diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 15 |
1 files changed, 15 insertions, 0 deletions
@@ -6477,6 +6477,21 @@ cse_insn (insn, in_libcall_block) sets[i].src_in_memory = hash_arg_in_memory; sets[i].src_in_struct = hash_arg_in_struct; + /* If SRC is a MEM, there is a REG_EQUIV note for SRC, and DEST is + a pseudo that is set more than once, do not record SRC. Using + SRC as a replacement for anything else will be incorrect in that + situation. Note that this usually occurs only for stack slots, + in which case all the RTL would be refering to SRC, so we don't + lose any optimization opportunities by not having SRC in the + hash table. */ + + if (GET_CODE (src) == MEM + && find_reg_note (insn, REG_EQUIV, src) != 0 + && GET_CODE (dest) == REG + && REGNO (dest) >= FIRST_PSEUDO_REGISTER + && reg_n_sets[REGNO (dest)] != 1) + sets[i].src_volatile = 1; + #if 0 /* It is no longer clear why we used to do this, but it doesn't appear to still be needed. So let's try without it since this |