| Message ID | 1294392387-24300-3-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Fri, Jan 07, 2011 at 09:26:25AM +0000, Peter Maydell wrote: > The implementation of the ARM VRSQRTS instruction (which calculates > (3 - op1 * op2) / 2) was missing the division operation. It also > did not handle the special cases of (0,inf) and (inf,0). > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > target-arm/helper.c | 10 +++++++++- > 1 files changed, 9 insertions(+), 1 deletions(-) Reviewed-by: Aurelien Jarno <aurelien@aurel32.net> > diff --git a/target-arm/helper.c b/target-arm/helper.c > index 705b99f..ac47de0 100644 > --- a/target-arm/helper.c > +++ b/target-arm/helper.c > @@ -2612,8 +2612,16 @@ float32 HELPER(recps_f32)(float32 a, float32 b, CPUState *env) > float32 HELPER(rsqrts_f32)(float32 a, float32 b, CPUState *env) > { > float_status *s = &env->vfp.fp_status; > + float32 two = int32_to_float32(2, s); > float32 three = int32_to_float32(3, s); > - return float32_sub(three, float32_mul(a, b, s), s); > + float32 product; > + if ((float32_is_infinity(a) && float32_is_zero_or_denormal(b)) || > + (float32_is_infinity(b) && float32_is_zero_or_denormal(a))) { > + product = float32_zero; > + } else { > + product = float32_mul(a, b, s); > + } > + return float32_div(float32_sub(three, product, s), two, s); > } > > /* NEON helpers. */ > -- > 1.6.3.3 > > >
diff --git a/target-arm/helper.c b/target-arm/helper.c index 705b99f..ac47de0 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -2612,8 +2612,16 @@ float32 HELPER(recps_f32)(float32 a, float32 b, CPUState *env) float32 HELPER(rsqrts_f32)(float32 a, float32 b, CPUState *env) { float_status *s = &env->vfp.fp_status; + float32 two = int32_to_float32(2, s); float32 three = int32_to_float32(3, s); - return float32_sub(three, float32_mul(a, b, s), s); + float32 product; + if ((float32_is_infinity(a) && float32_is_zero_or_denormal(b)) || + (float32_is_infinity(b) && float32_is_zero_or_denormal(a))) { + product = float32_zero; + } else { + product = float32_mul(a, b, s); + } + return float32_div(float32_sub(three, product, s), two, s); } /* NEON helpers. */
The implementation of the ARM VRSQRTS instruction (which calculates (3 - op1 * op2) / 2) was missing the division operation. It also did not handle the special cases of (0,inf) and (inf,0). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- target-arm/helper.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-)