Revert "Re-land "[MergeICmps] Disable mergeicmps if the target does not want to handle memcmp expansion."""

broken test on windows

This reverts commit c91479518344fd1fc071c5bd5848f6eb83e53dca.

llvm-svn: 314985

1 files changed, 10 insertions, 25 deletions

diff --git a/llvm/lib/Transforms/Scalar/MergeICmps.cpp b/llvm/lib/Transforms/Scalar/MergeICmps.cpp
index a8e109db3a2..a56cffcdfa0 100644
--- a/llvm/lib/Transforms/Scalar/MergeICmps.cpp
+++ b/llvm/lib/Transforms/Scalar/MergeICmps.cpp
@@ -28,8 +28,6 @@
 #include <vector>
 #include "llvm/ADT/APSInt.h"
 #include "llvm/Analysis/Loads.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/IntrinsicInst.h"
@@ -43,6 +41,8 @@ namespace {
 
 #define DEBUG_TYPE "mergeicmps"
 
+#define MERGEICMPS_DOT_ON
+
 // A BCE atom.
 struct BCEAtom {
   BCEAtom() : GEP(nullptr), LoadI(nullptr), Offset() {}
@@ -430,16 +430,10 @@ void BCECmpChain::mergeComparisons(ArrayRef<BCECmpBlock> Comparisons,
 
     IRBuilder<> Builder(BB);
     const auto &DL = Phi.getModule()->getDataLayout();
-    GetElementPtrInst *LhsArg = FirstComparison.Lhs().GEP;
-    GetElementPtrInst *RhsArg = FirstComparison.Rhs().GEP;
-    // If the values are named, use the smaller name as first argument to
-    // memcmp() so that results are reproducible.
-    if (LhsArg->hasName() && RhsArg->hasName() &&
-        LhsArg->getName() > RhsArg->getName())
-      std::swap(LhsArg, RhsArg);
-    Value *const MemCmpCall = emitMemCmp(
-        LhsArg, RhsArg, ConstantInt::get(DL.getIntPtrType(Context), TotalSize),
-        Builder, DL, TLI);
+    Value *const MemCmpCall =
+        emitMemCmp(FirstComparison.Lhs().GEP, FirstComparison.Rhs().GEP,
+                   ConstantInt::get(DL.getIntPtrType(Context), TotalSize),
+                   Builder, DL, TLI);
     Value *const MemCmpIsZero = Builder.CreateICmpEQ(
         MemCmpCall, ConstantInt::get(Type::getInt32Ty(Context), 0));
 
@@ -595,30 +589,22 @@ class MergeICmps : public FunctionPass {
   bool runOnFunction(Function &F) override {
     if (skipFunction(F)) return false;
     const auto &TLI = getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
-    const auto &TTI = getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
-    auto PA = runImpl(F, &TLI, &TTI);
+    auto PA = runImpl(F, &TLI);
     return !PA.areAllPreserved();
   }
 
  private:
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.addRequired<TargetLibraryInfoWrapperPass>();
-    AU.addRequired<TargetTransformInfoWrapperPass>();
   }
 
-  PreservedAnalyses runImpl(Function &F, const TargetLibraryInfo *TLI,
-                            const TargetTransformInfo *TTI);
+  PreservedAnalyses runImpl(Function &F, const TargetLibraryInfo *TLI);
 };
 
-PreservedAnalyses MergeICmps::runImpl(Function &F, const TargetLibraryInfo *TLI,
-                                      const TargetTransformInfo *TTI) {
+PreservedAnalyses MergeICmps::runImpl(Function &F,
+                                      const TargetLibraryInfo *TLI) {
   DEBUG(dbgs() << "MergeICmpsPass: " << F.getName() << "\n");
 
-  // We only try merging comparisons if the target wants to expand memcmp later.
-  // The rationale is to avoid turning small chains into memcmp calls.
-  unsigned MaxLoadSize;
-  if (!TTI->enableMemCmpExpansion(MaxLoadSize)) return PreservedAnalyses::all();
-
   bool MadeChange = false;
 
   for (auto BBIt = ++F.begin(); BBIt != F.end(); ++BBIt) {
@@ -637,7 +623,6 @@ char MergeICmps::ID = 0;
 INITIALIZE_PASS_BEGIN(MergeICmps, "mergeicmps",
                       "Merge contiguous icmps into a memcmp", false, false)
 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
 INITIALIZE_PASS_END(MergeICmps, "mergeicmps",
                     "Merge contiguous icmps into a memcmp", false, false)