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[1/4] target/arm: optimize aarch32 rev16

Message ID 20170516230159.4195-2-aurelien@aurel32.net (mailing list archive)
State New, archived
Headers show

Commit Message

Aurelien Jarno May 16, 2017, 11:01 p.m. UTC 
Use the same mask to avoid having to load two different constants, as
suggested by Richard Henderson.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 target/arm/translate.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Philippe Mathieu-Daudé May 17, 2017, 12:56 a.m. UTC | #1 
Hi Aurelien,

On 05/16/2017 08:01 PM, Aurelien Jarno wrote:
> Use the same mask to avoid having to load two different constants, as

> suggested by Richard Henderson.

What about
Suggested-by: Richard Henderson <rth@twiddle.net> ?

> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

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

> ---
>  target/arm/translate.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index 0b5a0bca06..5becb2bb89 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -339,11 +339,13 @@ static void gen_smul_dual(TCGv_i32 a, TCGv_i32 b)
>  static void gen_rev16(TCGv_i32 var)
>  {
>      TCGv_i32 tmp = tcg_temp_new_i32();
> +    TCGv_i32 mask = tcg_const_i32(0x00ff00ff);
>      tcg_gen_shri_i32(tmp, var, 8);
> -    tcg_gen_andi_i32(tmp, tmp, 0x00ff00ff);
> +    tcg_gen_and_i32(tmp, tmp, mask);
> +    tcg_gen_and_i32(var, var, mask);
>      tcg_gen_shli_i32(var, var, 8);
> -    tcg_gen_andi_i32(var, var, 0xff00ff00);
>      tcg_gen_or_i32(var, var, tmp);
> +    tcg_temp_free_i32(mask);
>      tcg_temp_free_i32(tmp);
>  }
>
>
Richard Henderson May 23, 2017, 12:21 a.m. UTC | #2 
On 05/16/2017 04:01 PM, Aurelien Jarno wrote:
> Use the same mask to avoid having to load two different constants, as
> suggested by Richard Henderson.
> 
> Signed-off-by: Aurelien Jarno<aurelien@aurel32.net>
> ---
>   target/arm/translate.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)

Reviewed-by: Richard Henderson <rth@twiddle.net>


r~
diff mbox

Patch

diff --git a/target/arm/translate.c b/target/arm/translate.c
index 0b5a0bca06..5becb2bb89 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -339,11 +339,13 @@  static void gen_smul_dual(TCGv_i32 a, TCGv_i32 b)
 static void gen_rev16(TCGv_i32 var)
 {
     TCGv_i32 tmp = tcg_temp_new_i32();
+    TCGv_i32 mask = tcg_const_i32(0x00ff00ff);
     tcg_gen_shri_i32(tmp, var, 8);
-    tcg_gen_andi_i32(tmp, tmp, 0x00ff00ff);
+    tcg_gen_and_i32(tmp, tmp, mask);
+    tcg_gen_and_i32(var, var, mask);
     tcg_gen_shli_i32(var, var, 8);
-    tcg_gen_andi_i32(var, var, 0xff00ff00);
     tcg_gen_or_i32(var, var, tmp);
+    tcg_temp_free_i32(mask);
     tcg_temp_free_i32(tmp);
 }