void *IP = nullptr;
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
- // If the input value is provably positive, build a zext instead.
- if (isKnownNonNegative(Op))
- return getZeroExtendExpr(Op, Ty);
-
// sext(trunc(x)) --> sext(x) or x or trunc(x)
if (const SCEVTruncateExpr *ST = dyn_cast<SCEVTruncateExpr>(Op)) {
// It's possible the bits taken off by the truncate were all sign bits. If
}
}
+ // If the input value is provably positive and we could not simplify
+ // away the sext build a zext instead.
+ if (isKnownNonNegative(Op))
+ return getZeroExtendExpr(Op, Ty);
+
// The cast wasn't folded; create an explicit cast node.
// Recompute the insert position, as it may have been invalidated.
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
--- /dev/null
+; RUN: opt -analyze -scalar-evolution < %s | FileCheck %s
+
+define void @f(i1 %c) {
+; CHECK-LABEL: Classifying expressions for: @f
+entry:
+ %start = select i1 %c, i32 100, i32 0
+ %step = select i1 %c, i32 -1, i32 1
+ br label %loop
+
+loop:
+ %iv = phi i32 [ %start, %entry ], [ %iv.dec, %loop ]
+ %iv.tc = phi i32 [ 0, %entry ], [ %iv.tc.inc, %loop ]
+ %iv.tc.inc = add i32 %iv.tc, 1
+ %iv.dec = add nsw i32 %iv, %step
+ %iv.sext = sext i32 %iv to i64
+; CHECK: %iv.sext = sext i32 %iv to i64
+; CHECK-NEXT: --> {(sext i32 %start to i64),+,(sext i32 %step to i64)}<nsw><%loop>
+ %be = icmp ne i32 %iv.tc.inc, 100
+ br i1 %be, label %loop, label %leave
+
+leave:
+ ret void
+}