1; RUN: llc -march=hexagon -mcpu=hexagonv5 -enable-pipeliner -verify-machineinstrs < %s | FileCheck %s
2
3; If the trip count is a compile-time constant, then decrement it instead
4; of computing a new LC0 value.
5
6; CHECK-LABEL: @test
7; CHECK: loop0(.LBB0_1, #998)
8
9define i32 @test(i32* %A, i32* %B, i32 %count) {
10entry:
11  br label %for.body
12
13for.body:
14  %sum.02 = phi i32 [ 0, %entry ], [ %add, %for.body ]
15  %arrayidx.phi = phi i32* [ %A, %entry ], [ %arrayidx.inc, %for.body ]
16  %i.01 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
17  %0 = load i32, i32* %arrayidx.phi, align 4
18  %add = add nsw i32 %0, %sum.02
19  %inc = add nsw i32 %i.01, 1
20  %exitcond = icmp eq i32 %inc, 1000
21  %arrayidx.inc = getelementptr i32, i32* %arrayidx.phi, i32 1
22  br i1 %exitcond, label %for.end, label %for.body
23
24for.end:
25  ret i32 %add
26}
27
28; The constant trip count is small enough that the kernel is not executed.
29
30; CHECK-LABEL: @test1
31; CHECK-NOT: loop0(
32
33define i32 @test1(i32* %A, i32* %B, i32 %count) {
34entry:
35  br label %for.body
36
37for.body:
38  %sum.02 = phi i32 [ 0, %entry ], [ %add, %for.body ]
39  %arrayidx.phi = phi i32* [ %A, %entry ], [ %arrayidx.inc, %for.body ]
40  %i.01 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
41  %0 = load i32, i32* %arrayidx.phi, align 4
42  %add = add nsw i32 %0, %sum.02
43  %inc = add nsw i32 %i.01, 1
44  %exitcond = icmp eq i32 %inc, 1
45  %arrayidx.inc = getelementptr i32, i32* %arrayidx.phi, i32 1
46  br i1 %exitcond, label %for.end, label %for.body
47
48for.end:
49  ret i32 %add
50}
51
52