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| author | Richard Guenther <rguenther@suse.de> | 2010-02-03 13:03:39 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2010-02-03 13:03:39 +0000 |
| commit | e3c70387dc0fdf85f15dab9b1499148a039841ea (patch) | |
| tree | cc0411dbf0232937e66a437fe07b60b01e85621a /gcc/tree-ssa-alias.c | |
| parent | 4cad6dba074f9325e3bc0c4fa80e7646cb50088a (diff) | |
| download | gcc-e3c70387dc0fdf85f15dab9b1499148a039841ea.tar.gz | |
re PR tree-optimization/42944 (errno misoptimization around malloc call)
2010-02-03 Richard Guenther <rguenther@suse.de>
PR tree-optimization/42944
* tree-ssa-alias.c (ref_maybe_used_by_call_p_1): Handle
calloc.
(call_may_clobber_ref_p_1): Likewise. Properly handle
malloc and calloc clobbering errno.
* gcc.dg/errno-1.c: New testcase.
From-SVN: r156467
Diffstat (limited to 'gcc/tree-ssa-alias.c')
| -rw-r--r-- | gcc/tree-ssa-alias.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index 6ace7e32680..16abb4c5222 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -963,6 +963,7 @@ ref_maybe_used_by_call_p_1 (gimple call, ao_ref *ref) /* The following builtins do not read from memory. */ case BUILT_IN_FREE: case BUILT_IN_MALLOC: + case BUILT_IN_CALLOC: case BUILT_IN_MEMSET: case BUILT_IN_FREXP: case BUILT_IN_FREXPF: @@ -1190,6 +1191,21 @@ call_may_clobber_ref_p_1 (gimple call, ao_ref *ref) /* Allocating memory does not have any side-effects apart from being the definition point for the pointer. */ case BUILT_IN_MALLOC: + case BUILT_IN_CALLOC: + /* Unix98 specifies that errno is set on allocation failure. + Until we properly can track the errno location assume it + is not a plain decl but anonymous storage in a different + translation unit. */ + if (flag_errno_math) + { + struct ptr_info_def *pi; + if (DECL_P (base)) + return false; + if (INDIRECT_REF_P (base) + && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME + && (pi = SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)))) + return pi->pt.anything || pi->pt.nonlocal; + } return false; /* Freeing memory kills the pointed-to memory. More importantly the call has to serve as a barrier for moving loads and stores |