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| author | Richard Biener <rguenther@suse.de> | 2013-03-20 13:26:19 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2013-03-20 13:26:19 +0000 |
| commit | 92a8d7a7332ca2d53a70d856052b148331da518a (patch) | |
| tree | 4cf6946974a9a59ae3ef87513ac71079e3170b97 /gcc | |
| parent | 54714c680a46d4290c10b7369c1c1b2afd1e8d97 (diff) | |
| download | gcc-92a8d7a7332ca2d53a70d856052b148331da518a.zip gcc-92a8d7a7332ca2d53a70d856052b148331da518a.tar.gz gcc-92a8d7a7332ca2d53a70d856052b148331da518a.tar.bz2 | |
re PR tree-optimization/56661 (Incorrect code with -O1 -ftree-pre)
2013-03-20 Richard Biener <rguenther@suse.de>
PR tree-optimization/56661
* tree-ssa-sccvn.c (visit_use): Only value-number calls if
the result does not have to be distinct.
* gcc.dg/torture/pr56661.c: New testcase.
From-SVN: r196825
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr56661.c | 46 | ||||
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 9 |
4 files changed, 64 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 217a76d..a238d53 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,11 @@ 2013-03-20 Richard Biener <rguenther@suse.de> + PR tree-optimization/56661 + * tree-ssa-sccvn.c (visit_use): Only value-number calls if + the result does not have to be distinct. + +2013-03-20 Richard Biener <rguenther@suse.de> + * tree-inline.c (copy_tree_body_r): Sync MEM_REF code with remap_gimple_op_r. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 29d5d60..96c0bc7 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2013-03-20 Richard Biener <rguenther@suse.de> + + PR tree-optimization/56661 + * gcc.dg/torture/pr56661.c: New testcase. + 2013-03-20 Bill Schmidt <wschmidt@linux.vnet.ibm.com> PR rtl-optimization/56605 diff --git a/gcc/testsuite/gcc.dg/torture/pr56661.c b/gcc/testsuite/gcc.dg/torture/pr56661.c new file mode 100644 index 0000000..6fdaedb --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr56661.c @@ -0,0 +1,46 @@ +/* { dg-do run } */ + +__attribute__((noinline, noclone)) void +bar (int *b) +{ + b[0] = b[1] = b[2] = 1; +} + +__attribute__((noinline, noclone)) int +baz (int x) +{ + if (x != 1) + __builtin_abort (); +} + +void +foo (int x) +{ + if (x == 0) + { + int *b = __builtin_malloc (3 * sizeof (int)); + while (b[0]) + ; + } + else if (x == 1) + { + int i, j; + int *b = __builtin_malloc (3 * sizeof (int)); + for (i = 0; i < 2; i++) + { + bar (b); + for (j = 0; j < 3; ++j) + baz (b[j]); + baz (b[0]); + } + } +} + +int +main () +{ + int x = 1; + asm volatile ("" : "+r" (x)); + foo (x); + return 0; +} diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index 8360cc7..e7aefbf 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -3506,8 +3506,13 @@ visit_use (tree use) We can value number 2 calls to the same function with the same vuse and the same operands which are not subsequent the same, because there is no code in the program that can - compare the 2 values. */ - || gimple_vdef (stmt))) + compare the 2 values... */ + || (gimple_vdef (stmt) + /* ... unless the call returns a pointer which does + not alias with anything else. In which case the + information that the values are distinct are encoded + in the IL. */ + && !(gimple_call_return_flags (stmt) & ERF_NOALIAS)))) changed = visit_reference_op_call (lhs, stmt); else changed = defs_to_varying (stmt); |