| ; RUN: llc -verify-machineinstrs -o - %s | FileCheck %s |
| target triple = "arm64--" |
| |
| ; AArch64InstrInfo::optimizeCondBranch() optimizes the |
| ; "x = and y, 256; cmp x, 0; br" from an "and; cbnz" to a tbnz instruction. |
| ; It forgot to clear the a flag resulting in a MachineVerifier complaint. |
| ; |
| ; Writing a stable/simple test is tricky since most tbz instructions are already |
| ; formed in SelectionDAG, optimizeCondBranch() only triggers if the and |
| ; instruction is in a different block than the conditional jump. |
| ; |
| ; CHECK-LABEL: func |
| ; CHECK-NOT: and |
| ; CHECK: tbz |
| define void @func() { |
| %c0 = icmp sgt i64 0, 0 |
| br i1 %c0, label %b1, label %b6 |
| |
| b1: |
| br i1 undef, label %b3, label %b2 |
| |
| b2: |
| %v0 = tail call i32 @extfunc() |
| br label %b5 |
| |
| b3: |
| %v1 = load i32, i32* undef, align 4 |
| %v2 = and i32 %v1, 256 |
| br label %b5 |
| |
| b5: |
| %v3 = phi i32 [ %v2, %b3 ], [ %v0, %b2 ] |
| %c1 = icmp eq i32 %v3, 0 |
| br i1 %c1, label %b8, label %b7 |
| |
| b6: |
| tail call i32 @extfunc() |
| ret void |
| |
| b7: |
| tail call i32 @extfunc() |
| ret void |
| |
| b8: |
| ret void |
| } |
| |
| declare i32 @extfunc() |
