add a fixme: ir isn't expressive enough.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123139 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 0c16bbc334cf069a9a990b4623a7afbb3338e1c9..922751fe3d13fd5ee859b81613584a3e48654eea 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -4863,6 +4863,7 @@ ScalarEvolution::HowFarToZero(const SCEV *V, const Loop *L) {
   // the stride is.  As such, NUW addrec's will always become zero in
   // "start / -stride" steps, and we know that the division is exact.
   if (AddRec->hasNoUnsignedWrap())
+    // FIXME: We really want an "isexact" bit for udiv.
     return getUDivExpr(Start, getNegativeSCEV(Step));
   
   // For now we handle only constant steps.