diff options
Diffstat (limited to 'test/Analysis')
| -rw-r--r-- | test/Analysis/ScalarEvolution/2011-03-09-ExactNoMaxBECount.ll | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/test/Analysis/ScalarEvolution/2011-03-09-ExactNoMaxBECount.ll b/test/Analysis/ScalarEvolution/2011-03-09-ExactNoMaxBECount.ll new file mode 100644 index 0000000..9f17e27 --- /dev/null +++ b/test/Analysis/ScalarEvolution/2011-03-09-ExactNoMaxBECount.ll @@ -0,0 +1,34 @@ +; RUN: opt -indvars %s +; PR9424: Attempt to use a SCEVCouldNotCompute object! +; The inner loop computes the Step and Start of the outer loop. +; Call that Vexit. The outer End value is max(2,Vexit), because +; the condition "icmp %4 < 2" does not guard the outer loop. +; SCEV knows that Vexit has range [2,4], so End == Vexit == Start. +; Now we have ExactBECount == 0. However, MinStart == 2 and MaxEnd == 4. +; Since the stride is variable and may wrap, we cannot compute +; MaxBECount. SCEV should override MaxBECount with ExactBECount. + +define void @bar() nounwind { +entry: + %. = select i1 undef, i32 2, i32 1 + br label %"5.preheader" + +"4": ; preds = %"5.preheader", %"4" + %0 = phi i32 [ 0, %"5.preheader" ], [ %1, %"4" ] + %1 = add nsw i32 %0, 1 + %2 = icmp sgt i32 %., %1 + br i1 %2, label %"4", label %"9" + +"9": ; preds = %"4" + %3 = add i32 %6, 1 + %4 = add i32 %3, %1 + %5 = icmp slt i32 %4, 2 + br i1 %5, label %"5.preheader", label %return + +"5.preheader": ; preds = %"9", %entry + %6 = phi i32 [ 0, %entry ], [ %4, %"9" ] + br label %"4" + +return: ; preds = %"9" + ret void +} |