This appears to do the same thing as the GLSL change. This patch is Reviewed-by: Ian Romanick <ian.d.roman...@intel.com>
On 01/24/2017 03:26 PM, Francisco Jerez wrote: > --- > src/compiler/spirv/vtn_glsl450.c | 22 +++++++++++++++++++++- > 1 file changed, 21 insertions(+), 1 deletion(-) > > diff --git a/src/compiler/spirv/vtn_glsl450.c > b/src/compiler/spirv/vtn_glsl450.c > index 508f218..7af2dad 100644 > --- a/src/compiler/spirv/vtn_glsl450.c > +++ b/src/compiler/spirv/vtn_glsl450.c > @@ -325,12 +325,32 @@ build_atan2(nir_builder *b, nir_ssa_def *y, nir_ssa_def > *x) > nir_ssa_def *rcp_scaled_t = nir_frcp(b, nir_fmul(b, t, scale)); > nir_ssa_def *s_over_t = nir_fmul(b, nir_fmul(b, s, scale), rcp_scaled_t); > > + /* For |x| = |y| assume tan = 1 even if infinite (i.e. pretend momentarily > + * that ∞/∞ = 1) in order to comply with the rather artificial rules > + * inherited from IEEE 754-2008, namely: > + * > + * "atan2(±∞, −∞) is ±3π/4 > + * atan2(±∞, +∞) is ±π/4" > + * > + * Note that this is inconsistent with the rules for the neighborhood of > + * zero that are based on iterated limits: > + * > + * "atan2(±0, −0) is ±π > + * atan2(±0, +0) is ±0" > + * > + * but GLSL specifically allows implementations to deviate from IEEE rules > + * at (0,0), so we take that license (i.e. pretend that 0/0 = 1 here as > + * well). > + */ > + nir_ssa_def *tan = nir_bcsel(b, nir_feq(b, nir_fabs(b, x), nir_fabs(b, > y)), > + one, nir_fabs(b, s_over_t)); > + > /* Calculate the arctangent and fix up the result if we had flipped the > * coordinate system. > */ > nir_ssa_def *arc = nir_fadd(b, nir_fmul(b, nir_b2f(b, flip), > nir_imm_float(b, M_PI_2f)), > - build_atan(b, nir_fabs(b, s_over_t))); > + build_atan(b, tan)); > > /* Rather convoluted calculation of the sign of the result. When x < 0 we > * cannot use fsign because we need to be able to distinguish between > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
