[v1] softfloat: Don't execute divdeu without power7

[Qemu-devel] [PATCH] softfloat: Don't execute divdeu without power7

Richard Henderson posted 1 patch 5 years, 5 months ago

Diff against v1
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git fetch https://github.com/patchew-project/qemu tags/patchew/20181101202617.6437-1-richard.henderson@linaro.org

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include/fpu/softfloat-macros.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

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[Qemu-devel] [PATCH] softfloat: Don't execute divdeu without power7

Posted by Richard Henderson 5 years, 5 months ago

The divdeu instruction was added to ISA 2.06 (Power7).
Exclude this block from older cpus.

Fixes: 27ae5109a2ba (softfloat: Specialize udiv_qrnnd for ppc64)
Reported-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/fpu/softfloat-macros.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/fpu/softfloat-macros.h b/include/fpu/softfloat-macros.h
index c86687fa5e..b1d772e6d4 100644
--- a/include/fpu/softfloat-macros.h
+++ b/include/fpu/softfloat-macros.h
@@ -647,8 +647,8 @@ static inline uint64_t udiv_qrnnd(uint64_t *r, uint64_t n1,
     asm("dlgr %0, %1" : "+r"(n) : "r"(d));
     *r = n >> 64;
     return n;
-#elif defined(_ARCH_PPC64)
-    /* From Power ISA 3.0B, programming note for divdeu.  */
+#elif defined(_ARCH_PPC64) && defined(_ARCH_PWR7)
+    /* From Power ISA 2.06, programming note for divdeu.  */
     uint64_t q1, q2, Q, r1, r2, R;
     asm("divdeu %0,%2,%4; divdu %1,%3,%4"
         : "=&r"(q1), "=r"(q2)
-- 
2.17.2

Re: [Qemu-devel] [PATCH] softfloat: Don't execute divdeu without power7

Posted by Laurent Vivier 5 years, 5 months ago

On 01/11/2018 21:26, Richard Henderson wrote:
> The divdeu instruction was added to ISA 2.06 (Power7).
> Exclude this block from older cpus.
> 
> Fixes: 27ae5109a2ba (softfloat: Specialize udiv_qrnnd for ppc64)
> Reported-by: Laurent Vivier <laurent@vivier.eu>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  include/fpu/softfloat-macros.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/fpu/softfloat-macros.h b/include/fpu/softfloat-macros.h
> index c86687fa5e..b1d772e6d4 100644
> --- a/include/fpu/softfloat-macros.h
> +++ b/include/fpu/softfloat-macros.h
> @@ -647,8 +647,8 @@ static inline uint64_t udiv_qrnnd(uint64_t *r, uint64_t n1,
>      asm("dlgr %0, %1" : "+r"(n) : "r"(d));
>      *r = n >> 64;
>      return n;
> -#elif defined(_ARCH_PPC64)
> -    /* From Power ISA 3.0B, programming note for divdeu.  */
> +#elif defined(_ARCH_PPC64) && defined(_ARCH_PWR7)
> +    /* From Power ISA 2.06, programming note for divdeu.  */
>      uint64_t q1, q2, Q, r1, r2, R;
>      asm("divdeu %0,%2,%4; divdu %1,%3,%4"
>          : "=&r"(q1), "=r"(q2)
> 

Tested-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>