[Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL*

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* [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL*
@ 2019-09-12 18:30 Richard Henderson
  2019-09-13  6:03 ` Laurent Desnogues
                   ` (2 more replies)
  0 siblings, 3 replies; 5+ messages in thread
From: Richard Henderson @ 2019-09-12 18:30 UTC (permalink / raw)
  To: qemu-devel; +Cc: laurent.desnogues, peter.maydell

The 32-bit product should be sign-extended, not zero-extended.

Fixes: ea96b374641b
Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/target/arm/translate.c b/target/arm/translate.c
index 34bb280e3d..fd2f0e3048 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -8045,7 +8045,9 @@ static bool op_smlaxxx(DisasContext *s, arg_rrrr *a,
     case 2:
         tl = load_reg(s, a->ra);
         th = load_reg(s, a->rd);
-        t1 = tcg_const_i32(0);
+        /* Sign-extend the 32-bit product to 64 bits.  */
+        t1 = tcg_temp_new_i32();
+        tcg_gen_sari_i32(t1, t0, 31);
         tcg_gen_add2_i32(tl, th, tl, th, t0, t1);
         tcg_temp_free_i32(t0);
         tcg_temp_free_i32(t1);
-- 
2.17.1



^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL*
  2019-09-12 18:30 [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL* Richard Henderson
@ 2019-09-13  6:03 ` Laurent Desnogues
  2019-09-13 11:01 ` Philippe Mathieu-Daudé
  2019-10-14 23:42 ` Richard Henderson
  2 siblings, 0 replies; 5+ messages in thread
From: Laurent Desnogues @ 2019-09-13  6:03 UTC (permalink / raw)
  To: Richard Henderson; +Cc: Peter Maydell, qemu-devel@nongnu.org

Hello,

On Thu, Sep 12, 2019 at 8:31 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> The 32-bit product should be sign-extended, not zero-extended.
>
> Fixes: ea96b374641b
> Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

No more failures on my tests.

Tested-by: Laurent Desnogues <laurent.desnogues@gmail.com>

Thanks,

Laurent

> ---
>  target/arm/translate.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index 34bb280e3d..fd2f0e3048 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -8045,7 +8045,9 @@ static bool op_smlaxxx(DisasContext *s, arg_rrrr *a,
>      case 2:
>          tl = load_reg(s, a->ra);
>          th = load_reg(s, a->rd);
> -        t1 = tcg_const_i32(0);
> +        /* Sign-extend the 32-bit product to 64 bits.  */
> +        t1 = tcg_temp_new_i32();
> +        tcg_gen_sari_i32(t1, t0, 31);
>          tcg_gen_add2_i32(tl, th, tl, th, t0, t1);
>          tcg_temp_free_i32(t0);
>          tcg_temp_free_i32(t1);
> --
> 2.17.1
>


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL*
  2019-09-12 18:30 [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL* Richard Henderson
  2019-09-13  6:03 ` Laurent Desnogues
@ 2019-09-13 11:01 ` Philippe Mathieu-Daudé
  2019-10-14 23:42 ` Richard Henderson
  2 siblings, 0 replies; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-09-13 11:01 UTC (permalink / raw)
  To: Richard Henderson, qemu-devel; +Cc: laurent.desnogues, peter.maydell

On 9/12/19 8:30 PM, Richard Henderson wrote:
> The 32-bit product should be sign-extended, not zero-extended.
> 
> Fixes: ea96b374641b
> Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> ---
>  target/arm/translate.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index 34bb280e3d..fd2f0e3048 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -8045,7 +8045,9 @@ static bool op_smlaxxx(DisasContext *s, arg_rrrr *a,
>      case 2:
>          tl = load_reg(s, a->ra);
>          th = load_reg(s, a->rd);
> -        t1 = tcg_const_i32(0);
> +        /* Sign-extend the 32-bit product to 64 bits.  */
> +        t1 = tcg_temp_new_i32();
> +        tcg_gen_sari_i32(t1, t0, 31);
>          tcg_gen_add2_i32(tl, th, tl, th, t0, t1);
>          tcg_temp_free_i32(t0);
>          tcg_temp_free_i32(t1);
> 


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] target/arm: Fix sign-extension for SMLAL*
  2019-09-12 18:30 [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL* Richard Henderson
  2019-09-13  6:03 ` Laurent Desnogues
  2019-09-13 11:01 ` Philippe Mathieu-Daudé
@ 2019-10-14 23:42 ` Richard Henderson
  2019-10-17 13:52   ` Peter Maydell
  2 siblings, 1 reply; 5+ messages in thread
From: Richard Henderson @ 2019-10-14 23:42 UTC (permalink / raw)
  To: qemu-devel; +Cc: laurent.desnogues, peter.maydell

Ping.

On 9/12/19 11:30 AM, Richard Henderson wrote:
> The 32-bit product should be sign-extended, not zero-extended.
> 
> Fixes: ea96b374641b
> Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/translate.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index 34bb280e3d..fd2f0e3048 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -8045,7 +8045,9 @@ static bool op_smlaxxx(DisasContext *s, arg_rrrr *a,
>      case 2:
>          tl = load_reg(s, a->ra);
>          th = load_reg(s, a->rd);
> -        t1 = tcg_const_i32(0);
> +        /* Sign-extend the 32-bit product to 64 bits.  */
> +        t1 = tcg_temp_new_i32();
> +        tcg_gen_sari_i32(t1, t0, 31);
>          tcg_gen_add2_i32(tl, th, tl, th, t0, t1);
>          tcg_temp_free_i32(t0);
>          tcg_temp_free_i32(t1);
> 



^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH] target/arm: Fix sign-extension for SMLAL*
  2019-10-14 23:42 ` Richard Henderson
@ 2019-10-17 13:52   ` Peter Maydell
  0 siblings, 0 replies; 5+ messages in thread
From: Peter Maydell @ 2019-10-17 13:52 UTC (permalink / raw)
  To: Richard Henderson; +Cc: Laurent Desnogues, QEMU Developers

On Tue, 15 Oct 2019 at 00:42, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Ping.
>
> On 9/12/19 11:30 AM, Richard Henderson wrote:
> > The 32-bit product should be sign-extended, not zero-extended.
> >
> > Fixes: ea96b374641b
> > Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org>



Applied to target-arm.next, thanks.

-- PMM


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2019-10-17 14:58 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2019-09-12 18:30 [Qemu-devel] [PATCH] target/arm: Fix sign-extension for SMLAL* Richard Henderson
2019-09-13  6:03 ` Laurent Desnogues
2019-09-13 11:01 ` Philippe Mathieu-Daudé
2019-10-14 23:42 ` Richard Henderson
2019-10-17 13:52   ` Peter Maydell

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