Factor out code for computing umin and smin for SCEV expressions into
helper functions. Based on a patch by Nick Lewycky.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73869 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index d851913..68aa595 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1903,6 +1903,18 @@
return Result;
}
+SCEVHandle ScalarEvolution::getSMinExpr(const SCEVHandle &LHS,
+ const SCEVHandle &RHS) {
+ // ~smax(~x, ~y) == smin(x, y).
+ return getNotSCEV(getSMaxExpr(getNotSCEV(LHS), getNotSCEV(RHS)));
+}
+
+SCEVHandle ScalarEvolution::getUMinExpr(const SCEVHandle &LHS,
+ const SCEVHandle &RHS) {
+ // ~umax(~x, ~y) == umin(x, y)
+ return getNotSCEV(getUMaxExpr(getNotSCEV(LHS), getNotSCEV(RHS)));
+}
+
SCEVHandle ScalarEvolution::getUnknown(Value *V) {
if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
return getConstant(CI);
@@ -2644,10 +2656,7 @@
if (LHS == U->getOperand(1) && RHS == U->getOperand(2))
return getSMaxExpr(getSCEV(LHS), getSCEV(RHS));
else if (LHS == U->getOperand(2) && RHS == U->getOperand(1))
- // ~smax(~x, ~y) == smin(x, y).
- return getNotSCEV(getSMaxExpr(
- getNotSCEV(getSCEV(LHS)),
- getNotSCEV(getSCEV(RHS))));
+ return getSMinExpr(getSCEV(LHS), getSCEV(RHS));
break;
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_ULE:
@@ -2658,9 +2667,7 @@
if (LHS == U->getOperand(1) && RHS == U->getOperand(2))
return getUMaxExpr(getSCEV(LHS), getSCEV(RHS));
else if (LHS == U->getOperand(2) && RHS == U->getOperand(1))
- // ~umax(~x, ~y) == umin(x, y)
- return getNotSCEV(getUMaxExpr(getNotSCEV(getSCEV(LHS)),
- getNotSCEV(getSCEV(RHS))));
+ return getUMinExpr(getSCEV(LHS), getSCEV(RHS));
break;
case ICmpInst::ICMP_NE:
// n != 0 ? n : 1 -> umax(n, 1)