diff options
| author | Jiong Wang <jiong.wang@arm.com> | 2015-09-10 10:37:17 +0000 |
|---|---|---|
| committer | Jiong Wang <jiwang@gcc.gnu.org> | 2015-09-10 10:37:17 +0000 |
| commit | fc4d140a5ce4b45523b9616634cfd5e0912115cc (patch) | |
| tree | e84aa112c9681d409599556739ef87d07606ee5a | |
| parent | fb155425c4cd07dcc0326aae14d094c1078ce62e (diff) | |
| download | gcc-fc4d140a5ce4b45523b9616634cfd5e0912115cc.zip gcc-fc4d140a5ce4b45523b9616634cfd5e0912115cc.tar.gz gcc-fc4d140a5ce4b45523b9616634cfd5e0912115cc.tar.bz2 | |
[Patch/expand] Cost instruction sequences when doing left wide shift
Patch background details:
https://gcc.gnu.org/ml/gcc-patches/2015-08/msg01147.html
gcc/
PR rtl-optimization/67421
* expr.c (expand_expr_real_2): Cost instrcution sequences when doing left wide
shift tranformation.
From-SVN: r227629
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/expr.c | 24 |
2 files changed, 29 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9266593..d5254fa 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2015-09-10 Jiong Wang <jiong.wang@arm.com> + + PR rtl-optimization/67421 + * expr.c (expand_expr_real_2): Cost instrcution sequences when doing + left wide shift tranformation. + 2015-09-10 Claudiu Zissulescu <claziss@synopsys.com> * common/config/arc/arc-common.c: Remove references to A5. @@ -8892,7 +8892,6 @@ expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode, && ! unsignedp && mode == GET_MODE_WIDER_MODE (word_mode) && GET_MODE_SIZE (mode) == 2 * GET_MODE_SIZE (word_mode) - && ! have_insn_for (ASHIFT, mode) && TREE_CONSTANT (treeop1) && TREE_CODE (treeop0) == SSA_NAME) { @@ -8908,6 +8907,7 @@ expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode, && ((TREE_INT_CST_LOW (treeop1) + GET_MODE_BITSIZE (rmode)) >= GET_MODE_BITSIZE (word_mode))) { + rtx_insn *seq, *seq_old; unsigned int high_off = subreg_highpart_offset (word_mode, mode); rtx low = lowpart_subreg (word_mode, op0, mode); @@ -8918,6 +8918,7 @@ expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode, - TREE_INT_CST_LOW (treeop1)); tree rshift = build_int_cst (TREE_TYPE (treeop1), ramount); + start_sequence (); /* dest_high = src_low >> (word_size - C). */ temp = expand_variable_shift (RSHIFT_EXPR, word_mode, low, rshift, dest_high, unsignedp); @@ -8930,7 +8931,28 @@ expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode, if (temp != dest_low) emit_move_insn (dest_low, temp); + seq = get_insns (); + end_sequence (); temp = target ; + + if (have_insn_for (ASHIFT, mode)) + { + bool speed_p = optimize_insn_for_speed_p (); + start_sequence (); + rtx ret_old = expand_variable_shift (code, mode, op0, + treeop1, target, + unsignedp); + + seq_old = get_insns (); + end_sequence (); + if (seq_cost (seq, speed_p) + >= seq_cost (seq_old, speed_p)) + { + seq = seq_old; + temp = ret_old; + } + } + emit_insn (seq); } } } |