test/CodeGen/M68k/Control/cmp-cse.ll

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=m68k-linux -verify-machineinstrs | FileCheck %s

; The purpose of this test is to ensure that %cmp2 doesn't emit a redundant
; compare instruction; it should be eliminated by CSE.
define i1 @cse(ptr %y) nounwind {
; CHECK-LABEL: cse:
; CHECK:       ; %bb.0:
; CHECK-NEXT:    move.l (4,%sp), %a0
; CHECK-NEXT:    move.w (%a0), %d0
; CHECK-NEXT:    cmpi.w #0, %d0
; CHECK-NEXT:    bmi .LBB0_2
; CHECK-NEXT:  ; %bb.1: ; %cmp2
; CHECK-NEXT:    beq .LBB0_3
; CHECK-NEXT:  .LBB0_2: ; %yes
; CHECK-NEXT:    moveq #1, %d0
; CHECK-NEXT:    rts
; CHECK-NEXT:  .LBB0_3: ; %no
; CHECK-NEXT:    clr.b %d0
; CHECK-NEXT:    rts
  %1 = load i16, ptr %y
  %2 = icmp slt i16 %1, 0
  br i1 %2, label %yes, label %cmp2

cmp2:
  %.not = icmp eq i16 %1, 0
  br i1 %.not, label %no, label %yes

yes:
  ret i1 1

no:
  ret i1 0
}

; The compare condition is different and therefore not eliminated by CSE.
define i1 @no_cse(ptr %y) nounwind {
; CHECK-LABEL: no_cse:
; CHECK:       ; %bb.0:
; CHECK-NEXT:    move.l (4,%sp), %a0
; CHECK-NEXT:    move.w (%a0), %d0
; CHECK-NEXT:    cmpi.w #0, %d0
; CHECK-NEXT:    bmi .LBB1_2
; CHECK-NEXT:  ; %bb.1: ; %cmp2
; CHECK-NEXT:    cmpi.w #10, %d0
; CHECK-NEXT:    bne .LBB1_2
; CHECK-NEXT:  ; %bb.3: ; %no
; CHECK-NEXT:    clr.b %d0
; CHECK-NEXT:    rts
; CHECK-NEXT:  .LBB1_2: ; %yes
; CHECK-NEXT:    moveq #1, %d0
; CHECK-NEXT:    rts
  %1 = load i16, ptr %y
  %2 = icmp slt i16 %1, 0
  br i1 %2, label %yes, label %cmp2

cmp2:
  %.not = icmp eq i16 %1, 10
  br i1 %.not, label %no, label %yes

yes:
  ret i1 1

no:
  ret i1 0
}