[PATCH 0/2] target/ppc: Use tcg_constant_*

[PATCH 0/2] target/ppc: Use tcg_constant_*

[Philippe Mathieu-Daudé]

Replace temporary TCG registers by tcg_constant_*() when possible.

Philippe Mathieu-Daudé (2):
  target/ppc: Use tcg_constant_i32() in gen_setb()
  target/ppc: Use tcg_constant_i64() in gen_brh()

 target/ppc/translate.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

-- 
2.31.1

[PATCH 1/2] target/ppc: Use tcg_constant_i32() in gen_setb()

[Philippe Mathieu-Daudé]

Avoid using TCG temporaries for the -1 and 8 constant values.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 target/ppc/translate.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index b985e9e55bc..193d8e89152 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -5074,19 +5074,15 @@ static void gen_mtspr(DisasContext *ctx)
 static void gen_setb(DisasContext *ctx)
 {
     TCGv_i32 t0 = tcg_temp_new_i32();
-    TCGv_i32 t8 = tcg_temp_new_i32();
-    TCGv_i32 tm1 = tcg_temp_new_i32();
+    TCGv_i32 t8 = tcg_constant_i32(8);
+    TCGv_i32 tm1 = tcg_constant_i32(-1);
     int crf = crfS(ctx->opcode);
 
     tcg_gen_setcondi_i32(TCG_COND_GEU, t0, cpu_crf[crf], 4);
-    tcg_gen_movi_i32(t8, 8);
-    tcg_gen_movi_i32(tm1, -1);
     tcg_gen_movcond_i32(TCG_COND_GEU, t0, cpu_crf[crf], t8, tm1, t0);
     tcg_gen_ext_i32_tl(cpu_gpr[rD(ctx->opcode)], t0);
 
     tcg_temp_free_i32(t0);
-    tcg_temp_free_i32(t8);
-    tcg_temp_free_i32(tm1);
 }
 #endif
 
-- 
2.31.1

[PATCH 2/2] target/ppc: Use tcg_constant_i64() in gen_brh()

[Philippe Mathieu-Daudé]

The mask of the Byte-Reverse Halfword opcode is a read-only
constant. We can avoid using a TCG temporary by moving the
mask to the constant pool.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 target/ppc/translate.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 193d8e89152..30a60d60973 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -7575,18 +7575,16 @@ static void gen_brw(DisasContext *ctx)
 /* brh */
 static void gen_brh(DisasContext *ctx)
 {
-    TCGv_i64 t0 = tcg_temp_new_i64();
+    TCGv_i64 mask = tcg_constant_i64(0x00ff00ff00ff00ffull);
     TCGv_i64 t1 = tcg_temp_new_i64();
     TCGv_i64 t2 = tcg_temp_new_i64();
 
-    tcg_gen_movi_i64(t0, 0x00ff00ff00ff00ffull);
     tcg_gen_shri_i64(t1, cpu_gpr[rS(ctx->opcode)], 8);
-    tcg_gen_and_i64(t2, t1, t0);
-    tcg_gen_and_i64(t1, cpu_gpr[rS(ctx->opcode)], t0);
+    tcg_gen_and_i64(t2, t1, mask);
+    tcg_gen_and_i64(t1, cpu_gpr[rS(ctx->opcode)], mask);
     tcg_gen_shli_i64(t1, t1, 8);
     tcg_gen_or_i64(cpu_gpr[rA(ctx->opcode)], t1, t2);
 
-    tcg_temp_free_i64(t0);
     tcg_temp_free_i64(t1);
     tcg_temp_free_i64(t2);
 }
-- 
2.31.1

Re: [PATCH 1/2] target/ppc: Use tcg_constant_i32() in gen_setb()

[Richard Henderson]

On 10/3/21 10:17 AM, Philippe Mathieu-Daudé wrote:
> Avoid using TCG temporaries for the -1 and 8 constant values.
> 
> Signed-off-by: Philippe Mathieu-Daudé<f4bug@amsat.org>
> ---
>   target/ppc/translate.c | 8 ++------
>   1 file changed, 2 insertions(+), 6 deletions(-)

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

r~

Re: [PATCH 2/2] target/ppc: Use tcg_constant_i64() in gen_brh()

[Richard Henderson]

On 10/3/21 10:17 AM, Philippe Mathieu-Daudé wrote:
> The mask of the Byte-Reverse Halfword opcode is a read-only
> constant. We can avoid using a TCG temporary by moving the
> mask to the constant pool.
> 
> Signed-off-by: Philippe Mathieu-Daudé<f4bug@amsat.org>
> ---
>   target/ppc/translate.c | 8 +++-----
>   1 file changed, 3 insertions(+), 5 deletions(-)

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

r~

Re: [PATCH 1/2] target/ppc: Use tcg_constant_i32() in gen_setb()

[David Gibson]

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On Sun, Oct 03, 2021 at 04:17:10PM +0200, Philippe Mathieu-Daudé wrote:
> Avoid using TCG temporaries for the -1 and 8 constant values.
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Both patches applied to ppc-for-6.2, thanks.

> ---
>  target/ppc/translate.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> index b985e9e55bc..193d8e89152 100644
> --- a/target/ppc/translate.c
> +++ b/target/ppc/translate.c
> @@ -5074,19 +5074,15 @@ static void gen_mtspr(DisasContext *ctx)
>  static void gen_setb(DisasContext *ctx)
>  {
>      TCGv_i32 t0 = tcg_temp_new_i32();
> -    TCGv_i32 t8 = tcg_temp_new_i32();
> -    TCGv_i32 tm1 = tcg_temp_new_i32();
> +    TCGv_i32 t8 = tcg_constant_i32(8);
> +    TCGv_i32 tm1 = tcg_constant_i32(-1);
>      int crf = crfS(ctx->opcode);
>  
>      tcg_gen_setcondi_i32(TCG_COND_GEU, t0, cpu_crf[crf], 4);
> -    tcg_gen_movi_i32(t8, 8);
> -    tcg_gen_movi_i32(tm1, -1);
>      tcg_gen_movcond_i32(TCG_COND_GEU, t0, cpu_crf[crf], t8, tm1, t0);
>      tcg_gen_ext_i32_tl(cpu_gpr[rD(ctx->opcode)], t0);
>  
>      tcg_temp_free_i32(t0);
> -    tcg_temp_free_i32(t8);
> -    tcg_temp_free_i32(tm1);
>  }
>  #endif
>  

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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