[InstCombine] We folded an fcmp to an i1 instead of a vector of i1

Remove an ad-hoc transform in InstCombine and replace it with more
general machinery (ValueTracking, InstructionSimplify and VectorUtils).

This fixes PR27332.

llvm-svn: 266175

1 files changed, 19 insertions, 12 deletions

diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 80b92b5..cefa187 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -794,7 +794,7 @@ static Value *SimplifyFAddInst(Value *Op0, Value *Op1, FastMathFlags FMF,
 
   // fadd X, 0 ==> X, when we know X is not -0
   if (match(Op1, m_Zero()) &&
-      (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
+      (FMF.noSignedZeros() || CannotBeNegativeZero(Op0, Q.TLI)))
     return Op0;
 
   // fadd [nnan ninf] X, (fsub [nnan ninf] 0, X) ==> 0
@@ -830,7 +830,7 @@ static Value *SimplifyFSubInst(Value *Op0, Value *Op1, FastMathFlags FMF,
 
   // fsub X, -0 ==> X, when we know X is not -0
   if (match(Op1, m_NegZero()) &&
-      (FMF.noSignedZeros() || CannotBeNegativeZero(Op0)))
+      (FMF.noSignedZeros() || CannotBeNegativeZero(Op0, Q.TLI)))
     return Op0;
 
   // fsub -0.0, (fsub -0.0, X) ==> X
@@ -3112,7 +3112,14 @@ static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
   }
 
   // Handle fcmp with constant RHS
-  if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHS)) {
+  const ConstantFP *CFP = nullptr;
+  if (const auto *RHSC = dyn_cast<Constant>(RHS)) {
+    if (RHS->getType()->isVectorTy())
+      CFP = dyn_cast_or_null<ConstantFP>(RHSC->getSplatValue());
+    else
+      CFP = dyn_cast<ConstantFP>(RHSC);
+  }
+  if (CFP) {
     // If the constant is a nan, see if we can fold the comparison based on it.
     if (CFP->getValueAPF().isNaN()) {
       if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo"
@@ -3120,7 +3127,7 @@ static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
       assert(FCmpInst::isUnordered(Pred) &&
              "Comparison must be either ordered or unordered!");
       // True if unordered.
-      return ConstantInt::getTrue(CFP->getContext());
+      return ConstantInt::get(GetCompareTy(LHS), 1);
     }
     // Check whether the constant is an infinity.
     if (CFP->getValueAPF().isInfinity()) {
@@ -3128,10 +3135,10 @@ static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
         switch (Pred) {
         case FCmpInst::FCMP_OLT:
           // No value is ordered and less than negative infinity.
-          return ConstantInt::getFalse(CFP->getContext());
+          return ConstantInt::get(GetCompareTy(LHS), 0);
         case FCmpInst::FCMP_UGE:
           // All values are unordered with or at least negative infinity.
-          return ConstantInt::getTrue(CFP->getContext());
+          return ConstantInt::get(GetCompareTy(LHS), 1);
         default:
           break;
         }
@@ -3139,10 +3146,10 @@ static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
         switch (Pred) {
         case FCmpInst::FCMP_OGT:
           // No value is ordered and greater than infinity.
-          return ConstantInt::getFalse(CFP->getContext());
+          return ConstantInt::get(GetCompareTy(LHS), 0);
         case FCmpInst::FCMP_ULE:
           // All values are unordered with and at most infinity.
-          return ConstantInt::getTrue(CFP->getContext());
+          return ConstantInt::get(GetCompareTy(LHS), 1);
         default:
           break;
         }
@@ -3151,13 +3158,13 @@ static Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
     if (CFP->getValueAPF().isZero()) {
       switch (Pred) {
       case FCmpInst::FCMP_UGE:
-        if (CannotBeOrderedLessThanZero(LHS))
-          return ConstantInt::getTrue(CFP->getContext());
+        if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
+          return ConstantInt::get(GetCompareTy(LHS), 1);
         break;
       case FCmpInst::FCMP_OLT:
         // X < 0
-        if (CannotBeOrderedLessThanZero(LHS))
-          return ConstantInt::getFalse(CFP->getContext());
+        if (CannotBeOrderedLessThanZero(LHS, Q.TLI))
+          return ConstantInt::get(GetCompareTy(LHS), 0);
         break;
       default:
         break;