Recognize n/1 in the SCEV divide function
n/1 generates a quotient equal to n and a remainder of 0.
If this case is not recognized, then the SCEV divide() function
can return a remainder that is greater than or equal to the
denominator, which means the delinearized subscripts for the
test case will be incorrect.
Differential Revision: http://reviews.llvm.org/D9003
llvm-svn: 235311
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 37377f0..d88b026 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -726,6 +726,13 @@
return;
}
+ // A simple case when N/1. The quotient is N.
+ if (Denominator->isOne()) {
+ *Quotient = Numerator;
+ *Remainder = D.Zero;
+ return;
+ }
+
// Split the Denominator when it is a product.
if (const SCEVMulExpr *T = dyn_cast<const SCEVMulExpr>(Denominator)) {
const SCEV *Q, *R;