test/CodeGen/PowerPC/livevars-crash1.mir

# RUN: llc -mtriple powerpc64le-unknown-linux-gnu %s -o - 2>&1 \
# RUN:   -run-pass=livevars,phi-node-elimination -verify-machineinstrs | \
# RUN:  FileCheck %s

--- |
  ; Function Attrs: noreturn nounwind
  define signext i32 @zext_free(ptr nocapture dereferenceable(8) %p) {
  entry:
    %.pre = load ptr, ptr %p, align 8
    br label %loop
  
  loop:                                             ; preds = %loop, %if.then3, %entry
    %0 = phi ptr [ %.pre, %entry ], [ %incdec.ptr4, %if.then3 ], [ %incdec.ptr, %loop ]
    %1 = load i8, ptr %0, align 1
    %tobool = icmp eq i8 %1, 0
    %incdec.ptr = getelementptr inbounds i8, ptr %0, i64 1
    store ptr %incdec.ptr, ptr %p, align 8
    %2 = load i8, ptr %incdec.ptr, align 1
    %tobool2 = icmp ne i8 %2, 0
    %or.cond = and i1 %tobool, %tobool2
    br i1 %or.cond, label %if.then3, label %loop
  
  if.then3:                                         ; preds = %loop
    %incdec.ptr4 = getelementptr inbounds i8, ptr %0, i64 2
    store ptr %incdec.ptr4, ptr %p, align 8
    br label %loop
  }
  

...
---
name:            zext_free
tracksRegLiveness: true
registers:
  - { id: 0, class: g8rc, preferred-register: '' }
  - { id: 1, class: g8rc_and_g8rc_nox0, preferred-register: '' }
  - { id: 2, class: g8rc, preferred-register: '' }
  - { id: 3, class: g8rc, preferred-register: '' }
  - { id: 4, class: g8rc_and_g8rc_nox0, preferred-register: '' }
  - { id: 5, class: gprc, preferred-register: '' }
  - { id: 6, class: crrc, preferred-register: '' }
  - { id: 7, class: crbitrc, preferred-register: '' }
  - { id: 8, class: gprc, preferred-register: '' }
  - { id: 9, class: crrc, preferred-register: '' }
  - { id: 10, class: crbitrc, preferred-register: '' }
  - { id: 11, class: crbitrc, preferred-register: '' }
liveins:
  - { reg: '$x3', virtual-reg: '%4' }
body:             |
  bb.0.entry:
    successors: %bb.1(0x80000000)
    liveins: $x3
  
    %4:g8rc_and_g8rc_nox0 = COPY killed $x3
    %0:g8rc = LD 0, %4 :: (dereferenceable load (s64) from %ir.p)
  
  bb.1.loop:
    successors: %bb.1(0x20000000), %bb.2(0x60000000)
  
    %1:g8rc_and_g8rc_nox0 = PHI %0, %bb.0, %2, %bb.1, %3, %bb.3, %2, %bb.2
    %5:gprc = LBZ 0, %1 :: (load (s8) from %ir.0)
    %6:crrc = CMPWI killed %5, 0
    %7:crbitrc = COPY killed %6.sub_eq
    %2:g8rc = nuw ADDI8 %1, 1
    STD %2, 0, %4 :: (store (s64) into %ir.p)
    %8:gprc = LBZ 1, %1 :: (load (s8) from %ir.incdec.ptr)
    BCn killed %7, %bb.1
    B %bb.2
  
  bb.2.loop:
    successors: %bb.3(0x55555555), %bb.1(0x2aaaaaab)
  
    %9:crrc = CMPWI killed %8, 0
    %10:crbitrc = COPY killed %9.sub_eq
    BC killed %10, %bb.1
    B %bb.3
  
  bb.3.if.then3:
    successors: %bb.1(0x80000000)
  
    %3:g8rc = nuw ADDI8 killed %1, 2
    STD %3, 0, %4 :: (store (s64) into %ir.p)
    B %bb.1

  ; CHECK-LABEL: name: zext_free
  ; CHECK: bb.0.entry:
  ; CHECK:   successors: %bb.1(0x80000000)
  ; CHECK:   liveins: $x3

  ; CHECK:   %4:g8rc_and_g8rc_nox0 = COPY killed $x3
  ; CHECK:   %0:g8rc = LD 0, %4 :: (dereferenceable load (s64) from %ir.p)
  ; CHECK:    %12:g8rc_and_g8rc_nox0 = COPY killed %0

  ; CHECK: bb.1.loop:
  ; CHECK:   successors: %bb.1(0x20000000), %bb.2(0x60000000)

  ; CHECK:   %1:g8rc_and_g8rc_nox0 = COPY killed %12
  ; CHECK:   %5:gprc = LBZ 0, %1 :: (load (s8) from %ir.0)
  ; CHECK:   %6:crrc = CMPWI killed %5, 0
  ; CHEXK:   %7:crbitrc = COPY killed %6.sub_eq
  ; CHECK:   %2:g8rc = nuw ADDI8 %1, 1
  ; CHECK:   STD %2, 0, %4 :: (store (s64) into %ir.p)
  ; CHECK:   %8:gprc = LBZ 1, %1 :: (load (s8) from %ir.incdec.ptr)
  ; CHECK:   %12:g8rc_and_g8rc_nox0 = COPY %2
  ; CHECK:   BCn killed %7, %bb.1
  ; CHECK:   B %bb.2

  ; CHECK: bb.2.loop:
  ; CHECK:   successors: %bb.3(0x55555555), %bb.1(0x2aaaaaab)

  ; CHECK:   %9:crrc = CMPWI killed %8, 0
  ; CHECK:   %10:crbitrc = COPY killed %9.sub_eq
  ; CHECK:   %12:g8rc_and_g8rc_nox0 = COPY killed %2
  ; CHECK:   BC killed %10, %bb.1
  ; CHECK:   B %bb.3

  ; CHECK: bb.3.if.then3:
  ; CHECK:   successors: %bb.1(0x80000000)

  ; CHECK:   %3:g8rc = nuw ADDI8 killed %1, 2
  ; CHECK:   STD %3, 0, %4 :: (store (s64) into %ir.p)
  ; CHECK:   %12:g8rc_and_g8rc_nox0 = COPY killed %3
  ; CHECK:   B %bb.1


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