source: icGREP/icgrep-devel/llvm-3.8.0.src/test/Analysis/ScalarEvolution/2011-03-09-ExactNoMaxBECount.ll @ 5027

Last change on this file since 5027 was 5027, checked in by cameron, 3 years ago

Upgrade to llvm 3.8

File size: 1.2 KB
Line 
1; RUN: opt -indvars < %s
2; PR9424: Attempt to use a SCEVCouldNotCompute object!
3; The inner loop computes the Step and Start of the outer loop.
4; Call that Vexit. The outer End value is max(2,Vexit), because
5; the condition "icmp %4 < 2" does not guard the outer loop.
6; SCEV knows that Vexit has range [2,4], so End == Vexit == Start.
7; Now we have ExactBECount == 0. However, MinStart == 2 and MaxEnd == 4.
8; Since the stride is variable and may wrap, we cannot compute
9; MaxBECount. SCEV should override MaxBECount with ExactBECount.
10
11define void @bar() nounwind {
12entry:
13  %. = select i1 undef, i32 2, i32 1
14  br label %"5.preheader"
15
16"4":                                              ; preds = %"5.preheader", %"4"
17  %0 = phi i32 [ 0, %"5.preheader" ], [ %1, %"4" ]
18  %1 = add nsw i32 %0, 1
19  %2 = icmp sgt i32 %., %1
20  br i1 %2, label %"4", label %"9"
21
22"9":                                              ; preds = %"4"
23  %3 = add i32 %6, 1
24  %4 = add i32 %3, %1
25  %5 = icmp slt i32 %4, 2
26  br i1 %5, label %"5.preheader", label %return
27
28"5.preheader":                                    ; preds = %"9", %entry
29  %6 = phi i32 [ 0, %entry ], [ %4, %"9" ]
30  br label %"4"
31
32return:                                           ; preds = %"9"
33  ret void
34}
Note: See TracBrowser for help on using the repository browser.