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[Qemu-devel] [PATCH 2/3] target-s390x: optimize (negative-) abs computat
From: |
Aurelien Jarno |
Subject: |
[Qemu-devel] [PATCH 2/3] target-s390x: optimize (negative-) abs computation |
Date: |
Mon, 18 May 2015 15:39:59 +0200 |
Now that movcond exists, it's easy to write (negative-) absolute value
using TCG code instead of an helper.
Cc: Richard Henderson <address@hidden>
Cc: Alexander Graf <address@hidden>
Signed-off-by: Aurelien Jarno <address@hidden>
---
target-s390x/helper.h | 2 --
target-s390x/int_helper.c | 22 ----------------------
target-s390x/translate.c | 16 ++++++++++++++--
3 files changed, 14 insertions(+), 26 deletions(-)
diff --git a/target-s390x/helper.h b/target-s390x/helper.h
index 8d2c859..c4ec3f1 100644
--- a/target-s390x/helper.h
+++ b/target-s390x/helper.h
@@ -17,8 +17,6 @@ DEF_HELPER_4(mvst, i64, env, i64, i64, i64)
DEF_HELPER_5(ex, i32, env, i32, i64, i64, i64)
DEF_HELPER_FLAGS_1(abs_i32, TCG_CALL_NO_RWG_SE, i32, s32)
DEF_HELPER_FLAGS_1(nabs_i32, TCG_CALL_NO_RWG_SE, s32, s32)
-DEF_HELPER_FLAGS_1(abs_i64, TCG_CALL_NO_RWG_SE, i64, s64)
-DEF_HELPER_FLAGS_1(nabs_i64, TCG_CALL_NO_RWG_SE, s64, s64)
DEF_HELPER_FLAGS_4(stam, TCG_CALL_NO_WG, void, env, i32, i64, i32)
DEF_HELPER_FLAGS_4(lam, TCG_CALL_NO_WG, void, env, i32, i64, i32)
DEF_HELPER_4(mvcle, i32, env, i32, i64, i32)
diff --git a/target-s390x/int_helper.c b/target-s390x/int_helper.c
index cb8dd98..f53723d 100644
--- a/target-s390x/int_helper.c
+++ b/target-s390x/int_helper.c
@@ -135,28 +135,6 @@ int32_t HELPER(nabs_i32)(int32_t val)
}
}
-/* absolute value 64-bit */
-uint64_t HELPER(abs_i64)(int64_t val)
-{
- HELPER_LOG("%s: val 0x%" PRIx64 "\n", __func__, val);
-
- if (val < 0) {
- return -val;
- } else {
- return val;
- }
-}
-
-/* negative absolute value 64-bit */
-int64_t HELPER(nabs_i64)(int64_t val)
-{
- if (val < 0) {
- return val;
- } else {
- return -val;
- }
-}
-
/* count leading zeros, for find leftmost one */
uint64_t HELPER(clz)(uint64_t v)
{
diff --git a/target-s390x/translate.c b/target-s390x/translate.c
index c297938..5898adb 100644
--- a/target-s390x/translate.c
+++ b/target-s390x/translate.c
@@ -1304,7 +1304,13 @@ static ExitStatus help_branch(DisasContext *s,
DisasCompare *c,
static ExitStatus op_abs(DisasContext *s, DisasOps *o)
{
- gen_helper_abs_i64(o->out, o->in2);
+ TCGv_i64 z, n;
+ z = tcg_const_i64(0);
+ n = tcg_temp_new_i64();
+ tcg_gen_neg_i64(n, o->in2);
+ tcg_gen_movcond_i64(TCG_COND_LT, o->out, o->in2, z, n, o->in2);
+ tcg_temp_free_i64(n);
+ tcg_temp_free_i64(z);
return NO_EXIT;
}
@@ -2675,7 +2681,13 @@ static ExitStatus op_msdb(DisasContext *s, DisasOps *o)
static ExitStatus op_nabs(DisasContext *s, DisasOps *o)
{
- gen_helper_nabs_i64(o->out, o->in2);
+ TCGv_i64 z, n;
+ z = tcg_const_i64(0);
+ n = tcg_temp_new_i64();
+ tcg_gen_neg_i64(n, o->in2);
+ tcg_gen_movcond_i64(TCG_COND_GE, o->out, o->in2, z, n, o->in2);
+ tcg_temp_free_i64(n);
+ tcg_temp_free_i64(z);
return NO_EXIT;
}
--
2.1.4