llvm/llvm/test/CodeGen/X86/block-placement.mir

# RUN: llc -mtriple=x86_64-apple-macosx10.12.0 -O3 -run-pass=block-placement -o - %s | FileCheck %s

--- |
  ; ModuleID = 'test.ll'
  source_filename = "test.ll"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  
  declare void @stub(ptr)
  
  define i32 @f(ptr %ptr, i1 %cond) {
  entry:
    br i1 %cond, label %left, label %right
  
  left:                                             ; preds = %entry
    %is_null = icmp eq ptr %ptr, null
    br i1 %is_null, label %null, label %not_null, !prof !0, !make.implicit !1
  
  not_null:                                         ; preds = %left
    %val = load i32, ptr %ptr
    ret i32 %val
  
  null:                                             ; preds = %left
    call void @stub(ptr %ptr)
    unreachable
  
  right:                                            ; preds = %entry
    call void @stub(ptr null)
    unreachable
  }
  
  ; Function Attrs: nounwind
  declare void @llvm.stackprotector(ptr, ptr) #0
  
  attributes #0 = { nounwind }
  
  !0 = !{!"branch_weights", i32 1048575, i32 1}
  !1 = !{}

...
---
# CHECK: name:            f
name:            f
alignment:       16
tracksRegLiveness: true
liveins:         
  - { reg: '$rdi' }
  - { reg: '$esi' }

# CHECK: $eax = FAULTING_OP 1, %bb.3, 1684, killed $rdi, 1, $noreg, 0, $noreg :: (load (s32) from %ir.ptr)
# CHECK-NEXT: JMP_1 %bb.2
# CHECK: bb.3.null:
# CHECK:  bb.4.right:
# CHECK:  bb.2.not_null:

body:             |
  bb.0.entry:
    successors: %bb.1(0x7ffff800), %bb.3(0x00000800)
    liveins: $esi, $rdi
  
    frame-setup PUSH64r undef $rax, implicit-def $rsp, implicit $rsp
    CFI_INSTRUCTION def_cfa_offset 16
    TEST8ri $sil, 1, implicit-def $eflags, implicit killed $esi
    JCC_1 %bb.3, 4, implicit killed $eflags
  
  bb.1.left:
    successors: %bb.2(0x7ffff800), %bb.4(0x00000800)
    liveins: $rdi
  
    $eax = FAULTING_OP 1, %bb.2, 1684, killed $rdi, 1, $noreg, 0, $noreg :: (load (s32) from %ir.ptr)
    JMP_1 %bb.4
  
  bb.4.not_null:
    liveins: $rdi, $eax
  
    $rcx = POP64r implicit-def $rsp, implicit $rsp
    RET64 $eax

  bb.2.null:
    liveins: $rdi
  
    CALL64pcrel32 @stub, csr_64, implicit $rsp, implicit $rdi, implicit-def $rsp
  
  bb.3.right:
    dead $edi = XOR32rr undef $edi, undef $edi, implicit-def dead $eflags, implicit-def $rdi
    CALL64pcrel32 @stub, csr_64, implicit $rsp, implicit $rdi, implicit-def $rsp
  
...