| ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py |
| ; RUN: llc -o - %s -mtriple=x86_64-- | FileCheck %s |
| ; Example of a decref operation with "immortal" objects. |
| ; void decref(long* refcount) { |
| ; long count = *refcount; |
| ; if (count == 1) { free_object() } |
| ; else if (count > 1) { *refcount = count - 1; } |
| ; else { /* immortal */ } |
| ; } |
| ; Resulting assembly should share flags from single CMP instruction for both |
| ; conditions! |
| define void @decref(ptr %p) { |
| ; CHECK-LABEL: decref: |
| ; CHECK: # %bb.0: |
| ; CHECK-NEXT: pushq %rax |
| ; CHECK-NEXT: .cfi_def_cfa_offset 16 |
| ; CHECK-NEXT: movl (%rdi), %eax |
| ; CHECK-NEXT: cmpl $1, %eax |
| ; CHECK-NEXT: jne .LBB0_2 |
| ; CHECK-NEXT: # %bb.1: # %bb_free |
| ; CHECK-NEXT: callq free_object@PLT |
| ; CHECK-NEXT: .LBB0_4: # %end |
| ; CHECK-NEXT: popq %rax |
| ; CHECK-NEXT: .cfi_def_cfa_offset 8 |
| ; CHECK-NEXT: retq |
| ; CHECK-NEXT: .LBB0_2: # %bb2 |
| ; CHECK-NEXT: .cfi_def_cfa_offset 16 |
| ; CHECK-NEXT: jle .LBB0_4 |
| ; CHECK-NEXT: # %bb.3: # %bb_dec |
| ; CHECK-NEXT: decl %eax |
| ; CHECK-NEXT: movl %eax, (%rdi) |
| ; CHECK-NEXT: popq %rax |
| ; CHECK-NEXT: .cfi_def_cfa_offset 8 |
| ; CHECK-NEXT: retq |
| %count = load i32, ptr %p, align 4 |
| %cmp0 = icmp eq i32 %count, 1 |
| br i1 %cmp0, label %bb_free, label %bb2 |
| |
| bb2: |
| %cmp1 = icmp sgt i32 %count, 1 |
| br i1 %cmp1, label %bb_dec, label %end |
| |
| bb_dec: |
| %dec = add nsw i32 %count, -1 |
| store i32 %dec, ptr %p, align 4 |
| br label %end |
| |
| bb_free: |
| call void @free_object() |
| br label %end |
| |
| end: |
| ret void |
| } |
| |
| declare void @free_object() |