glslangValidator not emitting Int64Atomics when expected

[ncesario-lunarg]

The validation layers have a test that effectively uses the following GLSL (this is contrived code, but expected to at least pass spirv-val):

#version 450
#extension GL_EXT_shader_explicit_arithmetic_types_int64 : enable
#extension GL_EXT_shader_image_int64 : enable
#extension GL_KHR_memory_scope_semantics : enable

layout(set = 0, binding = 0) buffer ssbo { uint64_t y; };
layout(set = 0, binding = 1, r64ui) uniform u64image2D z;

void main() {
    imageAtomicStore(z, ivec2(1, 1), y, gl_ScopeDevice, gl_StorageSemanticsImage, gl_SemanticsRelaxed);
}

Which produces the following error when running spirv-val:

error: line 50: AtomicStore: 64-bit atomics require the Int64Atomics capability
  OpAtomicStore %25 %int_1 %uint_2048 %20

spirv-dis shows that indeed Int64Atomics is not there:

               OpCapability Shader
               OpCapability Int64
               OpCapability Int64ImageEXT

Other imageAtomic* functions seem to cause the Int64Atomics capability to get added. e.g., replacing imageAtomicStore with imageAtomicExchange emits Int64Atomics, and the resulting spirv validates successfully.

Is there something special about imageAtomicStore such that it shouldn't emit the Int64Atomics capability?

[ncesario-lunarg]

cc @jeremy-lunarg @paul-lunarg.

[ncesario-lunarg]

This is using glslang at commit adbf0d3106b26daa237b10b9bf72b1af7c31092d. I'll try this on an updated version and see if I get the same results.

[ncesario-lunarg]

FWIW, same behavior on latest commit.