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| author | Richard Biener <rguenther@suse.de> | 2019-05-03 10:44:17 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2019-05-03 10:44:17 +0000 |
| commit | a4f9edf36c8ceebac5c34d6d913871bf1c0f5190 (patch) | |
| tree | fa4e96381aab2da90d4246d8e7ac8cbfa4246b38 /gcc | |
| parent | a7eb97ad269b6509bd7b31ca373daea98e4d7e85 (diff) | |
| download | gcc-a4f9edf36c8ceebac5c34d6d913871bf1c0f5190.zip gcc-a4f9edf36c8ceebac5c34d6d913871bf1c0f5190.tar.gz gcc-a4f9edf36c8ceebac5c34d6d913871bf1c0f5190.tar.bz2 | |
re PR tree-optimization/87314 (pointless comparison of malloc result to a string not eliminated)
2019-05-03 Richard Biener <rguenther@suse.de>
PR middle-end/87314
* match.pd (cmp (convert1?@2 addr@0) (convert2? addr@1)):
Handle STRING_CST vs DECL or STRING_CST.
* gcc.dg/pr87314-1.c: New testcase.
From-SVN: r270845
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/match.pd | 19 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr87314-1.c | 11 |
4 files changed, 40 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 80c34be..e9def2f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,11 @@ 2019-05-03 Richard Biener <rguenther@suse.de> + PR middle-end/87314 + * match.pd (cmp (convert1?@2 addr@0) (convert2? addr@1)): + Handle STRING_CST vs DECL or STRING_CST. + +2019-05-03 Richard Biener <rguenther@suse.de> + PR tree-optimization/88963 * tree-ssa-forwprop.c (pass_forwprop::execute): Rewrite vector loads feeding only BIT_FIELD_REFs to component diff --git a/gcc/match.pd b/gcc/match.pd index 039ddac..ec03a68 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -3905,7 +3905,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) equal = (base0 == base1); if (equal == 0) { - if (!DECL_P (base0) || !DECL_P (base1)) + HOST_WIDE_INT ioff0 = -1, ioff1 = -1; + off0.is_constant (&ioff0); + off1.is_constant (&ioff1); + if ((DECL_P (base0) && TREE_CODE (base1) == STRING_CST) + || (TREE_CODE (base0) == STRING_CST && DECL_P (base1)) + || (TREE_CODE (base0) == STRING_CST + && TREE_CODE (base1) == STRING_CST + && ioff0 >= 0 && ioff1 >= 0 + && ioff0 < TREE_STRING_LENGTH (base0) + && ioff1 < TREE_STRING_LENGTH (base1) + /* This is a too conservative test that the STRING_CSTs + will not end up being string-merged. */ + && strncmp (TREE_STRING_POINTER (base0) + ioff0, + TREE_STRING_POINTER (base1) + ioff1, + MIN (TREE_STRING_LENGTH (base0) - ioff0, + TREE_STRING_LENGTH (base1) - ioff1)) != 0)) + ; + else if (!DECL_P (base0) || !DECL_P (base1)) equal = 2; else if (cmp != EQ_EXPR && cmp != NE_EXPR) equal = 2; diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 57a07d1..0e23e57 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,10 @@ 2019-05-03 Richard Biener <rguenther@suse.de> + PR middle-end/87314 + * gcc.dg/pr87314-1.c: New testcase. + +2019-05-03 Richard Biener <rguenther@suse.de> + PR tree-optimization/88963 * gcc.dg/tree-ssa/ssa-fre-31.c: Disable forwprop. * gcc.target/i386/pr88963-1.c: New testcase. diff --git a/gcc/testsuite/gcc.dg/pr87314-1.c b/gcc/testsuite/gcc.dg/pr87314-1.c new file mode 100644 index 0000000..4dc85c8 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr87314-1.c @@ -0,0 +1,11 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-original" } */ + +int f(){ int a; return &a==(void *)"hello"; } +int g(){ return "bye"=="hello"; } +int h() { return "bye"=="hellobye"+5; } + +/* { dg-final { scan-tree-dump-times "hello" 1 "original" } } */ +/* The test in h() should be retained because the result depends on + string merging. */ +/* { dg-final { scan-assembler "hello" } } */ |