[PATCH v2 24/29] target/i386: Improve bswap translation

Richard Henderson posted 29 patches 4 years, 7 months ago
Maintainers: Alistair Francis <Alistair.Francis@wdc.com>, Peter Maydell <peter.maydell@linaro.org>, Huacai Chen <chenhuacai@kernel.org>, Cornelia Huck <cohuck@redhat.com>, Eduardo Habkost <ehabkost@redhat.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Andrzej Zaborowski <balrogg@gmail.com>, Thomas Huth <thuth@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Palmer Dabbelt <palmer@dabbelt.com>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, Paolo Bonzini <pbonzini@redhat.com>, Aurelien Jarno <aurelien@aurel32.net>
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[PATCH v2 24/29] target/i386: Improve bswap translation
Posted by Richard Henderson 4 years, 7 months ago
Use a break instead of an ifdefed else.
There's no need to move the values through s->T0.
Remove TCG_BSWAP_IZ and the preceding zero-extension.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/i386/tcg/translate.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index e8a9dcd21a..b21873ed23 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -7195,17 +7195,11 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
         reg = (b & 7) | REX_B(s);
 #ifdef TARGET_X86_64
         if (dflag == MO_64) {
-            gen_op_mov_v_reg(s, MO_64, s->T0, reg);
-            tcg_gen_bswap64_i64(s->T0, s->T0);
-            gen_op_mov_reg_v(s, MO_64, reg, s->T0);
-        } else
-#endif
-        {
-            gen_op_mov_v_reg(s, MO_32, s->T0, reg);
-            tcg_gen_ext32u_tl(s->T0, s->T0);
-            tcg_gen_bswap32_tl(s->T0, s->T0, TCG_BSWAP_IZ | TCG_BSWAP_OZ);
-            gen_op_mov_reg_v(s, MO_32, reg, s->T0);
+            tcg_gen_bswap64_i64(cpu_regs[reg], cpu_regs[reg]);
+            break;
         }
+#endif
+        tcg_gen_bswap32_tl(cpu_regs[reg], cpu_regs[reg], TCG_BSWAP_OZ);
         break;
     case 0xd6: /* salc */
         if (CODE64(s))
-- 
2.25.1