1 // RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s
2 
3 // We expect to get a loop structure like this:
4 //    do.body:                                       ; preds = %do.cond, ...
5 //      ...
6 //      br label %do.cond
7 //    do.cond:                                       ; preds = %do.body
8 //      ...
9 //      br i1 %cmp, label %do.body, label %do.end
10 //    do.end:                                        ; preds = %do.cond
11 //      ...
12 //
13 // Verify that the loop metadata only is put on the backedge.
14 //
15 // CHECK-NOT: llvm.loop
16 // CHECK-LABEL: do.cond:
17 // CHECK: br {{.*}}, label %do.body, label %do.end, !llvm.loop ![[LMD1:[0-9]+]]
18 // CHECK-LABEL: do.end:
19 // CHECK-NOT: llvm.loop
20 // CHECK: ![[LMD1]] = distinct !{![[LMD1]], [[LMD2:![0-9]+]], ![[LMD3:[0-9]+]]}
21 // CHECK: [[LMD2]] = !{!"llvm.loop.mustprogress"}
22 // CHECK: ![[LMD3]] = !{!"llvm.loop.unroll.count", i32 4}
23 
24 int test(int a[], int n) {
25   int i = 0;
26   int sum = 0;
27 
28 #pragma unroll 4
29   do
30   {
31     a[i] = a[i] + 1;
32     sum = sum + a[i];
33     i++;
34   } while (i < n);
35 
36   return sum;
37 }
38