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[Qemu-devel] [PULL v2 1/3] tcg: Improve tcg_gen_muli_i32/i64
From: |
Richard Henderson |
Subject: |
[Qemu-devel] [PULL v2 1/3] tcg: Improve tcg_gen_muli_i32/i64 |
Date: |
Fri, 16 Mar 2018 01:38:53 +0800 |
Convert multiplication by power of two to left shift.
Reviewed-by: Emilio G. Cota <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Signed-off-by: Richard Henderson <address@hidden>
---
tcg/tcg-op.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index 3467787323..34b96d68f3 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -277,9 +277,15 @@ void tcg_gen_setcondi_i32(TCGCond cond, TCGv_i32 ret,
void tcg_gen_muli_i32(TCGv_i32 ret, TCGv_i32 arg1, int32_t arg2)
{
- TCGv_i32 t0 = tcg_const_i32(arg2);
- tcg_gen_mul_i32(ret, arg1, t0);
- tcg_temp_free_i32(t0);
+ if (arg2 == 0) {
+ tcg_gen_movi_i32(ret, 0);
+ } else if (is_power_of_2(arg2)) {
+ tcg_gen_shli_i32(ret, arg1, ctz32(arg2));
+ } else {
+ TCGv_i32 t0 = tcg_const_i32(arg2);
+ tcg_gen_mul_i32(ret, arg1, t0);
+ tcg_temp_free_i32(t0);
+ }
}
void tcg_gen_div_i32(TCGv_i32 ret, TCGv_i32 arg1, TCGv_i32 arg2)
@@ -1430,9 +1436,15 @@ void tcg_gen_setcondi_i64(TCGCond cond, TCGv_i64 ret,
void tcg_gen_muli_i64(TCGv_i64 ret, TCGv_i64 arg1, int64_t arg2)
{
- TCGv_i64 t0 = tcg_const_i64(arg2);
- tcg_gen_mul_i64(ret, arg1, t0);
- tcg_temp_free_i64(t0);
+ if (arg2 == 0) {
+ tcg_gen_movi_i64(ret, 0);
+ } else if (is_power_of_2(arg2)) {
+ tcg_gen_shli_i64(ret, arg1, ctz64(arg2));
+ } else {
+ TCGv_i64 t0 = tcg_const_i64(arg2);
+ tcg_gen_mul_i64(ret, arg1, t0);
+ tcg_temp_free_i64(t0);
+ }
}
void tcg_gen_div_i64(TCGv_i64 ret, TCGv_i64 arg1, TCGv_i64 arg2)
--
2.14.3