I agree that the comment is incorrect and should say "sNaN square root".
On Thu, Feb 12, 2015 at 4:21 PM, Maciej W. Rozycki <ma...@linux-mips.org>
wrote:
> On Wed, 7 Jan 2015, Alexander Graf wrote:
>
> > diff --git a/target-ppc/fpu_helper.c b/target-ppc/fpu_helper.c
> > index 7f74466..81db60f 100644
> > --- a/target-ppc/fpu_helper.c
> > +++ b/target-ppc/fpu_helper.c
> > @@ -920,14 +923,16 @@ uint64_t helper_fsqrt(CPUPPCState *env, uint64_t
> arg)
> >
> > farg.ll = arg;
> >
> > - if (unlikely(float64_is_neg(farg.d) && !float64_is_zero(farg.d))) {
> > - /* Square root of a negative nonzero number */
> > - farg.ll = fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXSQRT, 1);
> > - } else {
> > + if (unlikely(float64_is_any_nan(farg.d))) {
> > if (unlikely(float64_is_signaling_nan(farg.d))) {
> > - /* sNaN square root */
> > + /* sNaN reciprocal square root */
>
> This change to the comment looks accidental, compare the changes below.
> Should it be reverted? [Found this while resolving merge conflicts.]
>
> > fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXSNAN, 1);
> > + farg.ll = float64_snan_to_qnan(farg.ll);
> > }
> > + } else if (unlikely(float64_is_neg(farg.d) &&
> !float64_is_zero(farg.d))) {
> > + /* Square root of a negative nonzero number */
> > + farg.ll = fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXSQRT, 1);
> > + } else {
> > farg.d = float64_sqrt(farg.d, &env->fp_status);
> > }
> > return farg.ll;
> > @@ -974,17 +979,20 @@ uint64_t helper_frsqrte(CPUPPCState *env, uint64_t
> arg)
> >
> > farg.ll = arg;
> >
> > - if (unlikely(float64_is_neg(farg.d) && !float64_is_zero(farg.d))) {
> > - /* Reciprocal square root of a negative nonzero number */
> > - farg.ll = fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXSQRT, 1);
> > - } else {
> > + if (unlikely(float64_is_any_nan(farg.d))) {
> > if (unlikely(float64_is_signaling_nan(farg.d))) {
> > /* sNaN reciprocal square root */
> > fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXSNAN, 1);
> > + farg.ll = float64_snan_to_qnan(farg.ll);
> > }
> > + } else if (unlikely(float64_is_neg(farg.d) &&
> !float64_is_zero(farg.d))) {
> > + /* Reciprocal square root of a negative nonzero number */
> > + farg.ll = fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXSQRT, 1);
> > + } else {
> > farg.d = float64_sqrt(farg.d, &env->fp_status);
> > farg.d = float64_div(float64_one, farg.d, &env->fp_status);
> > }
> > +
> > return farg.ll;
> > }
> >
>
> Maciej
>
