[llvm] r280427 - Refactor replaceDominatedUsesWith to have a flag to control whether to replace uses in BB itself.

[Dehao Chen via llvm-commits]

Author: dehao
Date: Thu Sep  1 18:26:48 2016
New Revision: 280427

URL: http://llvm.org/viewvc/llvm-project?rev=280427&view=rev
Log:
Refactor replaceDominatedUsesWith to have a flag to control whether to replace uses in BB itself.

Summary: This is in preparation for LoopSink pass which calls replaceDominatedUsesWith to update after sinking.

Reviewers: chandlerc, davidxl, danielcdh

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24170

Modified:
    llvm/trunk/include/llvm/Transforms/Utils/Local.h
    llvm/trunk/lib/Transforms/Scalar/GVN.cpp
    llvm/trunk/lib/Transforms/Utils/Local.cpp

Modified: llvm/trunk/include/llvm/Transforms/Utils/Local.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/Local.h?rev=280427&r1=280426&r2=280427&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/Local.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/Local.h Thu Sep  1 18:26:48 2016
@@ -326,10 +326,12 @@ void combineMetadataForCSE(Instruction *
 /// the given edge.  Returns the number of replacements made.
 unsigned replaceDominatedUsesWith(Value *From, Value *To, DominatorTree &DT,
                                   const BasicBlockEdge &Edge);
+
 /// Replace each use of 'From' with 'To' if that use is dominated by
-/// the end of the given BasicBlock. Returns the number of replacements made.
+/// the end of 'BB'. Returns the number of replacements made.
+/// Replace use of 'From' with 'To' in 'BB' if 'IncludeSelf' is true.
 unsigned replaceDominatedUsesWith(Value *From, Value *To, DominatorTree &DT,
-                                  const BasicBlock *BB);
+                                  const BasicBlock *BB, bool IncludeSelf);
 
 
 /// Return true if the CallSite CS calls a gc leaf function.

Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=280427&r1=280426&r2=280427&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Thu Sep  1 18:26:48 2016
@@ -1962,7 +1962,7 @@ bool GVN::propagateEquality(Value *LHS,
       unsigned NumReplacements =
           DominatesByEdge
               ? replaceDominatedUsesWith(LHS, RHS, *DT, Root)
-              : replaceDominatedUsesWith(LHS, RHS, *DT, Root.getStart());
+              : replaceDominatedUsesWith(LHS, RHS, *DT, Root.getStart(), false);
 
       Changed |= NumReplacements > 0;
       NumGVNEqProp += NumReplacements;
@@ -2038,7 +2038,7 @@ bool GVN::propagateEquality(Value *LHS,
               DominatesByEdge
                   ? replaceDominatedUsesWith(NotCmp, NotVal, *DT, Root)
                   : replaceDominatedUsesWith(NotCmp, NotVal, *DT,
-                                             Root.getStart());
+                                             Root.getStart(), false);
           Changed |= NumReplacements > 0;
           NumGVNEqProp += NumReplacements;
         }

Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=280427&r1=280426&r2=280427&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp Thu Sep  1 18:26:48 2016
@@ -1679,7 +1679,8 @@ unsigned llvm::replaceDominatedUsesWith(
 
 unsigned llvm::replaceDominatedUsesWith(Value *From, Value *To,
                                         DominatorTree &DT,
-                                        const BasicBlock *BB) {
+                                        const BasicBlock *BB,
+                                        bool IncludeSelf) {
   assert(From->getType() == To->getType());
 
   unsigned Count = 0;
@@ -1687,7 +1688,8 @@ unsigned llvm::replaceDominatedUsesWith(
        UI != UE;) {
     Use &U = *UI++;
     auto *I = cast<Instruction>(U.getUser());
-    if (DT.properlyDominates(BB, I->getParent())) {
+    if ((IncludeSelf && BB == I->getParent()) ||
+        DT.properlyDominates(BB, I->getParent())) {
       U.set(To);
       DEBUG(dbgs() << "Replace dominated use of '" << From->getName() << "' as "
                    << *To << " in " << *U << "\n");