xref: /llvm-project/llvm/test/Analysis/ScalarEvolution/ZeroStep.ll (revision 8b5b294ec2cf876bc5eb5bd5fcb56ef487e36d60)
1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
2; RUN: opt -disable-output "-passes=print<scalar-evolution>" < %s 2>&1 | FileCheck %s
3
4target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
5target triple = "x86_64-apple-macosx10.9.0"
6
7; Test that SCEV is capable of figuring out value of 'IV' that actually does not change.
8define void @foo() {
9; CHECK-LABEL: 'foo'
10; CHECK-NEXT:  Classifying expressions for: @foo
11; CHECK-NEXT:    %iv.i = phi i64 [ -5, %entry ], [ %iv.next.i, %loop ]
12; CHECK-NEXT:    --> -5 U: [-5,-4) S: [-5,-4) Exits: -5 LoopDispositions: { %loop: Invariant }
13; CHECK-NEXT:    %iv.next.i = add nsw i64 %iv.i, 0
14; CHECK-NEXT:    --> -5 U: [-5,-4) S: [-5,-4) Exits: -5 LoopDispositions: { %loop: Invariant }
15; CHECK-NEXT:  Determining loop execution counts for: @foo
16; CHECK-NEXT:  Loop %loop: <multiple exits> Unpredictable backedge-taken count.
17; CHECK-NEXT:  Loop %loop: Unpredictable constant max backedge-taken count.
18; CHECK-NEXT:  Loop %loop: Unpredictable symbolic max backedge-taken count.
19;
20entry:
21  br label %loop
22
23loop:
24  %iv.i = phi i64 [ -5, %entry ], [ %iv.next.i, %loop ]
25  %iv.next.i = add nsw i64 %iv.i, 0
26  br label %loop
27}
28