On Wed, Dec 05, 2012 at 12:29:10AM +0100, Petar Jovanovic wrote:
> From: Petar Jovanovic <pet...@mips.com>
>
> helper_shilo has not been shifting an accumulator value correctly for negative
> values in 'shift' field. Minor optimization for shift=0 case.
> This change also adds tests that will trigger issue and check for regressions.
>
> Signed-off-by: Petar Jovanovic <pet...@mips.com>
> ---
> target-mips/dsp_helper.c | 17 +++++++++--------
> tests/tcg/mips/mips32-dsp/shilo.c | 18 ++++++++++++++++++
> tests/tcg/mips/mips32-dsp/shilov.c | 20 ++++++++++++++++++++
> 3 files changed, 47 insertions(+), 8 deletions(-)
>
> diff --git a/target-mips/dsp_helper.c b/target-mips/dsp_helper.c
> index e7949c2..44f6dc7 100644
> --- a/target-mips/dsp_helper.c
> +++ b/target-mips/dsp_helper.c
> @@ -3814,17 +3814,18 @@ void helper_shilo(target_ulong ac, target_ulong rs,
> CPUMIPSState *env)
>
> rs5_0 = rs & 0x3F;
> rs5_0 = (int8_t)(rs5_0 << 2) >> 2;
> - rs5_0 = MIPSDSP_ABS(rs5_0);
> +
> + if (unlikely(rs5_0 == 0)) {
> + return;
> + }
> +
> acc = (((uint64_t)env->active_tc.HI[ac] << 32) & MIPSDSP_LHI) |
> ((uint64_t)env->active_tc.LO[ac] & MIPSDSP_LLO);
> - if (rs5_0 == 0) {
> - temp = acc;
> +
> + if (rs5_0 > 0) {
> + temp = acc >> rs5_0;
> } else {
> - if (rs5_0 > 0) {
> - temp = acc >> rs5_0;
> - } else {
> - temp = acc << rs5_0;
> - }
> + temp = acc << -rs5_0;
> }
>
> env->active_tc.HI[ac] = (target_ulong)(int32_t)((temp & MIPSDSP_LHI) >>
> 32);
> diff --git a/tests/tcg/mips/mips32-dsp/shilo.c
> b/tests/tcg/mips/mips32-dsp/shilo.c
> index b686616..ce8ebc6 100644
> --- a/tests/tcg/mips/mips32-dsp/shilo.c
> +++ b/tests/tcg/mips/mips32-dsp/shilo.c
> @@ -23,5 +23,23 @@ int main()
> assert(ach == resulth);
> assert(acl == resultl);
>
> +
> + ach = 0x1;
> + acl = 0x80000000;
> +
> + resulth = 0x3;
> + resultl = 0x0;
> +
> + __asm
> + ("mthi %0, $ac1\n\t"
> + "mtlo %1, $ac1\n\t"
> + "shilo $ac1, -1\n\t"
> + "mfhi %0, $ac1\n\t"
> + "mflo %1, $ac1\n\t"
> + : "+r"(ach), "+r"(acl)
> + );
> + assert(ach == resulth);
> + assert(acl == resultl);
> +
> return 0;
> }
> diff --git a/tests/tcg/mips/mips32-dsp/shilov.c
> b/tests/tcg/mips/mips32-dsp/shilov.c
> index f186032..e1d6cea 100644
> --- a/tests/tcg/mips/mips32-dsp/shilov.c
> +++ b/tests/tcg/mips/mips32-dsp/shilov.c
> @@ -25,5 +25,25 @@ int main()
> assert(ach == resulth);
> assert(acl == resultl);
>
> +
> + rs = 0xffffffff;
> + ach = 0x1;
> + acl = 0x80000000;
> +
> + resulth = 0x3;
> + resultl = 0x0;
> +
> + __asm
> + ("mthi %0, $ac1\n\t"
> + "mtlo %1, $ac1\n\t"
> + "shilov $ac1, %2\n\t"
> + "mfhi %0, $ac1\n\t"
> + "mflo %1, $ac1\n\t"
> + : "+r"(ach), "+r"(acl)
> + : "r"(rs)
> + );
> + assert(ach == resulth);
> + assert(acl == resultl);
> +
> return 0;
> }
Thanks, applied. I added a CC: to qemu-sta...@nongnu.org, as it is
definitely stable material.
--
Aurelien Jarno GPG: 1024D/F1BCDB73
aurel...@aurel32.net http://www.aurel32.net
