[ValueTracking] move helpers for SelectPatterns from InstCombine to ValueTracking

Most of the folds based on SelectPatternResult belong in InstSimplify rather than
InstCombine, so the helper code should be available to other passes/analysis.

llvm-svn: 326812

1 files changed, 24 insertions, 0 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 411ede4..c132586 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -4661,6 +4661,30 @@ SelectPatternResult llvm::matchSelectPattern(Value *V, Value *&LHS, Value *&RHS,
                               LHS, RHS, Depth);
 }
 
+CmpInst::Predicate llvm::getMinMaxPred(SelectPatternFlavor SPF, bool Ordered) {
+  if (SPF == SPF_SMIN) return ICmpInst::ICMP_SLT;
+  if (SPF == SPF_UMIN) return ICmpInst::ICMP_ULT;
+  if (SPF == SPF_SMAX) return ICmpInst::ICMP_SGT;
+  if (SPF == SPF_UMAX) return ICmpInst::ICMP_UGT;
+  if (SPF == SPF_FMINNUM)
+    return Ordered ? FCmpInst::FCMP_OLT : FCmpInst::FCMP_ULT;
+  if (SPF == SPF_FMAXNUM)
+    return Ordered ? FCmpInst::FCMP_OGT : FCmpInst::FCMP_UGT;
+  llvm_unreachable("unhandled!");
+}
+
+SelectPatternFlavor llvm::getInverseMinMaxFlavor(SelectPatternFlavor SPF) {
+  if (SPF == SPF_SMIN) return SPF_SMAX;
+  if (SPF == SPF_UMIN) return SPF_UMAX;
+  if (SPF == SPF_SMAX) return SPF_SMIN;
+  if (SPF == SPF_UMAX) return SPF_UMIN;
+  llvm_unreachable("unhandled!");
+}
+
+CmpInst::Predicate llvm::getInverseMinMaxPred(SelectPatternFlavor SPF) {
+  return getMinMaxPred(getInverseMinMaxFlavor(SPF));
+}
+
 /// Return true if "icmp Pred LHS RHS" is always true.
 static bool isTruePredicate(CmpInst::Predicate Pred, const Value *LHS,
                             const Value *RHS, const DataLayout &DL,