[CVP] tidy processCmp(); NFC

1. The variables were confusing: 'C' typically refers to a constant, but here it was the Cmp.
2. Formatting violations.
3. Simplify code to return true/false constant.

llvm-svn: 347868

diff --git a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
index 826df6c..d010570 100644 (file)
--- a/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -273,10 +273,11 @@ static bool processMemAccess(Instruction *I, LazyValueInfo *LVI) {
 /// information is sufficient to prove this comparison. Even for local
 /// conditions, this can sometimes prove conditions instcombine can't by
 /// exploiting range information.
-static bool processCmp(CmpInst *C, LazyValueInfo *LVI) {
-  Value *Op0 = C->getOperand(0);
-  Constant *Op1 = dyn_cast<Constant>(C->getOperand(1));
-  if (!Op1) return false;
+static bool processCmp(CmpInst *Cmp, LazyValueInfo *LVI) {
+  Value *Op0 = Cmp->getOperand(0);
+  auto *C = dyn_cast<Constant>(Cmp->getOperand(1));
+  if (!C)
+    return false;
 
   // As a policy choice, we choose not to waste compile time on anything where
   // the comparison is testing local values.  While LVI can sometimes reason
@@ -284,20 +285,18 @@ static bool processCmp(CmpInst *C, LazyValueInfo *LVI) {
   // the block local query for uses from terminator instructions, but that's
   // handled in the code for each terminator.
   auto *I = dyn_cast<Instruction>(Op0);
-  if (I && I->getParent() == C->getParent())
+  if (I && I->getParent() == Cmp->getParent())
     return false;
 
   LazyValueInfo::Tristate Result =
-    LVI->getPredicateAt(C->getPredicate(), Op0, Op1, C);
-  if (Result == LazyValueInfo::Unknown) return false;
+      LVI->getPredicateAt(Cmp->getPredicate(), Op0, C, Cmp);
+  if (Result == LazyValueInfo::Unknown)
+    return false;
 
   ++NumCmps;
-  if (Result == LazyValueInfo::True)
-    C->replaceAllUsesWith(ConstantInt::getTrue(C->getContext()));
-  else
-    C->replaceAllUsesWith(ConstantInt::getFalse(C->getContext()));
-  C->eraseFromParent();
-
+  Constant *TorF = ConstantInt::get(Type::getInt1Ty(Cmp->getContext()), Result);
+  Cmp->replaceAllUsesWith(TorF);
+  Cmp->eraseFromParent();
   return true;
 }
 
@@ -308,7 +307,8 @@ static bool processCmp(CmpInst *C, LazyValueInfo *LVI) {
 /// that cannot fire no matter what the incoming edge can safely be removed. If
 /// a case fires on every incoming edge then the entire switch can be removed
 /// and replaced with a branch to the case destination.
-static bool processSwitch(SwitchInst *SI, LazyValueInfo *LVI, DominatorTree *DT) {
+static bool processSwitch(SwitchInst *SI, LazyValueInfo *LVI,
+                          DominatorTree *DT) {
   DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Lazy);
   Value *Cond = SI->getCondition();
   BasicBlock *BB = SI->getParent();