Fix the predicate which checks for non-sensical formulae which have
constants in registers which partially cancel out their immediate fields.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104088 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 6bab98b..921f0b9 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -2572,10 +2572,11 @@
J = NewF.BaseRegs.begin(), JE = NewF.BaseRegs.end();
J != JE; ++J)
if (const SCEVConstant *C = dyn_cast<SCEVConstant>(*J))
- if (C->getValue()->getValue().isNegative() !=
- (NewF.AM.BaseOffs < 0) &&
- C->getValue()->getValue().abs()
- .ule(abs64(NewF.AM.BaseOffs)))
+ if ((C->getValue()->getValue() + NewF.AM.BaseOffs).abs().slt(
+ abs64(NewF.AM.BaseOffs)) &&
+ (C->getValue()->getValue() +
+ NewF.AM.BaseOffs).countTrailingZeros() >=
+ CountTrailingZeros_64(NewF.AM.BaseOffs))
goto skip_formula;
// Ok, looks good.