This patch adds CCMP selection based on rtx costs. This is based on Jiong's
already approved patch
https://gcc.gnu.org/ml/gcc-patches/2015-09/msg01434.html with some minor
refactoring and the tests updated.
OK for commit?
ChangeLog:
2015-11-13 Jiong Wang <jiong.w...@arm.com>
gcc/
* ccmp.c (expand_ccmp_expr_1): Cost the instruction sequences
generated from different expand order.
gcc/testsuite/
* gcc.target/aarch64/ccmp_1.c: Update test.
---
gcc/ccmp.c | 47
+++++++++++++++++++++++++++----
gcc/testsuite/gcc.target/aarch64/ccmp_1.c | 15 ++++++++--
2 files changed, 55 insertions(+), 7 deletions(-)
diff --git a/gcc/ccmp.c b/gcc/ccmp.c
index cbdbd6d..95a41a6 100644
--- a/gcc/ccmp.c
+++ b/gcc/ccmp.c
@@ -51,6 +51,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-outof-ssa.h"
#include "cfgexpand.h"
#include "ccmp.h"
+#include "predict.h"
/* The following functions expand conditional compare (CCMP) instructions.
Here is a short description about the over all algorithm:
@@ -159,6 +160,8 @@ expand_ccmp_next (gimple *g, enum tree_code code, rtx
prev,
static rtx
expand_ccmp_expr_1 (gimple *g, rtx *prep_seq, rtx *gen_seq)
{
+ rtx prep_seq_1, gen_seq_1;
+ rtx prep_seq_2, gen_seq_2;
tree exp = gimple_assign_rhs_to_tree (g);
enum tree_code code = TREE_CODE (exp);
gimple *gs0 = get_gimple_for_ssa_name (TREE_OPERAND (exp, 0));
@@ -174,19 +177,53 @@ expand_ccmp_expr_1 (gimple *g, rtx *prep_seq, rtx
*gen_seq)
{
if (TREE_CODE_CLASS (code1) == tcc_comparison)
{
- int unsignedp0;
- enum rtx_code rcode0;
+ int unsignedp0, unsignedp1;
+ enum rtx_code rcode0, rcode1;
+ int speed_p = optimize_insn_for_speed_p ();
+ rtx tmp2, ret, ret2;
+ unsigned cost1 = MAX_COST;
+ unsigned cost2 = MAX_COST;
unsignedp0 = TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (gs0)));
+ unsignedp1 = TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (gs1)));
rcode0 = get_rtx_code (code0, unsignedp0);
+ rcode1 = get_rtx_code (code1, unsignedp1);
- tmp = targetm.gen_ccmp_first (prep_seq, gen_seq, rcode0,
+ tmp = targetm.gen_ccmp_first (&prep_seq_1, &gen_seq_1, rcode0,
gimple_assign_rhs1 (gs0),
gimple_assign_rhs2 (gs0));
- if (!tmp)
+
+ tmp2 = targetm.gen_ccmp_first (&prep_seq_2, &gen_seq_2, rcode1,
+ gimple_assign_rhs1 (gs1),
+ gimple_assign_rhs2 (gs1));
+
+ if (!tmp && !tmp2)
return NULL_RTX;
- return expand_ccmp_next (gs1, code, tmp, prep_seq, gen_seq);
+ if (tmp != NULL)
+ {
+ ret = expand_ccmp_next (gs1, code, tmp, &prep_seq_1,
&gen_seq_1);
+ cost1 = seq_cost (safe_as_a <rtx_insn *> (prep_seq_1),
speed_p);
+ cost1 += seq_cost (safe_as_a <rtx_insn *> (gen_seq_1),
speed_p);
+ }
+ if (tmp2 != NULL)
+ {
+ ret2 = expand_ccmp_next (gs0, code, tmp2, &prep_seq_2,
+ &gen_seq_2);
+ cost2 = seq_cost (safe_as_a <rtx_insn *> (prep_seq_2),
speed_p);
+ cost2 += seq_cost (safe_as_a <rtx_insn *> (gen_seq_2),
speed_p);
+ }
+
+ if (cost2 < cost1)
+ {
+ *prep_seq = prep_seq_2;
+ *gen_seq = gen_seq_2;
+ return ret2;
+ }
+
+ *prep_seq = prep_seq_1;
+ *gen_seq = gen_seq_1;
+ return ret;
}
else
{
diff --git a/gcc/testsuite/gcc.target/aarch64/ccmp_1.c
b/gcc/testsuite/gcc.target/aarch64/ccmp_1.c
index ef077e0..7c39b61 100644
--- a/gcc/testsuite/gcc.target/aarch64/ccmp_1.c
+++ b/gcc/testsuite/gcc.target/aarch64/ccmp_1.c
@@ -80,5 +80,16 @@ f13 (int a, int b)
return a == 3 || a == 0;
}
-/* { dg-final { scan-assembler "fccmp\t" } } */
-/* { dg-final { scan-assembler "fccmpe\t" } } */
+/* { dg-final { scan-assembler "cmp\t(.)+32" } } */
+/* { dg-final { scan-assembler "cmp\t(.)+33" } } */
+/* { dg-final { scan-assembler "cmp\t(.)+34" } } */
+/* { dg-final { scan-assembler "cmp\t(.)+35" } } */
+
+/* { dg-final { scan-assembler-times "\tcmp\tw\[0-9\]+, 0" 4 } } */
+/* { dg-final { scan-assembler-times "fcmpe\t(.)+0\\.0" 2 } } */
+/* { dg-final { scan-assembler-times "fcmp\t(.)+0\\.0" 2 } } */
+
+/* { dg-final { scan-assembler "adds\t" } } */
+/* { dg-final { scan-assembler-times "\tccmp\t" 11 } } */
+/* { dg-final { scan-assembler-times "fccmp\t.*0\\.0" 1 } } */
+/* { dg-final { scan-assembler-times "fccmpe\t.*0\\.0" 1 } } */
--
1.9.1
