diff options
Diffstat (limited to 'gcc/cprop.c')
| -rw-r--r-- | gcc/cprop.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/gcc/cprop.c b/gcc/cprop.c index 584ffd202ba..d90f769e546 100644 --- a/gcc/cprop.c +++ b/gcc/cprop.c @@ -712,8 +712,8 @@ find_used_regs (rtx *xptr, void *data ATTRIBUTE_UNUSED) } } -/* Try to replace all non-SET_DEST occurrences of FROM in INSN with TO. - Returns nonzero is successful. */ +/* Try to replace all uses of FROM in INSN with TO. + Return nonzero if successful. */ static int try_replace_reg (rtx from, rtx to, rtx insn) @@ -764,6 +764,18 @@ try_replace_reg (rtx from, rtx to, rtx insn) note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src)); } + if (set && MEM_P (SET_DEST (set)) && reg_mentioned_p (from, SET_DEST (set))) + { + /* Registers can also appear as uses in SET_DEST if it is a MEM. + We could perhaps try this for multiple SETs, but it probably + won't buy us anything. */ + rtx dest = simplify_replace_rtx (SET_DEST (set), from, to); + + if (!rtx_equal_p (dest, SET_DEST (set)) + && validate_change (insn, &SET_DEST (set), dest, 0)) + success = 1; + } + /* REG_EQUAL may get simplified into register. We don't allow that. Remove that note. This code ought not to happen, because previous code ought to synthesize |