diff options
Diffstat (limited to 'gcc/cse.c')
| -rw-r--r-- | gcc/cse.c | 13 |
1 files changed, 11 insertions, 2 deletions
@@ -5074,7 +5074,7 @@ cse_insn (rtx_insn *insn) to prefer it. Copy it to src_related. The code below will then give it a negative cost. */ if (GET_CODE (dest) == code && rtx_equal_p (p->exp, dest)) - src_related = dest; + src_related = p->exp; } /* Find the cheapest valid equivalent, trying all the available @@ -5332,7 +5332,16 @@ cse_insn (rtx_insn *insn) && rtx_equal_p (trial, dest) && !side_effects_p (dest) && (cfun->can_delete_dead_exceptions - || insn_nothrow_p (insn))) + || insn_nothrow_p (insn)) + /* We can only remove the later store if the earlier aliases + at least all accesses the later one. */ + && (!MEM_P (trial) + || ((MEM_ALIAS_SET (dest) == MEM_ALIAS_SET (trial) + || alias_set_subset_of (MEM_ALIAS_SET (dest), + MEM_ALIAS_SET (trial))) + && (!MEM_EXPR (trial) + || refs_same_for_tbaa_p (MEM_EXPR (trial), + MEM_EXPR (dest)))))) { SET_SRC (sets[i].rtl) = trial; noop_insn = true; |