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[SPIRV] Upd SPV_KHR_shader_clock extension #160147

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Merged
merged 2 commits into from
Oct 23, 2025
Merged

[SPIRV] Upd SPV_KHR_shader_clock extension #160147

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151a17d
[SPIR-V] Upd SPV_KHR_shader_clock extension
KornevNikita Sep 22, 2025
c77497d
Merge branch 'main' into fix-clock-spirv-be
MrSidims Oct 23, 2025
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31 changes: 19 additions & 12 deletions llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1499,18 +1499,25 @@ static bool generateKernelClockInst(const SPIRV::IncomingCall *Call,

Register ResultReg = Call->ReturnRegister;

// Deduce the `Scope` operand from the builtin function name.
SPIRV::Scope::Scope ScopeArg =
StringSwitch<SPIRV::Scope::Scope>(Builtin->Name)
.EndsWith("device", SPIRV::Scope::Scope::Device)
.EndsWith("work_group", SPIRV::Scope::Scope::Workgroup)
.EndsWith("sub_group", SPIRV::Scope::Scope::Subgroup);
Register ScopeReg = buildConstantIntReg32(ScopeArg, MIRBuilder, GR);

MIRBuilder.buildInstr(SPIRV::OpReadClockKHR)
.addDef(ResultReg)
.addUse(GR->getSPIRVTypeID(Call->ReturnType))
.addUse(ScopeReg);
if (Builtin->Name == "__spirv_ReadClockKHR") {
MIRBuilder.buildInstr(SPIRV::OpReadClockKHR)
.addDef(ResultReg)
.addUse(GR->getSPIRVTypeID(Call->ReturnType))
.addUse(Call->Arguments[0]);
} else {
Comment on lines +1502 to +1507
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I believe it's not needed. I'm looking at #96790 and it seems like changing
defm : DemangledNativeBuiltin<"__spirv_ReadClockKHR", OpenCL_std, KernelClock, 1, 1, OpReadClockKHR>;
to
defm : DemangledGroupBuiltinWrapper<"__spirv_ReadClockKHR", OpenCL_std, 1, 1, OpReadClockKHR>;

should be enough

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Tried to apply this, but it doesn't work like that - llc crashes. I believe DemangledGroupBuiltinWrapper is intended for different Group operations. Looking at how other built-ins are processed, I guess the way suggested here should be correct.

// Deduce the `Scope` operand from the builtin function name.
SPIRV::Scope::Scope ScopeArg =
StringSwitch<SPIRV::Scope::Scope>(Builtin->Name)
.EndsWith("device", SPIRV::Scope::Scope::Device)
.EndsWith("work_group", SPIRV::Scope::Scope::Workgroup)
.EndsWith("sub_group", SPIRV::Scope::Scope::Subgroup);
Register ScopeReg = buildConstantIntReg32(ScopeArg, MIRBuilder, GR);

MIRBuilder.buildInstr(SPIRV::OpReadClockKHR)
.addDef(ResultReg)
.addUse(GR->getSPIRVTypeID(Call->ReturnType))
.addUse(ScopeReg);
}

return true;
}
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1 change: 1 addition & 0 deletions llvm/lib/Target/SPIRV/SPIRVBuiltins.td
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Expand Up @@ -1174,6 +1174,7 @@ defm : DemangledNativeBuiltin<"clock_read_sub_group", OpenCL_std, KernelClock, 0
defm : DemangledNativeBuiltin<"clock_read_hilo_device", OpenCL_std, KernelClock, 0, 0, OpReadClockKHR>;
defm : DemangledNativeBuiltin<"clock_read_hilo_work_group", OpenCL_std, KernelClock, 0, 0, OpReadClockKHR>;
defm : DemangledNativeBuiltin<"clock_read_hilo_sub_group", OpenCL_std, KernelClock, 0, 0, OpReadClockKHR>;
defm : DemangledNativeBuiltin<"__spirv_ReadClockKHR", OpenCL_std, KernelClock, 1, 1, OpReadClockKHR>;

//===----------------------------------------------------------------------===//
// Class defining an atomic instruction on floating-point numbers.
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9 changes: 9 additions & 0 deletions llvm/test/CodeGen/SPIRV/extensions/SPV_KHR_shader_clock/shader_clock.ll
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Expand Up @@ -20,6 +20,9 @@
; CHECK: OpReadClockKHR [[v2uint]] [[uint_1]]
; CHECK: OpReadClockKHR [[v2uint]] [[uint_2]]
; CHECK: OpReadClockKHR [[v2uint]] [[uint_3]]
; CHECK: OpReadClockKHR [[ulong]] [[uint_1]]
; CHECK: OpReadClockKHR [[ulong]] [[uint_2]]
; CHECK: OpReadClockKHR [[ulong]] [[uint_3]]

define dso_local spir_kernel void @test_clocks(ptr addrspace(1) nocapture noundef writeonly align 8 %out64, ptr addrspace(1) nocapture noundef writeonly align 8 %outv2) {
entry:
Expand All @@ -39,6 +42,9 @@ entry:
%call9 = tail call spir_func <2 x i32> @_Z25clock_read_hilo_sub_groupv()
%arrayidx10 = getelementptr inbounds i8, ptr addrspace(1) %outv2, i32 16
store <2 x i32> %call9, ptr addrspace(1) %arrayidx10, align 8
%call10 = call spir_func i64 @_Z27__spirv_ReadClockKHR_Rulongi(i32 1)
%call11 = call spir_func i64 @_Z27__spirv_ReadClockKHR_Rulongi(i32 2)
%call12 = call spir_func i64 @_Z27__spirv_ReadClockKHR_Rulongi(i32 3)
ret void
}

Expand All @@ -59,3 +65,6 @@ declare spir_func <2 x i32> @_Z26clock_read_hilo_work_groupv() local_unnamed_add

; Function Attrs: convergent nounwind
declare spir_func <2 x i32> @_Z25clock_read_hilo_sub_groupv() local_unnamed_addr

; Function Attrs: nounwind
declare spir_func i64 @_Z27__spirv_ReadClockKHR_Rulongi(i32)