target/i386: set rip_offset for some SSE4.1 instructions

[Qemu-devel] [PATCH] target/i386: set rip_offset for some SSE4.1 instructions

Posted by Joseph Myers 6 years, 8 months ago

When emulating various SSE4.1 instructions such as pinsrd, the address
of a memory operand is computed without allowing for the 8-bit
immediate operand located after the memory operand, meaning that the
memory operand uses the wrong address in the case where it is
rip-relative.  This patch adds the required rip_offset setting for
those instructions, so fixing some GCC test failures (13 in the gcc
testsuite in my GCC 6-based testing) when testing with a default CPU
setting enabling those instructions.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>

---

diff --git a/target/i386/translate.c b/target/i386/translate.c
index cab9e32..5fdadf9 100644
--- a/target/i386/translate.c
+++ b/target/i386/translate.c
@@ -4080,6 +4080,7 @@ static void gen_sse(CPUX86State *env, DisasContext *s, int b,
             if (sse_fn_eppi == SSE_SPECIAL) {
                 ot = mo_64_32(s->dflag);
                 rm = (modrm & 7) | REX_B(s);
+                s->rip_offset = 1;
                 if (mod != 3)
                     gen_lea_modrm(env, s, modrm);
                 reg = ((modrm >> 3) & 7) | rex_r;

-- 
Joseph S. Myers
joseph@codesourcery.com

Re: [Qemu-devel] [PATCH] target/i386: set rip_offset for some SSE4.1 instructions

Posted by Paolo Bonzini 6 years, 8 months ago

On 08/08/2017 02:43, Joseph Myers wrote:
> When emulating various SSE4.1 instructions such as pinsrd, the address
> of a memory operand is computed without allowing for the 8-bit
> immediate operand located after the memory operand, meaning that the
> memory operand uses the wrong address in the case where it is
> rip-relative.  This patch adds the required rip_offset setting for
> those instructions, so fixing some GCC test failures (13 in the gcc
> testsuite in my GCC 6-based testing) when testing with a default CPU
> setting enabling those instructions.
> 
> Signed-off-by: Joseph Myers <joseph@codesourcery.com>
> 
> ---
> 
> diff --git a/target/i386/translate.c b/target/i386/translate.c
> index cab9e32..5fdadf9 100644
> --- a/target/i386/translate.c
> +++ b/target/i386/translate.c
> @@ -4080,6 +4080,7 @@ static void gen_sse(CPUX86State *env, DisasContext *s, int b,
>              if (sse_fn_eppi == SSE_SPECIAL) {
>                  ot = mo_64_32(s->dflag);
>                  rm = (modrm & 7) | REX_B(s);
> +                s->rip_offset = 1;
>                  if (mod != 3)
>                      gen_lea_modrm(env, s, modrm);
>                  reg = ((modrm >> 3) & 7) | rex_r;
> 


Queued for 2.10, thanks Joseph.

Paolo