Disable strcmp/strncmp/memcmp inlining when optimization

level is lower than 2 or Os

From-SVN: r263028

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f5e8d62c7b9acce141f73ab896af611962644c0f..c2bf139a6597c56b37949178fadd0bfae997dbcb 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2018-07-26  Qing Zhao  <qing.zhao@oracle.com>
+
+       * builtins.c (inline_expand_builtin_string_cmp): Disable inlining
+       when optimization level is lower than 2 or optimize for size.
+
 2018-07-26  Martin Sebor  <msebor@redhat.com>
 
        PR tree-optimization/86043

diff --git a/gcc/builtins.c b/gcc/builtins.c
index aa3e0d80cd19a9cb2cfc6b707259ec3349b79f7a..c6596113801b23b682d16dc1e26b404de793eb50 100644 (file)
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -6854,6 +6854,11 @@ inline_expand_builtin_string_cmp (tree exp, rtx target)
   unsigned HOST_WIDE_INT length = 0;
   bool is_ncmp = (fcode == BUILT_IN_STRNCMP || fcode == BUILT_IN_MEMCMP);
 
+  /* Do NOT apply this inlining expansion when optimizing for size or 
+     optimization level below 2.  */
+  if (optimize < 2 || optimize_insn_for_size_p ())
+    return NULL_RTX;
+
   gcc_checking_assert (fcode == BUILT_IN_STRCMP
                       || fcode == BUILT_IN_STRNCMP
                       || fcode == BUILT_IN_MEMCMP);

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index eccfcd0caec2fb1fd967548784d641e66f2d8e9b..f48c3d3454d3631e491f8894e7132ecbb7d76acd 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-07-26  Qing Zhao  <qing.zhao@oracle.com>
+
+       * gcc.dg/strcmpopt_5.c: Change to O2 to enable the transformation.
+       * gcc.dg/strcmpopt_6.c: Likewise.
+
 2018-07-26  Pat Haugen  <pthaugen@us.ibm.com>
 
        PR target/86612

diff --git a/gcc/testsuite/gcc.dg/strcmpopt_5.c b/gcc/testsuite/gcc.dg/strcmpopt_5.c
index c30fb78eb64173a83a07ca532756d37f87424468..d368277bfbbd522a513e78529917d2f51902e75f 100644 (file)
--- a/gcc/testsuite/gcc.dg/strcmpopt_5.c
+++ b/gcc/testsuite/gcc.dg/strcmpopt_5.c
@@ -1,5 +1,5 @@
 /* { dg-do run } */
-/* { dg-options "-O -fdump-rtl-expand" } */
+/* { dg-options "-O2 -fdump-rtl-expand" } */
 
 typedef struct { char s[8]; int x; } S;
 __attribute__ ((noinline)) int

diff --git a/gcc/testsuite/gcc.dg/strcmpopt_6.c b/gcc/testsuite/gcc.dg/strcmpopt_6.c
index 0f8cf87fbd00d9531d060ed3a2efcac1a0a86822..964b9e4839fa16274f831a8a0ee112a19a602f0e 100644 (file)
--- a/gcc/testsuite/gcc.dg/strcmpopt_6.c
+++ b/gcc/testsuite/gcc.dg/strcmpopt_6.c
@@ -1,7 +1,7 @@
 /* When the specified length exceeds one of the arguments of the call to memcmp, 
    the call to memcmp should NOT be inlined.  */
 /* { dg-do run } */
-/* { dg-options "-O -fdump-rtl-expand -Wno-stringop-overflow" } */
+/* { dg-options "-O2 -fdump-rtl-expand -Wno-stringop-overflow" } */
 
 typedef struct { char s[8]; int x; } S;
 
@@ -33,4 +33,4 @@ int main (void)
 
 }
 
-/* { dg-final { scan-rtl-dump-times "__builtin_memcmp" 4 "expand" } } */
+/* { dg-final { scan-rtl-dump-times "__builtin_memcmp" 6 "expand" } } */