R600/SI: Convert v16i8 resource descriptors to i128

Now that compute support is better on SI, we can't continue using v16i8
for descriptors since this is also a legal type in OpenCL.

This patch fixes numerous hangs with the piglit OpenCL test and since
we now use a target specific DAG node for LOAD_CONSTANT with the
correct MemOperandFlags, this should also fix:

https://bugs.freedesktop.org/show_bug.cgi?id=66805

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188429 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 146 insertions, 0 deletions

diff --git a/lib/Target/R600/SITypeRewriter.cpp b/lib/Target/R600/SITypeRewriter.cpp
new file mode 100644
index 0000000..9da11e8
--- /dev/null
+++ b/lib/Target/R600/SITypeRewriter.cpp
@@ -0,0 +1,146 @@
+//===-- SITypeRewriter.cpp - Remove unwanted types ------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+/// \file
+/// This pass removes performs the following type substitution on all
+/// non-compute shaders:
+///
+/// v16i8 => i128
+///   - v16i8 is used for constant memory resource descriptors.  This type is
+///      legal for some compute APIs, and we don't want to declare it as legal
+///      in the backend, because we want the legalizer to expand all v16i8
+///      operations.
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPU.h"
+
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/InstVisitor.h"
+
+using namespace llvm;
+
+namespace {
+
+class SITypeRewriter : public FunctionPass,
+                       public InstVisitor<SITypeRewriter> {
+
+  static char ID;
+  Module *Mod;
+  Type *v16i8;
+  Type *i128;
+
+public:
+  SITypeRewriter() : FunctionPass(ID) { }
+  virtual bool doInitialization(Module &M);
+  virtual bool runOnFunction(Function &F);
+  virtual const char *getPassName() const {
+    return "SI Type Rewriter";
+  }
+  void visitLoadInst(LoadInst &I);
+  void visitCallInst(CallInst &I);
+  void visitBitCast(BitCastInst &I);
+};
+
+} // End anonymous namespace
+
+char SITypeRewriter::ID = 0;
+
+bool SITypeRewriter::doInitialization(Module &M) {
+  Mod = &M;
+  v16i8 = VectorType::get(Type::getInt8Ty(M.getContext()), 16);
+  i128 = Type::getIntNTy(M.getContext(), 128);
+  return false;
+}
+
+bool SITypeRewriter::runOnFunction(Function &F) {
+  AttributeSet Set = F.getAttributes();
+  Attribute A = Set.getAttribute(AttributeSet::FunctionIndex, "ShaderType");
+
+  unsigned ShaderType = ShaderType::COMPUTE;
+  if (A.isStringAttribute()) {
+    StringRef Str = A.getValueAsString();
+    Str.getAsInteger(0, ShaderType);
+  }
+  if (ShaderType != ShaderType::COMPUTE) {
+    visit(F);
+  }
+
+  visit(F);
+
+  return false;
+}
+
+void SITypeRewriter::visitLoadInst(LoadInst &I) {
+  Value *Ptr = I.getPointerOperand();
+  Type *PtrTy = Ptr->getType();
+  Type *ElemTy = PtrTy->getPointerElementType();
+  IRBuilder<> Builder(&I);
+  if (ElemTy == v16i8)  {
+    Value *BitCast = Builder.CreateBitCast(Ptr, Type::getIntNPtrTy(I.getContext(), 128, 2));
+    LoadInst *Load = Builder.CreateLoad(BitCast);
+    SmallVector <std::pair<unsigned, MDNode*>, 8> MD;
+    I.getAllMetadataOtherThanDebugLoc(MD);
+    for (unsigned i = 0, e = MD.size(); i != e; ++i) {
+      Load->setMetadata(MD[i].first, MD[i].second);
+    }
+    Value *BitCastLoad = Builder.CreateBitCast(Load, I.getType());
+    I.replaceAllUsesWith(BitCastLoad);
+    I.eraseFromParent();
+  }
+}
+
+void SITypeRewriter::visitCallInst(CallInst &I) {
+  IRBuilder<> Builder(&I);
+  SmallVector <Value*, 8> Args;
+  SmallVector <Type*, 8> Types;
+  bool NeedToReplace = false;
+  Function *F = I.getCalledFunction();
+  std::string Name = F->getName().str();
+  for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
+    Value *Arg = I.getArgOperand(i);
+    if (Arg->getType() == v16i8) {
+      Args.push_back(Builder.CreateBitCast(Arg, i128));
+      Types.push_back(i128);
+      NeedToReplace = true;
+      Name = Name + ".i128";
+    } else {
+      Args.push_back(Arg);
+      Types.push_back(Arg->getType());
+    }
+  }
+
+  if (!NeedToReplace) {
+    return;
+  }
+  Function *NewF = Mod->getFunction(Name);
+  if (!NewF) {
+    NewF = Function::Create(FunctionType::get(F->getReturnType(), Types, false), GlobalValue::ExternalLinkage, Name, Mod);
+    NewF->setAttributes(F->getAttributes());
+  }
+  I.replaceAllUsesWith(Builder.CreateCall(NewF, Args));
+  I.eraseFromParent();
+}
+
+void SITypeRewriter::visitBitCast(BitCastInst &I) {
+  IRBuilder<> Builder(&I);
+  if (I.getDestTy() != i128) {
+    return;
+  }
+
+  if (BitCastInst *Op = dyn_cast<BitCastInst>(I.getOperand(0))) {
+    if (Op->getSrcTy() == i128) {
+      I.replaceAllUsesWith(Op->getOperand(0));
+      I.eraseFromParent();
+    }
+  }
+}
+
+FunctionPass *llvm::createSITypeRewriter() {
+  return new SITypeRewriter();
+}