[v1] tcg: bswap improvements

[PATCH 22/28] target/arm: Improve REVSH

Richard Henderson posted 28 patches 3 years, 4 months ago

Diff against v2 v3
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Maintainers: Andrzej Zaborowski <balrogg@gmail.com>, Aurelien Jarno <aurelien@aurel32.net>, Richard Henderson <richard.henderson@linaro.org>, Cornelia Huck <cohuck@redhat.com>, David Hildenbrand <david@redhat.com>, Palmer Dabbelt <palmer@dabbelt.com>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Jiaxun Yang <jiaxun.yang@flygoat.com>, Huacai Chen <chenhuacai@kernel.org>, Eduardo Habkost <ehabkost@redhat.com>, Thomas Huth <thuth@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Stefan Weil <sw@weilnetz.de>, Paolo Bonzini <pbonzini@redhat.com>, Alistair Francis <Alistair.Francis@wdc.com>, Yoshinori Sato <ysato@users.sourceforge.jp>

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[PATCH 22/28] target/arm: Improve REVSH

Posted by Richard Henderson 3 years, 4 months ago

The new bswap flags can implement the semantics exactly.

Cc: Peter Maydell <peter.maydell@linaro.org> 
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/target/arm/translate.c b/target/arm/translate.c
index 6b88163e3a..46d95d75ae 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -341,9 +341,7 @@ void gen_rev16(TCGv_i32 dest, TCGv_i32 var)
 /* Byteswap low halfword and sign extend.  */
 static void gen_revsh(TCGv_i32 dest, TCGv_i32 var)
 {
-    tcg_gen_ext16u_i32(var, var);
-    tcg_gen_bswap16_i32(var, var, TCG_BSWAP_IZ | TCG_BSWAP_OZ);
-    tcg_gen_ext16s_i32(dest, var);
+    tcg_gen_bswap16_i32(var, var, TCG_BSWAP_OS);
 }
 
 /* Dual 16-bit add.  Result placed in t0 and t1 is marked as dead.
-- 
2.25.1

Re: [PATCH 22/28] target/arm: Improve REVSH

Posted by Peter Maydell 3 years, 4 months ago

On Mon, 14 Jun 2021 at 09:38, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> The new bswap flags can implement the semantics exactly.
>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/translate.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

Re: [PATCH 22/28] target/arm: Improve REVSH

Posted by Philippe Mathieu-Daudé 3 years, 4 months ago

On 6/14/21 10:37 AM, Richard Henderson wrote:
> The new bswap flags can implement the semantics exactly.
> 
> Cc: Peter Maydell <peter.maydell@linaro.org> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/translate.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>