[llvm] [clang] [AMDGPU] Enable OpenCL hostcall printf (WIP) (PR #72556)

[Sameer Sahasrabuddhe via cfe-commits]

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@@ -26,28 +26,34 @@ using namespace llvm;
 
 #define DEBUG_TYPE "amdgpu-emit-printf"
 
-static Value *fitArgInto64Bits(IRBuilder<> &Builder, Value *Arg) {
+static Value *fitArgInto64Bits(IRBuilder<> &Builder, Value *Arg,
+                               bool IsBuffered) {
+  const DataLayout &DL = Builder.GetInsertBlock()->getModule()->getDataLayout();
   auto Int64Ty = Builder.getInt64Ty();
   auto Ty = Arg->getType();
 
   if (auto IntTy = dyn_cast<IntegerType>(Ty)) {
-    switch (IntTy->getBitWidth()) {
-    case 32:
-      return Builder.CreateZExt(Arg, Int64Ty);
-    case 64:
-      return Arg;
+    if (IntTy->getBitWidth() < 64) {
+      return Builder.CreateZExt(Arg, Builder.getInt64Ty());
     }
   }
 
-  if (Ty->getTypeID() == Type::DoubleTyID) {
+  if (Ty->isFloatingPointTy()) {
+    if (DL.getTypeAllocSize(Ty) < 8)
+      Arg = Builder.CreateFPExt(Arg, Builder.getDoubleTy());
+    if (IsBuffered)
+      return Arg;
     return Builder.CreateBitCast(Arg, Int64Ty);
   }
 
-  if (isa<PointerType>(Ty)) {
+  // The cast is necessary for the hostcall case 
+  // for the argument to be compatible with device lib 
+  // functions.
+  if (!IsBuffered && isa<PointerType>(Ty)) {
     return Builder.CreatePtrToInt(Arg, Int64Ty);
   }
 
-  llvm_unreachable("unexpected type");
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ssahasra wrote:

This llvm_unreachable is preferred. It's clear documentation that all supported types have been handled by this point. Each if-block for integer, floating and pointer types should have its own default "return Arg".

https://github.com/llvm/llvm-project/pull/72556