diff options
Diffstat (limited to 'gcc/fold-const-call.c')
| -rw-r--r-- | gcc/fold-const-call.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/gcc/fold-const-call.c b/gcc/fold-const-call.c index f67b245..05a15f9 100644 --- a/gcc/fold-const-call.c +++ b/gcc/fold-const-call.c @@ -28,6 +28,7 @@ along with GCC; see the file COPYING3. If not see #include "fold-const-call.h" #include "case-cfn-macros.h" #include "tm.h" /* For C[LT]Z_DEFINED_AT_ZERO. */ +#include "builtins.h" /* Functions that test for certain constant types, abstracting away the decision about whether to check for overflow. */ @@ -1463,6 +1464,36 @@ fold_const_call_1 (combined_fn fn, tree type, tree arg0, tree arg1, tree arg2) return NULL_TREE; } + switch (fn) + { + case CFN_BUILT_IN_MEMCHR: + { + char c; + if (integer_zerop (arg2) + && !TREE_SIDE_EFFECTS (arg0) + && !TREE_SIDE_EFFECTS (arg1)) + return build_int_cst (type, 0); + + if (!tree_fits_uhwi_p (arg2) || !target_char_cst_p (arg1, &c)) + return NULL_TREE; + + unsigned HOST_WIDE_INT length = tree_to_uhwi (arg2); + unsigned HOST_WIDE_INT string_length; + const char *p1 = c_getstr (arg0, &string_length); + if (p1) + { + const char *r + = (const char *)memchr (p1, c, MIN (length, string_length)); + if (r == NULL && length <= string_length) + return build_int_cst (type, 0); + } + + break; + } + default: + break; + } + return NULL_TREE; } |