spirv-opt: The convert-relaxed-to-half optimization pass generates invalid SPIR-V. #3099
Description
Steps to repro:
With the following GLSL frag shader:
#version 410 core
precision mediump float;
layout(location = 1) in vec3 foo;
layout(location = 2) in mat2 bar;
vec3 func(vec3 tap, mat2 M) {
return vec3(M * tap.xy, 1.0);
// Doing this instead solves the issue:
// vec2 temp = M * tap.xy;
// return vec3(temp, 1.0);
}
void main() {
vec3 result = func(foo, bar);
}
Compile to SPIR-V, optimize, and validate:
$ glslangValidator -V -o test.spv test.frag
$ spirv-opt --convert-relaxed-to-half -o half.spv test.spv
$ spirv-val half.spv
The validator errors with the following:
error: line 71: Expected Constituents to be scalars or vectors of the same type as Result Type components
%24 = OpCompositeConstruct %v3float %22 %23 %float_1
The problematic SPIR-V:
%22 = OpCompositeExtract %half %20 0
%23 = OpCompositeExtract %half %20 1
%24 = OpCompositeConstruct %v3float %22 %23 %float_1