From f92a35d831cf54f2244d5510932fd17c97b02ce4 Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Wed, 27 Jan 2016 14:20:47 -0800 Subject: [PATCH] vtn: Fix Modf. We were botching this for negative numbers - floor of a negative rounds the wrong way. Additionally, both results are supposed to retain the sign of the original. To fix this, just take the abs of both values, then put the sign back. There's probably a better way to do this, but this works for now. --- src/glsl/nir/spirv/vtn_glsl450.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/src/glsl/nir/spirv/vtn_glsl450.c b/src/glsl/nir/spirv/vtn_glsl450.c index 515a743fe48..b98ef052cbf 100644 --- a/src/glsl/nir/spirv/vtn_glsl450.c +++ b/src/glsl/nir/spirv/vtn_glsl450.c @@ -418,16 +418,20 @@ handle_glsl450_alu(struct vtn_builder *b, enum GLSLstd450 entrypoint, case GLSLstd450InverseSqrt: op = nir_op_frsq; break; case GLSLstd450Modf: { - val->ssa->def = nir_ffract(nb, src[0]); + nir_ssa_def *sign = nir_fsign(nb, src[0]); + nir_ssa_def *abs = nir_fabs(nb, src[0]); + val->ssa->def = nir_fmul(nb, sign, nir_ffract(nb, abs)); nir_store_deref_var(nb, vtn_nir_deref(b, w[6]), - nir_ffloor(nb, src[0]), 0xf); + nir_fmul(nb, sign, nir_ffloor(nb, abs)), 0xf); return; } case GLSLstd450ModfStruct: { + nir_ssa_def *sign = nir_fsign(nb, src[0]); + nir_ssa_def *abs = nir_fabs(nb, src[0]); assert(glsl_type_is_struct(val->ssa->type)); - val->ssa->elems[0]->def = nir_ffract(nb, src[0]); - val->ssa->elems[1]->def = nir_ffloor(nb, src[0]); + val->ssa->elems[0]->def = nir_fmul(nb, sign, nir_ffract(nb, abs)); + val->ssa->elems[1]->def = nir_fmul(nb, sign, nir_ffloor(nb, abs)); return; } -- 2.30.2