diff options
Diffstat (limited to 'gcc/gcse.c')
| -rw-r--r-- | gcc/gcse.c | 25 |
1 files changed, 15 insertions, 10 deletions
@@ -3971,24 +3971,27 @@ try_replace_reg (from, to, insn) int success = 0; rtx set = single_set (insn); - success = validate_replace_src (from, to, insn); + if (reg_mentioned_p (from, PATTERN (insn))) + { + success = validate_replace_src (from, to, insn); + } - /* If above failed and this is a single set, try to simplify the source of - the set given our substitution. We could perhaps try this for multiple - SETs, but it probably won't buy us anything. */ - if (!success && set != 0) + if (!success && set && reg_mentioned_p (from, SET_SRC (set))) { + /* If above failed and this is a single set, try to simplify the source of + the set given our substitution. We could perhaps try this for multiple + SETs, but it probably won't buy us anything. */ src = simplify_replace_rtx (SET_SRC (set), from, to); if (!rtx_equal_p (src, SET_SRC (set)) && validate_change (insn, &SET_SRC (set), src, 0)) success = 1; - } - /* If we've failed to do replacement, have a single SET, and don't already - have a note, add a REG_EQUAL note to not lose information. */ - if (!success && note == 0 && set != 0) - note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src)); + /* If we've failed to do replacement, have a single SET, and don't already + have a note, add a REG_EQUAL note to not lose information. */ + if (!success && note == 0 && set != 0) + note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src)); + } /* If there is already a NOTE, update the expression in it with our replacement. */ @@ -5879,6 +5882,8 @@ hoist_expr_reaches_here_p (expr_bb, expr_index, bb, visited) if (pred->src == ENTRY_BLOCK_PTR) break; + else if (pred_bb == expr_bb) + continue; else if (visited[pred_bb->index]) continue; |