vendor/llvm/llvm-trunk-r366426

1 files changed, 41 insertions, 23 deletions

diff --git a/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp b/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
index 98e9ea662324..b764ca7d7061 100644
--- a/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
+++ b/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp
@@ -1,9 +1,8 @@
 //===- SIAnnotateControlFlow.cpp ------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
@@ -13,12 +12,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "AMDGPU.h"
+#include "AMDGPUSubtarget.h"
 #include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/LegacyDivergenceAnalysis.h"
 #include "llvm/Analysis/LoopInfo.h"
-#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constant.h"
@@ -38,6 +38,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
 #include <cassert>
 #include <utility>
 
@@ -56,13 +57,13 @@ class SIAnnotateControlFlow : public FunctionPass {
 
   Type *Boolean;
   Type *Void;
-  Type *Int64;
+  Type *IntMask;
   Type *ReturnStruct;
 
   ConstantInt *BoolTrue;
   ConstantInt *BoolFalse;
   UndefValue *BoolUndef;
-  Constant *Int64Zero;
+  Constant *IntMaskZero;
 
   Function *If;
   Function *Else;
@@ -75,6 +76,8 @@ class SIAnnotateControlFlow : public FunctionPass {
 
   LoopInfo *LI;
 
+  void initialize(Module &M, const GCNSubtarget &ST);
+
   bool isUniform(BranchInst *T);
 
   bool isTopOfStack(BasicBlock *BB);
@@ -104,8 +107,6 @@ public:
 
   SIAnnotateControlFlow() : FunctionPass(ID) {}
 
-  bool doInitialization(Module &M) override;
-
   bool runOnFunction(Function &F) override;
 
   StringRef getPassName() const override { return "SI annotate control flow"; }
@@ -115,6 +116,7 @@ public:
     AU.addRequired<DominatorTreeWrapperPass>();
     AU.addRequired<LegacyDivergenceAnalysis>();
     AU.addPreserved<DominatorTreeWrapperPass>();
+    AU.addRequired<TargetPassConfig>();
     FunctionPass::getAnalysisUsage(AU);
   }
 };
@@ -125,31 +127,34 @@ INITIALIZE_PASS_BEGIN(SIAnnotateControlFlow, DEBUG_TYPE,
                       "Annotate SI Control Flow", false, false)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(LegacyDivergenceAnalysis)
+INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
 INITIALIZE_PASS_END(SIAnnotateControlFlow, DEBUG_TYPE,
                     "Annotate SI Control Flow", false, false)
 
 char SIAnnotateControlFlow::ID = 0;
 
 /// Initialize all the types and constants used in the pass
-bool SIAnnotateControlFlow::doInitialization(Module &M) {
+void SIAnnotateControlFlow::initialize(Module &M, const GCNSubtarget &ST) {
   LLVMContext &Context = M.getContext();
 
   Void = Type::getVoidTy(Context);
   Boolean = Type::getInt1Ty(Context);
-  Int64 = Type::getInt64Ty(Context);
-  ReturnStruct = StructType::get(Boolean, Int64);
+  IntMask = ST.isWave32() ? Type::getInt32Ty(Context)
+                           : Type::getInt64Ty(Context);
+  ReturnStruct = StructType::get(Boolean, IntMask);
 
   BoolTrue = ConstantInt::getTrue(Context);
   BoolFalse = ConstantInt::getFalse(Context);
   BoolUndef = UndefValue::get(Boolean);
-  Int64Zero = ConstantInt::get(Int64, 0);
-
-  If = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_if);
-  Else = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_else);
-  IfBreak = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_if_break);
-  Loop = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_loop);
-  EndCf = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_end_cf);
-  return false;
+  IntMaskZero = ConstantInt::get(IntMask, 0);
+
+  If = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_if, { IntMask });
+  Else = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_else,
+                                   { IntMask, IntMask });
+  IfBreak = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_if_break,
+                                      { IntMask, IntMask });
+  Loop = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_loop, { IntMask });
+  EndCf = Intrinsic::getDeclaration(&M, Intrinsic::amdgcn_end_cf, { IntMask });
 }
 
 /// Is the branch condition uniform or did the StructurizeCFG pass
@@ -259,14 +264,23 @@ void SIAnnotateControlFlow::handleLoop(BranchInst *Term) {
     return;
 
   BasicBlock *Target = Term->getSuccessor(1);
-  PHINode *Broken = PHINode::Create(Int64, 0, "phi.broken", &Target->front());
+  PHINode *Broken = PHINode::Create(IntMask, 0, "phi.broken", &Target->front());
 
   Value *Cond = Term->getCondition();
   Term->setCondition(BoolTrue);
   Value *Arg = handleLoopCondition(Cond, Broken, L, Term);
 
-  for (BasicBlock *Pred : predecessors(Target))
-    Broken->addIncoming(Pred == BB ? Arg : Int64Zero, Pred);
+  for (BasicBlock *Pred : predecessors(Target)) {
+    Value *PHIValue = IntMaskZero;
+    if (Pred == BB) // Remember the value of the previous iteration.
+      PHIValue = Arg;
+    // If the backedge from Pred to Target could be executed before the exit
+    // of the loop at BB, it should not reset or change "Broken", which keeps
+    // track of the number of threads exited the loop at BB.
+    else if (L->contains(Pred) && DT->dominates(Pred, BB))
+      PHIValue = Broken;
+    Broken->addIncoming(PHIValue, Pred);
+  }
 
   Term->setCondition(CallInst::Create(Loop, Arg, "", Term));
 
@@ -308,6 +322,10 @@ bool SIAnnotateControlFlow::runOnFunction(Function &F) {
   DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
   LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
   DA = &getAnalysis<LegacyDivergenceAnalysis>();
+  TargetPassConfig &TPC = getAnalysis<TargetPassConfig>();
+  const TargetMachine &TM = TPC.getTM<TargetMachine>();
+
+  initialize(*F.getParent(), TM.getSubtarget<GCNSubtarget>(F));
 
   for (df_iterator<BasicBlock *> I = df_begin(&F.getEntryBlock()),
        E = df_end(&F.getEntryBlock()); I != E; ++I) {