test/CodeGen/Thumb/tbb-reuse.mir

# RUN: llc -run-pass arm-cp-islands %s -o - | FileCheck %s

--- |
  ; ModuleID = '<stdin>'
  source_filename = "<stdin>"
  target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
  target triple = "thumbv6m--none-eabi"
  
  declare void @exit0()
  
  declare void @exit1(i32)
  
  declare void @exit2()
  
  declare void @exit3()
  
  declare void @exit4()
  
  define void @jump_table(i32 %val, i32 %arg2, i32 %arg3, i32 %arg4) {
  entry:
    switch i32 %val, label %default [
      i32 1, label %lab1
      i32 2, label %lab2
      i32 3, label %lab3
      i32 4, label %lab4
    ]
  
  default:                                          ; preds = %entry
    tail call void @exit0()
    ret void
  
  lab1:                                             ; preds = %entry
    %b = sub i32 %val, 1
    %a = shl i32 %b, 2
    tail call void @exit1(i32 %a)
    ret void
  
  lab2:                                             ; preds = %entry
    tail call void @exit2()
    ret void
  
  lab3:                                             ; preds = %entry
    tail call void @exit3()
    ret void
  
  lab4:                                             ; preds = %entry
    tail call void @exit4()
    ret void
  }
  
  ; Function Attrs: nounwind
  declare void @llvm.stackprotector(i8*, i8**) #0
  
  attributes #0 = { nounwind }

...
---
name:            jump_table
alignment:       1
exposesReturnsTwice: false
legalized:       false
regBankSelected: false
selected:        false
tracksRegLiveness: true
liveins:         
  - { reg: '%r0' }
calleeSavedRegisters: [ '%lr', '%d8', '%d9', '%d10', '%d11', '%d12', '%d13', 
                        '%d14', '%d15', '%q4', '%q5', '%q6', '%q7', '%r4', 
                        '%r5', '%r6', '%r7', '%r8', '%r9', '%r10', '%r11', 
                        '%s16', '%s17', '%s18', '%s19', '%s20', '%s21', 
                        '%s22', '%s23', '%s24', '%s25', '%s26', '%s27', 
                        '%s28', '%s29', '%s30', '%s31', '%d8_d10', '%d9_d11', 
                        '%d10_d12', '%d11_d13', '%d12_d14', '%d13_d15', 
                        '%q4_q5', '%q5_q6', '%q6_q7', '%q4_q5_q6_q7', '%r4_r5', 
                        '%r6_r7', '%r8_r9', '%r10_r11', '%d8_d9_d10', '%d9_d10_d11', 
                        '%d10_d11_d12', '%d11_d12_d13', '%d12_d13_d14', 
                        '%d13_d14_d15', '%d8_d10_d12', '%d9_d11_d13', '%d10_d12_d14', 
                        '%d11_d13_d15', '%d8_d10_d12_d14', '%d9_d11_d13_d15', 
                        '%d9_d10', '%d11_d12', '%d13_d14', '%d9_d10_d11_d12', 
                        '%d11_d12_d13_d14' ]
frameInfo:       
  isFrameAddressTaken: false
  isReturnAddressTaken: false
  hasStackMap:     false
  hasPatchPoint:   false
  stackSize:       8
  offsetAdjustment: 0
  maxAlignment:    4
  adjustsStack:    true
  hasCalls:        true
  maxCallFrameSize: 0
  hasOpaqueSPAdjustment: false
  hasVAStart:      false
  hasMustTailInVarArgFunc: false
stack:           
  - { id: 0, type: spill-slot, offset: -4, size: 4, alignment: 4, callee-saved-register: '%lr', callee-saved-restored: false }
  - { id: 1, type: spill-slot, offset: -8, size: 4, alignment: 4, callee-saved-register: '%r7' }
jumpTable:       
  kind:            inline
  entries:         
    - id:              0
      blocks:          [ '%bb.3.lab1', '%bb.4.lab2', '%bb.5.lab3', '%bb.6.lab4' ]
# r1 is redefined in the middle of the recognizable jump sequence - it shouldn't be clobbered!
# CHECK-NOT: tTBB_JT 

body:             |
  bb.0.entry:
    successors: %bb.2.default(0x19999998), %bb.1.entry(0x66666668)
    liveins: %r0, %r7, %lr
  
    frame-setup tPUSH 14, _, killed %r7, killed %lr, implicit-def %sp, implicit %sp
    frame-setup CFI_INSTRUCTION def_cfa_offset 8
    frame-setup CFI_INSTRUCTION offset %lr, -4
    frame-setup CFI_INSTRUCTION offset %r7, -8
    %r1, dead %cpsr = tSUBi3 %r0, 1, 14, _
    tCMPi8 %r1, 3, 14, _, implicit-def %cpsr
    tBcc %bb.2.default, 8, killed %cpsr
  
  bb.1.entry:
    successors: %bb.3.lab1(0x20000000), %bb.4.lab2(0x20000000), %bb.5.lab3(0x20000000), %bb.6.lab4(0x20000000)
    liveins: %r0, %r1
  
    %r1, dead %cpsr = tLSLri killed %r1, 2, 14, _
    %r2 = tLEApcrelJT %jump-table.0, 14, _
    %r2 = tLDRr killed %r1, killed %r2, 14, _ :: (load 4 from jump-table)
    %r1, dead %cpsr = tLSLri %r2, 2, 14, _
    tBR_JTr killed %r2, %jump-table.0
  
  bb.2.default:
    tBL 14, _, @exit0, csr_aapcs, implicit-def dead %lr, implicit %sp, implicit-def %sp
    tPOP_RET 14, _, def %r7, def %pc, implicit-def %sp, implicit %sp
  
  bb.3.lab1:
    liveins: %r0,%r1
  
    tBL 14, _, @exit1, csr_aapcs, implicit-def dead %lr, implicit %sp, implicit %r0, implicit-def %sp
    tPOP_RET 14, _, def %r7, def %pc, implicit-def %sp, implicit %sp
  
  bb.4.lab2:
    tBL 14, _, @exit2, csr_aapcs, implicit-def dead %lr, implicit %sp, implicit-def %sp
    tPOP_RET 14, _, def %r7, def %pc, implicit-def %sp, implicit %sp
  
  bb.5.lab3:
    tBL 14, _, @exit3, csr_aapcs, implicit-def dead %lr, implicit %sp, implicit-def %sp
    tPOP_RET 14, _, def %r7, def %pc, implicit-def %sp, implicit %sp
  
  bb.6.lab4:
    tBL 14, _, @exit4, csr_aapcs, implicit-def dead %lr, implicit %sp, implicit-def %sp
    tPOP_RET 14, _, def %r7, def %pc, implicit-def %sp, implicit %sp

...