| /* PR tree-optimization/83821 - local aggregate initialization defeats |
| strlen optimization |
| Verify that with DSE disabled, a memset() call to zero out a subregion |
| of memory allocated by calloc() is not eliminated after a non-zero byte |
| is written into it using memset() in between the two calls. |
| { dg-do compile } |
| { dg-options "-O2 -fno-tree-dse -fdump-tree-optimized" } */ |
| |
| char* keep_memset_calls (void) |
| { |
| char *p = __builtin_calloc (12, 1); |
| |
| __builtin_memset (p + 5, 1, 2); /* dead store (not eliminated) */ |
| |
| __builtin_memset (p, 0, 12); /* must not be eliminated */ |
| |
| return p; |
| } |
| |
| /* { dg-final { scan-tree-dump-not "malloc" "optimized" } } |
| { dg-final { scan-tree-dump-times "_calloc \\\(" 1 "optimized" } } |
| { dg-final { scan-tree-dump-times "_memset \\\(" 2 "optimized" } } */ |
