int tmp __asm__("$t0") = -1;
+  __asm__ (""::"r"(tmp));
+
+  return res;
+}
+
+/* { dg-final { scan-assembler "\\\.reloc\t1f,R_MIPS_JALR,foo" } } */
+/* { dg-final { scan-assembler "\\\.reloc\t1f,R_MIPS_JALR,bar" } } */
+/* { dg-final { scan-assembler-not "\\.set\tnomacro\n\tjalr\t\\\$25" } } */
diff --git a/gcc/testsuite/gcc.target/mips/cfgcleanup-jalr3.c b/gcc/testsuite/gcc.target/mips/cfgcleanup-jalr3.c
new file mode 100644
index 0000000..580c6ec
--- /dev/null
+++ b/gcc/testsuite/gcc.target/mips/cfgcleanup-jalr3.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-mabicalls -fpic -mno-mips16 -mno-micromips" } */
+/* { dg-additional-options "-fno-inline -fipa-ra -mcompact-branches=never" } */
+/* { dg-skip-if "needs codesize optimization" { *-*-* } { "-O0" "-O1" "-O2" "-O3" } { "" } } */
+
+static int foo (void* p) { return 0; }
+
+static int bar (void* p) { return 1; }
+
+int
+test (void* p)
+{
+  int res = !p ? foo(p) : bar(p);
+
+  register int tmp __asm__("$t0") = -1;
+  __asm__ (""::"r"(tmp));
+
+  return res;
+}
+
+/* { dg-final { scan-assembler-not "\\\.reloc\t1f,R_MIPS_JALR,foo" } } */
+/* { dg-final { scan-assembler-not "\\\.reloc\t1f,R_MIPS_JALR,bar" } } */
+/* { dg-final { scan-assembler "\\.set\tnomacro\n\tjalr\t\\\$25" } } */
-- 
1.9.1

^ permalink raw reply	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2019-10-30 15:50 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-07-09 21:00 [RFC/PATCH v2][PR89245] Check REG_CALL_DECL note during the tail-merging Dragan Mladjenovic
2019-07-09 21:21 ` Jeff Law
2019-07-17  8:32   ` Dragan Mladjenovic
2019-07-24 19:02     ` Jeff Law
2019-09-06 10:23       ` [EXTERNAL]Re: " Dragan Mladjenovic
2019-10-01 19:35         ` Jeff Law
2019-10-30 15:53           ` Dragan Mladjenovic

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