| Matthias Braun | e25bbd0 | 2016-05-03 04:54:16 +0000 | [diff] [blame^] | 1 | ; RUN: llc -verify-machineinstrs -o - %s | FileCHeck %s |
| 2 | target triple = "arm64--" |
| 3 | |
| 4 | ; AArch64InstrInfo::optimizeCondBranch() optimizes the |
| 5 | ; "x = and y, 256; cmp x, 0; br" from an "and; cbnz" to a tbnz instruction. |
| 6 | ; It forgot to clear the a flag resulting in a MachineVerifier complaint. |
| 7 | ; |
| 8 | ; Writing a stable/simple test is tricky since most tbz instructions are already |
| 9 | ; formed in SelectionDAG, optimizeCondBranch() only triggers if the and |
| 10 | ; instruction is in a different block than the conditional jump. |
| 11 | ; |
| 12 | ; CHECK-LABEL: func |
| 13 | ; CHECK-NOT: and |
| 14 | ; CHECK: tbnz |
| 15 | define void @func() { |
| 16 | %c0 = icmp sgt i64 0, 0 |
| 17 | br i1 %c0, label %b1, label %b6 |
| 18 | |
| 19 | b1: |
| 20 | br i1 undef, label %b3, label %b2 |
| 21 | |
| 22 | b2: |
| 23 | %v0 = tail call i32 @extfunc() |
| 24 | br label %b5 |
| 25 | |
| 26 | b3: |
| 27 | %v1 = load i32, i32* undef, align 4 |
| 28 | %v2 = and i32 %v1, 256 |
| 29 | br label %b5 |
| 30 | |
| 31 | b5: |
| 32 | %v3 = phi i32 [ %v2, %b3 ], [ %v0, %b2 ] |
| 33 | %c1 = icmp eq i32 %v3, 0 |
| 34 | br i1 %c1, label %b8, label %b7 |
| 35 | |
| 36 | b6: |
| 37 | tail call i32 @extfunc() |
| 38 | ret void |
| 39 | |
| 40 | b7: |
| 41 | tail call i32 @extfunc() |
| 42 | ret void |
| 43 | |
| 44 | b8: |
| 45 | ret void |
| 46 | } |
| 47 | |
| 48 | declare i32 @extfunc() |