| // This tests loop unrolling and loop deletion (enabled under -O1) |
| // RUN: %clang_cc1 -std=c11 -O1 -fno-unroll-loops -S -o - %s -emit-llvm | FileCheck %s |
| // RUN: %clang_cc1 -std=c99 -O1 -fno-unroll-loops -S -o - %s -emit-llvm | FileCheck %s --check-prefix C99 |
| |
| extern int a[16]; |
| int b = 0; |
| int foo(void) { |
| #pragma unroll |
| for (int i = 0; i < 16; ++i) |
| a[i] = b += 2; |
| return b; |
| } |
| // Check br i1 to make sure that the loop is fully unrolled |
| // CHECK-LABEL: foo |
| // CHECK-NOT: br i1 |
| |
| void Helper() { |
| const int *nodes[5]; |
| int num_active = 5; |
| |
| while (num_active) |
| #pragma clang loop unroll(full) |
| for (int i = 0; i < 5; ++i) |
| if (nodes[i]) |
| --num_active; |
| } |
| |
| // Check br i1 to make sure the loop is gone, there will still be a label branch for the infinite loop. |
| // In C99, there was no forward progress requirement, so we expect the infinite loop to still exist, |
| // but for C11 and onwards, the infinite loop can be deleted. |
| // CHECK-LABEL: Helper |
| // C99: br label |
| // C99-NOT: br i1 |
| // C99: br label |
| // CHECK: entry: |
| // CHECK-NOT: br i1 |
| // CHECK-NEXT: ret void |
