; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=i386-unknown-linux-gnu -opaque-pointers | FileCheck %s --check-prefix=I386
;
; Make sure we don't zero out %eax when both %ah and %al are used.
;
; PR1766: https://github.com/ClangBuiltLinux/linux/issues/1766

%struct.maple_subtree_state = type { ptr }

@mas_data_end_type = dso_local local_unnamed_addr global i32 0, align 4
@ma_meta_end_mn_0_0_0_0_0_0 = dso_local local_unnamed_addr global i8 0, align 1
@mt_pivots_0 = dso_local local_unnamed_addr global i8 0, align 1
@mas_data_end___trans_tmp_2 = dso_local local_unnamed_addr global ptr null, align 4
@mt_slots_0 = dso_local local_unnamed_addr global i8 0, align 1

define dso_local zeroext i1 @test1(ptr nocapture noundef readonly %0) local_unnamed_addr "zero-call-used-regs"="used-gpr" nounwind {
; I386-LABEL: test1:
; I386:       # %bb.0:
; I386-NEXT:    pushl %ebx
; I386-NEXT:    subl $24, %esp
; I386-NEXT:    movl {{[0-9]+}}(%esp), %eax
; I386-NEXT:    movl (%eax), %eax
; I386-NEXT:    movzbl (%eax), %ebx
; I386-NEXT:    calll bar
; I386-NEXT:    testb %al, %al
; I386-NEXT:    # implicit-def: $al
; I386-NEXT:    # kill: killed $al
; I386-NEXT:    je .LBB0_6
; I386-NEXT:  # %bb.1:
; I386-NEXT:    cmpl $0, mas_data_end_type
; I386-NEXT:    je .LBB0_3
; I386-NEXT:  # %bb.2:
; I386-NEXT:    movzbl ma_meta_end_mn_0_0_0_0_0_0, %eax
; I386-NEXT:    movb %al, {{[-0-9]+}}(%e{{[sb]}}p) # 1-byte Spill
; I386-NEXT:    jmp .LBB0_6
; I386-NEXT:  .LBB0_3:
; I386-NEXT:    movb mt_pivots_0, %ah
; I386-NEXT:    movb %ah, %al
; I386-NEXT:    decb %al
; I386-NEXT:    movl mas_data_end___trans_tmp_2, %ecx
; I386-NEXT:    movsbl %al, %edx
; I386-NEXT:    cmpl $0, (%ecx,%edx,4)
; I386-NEXT:    je .LBB0_5
; I386-NEXT:  # %bb.4:
; I386-NEXT:    movb %al, %ah
; I386-NEXT:  .LBB0_5:
; I386-NEXT:    movb %ah, {{[-0-9]+}}(%e{{[sb]}}p) # 1-byte Spill
; I386-NEXT:  .LBB0_6:
; I386-NEXT:    movb mt_slots_0, %bh
; I386-NEXT:    leal {{[0-9]+}}(%esp), %eax
; I386-NEXT:    movl %eax, (%esp)
; I386-NEXT:    calll baz
; I386-NEXT:    subl $4, %esp
; I386-NEXT:    cmpb %bh, %bl
; I386-NEXT:    jae .LBB0_8
; I386-NEXT:  # %bb.7:
; I386-NEXT:    movsbl {{[-0-9]+}}(%e{{[sb]}}p), %eax # 1-byte Folded Reload
; I386-NEXT:    movl %eax, (%esp)
; I386-NEXT:    calll gaz
; I386-NEXT:  .LBB0_8:
; I386-NEXT:    movb $1, %al
; I386-NEXT:    addl $24, %esp
; I386-NEXT:    popl %ebx
; I386-NEXT:    xorl %ecx, %ecx
; I386-NEXT:    xorl %edx, %edx
; I386-NEXT:    retl
  %2 = alloca %struct.maple_subtree_state, align 4
  %3 = load ptr, ptr %0, align 4
  %4 = load i8, ptr %3, align 1
  %5 = tail call zeroext i1 @bar()
  br i1 %5, label %6, label %20

6:                                                ; preds = %1
  %7 = load i32, ptr @mas_data_end_type, align 4
  %8 = icmp eq i32 %7, 0
  br i1 %8, label %11, label %9

9:                                                ; preds = %6
  %10 = load i8, ptr @ma_meta_end_mn_0_0_0_0_0_0, align 1
  br label %20

11:                                               ; preds = %6
  %12 = load i8, ptr @mt_pivots_0, align 1
  %13 = add i8 %12, -1
  %14 = load ptr, ptr @mas_data_end___trans_tmp_2, align 4
  %15 = sext i8 %13 to i32
  %16 = getelementptr inbounds [1 x i32], ptr %14, i32 0, i32 %15
  %17 = load i32, ptr %16, align 4
  %18 = icmp eq i32 %17, 0
  %19 = select i1 %18, i8 %12, i8 %13
  br label %20

20:                                               ; preds = %11, %9, %1
  %21 = phi i8 [ undef, %1 ], [ %10, %9 ], [ %19, %11 ]
  %22 = load i8, ptr @mt_slots_0, align 1
  call void @baz(ptr nonnull sret(%struct.maple_subtree_state) align 4 %2)
  %23 = icmp ult i8 %4, %22
  br i1 %23, label %24, label %25

24:                                               ; preds = %20
  call void @gaz(i8 noundef signext %21)
  br label %25

25:                                               ; preds = %20, %24
  ret i1 true
}

declare dso_local zeroext i1 @bar(...) local_unnamed_addr

declare dso_local void @baz(ptr sret(%struct.maple_subtree_state) align 4, ...) local_unnamed_addr

declare dso_local void @gaz(i8 noundef signext) local_unnamed_addr