[llvm] c01b5bb - [SPIRV] Add OpAccessChain instruction support (#66253)
via llvm-commits
llvm-commits at lists.llvm.org
Tue Sep 26 07:33:21 PDT 2023
Author: Nathan Gauër
Date: 2023-09-26T16:33:17+02:00
New Revision: c01b5bbba3df64086fa456a53a06ec81495698af
URL: https://github.com/llvm/llvm-project/commit/c01b5bbba3df64086fa456a53a06ec81495698af
DIFF: https://github.com/llvm/llvm-project/commit/c01b5bbba3df64086fa456a53a06ec81495698af.diff
LOG: [SPIRV] Add OpAccessChain instruction support (#66253)
This commit adds 2 new instructions in the selector:
- OpAccessChain
- OpInBoundsAccessChain.
The choice between the two relies on the `inbounds` marker.
Those instruction are not used for OpenCL, to maintain the same
behavior as previously. They are only added when building for logical
SPIR-V, as it doesn't support the pointer equivalent.
Because logical SPIR-V doesn't support pointer cast either, the
assign_ptr_type intrinsic need to be generated so OpAccessChain gets
lowered with the correct pointer type, instead of i8*.
Fixes #66107
---------
Signed-off-by: Nathan Gauër <brioche at google.com>
Added:
llvm/test/CodeGen/SPIRV/logical-access-chain.ll
llvm/test/CodeGen/SPIRV/logical-struct-access.ll
Modified:
llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
index a05e108b8591a37..610d9a033aeea64 100644
--- a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
@@ -413,7 +413,7 @@ void SPIRVEmitIntrinsics::insertAssignPtrTypeIntrs(Instruction *I) {
EltTyConst = Constant::getNullValue(AI->getAllocatedType());
AddressSpace = AI->getAddressSpace();
} else if (auto *GEP = dyn_cast<GetElementPtrInst>(I)) {
- EltTyConst = Constant::getNullValue(GEP->getSourceElementType());
+ EltTyConst = Constant::getNullValue(GEP->getResultElementType());
AddressSpace = GEP->getPointerAddressSpace();
} else {
llvm_unreachable("Unexpected instruction!");
diff --git a/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp b/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
index febd4259e4e20f6..028258d73a3e9cc 100644
--- a/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
@@ -1299,18 +1299,28 @@ bool SPIRVInstructionSelector::selectExtractElt(Register ResVReg,
bool SPIRVInstructionSelector::selectGEP(Register ResVReg,
const SPIRVType *ResType,
MachineInstr &I) const {
- // In general we should also support OpAccessChain instrs here (i.e. not
- // PtrAccessChain) but SPIRV-LLVM Translator doesn't emit them at all and so
- // do we to stay compliant with its test and more importantly consumers.
- unsigned Opcode = I.getOperand(2).getImm() ? SPIRV::OpInBoundsPtrAccessChain
- : SPIRV::OpPtrAccessChain;
+ const bool isGEPInBounds = I.getOperand(2).getImm();
+
+ // OpAccessChain could be used for OpenCL, but the SPIRV-LLVM Translator only
+ // relies on PtrAccessChain, so we'll try not to deviate. For Vulkan however,
+ // we have to use Op[InBounds]AccessChain.
+ const unsigned Opcode = STI.isVulkanEnv()
+ ? (isGEPInBounds ? SPIRV::OpInBoundsAccessChain
+ : SPIRV::OpAccessChain)
+ : (isGEPInBounds ? SPIRV::OpInBoundsPtrAccessChain
+ : SPIRV::OpPtrAccessChain);
+
auto Res = BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opcode))
.addDef(ResVReg)
.addUse(GR.getSPIRVTypeID(ResType))
// Object to get a pointer to.
.addUse(I.getOperand(3).getReg());
// Adding indices.
- for (unsigned i = 4; i < I.getNumExplicitOperands(); ++i)
+ const unsigned StartingIndex =
+ (Opcode == SPIRV::OpAccessChain || Opcode == SPIRV::OpInBoundsAccessChain)
+ ? 5
+ : 4;
+ for (unsigned i = StartingIndex; i < I.getNumExplicitOperands(); ++i)
Res.addUse(I.getOperand(i).getReg());
return Res.constrainAllUses(TII, TRI, RBI);
}
diff --git a/llvm/test/CodeGen/SPIRV/logical-access-chain.ll b/llvm/test/CodeGen/SPIRV/logical-access-chain.ll
new file mode 100644
index 000000000000000..39f6d33712ef4c2
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/logical-access-chain.ll
@@ -0,0 +1,20 @@
+; RUN: llc -O0 -mtriple=spirv-unknown-unknown %s -o - | FileCheck %s
+
+; CHECK: [[uint:%[0-9]+]] = OpTypeInt 32 0
+; CHECK: [[uint2:%[0-9]+]] = OpTypeVector [[uint]] 2
+; CHECK: [[uint_1:%[0-9]+]] = OpConstant [[uint]] 1
+; CHECK: [[ptr_uint:%[0-9]+]] = OpTypePointer Function [[uint]]
+; CHECK: [[ptr_uint2:%[0-9]+]] = OpTypePointer Function [[uint2]]
+
+define void @main() #1 {
+entry:
+ %0 = alloca <2 x i32>, align 4
+; CHECK: [[var:%[0-9]+]] = OpVariable [[ptr_uint2]] Function
+
+ %1 = getelementptr <2 x i32>, ptr %0, i32 0, i32 1
+; CHECK: {{%[0-9]+}} = OpAccessChain [[ptr_uint]] [[var]] [[uint_1]]
+
+ ret void
+}
+
+attributes #1 = { "hlsl.numthreads"="4,8,16" "hlsl.shader"="compute" }
diff --git a/llvm/test/CodeGen/SPIRV/logical-struct-access.ll b/llvm/test/CodeGen/SPIRV/logical-struct-access.ll
new file mode 100644
index 000000000000000..617aa70ccdb7e6c
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/logical-struct-access.ll
@@ -0,0 +1,59 @@
+; RUN: llc -O0 -mtriple=spirv-unknown-unknown %s -o - | FileCheck %s
+
+; CHECK: [[uint:%[0-9]+]] = OpTypeInt 32 0
+
+%A = type {
+ i32,
+ i32
+}
+; CHECK: [[A:%[0-9]+]] = OpTypeStruct [[uint]] [[uint]]
+
+%B = type {
+ %A,
+ i32,
+ %A
+}
+; CHECK: [[B:%[0-9]+]] = OpTypeStruct [[A]] [[uint]] [[A]]
+
+; CHECK: [[uint_0:%[0-9]+]] = OpConstant [[uint]] 0
+; CHECK: [[uint_1:%[0-9]+]] = OpConstant [[uint]] 1
+; CHECK: [[uint_2:%[0-9]+]] = OpConstant [[uint]] 2
+
+; CHECK: [[ptr_uint:%[0-9]+]] = OpTypePointer Function [[uint]]
+; CHECK: [[ptr_A:%[0-9]+]] = OpTypePointer Function [[A]]
+; CHECK: [[ptr_B:%[0-9]+]] = OpTypePointer Function [[B]]
+
+define void @main() #1 {
+entry:
+ %0 = alloca %B, align 4
+; CHECK: [[tmp:%[0-9]+]] = OpVariable [[ptr_B]] Function
+
+ %1 = getelementptr %B, ptr %0, i32 0, i32 0
+; CHECK: {{%[0-9]+}} = OpAccessChain [[ptr_A]] [[tmp]] [[uint_0]]
+ %2 = getelementptr inbounds %B, ptr %0, i32 0, i32 0
+; CHECK: {{%[0-9]+}} = OpInBoundsAccessChain [[ptr_A]] [[tmp]] [[uint_0]]
+
+ %3 = getelementptr %B, ptr %0, i32 0, i32 1
+; CHECK: {{%[0-9]+}} = OpAccessChain [[ptr_uint]] [[tmp]] [[uint_1]]
+ %4 = getelementptr inbounds %B, ptr %0, i32 0, i32 1
+; CHECK: {{%[0-9]+}} = OpInBoundsAccessChain [[ptr_uint]] [[tmp]] [[uint_1]]
+
+ %5 = getelementptr %B, ptr %0, i32 0, i32 2
+; CHECK: {{%[0-9]+}} = OpAccessChain [[ptr_A]] [[tmp]] [[uint_2]]
+ %6 = getelementptr inbounds %B, ptr %0, i32 0, i32 2
+; CHECK: {{%[0-9]+}} = OpInBoundsAccessChain [[ptr_A]] [[tmp]] [[uint_2]]
+
+ %7 = getelementptr %B, ptr %0, i32 0, i32 2, i32 1
+; CHECK: {{%[0-9]+}} = OpAccessChain [[ptr_uint]] [[tmp]] [[uint_2]] [[uint_1]]
+ %8 = getelementptr inbounds %B, ptr %0, i32 0, i32 2, i32 1
+; CHECK: {{%[0-9]+}} = OpInBoundsAccessChain [[ptr_uint]] [[tmp]] [[uint_2]] [[uint_1]]
+
+ %9 = getelementptr %B, ptr %0, i32 0, i32 2
+ %10 = getelementptr %A, ptr %9, i32 0, i32 1
+; CHECK: [[x:%[0-9]+]] = OpAccessChain [[ptr_A]] [[tmp]] [[uint_2]]
+; CHECK: {{%[0-9]+}} = OpAccessChain [[ptr_uint]] [[x]] [[uint_1]]
+
+ ret void
+}
+
+attributes #1 = { "hlsl.numthreads"="4,8,16" "hlsl.shader"="compute" }
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