From 45106a1c931d86060df72bcd296b4a1d33fda9bb Mon Sep 17 00:00:00 2001 From: Neil Roberts Date: Wed, 9 May 2018 15:14:36 +0200 Subject: [PATCH] spirv: Fix InterpolateAt* instructions for vecs with dynamic index MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If the glsl is something like this: in vec4 some_input; interpolateAtCentroid(some_input[idx]) then it now gets generated as if it were: interpolateAtCentroid(some_input)[idx] This is necessary because the index will get generated as a series of nir_bcsel instructions so it would no longer be an input variable. It is similar to what is done for GLSL in ca63a5ed3e9efb2bd645b42. Although I can’t find anything explicit in the Vulkan specs to say this should be allowed, the SPIR-V spec just says “the operand interpolant must be a pointer to the Input Storage Class”, which I guess doesn’t rule out any type of pointer to an input. This was found using the spec/glsl-4.40/execution/fs-interpolateAt* Piglit tests with the ARB_gl_spirv branch. Signed-off-by: Neil Roberts Signed-off-by: Alejandro Piñeiro v2: update after nir_deref_instr land on master. Implemented by Alejandro Piñeiro. Special thanks to Jason Ekstrand for guidance at the new nir_deref_instr world. Reviewed-by: Jason Ekstrand --- src/compiler/spirv/vtn_glsl450.c | 38 +++++++++++++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 5 deletions(-) diff --git a/src/compiler/spirv/vtn_glsl450.c b/src/compiler/spirv/vtn_glsl450.c index 7f941ce..8393450 100644 --- a/src/compiler/spirv/vtn_glsl450.c +++ b/src/compiler/spirv/vtn_glsl450.c @@ -802,7 +802,22 @@ handle_glsl450_interpolation(struct vtn_builder *b, enum GLSLstd450 opcode, struct vtn_pointer *ptr = vtn_value(b, w[5], vtn_value_type_pointer)->pointer; - intrin->src[0] = nir_src_for_ssa(&vtn_pointer_to_deref(b, ptr)->dest.ssa); + nir_deref_instr *deref = vtn_pointer_to_deref(b, ptr); + + /* If the value we are interpolating has an index into a vector then + * interpolate the vector and index the result of that instead. This is + * necessary because the index will get generated as a series of nir_bcsel + * instructions so it would no longer be an input variable. + */ + const bool vec_array_deref = deref->deref_type == nir_deref_type_array && + glsl_type_is_vector(nir_deref_instr_parent(deref)->type); + + nir_deref_instr *vec_deref = NULL; + if (vec_array_deref) { + vec_deref = deref; + deref = nir_deref_instr_parent(deref); + } + intrin->src[0] = nir_src_for_ssa(&deref->dest.ssa); switch (opcode) { case GLSLstd450InterpolateAtCentroid: @@ -815,13 +830,26 @@ handle_glsl450_interpolation(struct vtn_builder *b, enum GLSLstd450 opcode, vtn_fail("Invalid opcode"); } - intrin->num_components = glsl_get_vector_elements(dest_type); + intrin->num_components = glsl_get_vector_elements(deref->type); nir_ssa_dest_init(&intrin->instr, &intrin->dest, - glsl_get_vector_elements(dest_type), - glsl_get_bit_size(dest_type), NULL); - val->ssa->def = &intrin->dest.ssa; + glsl_get_vector_elements(deref->type), + glsl_get_bit_size(deref->type), NULL); nir_builder_instr_insert(&b->nb, &intrin->instr); + + if (vec_array_deref) { + assert(vec_deref); + nir_const_value *const_index = nir_src_as_const_value(vec_deref->arr.index); + if (const_index) { + val->ssa->def = vtn_vector_extract(b, &intrin->dest.ssa, + const_index->u32[0]); + } else { + val->ssa->def = vtn_vector_extract_dynamic(b, &intrin->dest.ssa, + vec_deref->arr.index.ssa); + } + } else { + val->ssa->def = &intrin->dest.ssa; + } } bool -- 2.7.4