PR13326: Fix a subtle edge case in the udiv -> magic multiply generator.
This caused 6 of 65k possible 8 bit udivs to be wrong.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160058 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index 6a74883..38cfaed 100644
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -1446,7 +1446,7 @@
APInt signedMin = APInt::getSignedMinValue(d.getBitWidth());
APInt signedMax = APInt::getSignedMaxValue(d.getBitWidth());
- nc = allOnes - (-d).urem(d);
+ nc = allOnes - (allOnes - d).urem(d);
p = d.getBitWidth() - 1; // initialize p
q1 = signedMin.udiv(nc); // initialize q1 = 2p/nc
r1 = signedMin - q1*nc; // initialize r1 = rem(2p,nc)