qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH 6/8] target/mips: optimize bshfl() using extract


From: Philippe Mathieu-Daudé
Subject: Re: [Qemu-devel] [PATCH 6/8] target/mips: optimize bshfl() using extract op
Date: Thu, 11 May 2017 23:13:51 -0300
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0

Hi,

As noticed by Richard in another patch, this one is also WRONG:

$ docker run -it -v `pwd`:`pwd` -w `pwd` petersenna/coccinelle --sp-file scripts/coccinelle/tcg_gen_extract.cocci --macro-file scripts/cocci-macro-file.h target/mips/translate.c
init_defs_builtins: /usr/lib64/coccinelle/standard.h
init_defs: scripts/cocci-macro-file.h
HANDLING: target/mips/translate.c
candidate at target/mips/translate.c:4576
  op_size: tl/tl (same)
  low_bits: 8 (value: 0xff)
  len: 0xff00ff
  len_bits != low_bits
  candidate is NOT optimizable

candidate at target/mips/translate.c:4596
  op_size: tl/tl (same)
  low_bits: 8 (value: 0xff)
  len: 0xff00ff00ff00ff
  len_bits != low_bits
  candidate is NOT optimizable

candidate at target/mips/translate.c:4608
  op_size: tl/tl (same)
  low_bits: 16 (value: 0xffff)
  len: 0xffff0000ffff
  len_bits != low_bits
  candidate is NOT optimizable

On 05/10/2017 05:05 PM, Philippe Mathieu-Daudé wrote:
Applied using Coccinelle script.

Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
 target/mips/translate.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index 3022f349cb..96177da9ae 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -4573,8 +4573,7 @@ static void gen_bshfl (DisasContext *ctx, uint32_t op2, 
int rt, int rd)
         {
             TCGv t1 = tcg_temp_new();

-            tcg_gen_shri_tl(t1, t0, 8);
-            tcg_gen_andi_tl(t1, t1, 0x00FF00FF);
+            tcg_gen_extract_tl(t1, t0, 8, 0x00FF00FF);
             tcg_gen_shli_tl(t0, t0, 8);
             tcg_gen_andi_tl(t0, t0, ~0x00FF00FF);
             tcg_gen_or_tl(t0, t0, t1);
@@ -4593,8 +4592,7 @@ static void gen_bshfl (DisasContext *ctx, uint32_t op2, 
int rt, int rd)
         {
             TCGv t1 = tcg_temp_new();

-            tcg_gen_shri_tl(t1, t0, 8);
-            tcg_gen_andi_tl(t1, t1, 0x00FF00FF00FF00FFULL);
+            tcg_gen_extract_tl(t1, t0, 8, 0x00FF00FF00FF00FFULL);
             tcg_gen_shli_tl(t0, t0, 8);
             tcg_gen_andi_tl(t0, t0, ~0x00FF00FF00FF00FFULL);
             tcg_gen_or_tl(cpu_gpr[rd], t0, t1);
@@ -4605,8 +4603,7 @@ static void gen_bshfl (DisasContext *ctx, uint32_t op2, 
int rt, int rd)
         {
             TCGv t1 = tcg_temp_new();

-            tcg_gen_shri_tl(t1, t0, 16);
-            tcg_gen_andi_tl(t1, t1, 0x0000FFFF0000FFFFULL);
+            tcg_gen_extract_tl(t1, t0, 16, 0x0000FFFF0000FFFFULL);
             tcg_gen_shli_tl(t0, t0, 16);
             tcg_gen_andi_tl(t0, t0, ~0x0000FFFF0000FFFFULL);
             tcg_gen_or_tl(t0, t0, t1);




reply via email to

[Prev in Thread] Current Thread [Next in Thread]