[Backport to 16] Fix globals' type deduction in TypeScavenger (KhronosGroup#3243)

This is a follow up to KhronosGroup#3240. It backports one more commit that fixes
type dedcuction in type scavenger, and also adds a small fix for the
previous PR that resulted in double use of type scavenger.

---------

Co-authored-by: Maksim Shelegov <maksim.shelegov@intel.com>

Author: karolzwolak

lib/SPIRV/SPIRVTypeScavenger.cpp

@@ -584,6 +584,12 @@ void SPIRVTypeScavenger::typeGlobalValue(GlobalValue &GV, Constant *Init) {
       auto It = DeducedTypes.find(C);
       if (It != DeducedTypes.end())
         return It->second;
+    } else if (auto *GEP = dyn_cast<GEPOperator>(C)) {
+      auto *ResultTy =
+          TypedPointerType::get(GEP->getResultElementType(),
+                                GEP->getType()->getPointerAddressSpace());
+      DeducedTypes[C] = ResultTy;
+      return ResultTy;
     }
 
     return getUnknownTyped(C->getType());

lib/SPIRV/SPIRVWriter.cpp

@@ -1414,8 +1414,17 @@ SPIRVValue *LLVMToSPIRVBase::transConstant(Value *V) {
     return BM->addCompositeConstant(ExpectedType, BV);
   }
 
-  if (auto ConstUE = dyn_cast<ConstantExpr>(V)) {
-    auto Inst = ConstUE->getAsInstruction();
+  if (auto *ConstUE = dyn_cast<ConstantExpr>(V)) {
+    if (auto *GEP = dyn_cast<GEPOperator>(ConstUE)) {
+      std::vector<SPIRVValue *> Indices;
+      for (unsigned I = 0, E = GEP->getNumIndices(); I != E; ++I)
+        Indices.push_back(transValue(GEP->getOperand(I + 1), nullptr));
+      auto *TransPointerOperand = transValue(GEP->getPointerOperand(), nullptr);
+      SPIRVType *TranslatedTy = transScavengedType(GEP);
+      return BM->addPtrAccessChainInst(TranslatedTy, TransPointerOperand,
+                                       Indices, nullptr, GEP->isInBounds());
+    }
+    auto *Inst = ConstUE->getAsInstruction();
     SPIRVDBG(dbgs() << "ConstantExpr: " << *ConstUE << '\n';
              dbgs() << "Instruction: " << *Inst << '\n';)
     auto BI = transValue(Inst, nullptr, false);
@@ -5126,9 +5135,6 @@ bool LLVMToSPIRVBase::translate() {
   if (isEmptyLLVMModule(M))
     BM->addCapability(CapabilityLinkage);
 
-  // Use the type scavenger to recover pointer element types.
-  Scavenger = std::make_unique<SPIRVTypeScavenger>(*M);
-
   if (!lowerBuiltinCallsToVariables(M))
     return false;
 

test/type-scavenger/globals.ll

@@ -9,25 +9,37 @@ target triple = "spir-unknown-unknown"
 ; CHECK-DAG: TypeInt [[I8:[0-9]+]] 8 0
 ; CHECK-DAG: TypeInt [[I16:[0-9]+]] 16 0
 ; CHECK-DAG: TypeInt [[I32:[0-9]+]] 32 0
+; CHECK-DAG: TypeInt [[I64:[0-9]+]] 64 0
 ; CHECK-DAG: TypePointer [[I8PTR:[0-9]+]] 5 [[I8]]
 ; CHECK-DAG: TypePointer [[I16PTR:[0-9]+]] 5 [[I16]]
 ; CHECK-DAG: TypePointer [[I16PTRPTR:[0-9]+]] 5 [[I16PTR]]
 ; CHECK-DAG: TypePointer [[I32PTR:[0-9]+]] 5 [[I32]]
+; CHECK-DAG: TypePointer [[I32PTRPTR:[0-9]+]] 5 [[I32PTR]]
 ; CHECK-DAG: TypeArray [[I8PTRx2:[0-9]+]] [[I8PTR]]
 ; CHECK-DAG: TypePointer [[I8PTRx2PTR:[0-9]+]] 5 [[I8PTRx2]]
+; CHECK-DAG: TypeArray [[I32x4:[0-9]+]] [[I32]]
+; CHECK-DAG: TypeArray [[I32x3x4:[0-9]+]] [[I32x4]]
+; CHECK-DAG: TypeArray [[I32x2x3x4:[0-9]+]] [[I32x3x4]]
+; CHECK-DAG: TypePointer [[I32x2x3x4PTR:[0-9]+]] 5 [[I32x2x3x4]]
 ; CHECK: Variable [[I16PTR]] [[A:[0-9]+]] 5
 ; CHECK: Variable [[I32PTR]] [[B:[0-9]+]] 5
 ; CHECK: Variable [[I16PTRPTR]] [[C:[0-9]+]] 5 [[A]]
 ; CHECK: SpecConstantOp [[I8PTR]] [[AI8:[0-9]+]] 124 [[A]]
 ; CHECK: SpecConstantOp [[I8PTR]] [[BI8:[0-9]+]] 124 [[B]]
 ; CHECK: ConstantComposite [[I8PTRx2]] [[DINIT:[0-9]+]] [[AI8]] [[BI8]]
 ; CHECK: Variable [[I8PTRx2PTR]] [[D:[0-9]+]] 5 [[DINIT]]
+; CHECK: ConstantComposite [[I32x2x3x4]] [[FINIT:[0-9]+]]
+; CHECK: Variable [[I32x2x3x4PTR]] [[F:[0-9]+]] 5 [[FINIT]]
+; CHECK: SpecConstantOp [[I32PTR]] [[GINIT:[0-9]+]] 70 [[F]]
+; CHECK: Variable [[I32PTRPTR]] [[G:[0-9]+]] 5 [[GINIT]]
 
 @a = addrspace(1) global i16 0
 @b = external addrspace(1) global i32
 @c = addrspace(1) global ptr addrspace(1) @a
 @d = addrspace(1) global [2 x ptr addrspace(1)] [ptr addrspace(1) @a, ptr addrspace(1) @b]
 ;@e = global [1 x ptr] [ptr @foo]
+@f = addrspace(1) global [2 x [3 x [4 x i32]]] [[3 x [4 x i32]] [[4 x i32] [i32 1, i32 2, i32 3, i32 4], [4 x i32] [i32 1, i32 2, i32 3, i32 4], [4 x i32] [i32 1, i32 2, i32 3, i32 4]], [3 x [4 x i32]] [[4 x i32] [i32 1, i32 2, i32 3, i32 4], [4 x i32] [i32 1, i32 2, i32 3, i32 4], [4 x i32] [i32 1, i32 2, i32 3, i32 4]]]
+@g = addrspace(1) global ptr addrspace(1) getelementptr inbounds ([2 x [3 x [4 x i32]]], ptr addrspace(1) @f, i64 0, i64 1, i64 2, i64 3)
 
 ; Function Attrs: nounwind
 define spir_kernel void @foo() {