test/Verifier/test_phis_precede_nonphis.mir

# RUN: not llc -run-pass=machineverifier %s -o - 2>&1 | FileCheck %s
# REQUIRES: aarch64-registered-target

--- |
  target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
  target triple = "aarch64--"
  define void @valid(i8* %addr) {
  entry:
    br i1 0, label %if, label %else
  if:
    br label %exit
  else:
    br label %exit
  exit:
    ret void
  }

  define void @broken(i8* %addr) {
  entry:
    br i1 0, label %if, label %exit
  if:
    br label %exit
  exit:
    ret void
  }
...

---
name:            valid
tracksRegLiveness: true
body: |
  bb.0.entry:
    liveins: $w1
    successors: %bb.1(0x40000000), %bb.2(0x40000000); %bb.1(50.00%), %bb.2(50.00%)
    %1:_(s32) = COPY $w1
    %2:_(s32) = G_CONSTANT i32 1
    %3:_(s1) = G_ICMP intpred(ne), %1:_(s32), %2:_
    G_BRCOND %3:_(s1), %bb.1
    G_BR %bb.2.else
  bb.1.if:
    successors: %bb.3(0x80000000)
    %4:_(s32) = G_CONSTANT i32 1
    %5:_(s8) = G_TRUNC %4
    G_BR %bb.3.exit
  bb.2.else:
    successors: %bb.3(0x80000000)
    %6:_(s32) = G_CONSTANT i32 1
    %7:_(s8) = G_TRUNC %6
    G_BR %bb.3.exit
  bb.3.exit:
    %8:_(s8) = G_PHI %5:_(s8), %bb.1, %7:_(s8), %bb.2
    %9:_(s32) = G_ZEXT %8
    $w1 = COPY %9
...

---
name:            broken
tracksRegLiveness: true
body: |
  bb.0.entry:
    liveins: $w1
    successors: %bb.1(0x40000000), %bb.2(0x40000000); %bb.1(50.00%), %bb.2(50.00%)
    %1:_(s32) = COPY $w1
    %2:_(s32) = G_CONSTANT i32 1
    %3:_(s1) = G_ICMP intpred(ne), %1:_(s32), %2:_
    %4:_(s32) = G_CONSTANT i32 1
    %6:_(s8) = G_CONSTANT i8 2
    G_BRCOND %3:_(s1), %bb.1
    G_BR %bb.2.exit
  bb.1.if:
    successors: %bb.2(0x80000000)
    G_BR %bb.2.exit
  bb.2.exit:
    %5:_(s8) = G_TRUNC %4
    %8:_(s8) = G_PHI %5:_(s8), %bb.0, %6:_(s8), %bb.1
    %9:_(s32) = G_ZEXT %8
    $w1 = COPY %9
...
# CHECK-NOT: Bad machine code
# CHECK-LABEL: Bad machine code: Found PHI instruction after non-PHI
# CHECK-NEXT:  - function:    broken
# CHECK-NEXT:  - basic block: %bb.2 exit
# CHECK-NEXT:  - instruction: %6:_(s8) = G_PHI %5:_(s8), %bb.0, %4:_(s8), %bb.1
# CHECK-NOT: Bad machine code