[llvm] 0e3f550 - [SPIR-V] Simplify addrspacecast for null in composite constant preprocessing (#192030)
via llvm-commits
llvm-commits at lists.llvm.org
Thu Apr 16 07:05:54 PDT 2026
Author: Arseniy Obolenskiy
Date: 2026-04-16T16:05:48+02:00
New Revision: 0e3f5504beb0e4ac918f6934fdc7cbf847014e9d
URL: https://github.com/llvm/llvm-project/commit/0e3f5504beb0e4ac918f6934fdc7cbf847014e9d
DIFF: https://github.com/llvm/llvm-project/commit/0e3f5504beb0e4ac918f6934fdc7cbf847014e9d.diff
LOG: [SPIR-V] Simplify addrspacecast for null in composite constant preprocessing (#192030)
Fold addrspacecast(null) to a typed null pointer during composite
constant preprocessing so that null pointer members in structs and
arrays get the correct SPIR-V pointer type instead of being lowered as
integers. This fixes invalid SPIR-V where OpConstantNull had an integer
type instead of a pointer type, and where OpSpecConstantOp was
unnecessarily emitted for null casts
related to https://github.com/llvm/llvm-project/issues/190736
Added:
llvm/test/CodeGen/SPIRV/struct-null-pointer-member.ll
Modified:
llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-addrcast.ll
llvm/test/CodeGen/SPIRV/opencl/device_execution/execute_block.ll
llvm/test/CodeGen/SPIRV/pointers/PtrCast-null-in-OpSpecConstantOp.ll
Removed:
################################################################################
diff --git a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
index 7600b3a695a4e..7a886de005b88 100644
--- a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
@@ -241,6 +241,7 @@ class SPIRVEmitIntrinsics
void preprocessCompositeConstants(IRBuilder<> &B);
void preprocessUndefs(IRBuilder<> &B);
+ void simplifyNullAddrSpaceCasts();
Type *reconstructType(Value *Op, bool UnknownElemTypeI8,
bool IsPostprocessing);
@@ -1533,6 +1534,20 @@ void SPIRVEmitIntrinsics::preprocessUndefs(IRBuilder<> &B) {
}
}
+// Simplify addrspacecast(null) instructions to ConstantPointerNull of the
+// target type. Casting null always yields null, and this avoids SPIR-V
+// lowering issues where the null gets typed as an integer instead of a
+// pointer.
+void SPIRVEmitIntrinsics::simplifyNullAddrSpaceCasts() {
+ for (Instruction &I : make_early_inc_range(instructions(CurrF)))
+ if (auto *ASC = dyn_cast<AddrSpaceCastInst>(&I))
+ if (isa<ConstantPointerNull>(ASC->getPointerOperand())) {
+ ASC->replaceAllUsesWith(
+ ConstantPointerNull::get(cast<PointerType>(ASC->getType())));
+ ASC->eraseFromParent();
+ }
+}
+
void SPIRVEmitIntrinsics::preprocessCompositeConstants(IRBuilder<> &B) {
std::queue<Instruction *> Worklist;
for (auto &I : instructions(CurrF))
@@ -1568,7 +1583,15 @@ void SPIRVEmitIntrinsics::preprocessCompositeConstants(IRBuilder<> &B) {
for (unsigned i = 0; i < COp->getNumElements(); ++i)
Args.push_back(COp->getElementAsConstant(i));
else
- llvm::append_range(Args, AggrConst->operands());
+ for (Value *Op : AggrConst->operands()) {
+ // Simplify addrspacecast(null) to null in the target address space
+ // so that null pointers get the correct pointer type when lowered.
+ if (auto *CE = dyn_cast<ConstantExpr>(Op);
+ CE && CE->getOpcode() == Instruction::AddrSpaceCast &&
+ isa<ConstantPointerNull>(CE->getOperand(0)))
+ Op = ConstantPointerNull::get(cast<PointerType>(CE->getType()));
+ Args.push_back(Op);
+ }
if (!BPrepared) {
IsPhi ? B.SetInsertPointPastAllocas(I->getParent()->getParent())
: B.SetInsertPoint(I);
@@ -3172,6 +3195,7 @@ bool SPIRVEmitIntrinsics::runOnFunction(Function &Func) {
processGlobalValue(GV, B);
preprocessUndefs(B);
+ simplifyNullAddrSpaceCasts();
preprocessCompositeConstants(B);
for (BasicBlock &BB : Func)
diff --git a/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-addrcast.ll b/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-addrcast.ll
index e5111304765e2..bd67305968973 100644
--- a/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-addrcast.ll
+++ b/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-addrcast.ll
@@ -8,8 +8,10 @@
; %_ptr_Generic_7 = OpTypePointer Generic %7
; TODO: %if spirv-tools %{ llc -O0 -mtriple=spirv32-unknown-unknown %s -o - -filetype=obj --spirv-ext=+SPV_INTEL_function_pointers | spirv-val %}
-; CHECK-COUNT-3: %[[#]] = OpSpecConstantOp %[[#]] PtrCastToGeneric %[[#]]
-; CHECK-COUNT-3: OpPtrCastToGeneric
+; CHECK-DAG: %[[#GENPTR:]] = OpTypePointer Generic %[[#]]
+; CHECK-DAG: %[[#]] = OpConstantNull %[[#GENPTR]]
+; CHECK-COUNT-2: %[[#]] = OpSpecConstantOp %[[#]] PtrCastToGeneric %[[#]]
+; CHECK-COUNT-2: OpPtrCastToGeneric
@G1 = addrspace(1) constant { [3 x ptr addrspace(4)] } { [3 x ptr addrspace(4)] [ptr addrspace(4) null, ptr addrspace(4) addrspacecast (ptr @foo to ptr addrspace(4)), ptr addrspace(4) addrspacecast (ptr @bar to ptr addrspace(4))] }
@G2 = addrspace(1) constant { [3 x ptr addrspace(4)] } { [3 x ptr addrspace(4)] [ptr addrspace(4) addrspacecast (ptr null to ptr addrspace(4)), ptr addrspace(4) addrspacecast (ptr @bar to ptr addrspace(4)), ptr addrspace(4) addrspacecast (ptr @foo to ptr addrspace(4))] }
diff --git a/llvm/test/CodeGen/SPIRV/opencl/device_execution/execute_block.ll b/llvm/test/CodeGen/SPIRV/opencl/device_execution/execute_block.ll
index 54a6e8e38d536..ab4fec3121dd3 100644
--- a/llvm/test/CodeGen/SPIRV/opencl/device_execution/execute_block.ll
+++ b/llvm/test/CodeGen/SPIRV/opencl/device_execution/execute_block.ll
@@ -1,4 +1,5 @@
; RUN: llc -O0 -mtriple=spirv64-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}
; CHECK: %[[#bool:]] = OpTypeBool
; CHECK: %[[#true:]] = OpConstantTrue %[[#bool]]
diff --git a/llvm/test/CodeGen/SPIRV/pointers/PtrCast-null-in-OpSpecConstantOp.ll b/llvm/test/CodeGen/SPIRV/pointers/PtrCast-null-in-OpSpecConstantOp.ll
index 49fb43d7e9625..d8d1efc02bacb 100644
--- a/llvm/test/CodeGen/SPIRV/pointers/PtrCast-null-in-OpSpecConstantOp.ll
+++ b/llvm/test/CodeGen/SPIRV/pointers/PtrCast-null-in-OpSpecConstantOp.ll
@@ -1,12 +1,13 @@
; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv64-unknown-unknown %s -o - | FileCheck %s
-; TODO: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}
-; CHECK-DAG: %[[Array:.*]] = OpTypeArray %[[#]] %[[#]]
+; CHECK-DAG: %[[Char:.*]] = OpTypeInt 8 0
+; CHECK-DAG: %[[GenPtr:.*]] = OpTypePointer Generic %[[Char]]
+; CHECK-DAG: %[[Array:.*]] = OpTypeArray %[[GenPtr]] %[[#]]
; CHECK-DAG: %[[Struct:.*]] = OpTypeStruct %[[Array]]
-; CHECK-DAG: %[[Zero:.*]] = OpTypeInt 64 0
-; CHECK-DAG: %[[Null:.*]] = OpConstantNull %[[Zero]]
-; CHECK-DAG: %[[R:.*]] = OpSpecConstantComposite %[[Array]] %[[Null]]
-; CHECK-DAG: %[[#]] = OpSpecConstantComposite %[[Struct]] %[[R]]
+; CHECK-DAG: %[[Null:.*]] = OpConstantNull %[[GenPtr]]
+; CHECK-DAG: %[[R:.*]] = OpConstantComposite %[[Array]] %[[Null]]
+; CHECK-DAG: %[[#]] = OpConstantComposite %[[Struct]] %[[R]]
@G1 = addrspace(1) constant { [1 x ptr addrspace(4)] } { [1 x ptr addrspace(4)] [ptr addrspace(4) addrspacecast (ptr null to ptr addrspace(4))] }
@G2 = addrspace(1) constant { [1 x ptr addrspace(4)] } { [1 x ptr addrspace(4)] [ptr addrspace(4) addrspacecast (ptr addrspace(1) null to ptr addrspace(4))] }
diff --git a/llvm/test/CodeGen/SPIRV/struct-null-pointer-member.ll b/llvm/test/CodeGen/SPIRV/struct-null-pointer-member.ll
new file mode 100644
index 0000000000000..c53ceba5f9d03
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/struct-null-pointer-member.ll
@@ -0,0 +1,40 @@
+; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv64-unknown-unknown %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown %s -o - -filetype=obj | spirv-val %}
+
+; Test that addrspacecast(null) is simplified to null of the target address
+; space type in all contexts: composite constants, instruction operands, and
+; global initializers.
+
+%struct = type { i32, ptr addrspace(4) }
+
+ at gv = internal addrspace(1) constant %struct { i32 42, ptr addrspace(4) addrspacecast (ptr null to ptr addrspace(4)) }, align 8
+
+; CHECK-DAG: %[[#INT:]] = OpTypeInt 32 0
+; CHECK-DAG: %[[#CHAR:]] = OpTypeInt 8 0
+; CHECK-DAG: %[[#GENPTR:]] = OpTypePointer Generic %[[#CHAR]]
+; CHECK-DAG: %[[#CWGPTR:]] = OpTypePointer CrossWorkgroup %[[#CHAR]]
+; CHECK-DAG: %[[#STRUCT:]] = OpTypeStruct %[[#INT]] %[[#GENPTR]]
+; CHECK-DAG: %[[#CONST:]] = OpConstant %[[#INT]] 42
+; CHECK-DAG: %[[#NULL:]] = OpConstantNull %[[#GENPTR]]
+; CHECK-DAG: %[[#CWGNULL:]] = OpConstantNull %[[#CWGPTR]]
+; CHECK-DAG: %[[#BOOL:]] = OpTypeBool
+
+; Composite constant: addrspacecast(null) in struct member should become
+; OpConstantNull of the pointer type.
+; CHECK-DAG: OpConstantComposite %[[#STRUCT]] %[[#CONST]] %[[#NULL]]
+
+define spir_kernel void @test(ptr addrspace(1) %out) {
+entry:
+ ret void
+}
+
+; Instruction operand: addrspacecast(null) in icmp should become
+; OpConstantNull of the pointer type, not a cast from integer-typed null.
+; CHECK: %[[#]] = OpPtrEqual %[[#BOOL]] %[[#CWGNULL]] %[[#]]
+define spir_kernel void @test_icmp(ptr addrspace(1) %arg, ptr addrspace(1) %out) {
+entry:
+ %cmp = icmp eq ptr addrspace(1) addrspacecast (ptr null to ptr addrspace(1)), %arg
+ %zext = zext i1 %cmp to i32
+ store i32 %zext, ptr addrspace(1) %out
+ ret void
+}
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