On Sun, Sep 09, 2012 at 10:51:20AM +0100, Peter Maydell wrote:
> On 8 September 2012 22:12, Aurelien Jarno <aurel...@aurel32.net> wrote:
> > +#define VARITHFPFMA(suffix, type) \
> > + void helper_v##suffix(CPUPPCState *env, ppc_avr_t *r, ppc_avr_t *a, \
> > + ppc_avr_t *b, ppc_avr_t *c) \
> > + { \
> > + int i; \
> > + for (i = 0; i < ARRAY_SIZE(r->f); i++) { \
> > + r->f[i] = float32_muladd(a->f[i], c->f[i], b->f[i], \
> > + type, &env->vec_status); \
> > + } \
> > + }
> > +VARITHFPFMA(maddfp, 0);
> > +VARITHFPFMA(nmsubfp, float_muladd_negate_result);
> > +#undef VARITHFPFMA
> > +
> > #define VARITHSAT_CASE(type, op, cvt, element) \
> > { \
> > type result = (type)a->element[i] op (type)b->element[i]; \
> > -void helper_vnmsubfp(CPUPPCState *env, ppc_avr_t *r, ppc_avr_t *a,
> > - ppc_avr_t *b, ppc_avr_t *c)
> > -{
> > - int i;
> > -
> > - for (i = 0; i < ARRAY_SIZE(r->f); i++) {
> > - HANDLE_NAN3(r->f[i], a->f[i], b->f[i], c->f[i]) {
> > - /* Need to do the computation is higher precision and round
> > - * once at the end. */
> > - float64 af, bf, cf, t;
> > -
> > - af = float32_to_float64(a->f[i], &env->vec_status);
> > - bf = float32_to_float64(b->f[i], &env->vec_status);
> > - cf = float32_to_float64(c->f[i], &env->vec_status);
> > - t = float64_mul(af, cf, &env->vec_status);
> > - t = float64_sub(t, bf, &env->vec_status);
> > - t = float64_chs(t);
> > - r->f[i] = float64_to_float32(t, &env->vec_status);
> > - }
> > - }
> > -}
>
> I mentioned this in my comment on the other patch, but just to attach
> it to the right patch for the benefit of the archives:
> the code here for vnmsub is (correctly) doing a subtraction of bf
> and then negating the final result, so you need to pass float_muladd
> the flags negate_result | negate_c, not just negate_result.
>
Correct, or alternatively it could use negate_product. I'll send an
updated patch later.
--
Aurelien Jarno GPG: 1024D/F1BCDB73
aurel...@aurel32.net http://www.aurel32.net
