[PowerPC] Fix compile time issue in recursive CTR analysis code

author Teresa Johnson <tejohnson@google.com>

Sat, 7 Mar 2020 01:48:22 +0000 (17:48 -0800)

committer Teresa Johnson <tejohnson@google.com>

Wed, 11 Mar 2020 23:11:14 +0000 (16:11 -0700)
author Teresa Johnson <tejohnson@google.com>
Sat, 7 Mar 2020 01:48:22 +0000 (17:48 -0800)
committer Teresa Johnson <tejohnson@google.com>
Wed, 11 Mar 2020 23:11:14 +0000 (16:11 -0700)
diff --git a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp

index 1bb78ed..db57097 100644 (file)
--- a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
@@ -217,8 +217,8 @@ unsigned PPCTTIImpl::getUserCost(const User *U,
    return BaseT::getUserCost(U, Operands);
  }
  
-bool PPCTTIImpl::mightUseCTR(BasicBlock *BB,
-                             TargetLibraryInfo *LibInfo) {
+bool PPCTTIImpl::mightUseCTR(BasicBlock *BB, TargetLibraryInfo *LibInfo,
+                             SmallPtrSetImpl<const Value *> &Visited) {
    const PPCTargetMachine &TM = ST->getTargetMachine();
  
    // Loop through the inline asm constraints and look for something that
@@ -237,8 +237,11 @@ bool PPCTTIImpl::mightUseCTR(BasicBlock *BB,
  
    // Determining the address of a TLS variable results in a function call in
    // certain TLS models.
-  std::function<bool(const Value*)> memAddrUsesCTR =
-    [&memAddrUsesCTR, &TM](const Value *MemAddr) -> bool {
+  std::function<bool(const Value *)> memAddrUsesCTR =
+      [&memAddrUsesCTR, &TM, &Visited](const Value *MemAddr) -> bool {
+    // No need to traverse again if we already checked this operand.
+    if (!Visited.insert(MemAddr).second)
+      return false;
      const auto *GV = dyn_cast<GlobalValue>(MemAddr);
      if (!GV) {
        // Recurse to check for constants that refer to TLS global variables.
@@ -502,9 +505,10 @@ bool PPCTTIImpl::isHardwareLoopProfitable(Loop *L, ScalarEvolution &SE,
  
    // We don't want to spill/restore the counter register, and so we don't
    // want to use the counter register if the loop contains calls.
+  SmallPtrSet<const Value *, 4> Visited;
    for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
         I != IE; ++I)
-    if (mightUseCTR(*I, LibInfo))
+    if (mightUseCTR(*I, LibInfo, Visited))
        return false;
  
    SmallVector<BasicBlock*, 4> ExitingBlocks;
diff --git a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.h b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.h

index 5aea524..36ed6ff 100644 (file)
--- a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.h
+++ b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.h
@@ -33,7 +33,8 @@ class PPCTTIImpl : public BasicTTIImplBase<PPCTTIImpl> {
  
    const PPCSubtarget *getST() const { return ST; }
    const PPCTargetLowering *getTLI() const { return TLI; }
-  bool mightUseCTR(BasicBlock *BB, TargetLibraryInfo *LibInfo);
+  bool mightUseCTR(BasicBlock *BB, TargetLibraryInfo *LibInfo,
+                   SmallPtrSetImpl<const Value *> &Visited);
  
  public:
    explicit PPCTTIImpl(const PPCTargetMachine *TM, const Function &F)
author	Teresa Johnson <tejohnson@google.com>
	Sat, 7 Mar 2020 01:48:22 +0000 (17:48 -0800)
committer	Teresa Johnson <tejohnson@google.com>
	Wed, 11 Mar 2020 23:11:14 +0000 (16:11 -0700)
llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp		patch \| blob \| history
llvm/lib/Target/PowerPC/PPCTargetTransformInfo.h		patch \| blob \| history