third_party/llvm-7.0/llvm/test/CodeGen/X86/update-terminator.mir

# RUN: llc -mtriple=x86_64-- -verify-machineinstrs -run-pass block-placement -o - %s | FileCheck %s
# Check the conditional jump in bb.1 is changed to unconditional after block placement swaps bb.2 and bb.3.

--- |
  @a = external global i16
  @b = external global i32

  declare void @dummy1()
  declare void @dummy2()
  declare void @dummy3()

  ; Function Attrs: nounwind
  define void @f2() {
    br i1 undef, label %bb1, label %bb3

  bb1:
    call void @dummy1()
    call void @dummy1()
    call void @dummy1()
    br i1 undef, label %bb2, label %bb2

  bb2:
    call void @dummy2()
    call void @dummy2()
    call void @dummy2()
    br label %bb4

  bb3:
    call void @dummy3()
    call void @dummy3()
    call void @dummy3()
    br label %bb2

  bb4:
    ret void
  }


...
---
# CHECK-LABEL: name: f2
# CHECK: bb.1:
# CHECK: JMP_1 %bb.2
# CHECK: bb.3:
# CHECK: bb.2:
name:            f2
body:             |
  bb.0 (%ir-block.0):
    successors: %bb.1(50), %bb.3(50)

    JNE_1 %bb.1, implicit $eflags
    JMP_1 %bb.3
  bb.1:
    successors: %bb.2(100)

    CALL64pcrel32 @dummy1, csr_64, implicit $rsp, implicit-def $rsp
    CALL64pcrel32 @dummy1, csr_64, implicit $rsp, implicit-def $rsp
    CALL64pcrel32 @dummy1, csr_64, implicit $rsp, implicit-def $rsp
    JNE_1 %bb.2, implicit $eflags

  bb.2:
    successors: %bb.4(100)

    CALL64pcrel32 @dummy2, csr_64, implicit $rsp, implicit-def $rsp
    CALL64pcrel32 @dummy2, csr_64, implicit $rsp, implicit-def $rsp
    CALL64pcrel32 @dummy2, csr_64, implicit $rsp, implicit-def $rsp
    JMP_1 %bb.4

  bb.3:
    successors: %bb.2(100)
    CALL64pcrel32 @dummy3, csr_64, implicit $rsp, implicit-def $rsp
    CALL64pcrel32 @dummy3, csr_64, implicit $rsp, implicit-def $rsp
    CALL64pcrel32 @dummy3, csr_64, implicit $rsp, implicit-def $rsp
    JMP_1 %bb.2

  bb.4:
    RETQ

...