[Qemu-devel] [PATCH 2/6] target/m68k: Optimize the partset instruction using deposit_i32()

Philippe Mathieu-Daudé posted 6 patches 6 years, 8 months ago
[Qemu-devel] [PATCH 2/6] target/m68k: Optimize the partset instruction using deposit_i32()
Posted by Philippe Mathieu-Daudé 6 years, 8 months ago
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 target/m68k/translate.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index ab801b6ceb..55766fd7ef 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -720,17 +720,15 @@ static void gen_partset_reg(int opsize, TCGv reg, TCGv val)
     TCGv tmp;
     switch (opsize) {
     case OS_BYTE:
-        tcg_gen_andi_i32(reg, reg, 0xffffff00);
         tmp = tcg_temp_new();
         tcg_gen_ext8u_i32(tmp, val);
-        tcg_gen_or_i32(reg, reg, tmp);
+        tcg_gen_deposit_i32(reg, tmp, reg, 8, 24);
         tcg_temp_free(tmp);
         break;
     case OS_WORD:
-        tcg_gen_andi_i32(reg, reg, 0xffff0000);
         tmp = tcg_temp_new();
         tcg_gen_ext16u_i32(tmp, val);
-        tcg_gen_or_i32(reg, reg, tmp);
+        tcg_gen_deposit_i32(reg, tmp, reg, 16, 16);
         tcg_temp_free(tmp);
         break;
     case OS_LONG:
-- 
2.19.1


Re: [Qemu-devel] [PATCH 2/6] target/m68k: Optimize the partset instruction using deposit_i32()
Posted by Richard Henderson 6 years, 8 months ago
On 3/9/19 4:34 PM, Philippe Mathieu-Daudé wrote:
>      case OS_BYTE:
> -        tcg_gen_andi_i32(reg, reg, 0xffffff00);
>          tmp = tcg_temp_new();
>          tcg_gen_ext8u_i32(tmp, val);

Might as well elide this as well.

> -        tcg_gen_or_i32(reg, reg, tmp);
> +        tcg_gen_deposit_i32(reg, tmp, reg, 8, 24);
>          tcg_temp_free(tmp);
>          break;
>      case OS_WORD:
> -        tcg_gen_andi_i32(reg, reg, 0xffff0000);
>          tmp = tcg_temp_new();
>          tcg_gen_ext16u_i32(tmp, val);

Likewise.

> -        tcg_gen_or_i32(reg, reg, tmp);
> +        tcg_gen_deposit_i32(reg, tmp, reg, 16, 16);
>          tcg_temp_free(tmp);
>          break;