Compiler projects using llvm
# RUN: llc -mtriple=aarch64-unknown-unknown -run-pass=early-ifcvt -verify-machineinstrs %s -o - | FileCheck %s
--- |
  target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
  target triple = "arm64-apple-ios13.3.0"
  define hidden void @phi_operands_regclasses_different() #0 {
  entry:
    br i1 undef, label %if.then139.i, label %if.else142.i

  if.then139.i:                                     ; preds = %entry
    %0 = load double, double* undef, align 8
    br label %if.end161.i

  if.else142.i:                                     ; preds = %entry
    %tobool154.i = icmp eq i8 undef, 0
    br i1 %tobool154.i, label %if.then155.i, label %if.end161.i

  if.then155.i:                                     ; preds = %if.else142.i
    %add158.i = fadd double undef, 0.000000e+00
    br label %if.end161.i

  if.end161.i:                                      ; preds = %if.then155.i, %if.else142.i, %if.then139.i
    %y2.0.i = phi double [ %0, %if.then139.i ], [ 0.000000e+00, %if.else142.i ], [ 0.000000e+00, %if.then155.i ]
    %add169.i = fadd double 0.000000e+00, %y2.0.i
    %1 = fmul double undef, %add169.i
    %add174.i = fsub double undef, %1
    %2 = call double @llvm.fabs.f64(double %add174.i) #2
    %cmp.i516.i = fcmp olt double %2, 0x3BC79CA10C924223
    br i1 %cmp.i516.i, label %if.then.i.i, label %if.end9.i.i

  if.then.i.i:                                      ; preds = %if.end161.i
    %3 = call double @llvm.fabs.f64(double undef) #2
    unreachable

  if.end9.i.i:                                      ; preds = %if.end161.i
    ret void
  }
  declare double @llvm.fabs.f64(double) #1
  declare void @llvm.stackprotector(i8*, i8**) #2

  attributes #0 = { "target-cpu"="apple-a7" }
  attributes #1 = { nounwind readnone speculatable willreturn }
  attributes #2 = { nounwind }

  !llvm.ident = !{!0}

  !0 = !{!"clang"}

...
---
name:            phi_operands_regclasses_different
alignment:       4
exposesReturnsTwice: false
legalized:       true
regBankSelected: true
selected:        true
failedISel:      false
tracksRegLiveness: true
hasWinCFI:       false
registers:
  - { id: 0, class: gpr32, preferred-register: '' }
  - { id: 1, class: _, preferred-register: '' }
  - { id: 2, class: _, preferred-register: '' }
  - { id: 3, class: gpr, preferred-register: '' }
  - { id: 4, class: gpr64, preferred-register: '' }
  - { id: 5, class: fpr, preferred-register: '' }
  - { id: 6, class: _, preferred-register: '' }
  - { id: 7, class: gpr64, preferred-register: '' }
  - { id: 8, class: gpr64common, preferred-register: '' }
  - { id: 9, class: gpr64, preferred-register: '' }
  - { id: 10, class: fpr64, preferred-register: '' }
  - { id: 11, class: fpr64, preferred-register: '' }
  - { id: 12, class: fpr, preferred-register: '' }
  - { id: 13, class: fpr64, preferred-register: '' }
  - { id: 14, class: fpr, preferred-register: '' }
  - { id: 15, class: gpr32, preferred-register: '' }
  - { id: 16, class: _, preferred-register: '' }
  - { id: 17, class: gpr32, preferred-register: '' }
  - { id: 18, class: gpr32, preferred-register: '' }
  - { id: 19, class: gpr32, preferred-register: '' }
  - { id: 20, class: gpr, preferred-register: '' }
  - { id: 21, class: fpr64, preferred-register: '' }
  - { id: 22, class: fpr64, preferred-register: '' }
  - { id: 23, class: fpr64, preferred-register: '' }
  - { id: 24, class: fpr64, preferred-register: '' }
  - { id: 25, class: fpr64, preferred-register: '' }
  - { id: 26, class: fpr64, preferred-register: '' }
  - { id: 27, class: fpr64, preferred-register: '' }
  - { id: 28, class: gpr64, preferred-register: '' }
liveins:         []
frameInfo:
  isFrameAddressTaken: false
  isReturnAddressTaken: false
  hasStackMap:     false
  hasPatchPoint:   false
  stackSize:       0
  offsetAdjustment: 0
  maxAlignment:    1
  adjustsStack:    false
  hasCalls:        false
  stackProtector:  ''
  maxCallFrameSize: 0
  cvBytesOfCalleeSavedRegisters: 0
  hasOpaqueSPAdjustment: false
  hasVAStart:      false
  hasMustTailInVarArgFunc: false
  localFrameSize:  0
  savePoint:       ''
  restorePoint:    ''
fixedStack:      []
stack:           []
callSites:       []
constants:       []
machineFunctionInfo: {}
body:             |
  ; Here we check that we don't ifcvt to a CSEL that uses GPRs, because
  ; some operands to the PHI have the fpr64 regclass.
  ; CHECK-LABEL: name: phi_operands_regclasses_different
  ; CHECK-NOT: CSELXr
  bb.1.entry:
    successors: %bb.2(0x40000000), %bb.3(0x40000000)

    %0:gpr32 = IMPLICIT_DEF
    %4:gpr64 = IMPLICIT_DEF
    %8:gpr64common = IMPLICIT_DEF
    TBNZW %0, 0, %bb.2
    B %bb.3

  bb.2.if.then139.i:
    successors: %bb.5(0x80000000)

    %7:gpr64 = LDRXui %8, 0 :: (load (s64) from `double* undef`)
    B %bb.5

  bb.3.if.else142.i:
    successors: %bb.4(0x40000000), %bb.5(0x40000000)

    %26:fpr64 = FMOVD0
    %19:gpr32 = COPY $wzr
    CBNZW %19, %bb.5

  bb.4.if.then155.i:
    successors: %bb.5(0x80000000)

    %27:fpr64 = FMOVD0

  bb.5.if.end161.i:
    successors: %bb.6(0x40000000), %bb.7(0x40000000)

    %9:gpr64 = PHI %7, %bb.2, %26, %bb.3, %27, %bb.4
    %21:fpr64 = COPY %9
    %25:fpr64 = FMOVD0
    %10:fpr64 = FADDDrr %25, %21
    %22:fpr64 = COPY %4
    %11:fpr64 = FMULDrr %22, %10
    %23:fpr64 = COPY %4
    %13:fpr64 = FABD64 %23, %11
    %28:gpr64 = MOVi64imm 4307583784117748259
    %24:fpr64 = COPY %28
    FCMPDrr %13, %24, implicit-def $nzcv
    %17:gpr32 = CSINCWr $wzr, $wzr, 5, implicit $nzcv
    TBNZW %17, 0, %bb.6
    B %bb.7

  bb.6.if.then.i.i:
    successors:


  bb.7.if.end9.i.i:
    RET_ReallyLR

...