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target-s390x: optimize (negative-) abs computation 

Now that movcond exists, it's easy to write (negative-) absolute value
using TCG code instead of an helper.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Aurelien Jarno 2015-05-18 15:39:59 +02:00 committed by Alexander Graf
parent 2aaa194068
commit d30107814c
3 changed files with 14 additions and 26 deletions
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2
target-s390x/helper.h
View File

@ -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)

22
target-s390x/int_helper.c
View File

@ -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)
{

16
target-s390x/translate.c
View File

@ -1310,7 +1310,13 @@ 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;
}
@ -2680,7 +2686,13 @@ 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;
}