Add a getUMinFromMismatchedTypes helper function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73883 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 22 insertions, 0 deletions

diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index 8d5136cea2..d73c30fb07 100644
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -553,6 +553,12 @@ namespace llvm {
     SCEVHandle getUMaxFromMismatchedTypes(const SCEVHandle &LHS,
                                           const SCEVHandle &RHS);
 
+    /// getUMinFromMismatchedTypes - Promote the operands to the wider of
+    /// the types using zero-extension, and then perform a umin operation
+    /// with them.
+    SCEVHandle getUMinFromMismatchedTypes(const SCEVHandle &LHS,
+                                          const SCEVHandle &RHS);
+
     /// hasSCEV - Return true if the SCEV for this value has already been
     /// computed.
     bool hasSCEV(Value *V) const;
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 68aa595aa8..d67761c60a 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -2156,6 +2156,22 @@ SCEVHandle ScalarEvolution::getUMaxFromMismatchedTypes(const SCEVHandle &LHS,
   return getUMaxExpr(PromotedLHS, PromotedRHS);
 }
 
+/// getUMinFromMismatchedTypes - Promote the operands to the wider of
+/// the types using zero-extension, and then perform a umin operation
+/// with them.
+SCEVHandle ScalarEvolution::getUMinFromMismatchedTypes(const SCEVHandle &LHS,
+                                                       const SCEVHandle &RHS) {
+  SCEVHandle PromotedLHS = LHS;
+  SCEVHandle PromotedRHS = RHS;
+
+  if (getTypeSizeInBits(LHS->getType()) > getTypeSizeInBits(RHS->getType()))
+    PromotedRHS = getZeroExtendExpr(RHS, LHS->getType());
+  else
+    PromotedLHS = getNoopOrZeroExtend(LHS, RHS->getType());
+
+  return getUMinExpr(PromotedLHS, PromotedRHS);
+}
+
 /// ReplaceSymbolicValueWithConcrete - This looks up the computed SCEV value for
 /// the specified instruction and replaces any references to the symbolic value
 /// SymName with the specified value.  This is used during PHI resolution.