[llvm] [SPIRV] Add pass to replace gethandlefromimplicitbinding (PR #146756)
Steven Perron via llvm-commits
llvm-commits at lists.llvm.org
Wed Jul 2 11:36:46 PDT 2025
https://github.com/s-perron created https://github.com/llvm/llvm-project/pull/146756
The HLSL frontend generates call to the intrinsic
@llvm.spv.resource.handlefromimplicitbinding to be able to access a
resource where the set and binding were not explicitly given in the
source code. Determining the correct set and binding cannot be done
during Clang's codegen or earlier because in DXIL, they must first
remove resource that are not accessed before assigning binding locations
to the resource without an explicit binding.
We will follow their lead.
This is a change from DXC, where implicit binding for SPIR-V are
assigned before optimizations. **NOTE: Before merging we will need input for the HLSL-SPIR-V community
to know if this will work for them.**
>From f355f4fa4d7e6d8c96ece277afaf532cc3809c80 Mon Sep 17 00:00:00 2001
From: Steven Perron <stevenperron at google.com>
Date: Wed, 2 Jul 2025 12:46:17 -0400
Subject: [PATCH] [SPIRV] Add pass to replace gethandlefromimplicitbinding
The HLSL frontend generates call to the intrinsic
@llvm.spv.resource.handlefromimplicitbinding to be able to access a
resource where the set and binding were not explicitly given in the
source code. Determining the correct set and binding cannot be done
during Clang's codegen or earlier because in DXIL, they must first
remove resource that are not accessed before assigning binding locations
to the resource without an explicit binding.
We will follow their lead.
This is a change from DXC, where implicit binding for SPIR-V are
assigned before optimizations. **NOTE: Before merging we will need input for the HLSL-SPIR-V community
to know if this will work for them.**
---
llvm/lib/Target/SPIRV/CMakeLists.txt | 1 +
llvm/lib/Target/SPIRV/SPIRV.h | 2 +
.../SPIRV/SPIRVLegalizeImplicitBinding.cpp | 160 ++++++++++++++++++
llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp | 1 +
.../SPIRV/hlsl-resources/ImplicitBinding.ll | 75 ++++++++
5 files changed, 239 insertions(+)
create mode 100644 llvm/lib/Target/SPIRV/SPIRVLegalizeImplicitBinding.cpp
create mode 100644 llvm/test/CodeGen/SPIRV/hlsl-resources/ImplicitBinding.ll
diff --git a/llvm/lib/Target/SPIRV/CMakeLists.txt b/llvm/lib/Target/SPIRV/CMakeLists.txt
index 4a2b534b948d6..c61cb114f9d20 100644
--- a/llvm/lib/Target/SPIRV/CMakeLists.txt
+++ b/llvm/lib/Target/SPIRV/CMakeLists.txt
@@ -26,6 +26,7 @@ add_llvm_target(SPIRVCodeGen
SPIRVGlobalRegistry.cpp
SPIRVInstrInfo.cpp
SPIRVInstructionSelector.cpp
+ SPIRVLegalizeImplicitBinding.cpp
SPIRVStripConvergentIntrinsics.cpp
SPIRVLegalizePointerCast.cpp
SPIRVMergeRegionExitTargets.cpp
diff --git a/llvm/lib/Target/SPIRV/SPIRV.h b/llvm/lib/Target/SPIRV/SPIRV.h
index 1688fa32ce436..1934e98ca512f 100644
--- a/llvm/lib/Target/SPIRV/SPIRV.h
+++ b/llvm/lib/Target/SPIRV/SPIRV.h
@@ -23,6 +23,7 @@ ModulePass *createSPIRVPrepareFunctionsPass(const SPIRVTargetMachine &TM);
FunctionPass *createSPIRVStructurizerPass();
FunctionPass *createSPIRVMergeRegionExitTargetsPass();
FunctionPass *createSPIRVStripConvergenceIntrinsicsPass();
+ModulePass *createSPIRVLegalizeImplicitBindingPass();
FunctionPass *createSPIRVLegalizePointerCastPass(SPIRVTargetMachine *TM);
FunctionPass *createSPIRVRegularizerPass();
FunctionPass *createSPIRVPreLegalizerCombiner();
@@ -49,6 +50,7 @@ void initializeSPIRVRegularizerPass(PassRegistry &);
void initializeSPIRVMergeRegionExitTargetsPass(PassRegistry &);
void initializeSPIRVPrepareFunctionsPass(PassRegistry &);
void initializeSPIRVStripConvergentIntrinsicsPass(PassRegistry &);
+void initializeSPIRVLegalizeImplicitBindingPass(PassRegistry &);
} // namespace llvm
#endif // LLVM_LIB_TARGET_SPIRV_SPIRV_H
diff --git a/llvm/lib/Target/SPIRV/SPIRVLegalizeImplicitBinding.cpp b/llvm/lib/Target/SPIRV/SPIRVLegalizeImplicitBinding.cpp
new file mode 100644
index 0000000000000..08d733ba3f793
--- /dev/null
+++ b/llvm/lib/Target/SPIRV/SPIRVLegalizeImplicitBinding.cpp
@@ -0,0 +1,160 @@
+//===- SPIRVLegalizeImplicitBinding.cpp - Legalize implicit bindings ----*- C++
+//-*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass legalizes the @llvm.spv.resource.handlefromimplicitbinding
+// intrinsic by replacing it with a call to
+// @llvm.spv.resource.handlefrombinding.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SPIRV.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/InstVisitor.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/IntrinsicsSPIRV.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+#include <algorithm>
+#include <vector>
+
+using namespace llvm;
+
+namespace {
+class SPIRVLegalizeImplicitBinding : public ModulePass {
+public:
+ static char ID;
+ SPIRVLegalizeImplicitBinding() : ModulePass(ID) {}
+
+ bool runOnModule(Module &M) override;
+
+private:
+ void collectAndSortImplicitBindings(Module &M);
+ unsigned findAndReserveFirstUnusedBinding(unsigned DescSet);
+ void replaceImplicitBindingCalls(Module &M);
+
+ // A map from descriptor set to a bit vector of used binding numbers.
+ std::vector<BitVector> UsedBindings;
+ // A list of all implicit binding calls, to be sorted by order ID.
+ SmallVector<CallInst *, 16> ImplicitBindingCalls;
+};
+
+struct ImplicitBindingInfoCollector
+ : public InstVisitor<ImplicitBindingInfoCollector> {
+ std::vector<BitVector> &UsedBindings;
+ SmallVector<CallInst *, 16> &ImplicitBindingCalls;
+
+ ImplicitBindingInfoCollector(
+ std::vector<BitVector> &UsedBindings,
+ SmallVector<CallInst *, 16> &ImplicitBindingCalls)
+ : UsedBindings(UsedBindings), ImplicitBindingCalls(ImplicitBindingCalls) {
+ }
+
+ void visitCallInst(CallInst &CI) {
+ if (CI.getIntrinsicID() == Intrinsic::spv_resource_handlefrombinding) {
+ // Extract descriptor set and binding.
+ // Arguments are: desc set, binding, ...
+ const unsigned DescSet =
+ cast<ConstantInt>(CI.getArgOperand(0))->getZExtValue();
+ const unsigned Binding =
+ cast<ConstantInt>(CI.getArgOperand(1))->getZExtValue();
+
+ if (UsedBindings.size() <= DescSet) {
+ UsedBindings.resize(DescSet + 1);
+ }
+ if (UsedBindings[DescSet].size() <= Binding) {
+ UsedBindings[DescSet].resize(Binding + 1);
+ }
+ UsedBindings[DescSet].set(Binding);
+ } else if (CI.getIntrinsicID() ==
+ Intrinsic::spv_resource_handlefromimplicitbinding) {
+ ImplicitBindingCalls.push_back(&CI);
+ }
+ }
+};
+
+void SPIRVLegalizeImplicitBinding::collectAndSortImplicitBindings(Module &M) {
+ ImplicitBindingInfoCollector InfoCollector(UsedBindings,
+ ImplicitBindingCalls);
+ InfoCollector.visit(M);
+
+ // Sort the collected calls by their order ID (the first argument).
+ std::sort(ImplicitBindingCalls.begin(), ImplicitBindingCalls.end(),
+ [](const CallInst *A, const CallInst *B) {
+ const unsigned OrderA =
+ cast<ConstantInt>(A->getArgOperand(0))->getZExtValue();
+ const unsigned OrderB =
+ cast<ConstantInt>(B->getArgOperand(0))->getZExtValue();
+ return OrderA < OrderB;
+ });
+}
+
+unsigned SPIRVLegalizeImplicitBinding::findAndReserveFirstUnusedBinding(
+ unsigned DescSet) {
+ if (UsedBindings.size() <= DescSet) {
+ UsedBindings.resize(DescSet + 1);
+ }
+
+ int NewBinding = UsedBindings[DescSet].find_first_unset();
+ if (NewBinding == -1) {
+ NewBinding = UsedBindings[DescSet].size();
+ UsedBindings[DescSet].resize(NewBinding + 1);
+ }
+
+ UsedBindings[DescSet].set(NewBinding);
+ return NewBinding;
+}
+
+void SPIRVLegalizeImplicitBinding::replaceImplicitBindingCalls(Module &M) {
+ for (CallInst *OldCI : ImplicitBindingCalls) {
+ IRBuilder<> Builder(OldCI);
+ const unsigned DescSet =
+ cast<ConstantInt>(OldCI->getArgOperand(1))->getZExtValue();
+ const unsigned NewBinding = findAndReserveFirstUnusedBinding(DescSet);
+
+ SmallVector<Value *, 8> Args;
+ Args.push_back(Builder.getInt32(DescSet));
+ Args.push_back(Builder.getInt32(NewBinding));
+
+ // Copy the remaining arguments from the old call.
+ for (unsigned i = 2; i < OldCI->arg_size(); ++i) {
+ Args.push_back(OldCI->getArgOperand(i));
+ }
+
+ Function *NewFunc = Intrinsic::getOrInsertDeclaration(
+ &M, Intrinsic::spv_resource_handlefrombinding, OldCI->getType());
+ CallInst *NewCI = Builder.CreateCall(NewFunc, Args);
+ NewCI->setCallingConv(OldCI->getCallingConv());
+
+ OldCI->replaceAllUsesWith(NewCI);
+ OldCI->eraseFromParent();
+ }
+}
+
+bool SPIRVLegalizeImplicitBinding::runOnModule(Module &M) {
+ collectAndSortImplicitBindings(M);
+ if (ImplicitBindingCalls.empty()) {
+ return false;
+ }
+
+ replaceImplicitBindingCalls(M);
+ return true;
+}
+} // namespace
+
+char SPIRVLegalizeImplicitBinding::ID = 0;
+
+INITIALIZE_PASS(SPIRVLegalizeImplicitBinding, "legalize-spirv-implicit-binding",
+ "Legalize SPIR-V implicit bindings", false, false)
+
+ModulePass *llvm::createSPIRVLegalizeImplicitBindingPass() {
+ return new SPIRVLegalizeImplicitBinding();
+}
\ No newline at end of file
diff --git a/llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp b/llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp
index d7cf211ba84dc..e0bfb77f4b530 100644
--- a/llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVTargetMachine.cpp
@@ -226,6 +226,7 @@ void SPIRVPassConfig::addIRPasses() {
}
void SPIRVPassConfig::addISelPrepare() {
+ addPass(createSPIRVLegalizeImplicitBindingPass());
addPass(createSPIRVEmitIntrinsicsPass(&getTM<SPIRVTargetMachine>()));
if (TM.getSubtargetImpl()->isLogicalSPIRV())
addPass(createSPIRVLegalizePointerCastPass(&getTM<SPIRVTargetMachine>()));
diff --git a/llvm/test/CodeGen/SPIRV/hlsl-resources/ImplicitBinding.ll b/llvm/test/CodeGen/SPIRV/hlsl-resources/ImplicitBinding.ll
new file mode 100644
index 0000000000000..00e9185822ad5
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/hlsl-resources/ImplicitBinding.ll
@@ -0,0 +1,75 @@
+; RUN: llc -O0 -verify-machineinstrs -mtriple=spirv1.6-vulkan1.3-library %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv1.6-vulkan1.3-library %s -o - -filetype=obj | spirv-val --target-env vulkan1.3 %}
+
+ at .str = private unnamed_addr constant [2 x i8] c"b\00", align 1
+ at .str.2 = private unnamed_addr constant [2 x i8] c"c\00", align 1
+ at .str.4 = private unnamed_addr constant [2 x i8] c"d\00", align 1
+ at .str.6 = private unnamed_addr constant [2 x i8] c"e\00", align 1
+ at .str.8 = private unnamed_addr constant [2 x i8] c"f\00", align 1
+ at .str.10 = private unnamed_addr constant [2 x i8] c"g\00", align 1
+ at .str.12 = private unnamed_addr constant [2 x i8] c"h\00", align 1
+ at .str.14 = private unnamed_addr constant [2 x i8] c"i\00", align 1
+
+; CHECK-DAG: OpName [[b:%[0-9]+]] "b"
+; CHECK-DAG: OpName [[c:%[0-9]+]] "c"
+; CHECK-DAG: OpName [[d:%[0-9]+]] "d"
+; CHECK-DAG: OpName [[e:%[0-9]+]] "e"
+; CHECK-DAG: OpName [[f:%[0-9]+]] "f"
+; CHECK-DAG: OpName [[g:%[0-9]+]] "g"
+; CHECK-DAG: OpName [[h:%[0-9]+]] "h"
+; CHECK-DAG: OpName [[i:%[0-9]+]] "i"
+; CHECK-DAG: OpDecorate [[b]] DescriptorSet 0
+; CHECK-DAG: OpDecorate [[b]] Binding 1
+; CHECK-DAG: OpDecorate [[c]] DescriptorSet 0
+; CHECK-DAG: OpDecorate [[c]] Binding 0
+; CHECK-DAG: OpDecorate [[d]] DescriptorSet 0
+; CHECK-DAG: OpDecorate [[d]] Binding 3
+; CHECK-DAG: OpDecorate [[e]] DescriptorSet 0
+; CHECK-DAG: OpDecorate [[e]] Binding 2
+; CHECK-DAG: OpDecorate [[f]] DescriptorSet 10
+; CHECK-DAG: OpDecorate [[f]] Binding 1
+; CHECK-DAG: OpDecorate [[g]] DescriptorSet 10
+; CHECK-DAG: OpDecorate [[g]] Binding 0
+; CHECK-DAG: OpDecorate [[h]] DescriptorSet 10
+; CHECK-DAG: OpDecorate [[h]] Binding 3
+; CHECK-DAG: OpDecorate [[i]] DescriptorSet 10
+; CHECK-DAG: OpDecorate [[i]] Binding 2
+
+
+define void @main() local_unnamed_addr #0 {
+entry:
+ %0 = tail call target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) @llvm.spv.resource.handlefromimplicitbinding.tspirv.SignedImage_i32_5_2_0_0_2_0t(i32 0, i32 0, i32 1, i32 0, i1 false, ptr nonnull @.str)
+ %1 = tail call target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) @llvm.spv.resource.handlefrombinding.tspirv.SignedImage_i32_5_2_0_0_2_0t(i32 0, i32 0, i32 1, i32 0, i1 false, ptr nonnull @.str.2)
+ %2 = tail call target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) @llvm.spv.resource.handlefromimplicitbinding.tspirv.SignedImage_i32_5_2_0_0_2_0t(i32 1, i32 0, i32 1, i32 0, i1 false, ptr nonnull @.str.4)
+ %3 = tail call target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) @llvm.spv.resource.handlefrombinding.tspirv.SignedImage_i32_5_2_0_0_2_0t(i32 0, i32 2, i32 1, i32 0, i1 false, ptr nonnull @.str.6)
+ %4 = tail call target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) @llvm.spv.resource.handlefrombinding.tspirv.SignedImage_i32_5_2_0_0_2_0t(i32 10, i32 1, i32 1, i32 0, i1 false, ptr nonnull @.str.8)
+ %5 = tail call target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) @llvm.spv.resource.handlefromimplicitbinding.tspirv.SignedImage_i32_5_2_0_0_2_0t(i32 2, i32 10, i32 1, i32 0, i1 false, ptr nonnull @.str.10)
+ %6 = tail call target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) @llvm.spv.resource.handlefromimplicitbinding.tspirv.SignedImage_i32_5_2_0_0_2_0t(i32 3, i32 10, i32 1, i32 0, i1 false, ptr nonnull @.str.12)
+ %7 = tail call target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) @llvm.spv.resource.handlefrombinding.tspirv.SignedImage_i32_5_2_0_0_2_0t(i32 10, i32 2, i32 1, i32 0, i1 false, ptr nonnull @.str.14)
+ %8 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.SignedImage_i32_5_2_0_0_2_0t(target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) %1, i32 0)
+ %9 = load i32, ptr addrspace(11) %8, align 4
+ %10 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.SignedImage_i32_5_2_0_0_2_0t(target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) %2, i32 0)
+ %11 = load i32, ptr addrspace(11) %10, align 4
+ %add.i = add nsw i32 %11, %9
+ %12 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.SignedImage_i32_5_2_0_0_2_0t(target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) %3, i32 0)
+ %13 = load i32, ptr addrspace(11) %12, align 4
+ %add4.i = add nsw i32 %add.i, %13
+ %14 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.SignedImage_i32_5_2_0_0_2_0t(target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) %4, i32 0)
+ %15 = load i32, ptr addrspace(11) %14, align 4
+ %add6.i = add nsw i32 %add4.i, %15
+ %16 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.SignedImage_i32_5_2_0_0_2_0t(target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) %5, i32 0)
+ %17 = load i32, ptr addrspace(11) %16, align 4
+ %add8.i = add nsw i32 %add6.i, %17
+ %18 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.SignedImage_i32_5_2_0_0_2_0t(target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) %6, i32 0)
+ %19 = load i32, ptr addrspace(11) %18, align 4
+ %add10.i = add nsw i32 %add8.i, %19
+ %20 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.SignedImage_i32_5_2_0_0_2_0t(target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) %7, i32 0)
+ %21 = load i32, ptr addrspace(11) %20, align 4
+ %add12.i = add nsw i32 %add10.i, %21
+ %22 = tail call noundef align 4 dereferenceable(4) ptr addrspace(11) @llvm.spv.resource.getpointer.p11.tspirv.SignedImage_i32_5_2_0_0_2_0t(target("spirv.SignedImage", i32, 5, 2, 0, 0, 2, 0) %0, i32 0)
+ store i32 %add12.i, ptr addrspace(11) %22, align 4
+ ret void
+}
+
+
+attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
\ No newline at end of file
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