max-of-nots.ll 12.8 KB
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -instcombine < %s | FileCheck %s

define <2 x i32> @umin_of_nots(<2 x i32> %x, <2 x i32> %y) {
; CHECK-LABEL: @umin_of_nots(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult <2 x i32> [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT:    [[TMP2:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[X]], <2 x i32> [[Y]]
; CHECK-NEXT:    [[MIN:%.*]] = xor <2 x i32> [[TMP2]], <i32 -1, i32 -1>
; CHECK-NEXT:    ret <2 x i32> [[MIN]]
;
  %notx = xor <2 x i32> %x, <i32 -1, i32 -1>
  %noty = xor <2 x i32> %y, <i32 -1, i32 -1>
  %cmp = icmp ult <2 x i32> %notx, %noty
  %min = select <2 x i1> %cmp, <2 x i32> %notx, <2 x i32> %noty
  ret <2 x i32> %min
}

define <2 x i32> @smin_of_nots(<2 x i32> %x, <2 x i32> %y) {
; CHECK-LABEL: @smin_of_nots(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp slt <2 x i32> [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT:    [[TMP2:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[X]], <2 x i32> [[Y]]
; CHECK-NEXT:    [[MIN:%.*]] = xor <2 x i32> [[TMP2]], <i32 -1, i32 -1>
; CHECK-NEXT:    ret <2 x i32> [[MIN]]
;
  %notx = xor <2 x i32> %x, <i32 -1, i32 -1>
  %noty = xor <2 x i32> %y, <i32 -1, i32 -1>
  %cmp = icmp sle <2 x i32> %notx, %noty
  %min = select <2 x i1> %cmp, <2 x i32> %notx, <2 x i32> %noty
  ret <2 x i32> %min
}

define i32 @compute_min_2(i32 %x, i32 %y) {
; CHECK-LABEL: @compute_min_2(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i32 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP1]], i32 [[X]], i32 [[Y]]
; CHECK-NEXT:    ret i32 [[TMP2]]
;
  %not_x = sub i32 -1, %x
  %not_y = sub i32 -1, %y
  %cmp = icmp sgt i32 %not_x, %not_y
  %not_min = select i1 %cmp, i32 %not_x, i32 %not_y
  %min = sub i32 -1, %not_min
  ret i32 %min
}

declare void @extra_use(i8)
define i8 @umin_not_1_extra_use(i8 %x, i8 %y) {
; CHECK-LABEL: @umin_not_1_extra_use(
; CHECK-NEXT:    [[NX:%.*]] = xor i8 [[X:%.*]], -1
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i8 [[X]], [[Y:%.*]]
; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP1]], i8 [[Y]], i8 [[X]]
; CHECK-NEXT:    [[MINXY:%.*]] = xor i8 [[TMP2]], -1
; CHECK-NEXT:    call void @extra_use(i8 [[NX]])
; CHECK-NEXT:    ret i8 [[MINXY]]
;
  %nx = xor i8 %x, -1
  %ny = xor i8 %y, -1
  %cmpxy = icmp ult i8 %nx, %ny
  %minxy = select i1 %cmpxy, i8 %nx, i8 %ny
  call void @extra_use(i8 %nx)
  ret i8 %minxy
}

define i8 @umin_not_2_extra_use(i8 %x, i8 %y) {
; CHECK-LABEL: @umin_not_2_extra_use(
; CHECK-NEXT:    [[NX:%.*]] = xor i8 [[X:%.*]], -1
; CHECK-NEXT:    [[NY:%.*]] = xor i8 [[Y:%.*]], -1
; CHECK-NEXT:    [[CMPXY:%.*]] = icmp ult i8 [[NX]], [[NY]]
; CHECK-NEXT:    [[MINXY:%.*]] = select i1 [[CMPXY]], i8 [[NX]], i8 [[NY]]
; CHECK-NEXT:    call void @extra_use(i8 [[NX]])
; CHECK-NEXT:    call void @extra_use(i8 [[NY]])
; CHECK-NEXT:    ret i8 [[MINXY]]
;
  %nx = xor i8 %x, -1
  %ny = xor i8 %y, -1
  %cmpxy = icmp ult i8 %nx, %ny
  %minxy = select i1 %cmpxy, i8 %nx, i8 %ny
  call void @extra_use(i8 %nx)
  call void @extra_use(i8 %ny)
  ret i8 %minxy
}

; PR35834 - https://bugs.llvm.org/show_bug.cgi?id=35834

define i8 @umin3_not(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @umin3_not(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i8 [[Z:%.*]], [[X:%.*]]
; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP1]], i8 [[X]], i8 [[Z]]
; CHECK-NEXT:    [[TMP3:%.*]] = icmp ugt i8 [[TMP2]], [[Y:%.*]]
; CHECK-NEXT:    [[R_V:%.*]] = select i1 [[TMP3]], i8 [[TMP2]], i8 [[Y]]
; CHECK-NEXT:    [[R:%.*]] = xor i8 [[R_V]], -1
; CHECK-NEXT:    ret i8 [[R]]
;
  %nx = xor i8 %x, -1
  %ny = xor i8 %y, -1
  %nz = xor i8 %z, -1
  %cmpyx = icmp ult i8 %y, %x
  %cmpxz = icmp ult i8 %nx, %nz
  %minxz = select i1 %cmpxz, i8 %nx, i8 %nz
  %cmpyz = icmp ult i8 %ny, %nz
  %minyz = select i1 %cmpyz, i8 %ny, i8 %nz
  %r = select i1 %cmpyx, i8 %minxz, i8 %minyz
  ret i8 %r
}

; PR35875 - https://bugs.llvm.org/show_bug.cgi?id=35875

define i8 @umin3_not_more_uses(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @umin3_not_more_uses(
; CHECK-NEXT:    [[NX:%.*]] = xor i8 [[X:%.*]], -1
; CHECK-NEXT:    [[NY:%.*]] = xor i8 [[Y:%.*]], -1
; CHECK-NEXT:    [[TMP1:%.*]] = icmp ult i8 [[X]], [[Z:%.*]]
; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP1]], i8 [[Z]], i8 [[X]]
; CHECK-NEXT:    [[TMP3:%.*]] = icmp ugt i8 [[TMP2]], [[Y]]
; CHECK-NEXT:    [[TMP4:%.*]] = select i1 [[TMP3]], i8 [[TMP2]], i8 [[Y]]
; CHECK-NEXT:    [[R:%.*]] = xor i8 [[TMP4]], -1
; CHECK-NEXT:    call void @extra_use(i8 [[NX]])
; CHECK-NEXT:    call void @extra_use(i8 [[NY]])
; CHECK-NEXT:    ret i8 [[R]]
;
  %nx = xor i8 %x, -1
  %ny = xor i8 %y, -1
  %nz = xor i8 %z, -1
  %cmpxz = icmp ult i8 %nx, %nz
  %minxz = select i1 %cmpxz, i8 %nx, i8 %nz
  %cmpyz = icmp ult i8 %ny, %nz
  %minyz = select i1 %cmpyz, i8 %ny, i8 %nz
  %cmpyx = icmp ult i8 %y, %x
  %r = select i1 %cmpyx, i8 %minxz, i8 %minyz
  call void @extra_use(i8 %nx)
  call void @extra_use(i8 %ny)
  ret i8 %r
}

declare void @use8(i8)

define i8 @umin3_not_all_ops_extra_uses(i8 %x, i8 %y, i8 %z) {
; CHECK-LABEL: @umin3_not_all_ops_extra_uses(
; CHECK-NEXT:    [[XN:%.*]] = xor i8 [[X:%.*]], -1
; CHECK-NEXT:    [[YN:%.*]] = xor i8 [[Y:%.*]], -1
; CHECK-NEXT:    [[ZN:%.*]] = xor i8 [[Z:%.*]], -1
; CHECK-NEXT:    [[CMPXZ:%.*]] = icmp ult i8 [[XN]], [[ZN]]
; CHECK-NEXT:    [[MINXZ:%.*]] = select i1 [[CMPXZ]], i8 [[XN]], i8 [[ZN]]
; CHECK-NEXT:    [[CMPXYZ:%.*]] = icmp ult i8 [[MINXZ]], [[YN]]
; CHECK-NEXT:    [[MINXYZ:%.*]] = select i1 [[CMPXYZ]], i8 [[MINXZ]], i8 [[YN]]
; CHECK-NEXT:    call void @use8(i8 [[XN]])
; CHECK-NEXT:    call void @use8(i8 [[YN]])
; CHECK-NEXT:    call void @use8(i8 [[ZN]])
; CHECK-NEXT:    ret i8 [[MINXYZ]]
;
  %xn = xor i8 %x, -1
  %yn = xor i8 %y, -1
  %zn = xor i8 %z, -1
  %cmpxz = icmp ult i8 %xn, %zn
  %minxz = select i1 %cmpxz, i8 %xn, i8 %zn
  %cmpxyz = icmp ult i8 %minxz, %yn
  %minxyz = select i1 %cmpxyz, i8 %minxz, i8 %yn
  call void @use8(i8 %xn)
  call void @use8(i8 %yn)
  call void @use8(i8 %zn)
  ret i8 %minxyz
}

define i32 @compute_min_3(i32 %x, i32 %y, i32 %z) {
; CHECK-LABEL: @compute_min_3(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i32 [[Y:%.*]], [[X:%.*]]
; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP1]], i32 [[X]], i32 [[Y]]
; CHECK-NEXT:    [[TMP3:%.*]] = icmp slt i32 [[TMP2]], [[Z:%.*]]
; CHECK-NEXT:    [[TMP4:%.*]] = select i1 [[TMP3]], i32 [[TMP2]], i32 [[Z]]
; CHECK-NEXT:    ret i32 [[TMP4]]
;
  %not_x = sub i32 -1, %x
  %not_y = sub i32 -1, %y
  %not_z = sub i32 -1, %z
  %cmp_1 = icmp sgt i32 %not_x, %not_y
  %not_min_1 = select i1 %cmp_1, i32 %not_x, i32 %not_y
  %cmp_2 = icmp sgt i32 %not_min_1, %not_z
  %not_min_2 = select i1 %cmp_2, i32 %not_min_1, i32 %not_z
  %min = sub i32 -1, %not_min_2
  ret i32 %min
}

; Don't increase the critical path by moving the 'not' op after the 'select'.

define i32 @compute_min_arithmetic(i32 %x, i32 %y) {
; CHECK-LABEL: @compute_min_arithmetic(
; CHECK-NEXT:    [[NOT_VALUE:%.*]] = sub i32 3, [[X:%.*]]
; CHECK-NEXT:    [[NOT_Y:%.*]] = xor i32 [[Y:%.*]], -1
; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[NOT_VALUE]], [[NOT_Y]]
; CHECK-NEXT:    [[NOT_MIN:%.*]] = select i1 [[CMP]], i32 [[NOT_VALUE]], i32 [[NOT_Y]]
; CHECK-NEXT:    ret i32 [[NOT_MIN]]
;
  %not_value = sub i32 3, %x
  %not_y = sub i32 -1, %y
  %cmp = icmp sgt i32 %not_value, %not_y
  %not_min = select i1 %cmp, i32 %not_value, i32 %not_y
  ret i32 %not_min
}

declare void @fake_use(i32)

define i32 @compute_min_pessimization(i32 %x, i32 %y) {
; CHECK-LABEL: @compute_min_pessimization(
; CHECK-NEXT:    [[NOT_VALUE:%.*]] = sub i32 3, [[X:%.*]]
; CHECK-NEXT:    call void @fake_use(i32 [[NOT_VALUE]])
; CHECK-NEXT:    [[TMP1:%.*]] = add i32 [[X]], -4
; CHECK-NEXT:    [[TMP2:%.*]] = icmp slt i32 [[TMP1]], [[Y:%.*]]
; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[TMP2]], i32 [[TMP1]], i32 [[Y]]
; CHECK-NEXT:    ret i32 [[MIN]]
;
  %not_value = sub i32 3, %x
  call void @fake_use(i32 %not_value)
  %not_y = sub i32 -1, %y
  %cmp = icmp sgt i32 %not_value, %not_y
  %not_min = select i1 %cmp, i32 %not_value, i32 %not_y
  %min = sub i32 -1, %not_min
  ret i32 %min
}

define i32 @max_of_nots(i32 %x, i32 %y) {
; CHECK-LABEL: @max_of_nots(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt i32 [[Y:%.*]], 0
; CHECK-NEXT:    [[TMP2:%.*]] = select i1 [[TMP1]], i32 [[Y]], i32 0
; CHECK-NEXT:    [[TMP3:%.*]] = icmp slt i32 [[TMP2]], [[X:%.*]]
; CHECK-NEXT:    [[TMP4:%.*]] = select i1 [[TMP3]], i32 [[TMP2]], i32 [[X]]
; CHECK-NEXT:    [[TMP5:%.*]] = xor i32 [[TMP4]], -1
; CHECK-NEXT:    ret i32 [[TMP5]]
;
  %c0 = icmp sgt i32 %y, 0
  %xor_y = xor i32 %y, -1
  %s0 = select i1 %c0, i32 %xor_y, i32 -1
  %xor_x = xor i32 %x, -1
  %c1 = icmp slt i32 %s0, %xor_x
  %smax96 = select i1 %c1, i32 %xor_x, i32 %s0
  ret i32 %smax96
}

 ; negative test case (i.e. can not simplify) : ABS(MIN(NOT x,y))
define i32 @abs_of_min_of_not(i32 %x, i32 %y) {
; CHECK-LABEL: @abs_of_min_of_not(
; CHECK-NEXT:    [[XORD:%.*]] = xor i32 [[X:%.*]], -1
; CHECK-NEXT:    [[YADD:%.*]] = add i32 [[Y:%.*]], 2
; CHECK-NEXT:    [[COND_I:%.*]] = icmp slt i32 [[YADD]], [[XORD]]
; CHECK-NEXT:    [[MIN:%.*]] = select i1 [[COND_I]], i32 [[YADD]], i32 [[XORD]]
; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 [[MIN]], 0
; CHECK-NEXT:    [[SUB:%.*]] = sub i32 0, [[MIN]]
; CHECK-NEXT:    [[ABS:%.*]] = select i1 [[CMP2]], i32 [[SUB]], i32 [[MIN]]
; CHECK-NEXT:    ret i32 [[ABS]]
;

  %xord = xor i32 %x, -1
  %yadd = add i32 %y, 2
  %cond.i = icmp sge i32 %yadd, %xord
  %min = select i1 %cond.i, i32 %xord, i32 %yadd
  %cmp2 = icmp sgt i32 %min, -1
  %sub = sub i32 0, %min
  %abs = select i1 %cmp2, i32 %min, i32 %sub
  ret i32  %abs
}

define <2 x i32> @max_of_nots_vec(<2 x i32> %x, <2 x i32> %y) {
; CHECK-LABEL: @max_of_nots_vec(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <2 x i32> [[Y:%.*]], zeroinitializer
; CHECK-NEXT:    [[TMP2:%.*]] = select <2 x i1> [[TMP1]], <2 x i32> [[Y]], <2 x i32> zeroinitializer
; CHECK-NEXT:    [[TMP3:%.*]] = icmp slt <2 x i32> [[TMP2]], [[X:%.*]]
; CHECK-NEXT:    [[TMP4:%.*]] = select <2 x i1> [[TMP3]], <2 x i32> [[TMP2]], <2 x i32> [[X]]
; CHECK-NEXT:    [[TMP5:%.*]] = xor <2 x i32> [[TMP4]], <i32 -1, i32 -1>
; CHECK-NEXT:    ret <2 x i32> [[TMP5]]
;
  %c0 = icmp sgt <2 x i32> %y, zeroinitializer
  %xor_y = xor <2 x i32> %y, <i32 -1, i32 -1>
  %s0 = select <2 x i1> %c0, <2 x i32> %xor_y, <2 x i32> <i32 -1, i32 -1>
  %xor_x = xor <2 x i32> %x, <i32 -1, i32 -1>
  %c1 = icmp slt <2 x i32> %s0, %xor_x
  %smax96 = select <2 x i1> %c1, <2 x i32> %xor_x, <2 x i32> %s0
  ret <2 x i32> %smax96
}

define <2 x i37> @max_of_nots_weird_type_vec(<2 x i37> %x, <2 x i37> %y) {
; CHECK-LABEL: @max_of_nots_weird_type_vec(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp sgt <2 x i37> [[Y:%.*]], zeroinitializer
; CHECK-NEXT:    [[TMP2:%.*]] = select <2 x i1> [[TMP1]], <2 x i37> [[Y]], <2 x i37> zeroinitializer
; CHECK-NEXT:    [[TMP3:%.*]] = icmp slt <2 x i37> [[TMP2]], [[X:%.*]]
; CHECK-NEXT:    [[TMP4:%.*]] = select <2 x i1> [[TMP3]], <2 x i37> [[TMP2]], <2 x i37> [[X]]
; CHECK-NEXT:    [[TMP5:%.*]] = xor <2 x i37> [[TMP4]], <i37 -1, i37 -1>
; CHECK-NEXT:    ret <2 x i37> [[TMP5]]
;
  %c0 = icmp sgt <2 x i37> %y, zeroinitializer
  %xor_y = xor <2 x i37> %y, <i37 -1, i37 -1>
  %s0 = select <2 x i1> %c0, <2 x i37> %xor_y, <2 x i37> <i37 -1, i37 -1>
  %xor_x = xor <2 x i37> %x, <i37 -1, i37 -1>
  %c1 = icmp slt <2 x i37> %s0, %xor_x
  %smax96 = select <2 x i1> %c1, <2 x i37> %xor_x, <2 x i37> %s0
  ret <2 x i37> %smax96
}

; max(min(%a, -1), -1) == -1
define i32 @max_of_min(i32 %a) {
; CHECK-LABEL: @max_of_min(
; CHECK-NEXT:    ret i32 -1
;
  %not_a = xor i32 %a, -1
  %c0 = icmp sgt i32 %a, 0
  %s0 = select i1 %c0, i32 %not_a, i32 -1
  %c1 = icmp sgt i32 %s0, -1
  %s1 = select i1 %c1, i32 %s0, i32 -1
  ret i32 %s1
}

; max(min(%a, -1), -1) == -1 (swap predicate and select ops)
define i32 @max_of_min_swap(i32 %a) {
; CHECK-LABEL: @max_of_min_swap(
; CHECK-NEXT:    ret i32 -1
;
  %not_a = xor i32 %a, -1
  %c0 = icmp slt i32 %a, 0
  %s0 = select i1 %c0, i32 -1, i32 %not_a
  %c1 = icmp sgt i32 %s0, -1
  %s1 = select i1 %c1, i32 %s0, i32 -1
  ret i32 %s1
}

; min(max(%a, -1), -1) == -1
define i32 @min_of_max(i32 %a) {
; CHECK-LABEL: @min_of_max(
; CHECK-NEXT:    ret i32 -1
;
  %not_a = xor i32 %a, -1
  %c0 = icmp slt i32 %a, 0
  %s0 = select i1 %c0, i32 %not_a, i32 -1
  %c1 = icmp slt i32 %s0, -1
  %s1 = select i1 %c1, i32 %s0, i32 -1
  ret i32 %s1
}

; min(max(%a, -1), -1) == -1 (swap predicate and select ops)
define i32 @min_of_max_swap(i32 %a) {
; CHECK-LABEL: @min_of_max_swap(
; CHECK-NEXT:    ret i32 -1
;
  %not_a = xor i32 %a, -1
  %c0 = icmp sgt i32 %a, 0
  %s0 = select i1 %c0, i32 -1, i32 %not_a
  %c1 = icmp slt i32 %s0, -1
  %s1 = select i1 %c1, i32 %s0, i32 -1
  ret i32 %s1
}

define <2 x i32> @max_of_min_vec(<2 x i32> %a) {
; CHECK-LABEL: @max_of_min_vec(
; CHECK-NEXT:    ret <2 x i32> <i32 -1, i32 -1>
;
  %not_a = xor <2 x i32> %a, <i32 -1, i32 -1>
  %c0 = icmp sgt <2 x i32> %a, zeroinitializer
  %s0 = select <2 x i1> %c0, <2 x i32> %not_a, <2 x i32> <i32 -1, i32 -1>
  %c1 = icmp sgt <2 x i32> %s0, <i32 -1, i32 -1>
  %s1 = select <2 x i1> %c1, <2 x i32> %s0, <2 x i32> <i32 -1, i32 -1>
  ret <2 x i32> %s1
}