[GlobalISel] Handle ptr size != index size in IRTranslator, CodeGenPrepare

[krzysz00]

Summary

While the original motivation for this patch (address space 7 on
AMDGPU) has been reworked and is not presently planned to reach IR
translation, the incorrect (by the spec) handling of index offset
width in IR translation and CodeGenPrepare is likely to trip someone

• possibly future AMD, since we have a p7:160:256:256:32 now, so we

convert to the other API now.

[arsenm]

Test coverage looks incomplete

[krzysz00]

@arsenm Do you have suggestions on what additional tests would be needed? I'm not terribly familiar with this portion of the codebase.

[arsenm]

llvm/lib/CodeGen/CodeGenPrepare.cpp

6063

Some addressing mode thing, probably would be best to hack up a test that hits an unreachable here

6093

Ditto for these other CGP parts, which are really separate from the IRTranslator part

llvm/lib/CodeGen/GlobalISel/CallLowering.cpp

850

this would be an ptr addrspace(7) at the end of a large struct return value, on the caller side

879

this would be an ptr addrspace(7) at the end of a large struct return value

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

1516

vector GEP with a scalar index?

llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-non-integral-address-spaces.ll

20

Some vector GEP cases

[krzysz00]

Wherein I noticed getIndexType() exists, cascading rebase

llvm/lib/CodeGen/GlobalISel/CallLowering.cpp

879

Having looked at the context, I think we'd have to invent a target to test this. That is, we'd need a target where the stack lives in a intptr_t > size_t world, which ... well, that's CHERI, but not anything upstream.

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

1516

I figure that already either worked or didn't?

[arsenm]

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

1516

There certainly isn't a test using a fat pointer using this

[krzysz00]

Added missing test

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

1516

Good point, added.

[arsenm]

GlobalISel part lgtm but the cgp part should be split out

llvm/lib/CodeGen/CodeGenPrepare.cpp

6063

CGP part is still separate and separately testable

[krzysz00]

Rebase, remove updates to a test that doesn't exist anymore.

Annoyingly, since llc pulls in the data layout, there's not currently good ways to test this that live in the repo.

[krzysz00]

Now we have a test

llvm/lib/CodeGen/CodeGenPrepare.cpp

while (LargeOffsetGEP != LargeOffsetGEPs.end()) {
           BaseGEP = GEP;
           BaseOffset = Offset;
           NewBaseGEP = nullptr;
         }
       }
 
       // Generate a new GEP to replace the current one.
       LLVMContext &Ctx = GEP->getContext();
-      Type *IntPtrTy = DL->getIntPtrType(GEP->getType());
+      Type *PtrIdxTy = DL->getIndexType(GEP->getType());
       Type *I8PtrTy =
           Type::getInt8PtrTy(Ctx, GEP->getType()->getPointerAddressSpace());
       Type *I8Ty = Type::getInt8Ty(Ctx);
 
       if (!NewBaseGEP) {
         // Create a new base if we don't have one yet.  Find the insertion
         // pointer for the new base first.
         BasicBlock::iterator NewBaseInsertPt;
while (LargeOffsetGEP != LargeOffsetGEPs.end()) {
         } else {
           // If the current base is an argument or global value, the new base
           // will be inserted to the entry block.
           NewBaseInsertBB = &BaseGEP->getFunction()->getEntryBlock();
           NewBaseInsertPt = NewBaseInsertBB->getFirstInsertionPt();
         }
         IRBuilder<> NewBaseBuilder(NewBaseInsertBB, NewBaseInsertPt);
         // Create a new base.
-        Value *BaseIndex = ConstantInt::get(IntPtrTy, BaseOffset);
+        Value *BaseIndex = ConstantInt::get(PtrIdxTy, BaseOffset);
         NewBaseGEP = OldBase;
         if (NewBaseGEP->getType() != I8PtrTy)
           NewBaseGEP = NewBaseBuilder.CreatePointerCast(NewBaseGEP, I8PtrTy);
         NewBaseGEP =
             NewBaseBuilder.CreateGEP(I8Ty, NewBaseGEP, BaseIndex, "splitgep");
         NewGEPBases.insert(NewBaseGEP);
       }
 
       IRBuilder<> Builder(GEP);
       Value *NewGEP = NewBaseGEP;
       if (Offset == BaseOffset) {
         if (GEP->getType() != I8PtrTy)
           NewGEP = Builder.CreatePointerCast(NewGEP, GEP->getType());
       } else {
         // Calculate the new offset for the new GEP.
-        Value *Index = ConstantInt::get(IntPtrTy, Offset - BaseOffset);
+        Value *Index = ConstantInt::get(PtrIdxTy, Offset - BaseOffset);
         NewGEP = Builder.CreateGEP(I8Ty, NewBaseGEP, Index);
 
         if (GEP->getType() != I8PtrTy)
           NewGEP = Builder.CreatePointerCast(NewGEP, GEP->getType());
       }
       replaceAllUsesWith(GEP, NewGEP, FreshBBs, IsHugeFunc);
       LargeOffsetGEPID.erase(GEP);
       LargeOffsetGEP = LargeOffsetGEPs.erase(LargeOffsetGEP);

llvm/lib/CodeGen/GlobalISel/CallLowering.cpp

void CallLowering::insertSRetLoads(MachineIRBuilder &MIRBuilder, Type *RetTy,
   SmallVector<uint64_t, 4> Offsets;
   ComputeValueVTs(*TLI, DL, RetTy, SplitVTs, &Offsets, 0);
 
   assert(VRegs.size() == SplitVTs.size());
 
   unsigned NumValues = SplitVTs.size();
   Align BaseAlign = DL.getPrefTypeAlign(RetTy);
   Type *RetPtrTy = RetTy->getPointerTo(DL.getAllocaAddrSpace());
-  LLT OffsetLLTy = getLLTForType(*DL.getIntPtrType(RetPtrTy), DL);
+  LLT OffsetLLTy = getLLTForType(*DL.getIndexType(RetPtrTy), DL);
 
   MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(MF, FI);
 
   for (unsigned I = 0; I < NumValues; ++I) {
     Register Addr;
     MIRBuilder.materializePtrAdd(Addr, DemoteReg, OffsetLLTy, Offsets[I]);
     auto *MMO = MF.getMachineMemOperand(PtrInfo, MachineMemOperand::MOLoad,
                                         MRI.getType(VRegs[I]),
                                         commonAlignment(BaseAlign, Offsets[I]));
void CallLowering::insertSRetStores(MachineIRBuilder &MIRBuilder, Type *RetTy,
   SmallVector<uint64_t, 4> Offsets;
   ComputeValueVTs(*TLI, DL, RetTy, SplitVTs, &Offsets, 0);
 
   assert(VRegs.size() == SplitVTs.size());
 
   unsigned NumValues = SplitVTs.size();
   Align BaseAlign = DL.getPrefTypeAlign(RetTy);
   unsigned AS = DL.getAllocaAddrSpace();
-  LLT OffsetLLTy =
-      getLLTForType(*DL.getIntPtrType(RetTy->getPointerTo(AS)), DL);
+  LLT OffsetLLTy = getLLTForType(*DL.getIndexType(RetTy->getPointerTo(AS)), DL);
 
   MachinePointerInfo PtrInfo(AS);
 
   for (unsigned I = 0; I < NumValues; ++I) {
     Register Addr;
     MIRBuilder.materializePtrAdd(Addr, DemoteReg, OffsetLLTy, Offsets[I]);
     auto *MMO = MF.getMachineMemOperand(PtrInfo, MachineMemOperand::MOStore,
                                         MRI.getType(VRegs[I]),

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

if (StoreSize == 0)
     return true;
 
   ArrayRef<Register> Regs = getOrCreateVRegs(LI);
   ArrayRef<uint64_t> Offsets = *VMap.getOffsets(LI);
   Register Base = getOrCreateVReg(*LI.getPointerOperand());
   AAMDNodes AAInfo = LI.getAAMetadata();
 
   const Value *Ptr = LI.getPointerOperand();
-  Type *OffsetIRTy = DL->getIntPtrType(Ptr->getType());
+  Type *OffsetIRTy = DL->getIndexType(Ptr->getType());
   LLT OffsetTy = getLLTForType(*OffsetIRTy, *DL);
 
   if (CLI->supportSwiftError() && isSwiftError(Ptr)) {
     assert(Regs.size() == 1 && "swifterror should be single pointer");
     Register VReg =
         SwiftError.getOrCreateVRegUseAt(&LI, &MIRBuilder.getMBB(), Ptr);
     MIRBuilder.buildCopy(Regs[0], VReg);
     return true;
bool IRTranslator::translateStore(const User &U, MachineIRBuilder &MIRBuilder) {
   const StoreInst &SI = cast<StoreInst>(U);
   if (DL->getTypeStoreSize(SI.getValueOperand()->getType()) == 0)
     return true;
 
   ArrayRef<Register> Vals = getOrCreateVRegs(*SI.getValueOperand());
   ArrayRef<uint64_t> Offsets = *VMap.getOffsets(*SI.getValueOperand());
   Register Base = getOrCreateVReg(*SI.getPointerOperand());
 
-  Type *OffsetIRTy = DL->getIntPtrType(SI.getPointerOperandType());
+  Type *OffsetIRTy = DL->getIndexType(SI.getPointerOperandType());
   LLT OffsetTy = getLLTForType(*OffsetIRTy, *DL);
 
   if (CLI->supportSwiftError() && isSwiftError(SI.getPointerOperand())) {
     assert(Vals.size() == 1 && "swifterror should be single pointer");
 
     Register VReg = SwiftError.getOrCreateVRegDefAt(&SI, &MIRBuilder.getMBB(),
                                                     SI.getPointerOperand());
     MIRBuilder.buildCopy(VReg, Vals[0]);

 }
 
 bool IRTranslator::translateGetElementPtr(const User &U,
                                           MachineIRBuilder &MIRBuilder) {
   Value &Op0 = *U.getOperand(0);
   Register BaseReg = getOrCreateVReg(Op0);
   Type *PtrIRTy = Op0.getType();
   LLT PtrTy = getLLTForType(*PtrIRTy, *DL);
-  Type *OffsetIRTy = DL->getIntPtrType(PtrIRTy);
+  Type *OffsetIRTy = DL->getIndexType(PtrIRTy);
   LLT OffsetTy = getLLTForType(*OffsetIRTy, *DL);
 
   // Normalize Vector GEP - all scalar operands should be converted to the
   // splat vector.
   unsigned VectorWidth = 0;
 
   // True if we should use a splat vector; using VectorWidth alone is not
   // sufficient.
   bool WantSplatVector = false;
   if (auto *VT = dyn_cast<VectorType>(U.getType())) {
     VectorWidth = cast<FixedVectorType>(VT)->getNumElements();
     // We don't produce 1 x N vectors; those are treated as scalars.
     WantSplatVector = VectorWidth > 1;
   }
 
   // We might need to splat the base pointer into a vector if the offsets
   // are vectors.
   if (WantSplatVector && !PtrTy.isVector()) {
     BaseReg =
         MIRBuilder
             .buildSplatVector(LLT::fixed_vector(VectorWidth, PtrTy), BaseReg)
             .getReg(0);
     PtrIRTy = FixedVectorType::get(PtrIRTy, VectorWidth);
     PtrTy = getLLTForType(*PtrIRTy, *DL);
-    OffsetIRTy = DL->getIntPtrType(PtrIRTy);
+    OffsetIRTy = DL->getIndexType(PtrIRTy);
     OffsetTy = getLLTForType(*OffsetIRTy, *DL);
   }
 
   int64_t Offset = 0;
   for (gep_type_iterator GTI = gep_type_begin(&U), E = gep_type_end(&U);
        GTI != E; ++GTI) {
     const Value *Idx = GTI.getOperand();
     if (StructType *StTy = GTI.getStructTypeOrNull()) {

llvm/test/CodeGen/AMDGPU/GlobalISel/irtranslator-non-integral-address-spaces.ll

 ; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
 ; RUN: llc -global-isel -mtriple=amdgcn-amd-amdpal -mcpu=gfx900 -o - -stop-after=irtranslator %s | FileCheck %s
 
 ; Check that the CSEMIRBuilder doesn't fold away the getelementptr during IRTranslator
 define ptr addrspace(7) @no_auto_constfold_gep() {
   ; CHECK-LABEL: name: no_auto_constfold_gep
   ; CHECK: bb.1 (%ir-block.0):
   ; CHECK-NEXT:   [[C:%[0-9]+]]:_(p7) = G_CONSTANT i160 0
-  ; CHECK-NEXT:   [[C1:%[0-9]+]]:_(s160) = G_CONSTANT i160 123
-  ; CHECK-NEXT:   [[PTR_ADD:%[0-9]+]]:_(p7) = G_PTR_ADD [[C]], [[C1]](s160)
+  ; CHECK-NEXT:   [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 123
+  ; CHECK-NEXT:   [[PTR_ADD:%[0-9]+]]:_(p7) = G_PTR_ADD [[C]], [[C1]](s32)
   ; CHECK-NEXT:   [[UV:%[0-9]+]]:_(s32), [[UV1:%[0-9]+]]:_(s32), [[UV2:%[0-9]+]]:_(s32), [[UV3:%[0-9]+]]:_(s32), [[UV4:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[PTR_ADD]](p7)
   ; CHECK-NEXT:   $vgpr0 = COPY [[UV]](s32)
   ; CHECK-NEXT:   $vgpr1 = COPY [[UV1]](s32)
   ; CHECK-NEXT:   $vgpr2 = COPY [[UV2]](s32)
   ; CHECK-NEXT:   $vgpr3 = COPY [[UV3]](s32)
   ; CHECK-NEXT:   $vgpr4 = COPY [[UV4]](s32)
   ; CHECK-NEXT:   SI_RETURN implicit $vgpr0, implicit $vgpr1, implicit $vgpr2, implicit $vgpr3, implicit $vgpr4
   %gep = getelementptr i8, ptr addrspace(7) null, i32 123
   ret ptr addrspace(7) %gep
 }