[OPENMP] Fix casting in NVPTX support library.

If the reduction required shuffle in the NVPTX codegen, we may need to
cast the reduced value to the integer type. This casting was implemented
incorrectly and may cause compiler crash. Patch fixes this problem.

llvm-svn: 321818

1 files changed, 49 insertions, 37 deletions

diff --git a/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp b/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
index eb4c1202586..ac82737e777 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
@@ -1059,19 +1059,41 @@ void CGOpenMPRuntimeNVPTX::emitSpmdParallelCall(
   emitOutlinedFunctionCall(CGF, Loc, OutlinedFn, OutlinedFnArgs);
 }
 
+/// Cast value to the specified type.
+static llvm::Value *
+castValueToType(CodeGenFunction &CGF, llvm::Value *Val, llvm::Type *CastTy,
+                llvm::Optional<bool> IsSigned = llvm::None) {
+  if (Val->getType() == CastTy)
+    return Val;
+  if (Val->getType()->getPrimitiveSizeInBits() > 0 &&
+      CastTy->getPrimitiveSizeInBits() > 0 &&
+      Val->getType()->getPrimitiveSizeInBits() ==
+          CastTy->getPrimitiveSizeInBits())
+    return CGF.Builder.CreateBitCast(Val, CastTy);
+  if (IsSigned.hasValue() && CastTy->isIntegerTy() &&
+      Val->getType()->isIntegerTy())
+    return CGF.Builder.CreateIntCast(Val, CastTy, *IsSigned);
+  Address CastItem = CGF.CreateTempAlloca(
+      CastTy,
+      CharUnits::fromQuantity(
+          CGF.CGM.getDataLayout().getPrefTypeAlignment(Val->getType())));
+  Address ValCastItem = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(
+      CastItem, Val->getType()->getPointerTo(CastItem.getAddressSpace()));
+  CGF.Builder.CreateStore(Val, ValCastItem);
+  return CGF.Builder.CreateLoad(CastItem);
+}
+
 /// This function creates calls to one of two shuffle functions to copy
 /// variables between lanes in a warp.
 static llvm::Value *createRuntimeShuffleFunction(CodeGenFunction &CGF,
-                                                 QualType ElemTy,
                                                  llvm::Value *Elem,
                                                  llvm::Value *Offset) {
   auto &CGM = CGF.CGM;
-  auto &C = CGM.getContext();
   auto &Bld = CGF.Builder;
   CGOpenMPRuntimeNVPTX &RT =
       *(static_cast<CGOpenMPRuntimeNVPTX *>(&CGM.getOpenMPRuntime()));
 
-  unsigned Size = CGM.getContext().getTypeSizeInChars(ElemTy).getQuantity();
+  unsigned Size = CGM.getDataLayout().getTypeStoreSize(Elem->getType());
   assert(Size <= 8 && "Unsupported bitwidth in shuffle instruction.");
 
   OpenMPRTLFunctionNVPTX ShuffleFn = Size <= 4
@@ -1079,17 +1101,16 @@ static llvm::Value *createRuntimeShuffleFunction(CodeGenFunction &CGF,
                                          : OMPRTL_NVPTX__kmpc_shuffle_int64;
 
   // Cast all types to 32- or 64-bit values before calling shuffle routines.
-  auto CastTy = Size <= 4 ? CGM.Int32Ty : CGM.Int64Ty;
-  auto *ElemCast = Bld.CreateSExtOrBitCast(Elem, CastTy);
-  auto *WarpSize = CGF.EmitScalarConversion(
-      getNVPTXWarpSize(CGF), C.getIntTypeForBitwidth(32, /* Signed */ true),
-      C.getIntTypeForBitwidth(16, /* Signed */ true), SourceLocation());
+  llvm::Type *CastTy = Size <= 4 ? CGM.Int32Ty : CGM.Int64Ty;
+  llvm::Value *ElemCast = castValueToType(CGF, Elem, CastTy, /*isSigned=*/true);
+  auto *WarpSize =
+      Bld.CreateIntCast(getNVPTXWarpSize(CGF), CGM.Int16Ty, /*isSigned=*/true);
 
   auto *ShuffledVal =
       CGF.EmitRuntimeCall(RT.createNVPTXRuntimeFunction(ShuffleFn),
                           {ElemCast, Offset, WarpSize});
 
-  return Bld.CreateTruncOrBitCast(ShuffledVal, CGF.ConvertTypeForMem(ElemTy));
+  return castValueToType(CGF, ShuffledVal, Elem->getType(), /*isSigned=*/true);
 }
 
 namespace {
@@ -1151,10 +1172,9 @@ static void emitReductionListCopy(
       // Step 1.1: Get the address for the src element in the Reduce list.
       Address SrcElementPtrAddr =
           Bld.CreateConstArrayGEP(SrcBase, Idx, CGF.getPointerSize());
-      llvm::Value *SrcElementPtrPtr = CGF.EmitLoadOfScalar(
-          SrcElementPtrAddr, /*Volatile=*/false, C.VoidPtrTy, SourceLocation());
-      SrcElementAddr =
-          Address(SrcElementPtrPtr, C.getTypeAlignInChars(Private->getType()));
+      SrcElementAddr = CGF.EmitLoadOfPointer(
+          SrcElementPtrAddr,
+          C.getPointerType(Private->getType())->castAs<PointerType>());
 
       // Step 1.2: Create a temporary to store the element in the destination
       // Reduce list.
@@ -1170,32 +1190,26 @@ static void emitReductionListCopy(
       // Step 1.1: Get the address for the src element in the Reduce list.
       Address SrcElementPtrAddr =
           Bld.CreateConstArrayGEP(SrcBase, Idx, CGF.getPointerSize());
-      llvm::Value *SrcElementPtrPtr = CGF.EmitLoadOfScalar(
-          SrcElementPtrAddr, /*Volatile=*/false, C.VoidPtrTy, SourceLocation());
-      SrcElementAddr =
-          Address(SrcElementPtrPtr, C.getTypeAlignInChars(Private->getType()));
+      SrcElementAddr = CGF.EmitLoadOfPointer(
+          SrcElementPtrAddr,
+          C.getPointerType(Private->getType())->castAs<PointerType>());
 
       // Step 1.2: Get the address for dest element.  The destination
       // element has already been created on the thread's stack.
       DestElementPtrAddr =
           Bld.CreateConstArrayGEP(DestBase, Idx, CGF.getPointerSize());
-      llvm::Value *DestElementPtr =
-          CGF.EmitLoadOfScalar(DestElementPtrAddr, /*Volatile=*/false,
-                               C.VoidPtrTy, SourceLocation());
-      Address DestElemAddr =
-          Address(DestElementPtr, C.getTypeAlignInChars(Private->getType()));
-      DestElementAddr = Bld.CreateElementBitCast(
-          DestElemAddr, CGF.ConvertTypeForMem(Private->getType()));
+      DestElementAddr = CGF.EmitLoadOfPointer(
+          DestElementPtrAddr,
+          C.getPointerType(Private->getType())->castAs<PointerType>());
       break;
     }
     case ThreadToScratchpad: {
       // Step 1.1: Get the address for the src element in the Reduce list.
       Address SrcElementPtrAddr =
           Bld.CreateConstArrayGEP(SrcBase, Idx, CGF.getPointerSize());
-      llvm::Value *SrcElementPtrPtr = CGF.EmitLoadOfScalar(
-          SrcElementPtrAddr, /*Volatile=*/false, C.VoidPtrTy, SourceLocation());
-      SrcElementAddr =
-          Address(SrcElementPtrPtr, C.getTypeAlignInChars(Private->getType()));
+      SrcElementAddr = CGF.EmitLoadOfPointer(
+          SrcElementPtrAddr,
+          C.getPointerType(Private->getType())->castAs<PointerType>());
 
       // Step 1.2: Get the address for dest element:
       // address = base + index * ElementSizeInChars.
@@ -1208,11 +1222,8 @@ static void emitReductionListCopy(
           Bld.CreateAdd(DestBase.getPointer(), CurrentOffset);
       ScratchPadElemAbsolutePtrVal =
           Bld.CreateIntToPtr(ScratchPadElemAbsolutePtrVal, CGF.VoidPtrTy);
-      Address ScratchpadPtr =
-          Address(ScratchPadElemAbsolutePtrVal,
-                  C.getTypeAlignInChars(Private->getType()));
-      DestElementAddr = Bld.CreateElementBitCast(
-          ScratchpadPtr, CGF.ConvertTypeForMem(Private->getType()));
+      DestElementAddr = Address(ScratchPadElemAbsolutePtrVal,
+                                C.getTypeAlignInChars(Private->getType()));
       IncrScratchpadDest = true;
       break;
     }
@@ -1253,10 +1264,11 @@ static void emitReductionListCopy(
 
     // Now that all active lanes have read the element in the
     // Reduce list, shuffle over the value from the remote lane.
-    if (ShuffleInElement) {
-      Elem = createRuntimeShuffleFunction(CGF, Private->getType(), Elem,
-                                          RemoteLaneOffset);
-    }
+    if (ShuffleInElement)
+      Elem = createRuntimeShuffleFunction(CGF, Elem, RemoteLaneOffset);
+
+    DestElementAddr = Bld.CreateElementBitCast(DestElementAddr,
+                                               SrcElementAddr.getElementType());
 
     // Store the source element value to the dest element address.
     CGF.EmitStoreOfScalar(Elem, DestElementAddr, /*Volatile=*/false,