[v3] tcg: Simplify calls to load/store helpers

[PATCH v3 03/57] tcg/i386: Conditionalize tcg_out_extu_i32_i64

Richard Henderson posted 57 patches 2 years, 9 months ago

Diff against v1 v2 v4 v5
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Maintainers: Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, WANG Xuerui <git@xen0n.name>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Aurelien Jarno <aurelien@aurel32.net>, Huacai Chen <chenhuacai@kernel.org>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <Alistair.Francis@wdc.com>

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[PATCH v3 03/57] tcg/i386: Conditionalize tcg_out_extu_i32_i64

Posted by Richard Henderson 2 years, 9 months ago

Since TCG_TYPE_I32 values are kept zero-extended in registers, via
omission of the REXW bit, we need not extend if the register matches.
This is already relied upon by qemu_{ld,st}.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/i386/tcg-target.c.inc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc
index c8e2bf537f..ce87f8fbc9 100644
--- a/tcg/i386/tcg-target.c.inc
+++ b/tcg/i386/tcg-target.c.inc
@@ -1314,7 +1314,9 @@ static void tcg_out_exts_i32_i64(TCGContext *s, TCGReg dest, TCGReg src)
 
 static void tcg_out_extu_i32_i64(TCGContext *s, TCGReg dest, TCGReg src)
 {
-    tcg_out_ext32u(s, dest, src);
+    if (dest != src) {
+        tcg_out_ext32u(s, dest, src);
+    }
 }
 
 static void tcg_out_extrl_i64_i32(TCGContext *s, TCGReg dest, TCGReg src)
-- 
2.34.1

Re: [PATCH v3 03/57] tcg/i386: Conditionalize tcg_out_extu_i32_i64

Posted by Philippe Mathieu-Daudé 2 years, 9 months ago

On 24/4/23 07:40, Richard Henderson wrote:
> Since TCG_TYPE_I32 values are kept zero-extended in registers, via
> omission of the REXW bit, we need not extend if the register matches.
> This is already relied upon by qemu_{ld,st}.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   tcg/i386/tcg-target.c.inc | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>