llvm/test/CodeGen/X86/atomic-flags.ll

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-unknown-unknown -verify-machineinstrs | FileCheck %s --check-prefix=X64
; RUN: llc < %s -mtriple=i686-unknown-unknown -verify-machineinstrs | FileCheck %s --check-prefix=X86

; Make sure that flags are properly preserved despite atomic optimizations.

define i32 @atomic_and_flags_1(i8* %p, i32 %a, i32 %b) {
; X64-LABEL: atomic_and_flags_1:
; X64:       # %bb.0:
; X64-NEXT:    cmpl %edx, %esi
; X64-NEXT:    jne .LBB0_3
; X64-NEXT:  # %bb.1: # %L1
; X64-NEXT:    incb (%rdi)
; X64-NEXT:    cmpl %edx, %esi
; X64-NEXT:    jne .LBB0_2
; X64-NEXT:  # %bb.4: # %L3
; X64-NEXT:    movl $3, %eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB0_3: # %L2
; X64-NEXT:    movl $2, %eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB0_2: # %L4
; X64-NEXT:    movl $4, %eax
; X64-NEXT:    retq
;
; X86-LABEL: atomic_and_flags_1:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-NEXT:    cmpl %eax, %ecx
; X86-NEXT:    jne .LBB0_3
; X86-NEXT:  # %bb.1: # %L1
; X86-NEXT:    movl {{[0-9]+}}(%esp), %edx
; X86-NEXT:    incb (%edx)
; X86-NEXT:    cmpl %eax, %ecx
; X86-NEXT:    jne .LBB0_2
; X86-NEXT:  # %bb.4: # %L3
; X86-NEXT:    movl $3, %eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB0_3: # %L2
; X86-NEXT:    movl $2, %eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB0_2: # %L4
; X86-NEXT:    movl $4, %eax
; X86-NEXT:    retl
  ; Generate flags value, and use it.
  %cmp = icmp eq i32 %a, %b
  br i1 %cmp, label %L1, label %L2

L1:
  ; The following pattern will get folded.
  %1 = load atomic i8, i8* %p seq_cst, align 1
  %2 = add i8 %1, 1 ; This forces the INC instruction to be generated.
  store atomic i8 %2, i8* %p release, align 1

  ; Use the comparison result again. We need to rematerialize the comparison
  ; somehow. This test checks that cmpl gets emitted again, but any
  ; rematerialization would work (the optimizer used to clobber the flags with
  ; the add).
  br i1 %cmp, label %L3, label %L4

L2:
  ret i32 2

L3:
  ret i32 3

L4:
  ret i32 4
}

; Same as above, but using 2 as immediate to avoid the INC instruction.
define i32 @atomic_and_flags_2(i8* %p, i32 %a, i32 %b) {
; X64-LABEL: atomic_and_flags_2:
; X64:       # %bb.0:
; X64-NEXT:    cmpl %edx, %esi
; X64-NEXT:    jne .LBB1_3
; X64-NEXT:  # %bb.1: # %L1
; X64-NEXT:    addb $2, (%rdi)
; X64-NEXT:    cmpl %edx, %esi
; X64-NEXT:    jne .LBB1_2
; X64-NEXT:  # %bb.4: # %L3
; X64-NEXT:    movl $3, %eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB1_3: # %L2
; X64-NEXT:    movl $2, %eax
; X64-NEXT:    retq
; X64-NEXT:  .LBB1_2: # %L4
; X64-NEXT:    movl $4, %eax
; X64-NEXT:    retq
;
; X86-LABEL: atomic_and_flags_2:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
; X86-NEXT:    cmpl %eax, %ecx
; X86-NEXT:    jne .LBB1_3
; X86-NEXT:  # %bb.1: # %L1
; X86-NEXT:    movl {{[0-9]+}}(%esp), %edx
; X86-NEXT:    addb $2, (%edx)
; X86-NEXT:    cmpl %eax, %ecx
; X86-NEXT:    jne .LBB1_2
; X86-NEXT:  # %bb.4: # %L3
; X86-NEXT:    movl $3, %eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB1_3: # %L2
; X86-NEXT:    movl $2, %eax
; X86-NEXT:    retl
; X86-NEXT:  .LBB1_2: # %L4
; X86-NEXT:    movl $4, %eax
; X86-NEXT:    retl
  %cmp = icmp eq i32 %a, %b
  br i1 %cmp, label %L1, label %L2
L1:
  %1 = load atomic i8, i8* %p seq_cst, align 1
  %2 = add i8 %1, 2
  store atomic i8 %2, i8* %p release, align 1
  br i1 %cmp, label %L3, label %L4
L2:
  ret i32 2
L3:
  ret i32 3
L4:
  ret i32 4
}

; PR20841 - ensure we don't reuse the ZF flag from XADD for compares with zero,
; the flags are set for the result of the add result (the value stored to memory),
; not the value returned by the atomicrmw add.

define zeroext i1 @xadd_cmp0_i64(i64* %x) nounwind {
; X64-LABEL: xadd_cmp0_i64:
; X64:       # %bb.0:
; X64-NEXT:    movl $1, %eax
; X64-NEXT:    lock xaddq %rax, (%rdi)
; X64-NEXT:    testq %rax, %rax
; X64-NEXT:    sete %al
; X64-NEXT:    retq
;
; X86-LABEL: xadd_cmp0_i64:
; X86:       # %bb.0:
; X86-NEXT:    pushl %ebx
; X86-NEXT:    pushl %esi
; X86-NEXT:    movl {{[0-9]+}}(%esp), %esi
; X86-NEXT:    movl (%esi), %eax
; X86-NEXT:    movl 4(%esi), %edx
; X86-NEXT:    .p2align 4, 0x90
; X86-NEXT:  .LBB2_1: # %atomicrmw.start
; X86-NEXT:    # =>This Inner Loop Header: Depth=1
; X86-NEXT:    movl %eax, %ebx
; X86-NEXT:    addl $1, %ebx
; X86-NEXT:    movl %edx, %ecx
; X86-NEXT:    adcl $0, %ecx
; X86-NEXT:    lock cmpxchg8b (%esi)
; X86-NEXT:    jne .LBB2_1
; X86-NEXT:  # %bb.2: # %atomicrmw.end
; X86-NEXT:    orl %edx, %eax
; X86-NEXT:    sete %al
; X86-NEXT:    popl %esi
; X86-NEXT:    popl %ebx
; X86-NEXT:    retl
  %add = atomicrmw add i64* %x, i64 1 seq_cst
  %cmp = icmp eq i64 %add, 0
  ret i1 %cmp
}

define zeroext i1 @xadd_cmp0_i32(i32* %x) nounwind {
; X64-LABEL: xadd_cmp0_i32:
; X64:       # %bb.0:
; X64-NEXT:    movl $1, %eax
; X64-NEXT:    lock xaddl %eax, (%rdi)
; X64-NEXT:    testl %eax, %eax
; X64-NEXT:    setne %al
; X64-NEXT:    retq
;
; X86-LABEL: xadd_cmp0_i32:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    movl $1, %ecx
; X86-NEXT:    lock xaddl %ecx, (%eax)
; X86-NEXT:    testl %ecx, %ecx
; X86-NEXT:    setne %al
; X86-NEXT:    retl
  %add = atomicrmw add i32* %x, i32 1 seq_cst
  %cmp = icmp ne i32 %add, 0
  ret i1 %cmp
}

define zeroext i1 @xadd_cmp0_i16(i16* %x) nounwind {
; X64-LABEL: xadd_cmp0_i16:
; X64:       # %bb.0:
; X64-NEXT:    movw $1, %ax
; X64-NEXT:    lock xaddw %ax, (%rdi)
; X64-NEXT:    testw %ax, %ax
; X64-NEXT:    sete %al
; X64-NEXT:    retq
;
; X86-LABEL: xadd_cmp0_i16:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    movw $1, %cx
; X86-NEXT:    lock xaddw %cx, (%eax)
; X86-NEXT:    testw %cx, %cx
; X86-NEXT:    sete %al
; X86-NEXT:    retl
  %add = atomicrmw add i16* %x, i16 1 seq_cst
  %cmp = icmp eq i16 %add, 0
  ret i1 %cmp
}

define zeroext i1 @xadd_cmp0_i8(i8* %x) nounwind {
; X64-LABEL: xadd_cmp0_i8:
; X64:       # %bb.0:
; X64-NEXT:    movb $1, %al
; X64-NEXT:    lock xaddb %al, (%rdi)
; X64-NEXT:    testb %al, %al
; X64-NEXT:    setne %al
; X64-NEXT:    retq
;
; X86-LABEL: xadd_cmp0_i8:
; X86:       # %bb.0:
; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
; X86-NEXT:    movb $1, %cl
; X86-NEXT:    lock xaddb %cl, (%eax)
; X86-NEXT:    testb %cl, %cl
; X86-NEXT:    setne %al
; X86-NEXT:    retl
  %add = atomicrmw add i8* %x, i8 1 seq_cst
  %cmp = icmp ne i8 %add, 0
  ret i1 %cmp
}