| Summary: | [4.7 Regression] __builtin_memcpy etc. with constant first argument optimized away by ccp | ||
|---|---|---|---|
| Product: | gcc | Reporter: | Jakub Jelinek <jakub> |
| Component: | tree-optimization | Assignee: | Jakub Jelinek <jakub> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | Keywords: | wrong-code |
| Priority: | P3 | ||
| Version: | 4.7.0 | ||
| Target Milestone: | 4.7.0 | ||
| Host: | Target: | ||
| Build: | Known to work: | ||
| Known to fail: | Last reconfirmed: | 2011-12-27 00:00:00 | |
| Attachments: | gcc47-pr51683.patch | ||
Created attachment 26188 [details] gcc47-pr51683.patch Untested fix. Author: jakub Date: Sat Dec 31 23:53:57 2011 New Revision: 182761 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=182761 Log: PR tree-optimization/51683 * tree-ssa-propagate.c (substitute_and_fold): Don't optimize away calls with side-effects. * tree-ssa-ccp.c (ccp_fold_stmt): Likewise. * gcc.dg/pr51683.c: New test. Added: trunk/gcc/testsuite/gcc.dg/pr51683.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-ssa-ccp.c trunk/gcc/tree-ssa-propagate.c Fixed. |
static inline void * bar (void *p, void *q, int r) { return __builtin_memcpy (p, q, r); } void * foo (void *p) { return bar ((void *) 0x12345000, p, 256); } at -O2 starting with http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175290 is optimized away. While the return value from memcpy is known to be constant and we know that constant, we ignore the other side-effects of the call.