tcg: Improve tcg_gen_muli_i32/i64

Message ID 20180211203934.15546-1-richard.henderson@linaro.org
State Superseded
Headers show
Series
  • tcg: Improve tcg_gen_muli_i32/i64
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Commit Message

Richard Henderson Feb. 11, 2018, 8:39 p.m.
Convert multiplication by power of two to left shift.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 tcg/tcg-op.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

-- 
2.14.3

Comments

Emilio G. Cota Feb. 12, 2018, 10:43 p.m. | #1
On Sun, Feb 11, 2018 at 12:39:34 -0800, Richard Henderson wrote:
> Convert multiplication by power of two to left shift.

> 

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>


Reviewed-by: Emilio G. Cota <cota@braap.org>


Thanks,

		Emilio
Philippe Mathieu-Daudé Feb. 13, 2018, 4:10 a.m. | #2
On 02/11/2018 05:39 PM, Richard Henderson wrote:
> Convert multiplication by power of two to left shift.

> 

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>


Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>


> ---

>  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)

>

Patch

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)