test/Transforms/InstCombine/integer-round-up-pow2-alignment.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

declare void @use.i8(i8)
declare void @use.v2i4(<2 x i4>)
declare void @use.i1(i1)

declare void @llvm.assume(i1)

; Basic pattern
define i8 @t0(i8 %x) {
; CHECK-LABEL: @t0(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add i8 [[X:%.*]], 15
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = and i8 [[X_BIASED]], -16
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x, 16
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; Another alignment is fine
define i8 @t1(i8 %x) {
; CHECK-LABEL: @t1(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add i8 [[X:%.*]], 31
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = and i8 [[X_BIASED]], -32
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 31
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x, 32
  %x.biased.highbits = and i8 %x.biased, -32
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; Bias can be either the alignment or alignment-1
define i8 @t2(i8 %x) {
; CHECK-LABEL: @t2(
; CHECK-NEXT:    [[X_BIASED1:%.*]] = add i8 [[X:%.*]], 15
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = and i8 [[X_BIASED1]], -16
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x, 15
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; select is commutative
define i8 @t3_commutative(i8 %x) {
; CHECK-LABEL: @t3_commutative(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 15
; CHECK-NEXT:    [[X_LOWBITS_ARE_NOT_ZERO:%.*]] = icmp ne i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    call void @use.i1(i1 [[X_LOWBITS_ARE_NOT_ZERO]])
; CHECK-NEXT:    [[X_BIASED:%.*]] = add i8 [[X]], 15
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = and i8 [[X_BIASED]], -16
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 15
  %x.lowbits.are.not.zero = icmp ne i8 %x.lowbits, 0
  call void @use.i1(i1 %x.lowbits.are.not.zero)
  %x.biased = add i8 %x, 16
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.not.zero, i8 %x.biased.highbits, i8 %x
  ret i8 %x.roundedup
}

; Basic splat vector test
define <2 x i8> @t4_splat(<2 x i8> %x) {
; CHECK-LABEL: @t4_splat(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i8> [[X:%.*]], <i8 15, i8 15>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = and <2 x i8> [[X_BIASED]], <i8 -16, i8 -16>
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 15>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 0>
  %x.biased = add <2 x i8> %x, <i8 16, i8 16>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 -16>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}

; Splat-with-poison
define <2 x i8> @t5_splat_poison_0b0001(<2 x i8> %x) {
; CHECK-LABEL: @t5_splat_poison_0b0001(
; CHECK-NEXT:    [[X_BIASED1:%.*]] = add <2 x i8> [[X:%.*]], <i8 15, i8 15>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = and <2 x i8> [[X_BIASED1]], <i8 -16, i8 -16>
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 15>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 0>
  %x.biased = add <2 x i8> %x, <i8 16, i8 16>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 poison>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}
define <2 x i8> @t5_splat_poison_0b0010(<2 x i8> %x) {
; CHECK-LABEL: @t5_splat_poison_0b0010(
; CHECK-NEXT:    [[X_BIASED1:%.*]] = add <2 x i8> [[X:%.*]], <i8 15, i8 15>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = and <2 x i8> [[X_BIASED1]], <i8 -16, i8 -16>
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 15>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 0>
  %x.biased = add <2 x i8> %x, <i8 16, i8 poison>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 -16>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}
define <2 x i8> @t5_splat_poison_0b0100(<2 x i8> %x) {
; CHECK-LABEL: @t5_splat_poison_0b0100(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i8> [[X:%.*]], <i8 15, i8 15>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = and <2 x i8> [[X_BIASED]], <i8 -16, i8 -16>
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 15>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 poison>
  %x.biased = add <2 x i8> %x, <i8 16, i8 16>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 -16>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}
define <2 x i8> @t5_splat_poison_0b1000(<2 x i8> %x) {
; CHECK-LABEL: @t5_splat_poison_0b1000(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i8> [[X:%.*]], <i8 15, i8 15>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = and <2 x i8> [[X_BIASED]], <i8 -16, i8 -16>
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 poison>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 0>
  %x.biased = add <2 x i8> %x, <i8 16, i8 16>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 -16>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}

; Basic non-splat vector test
define <2 x i8> @t6_nonsplat(<2 x i8> %x) {
; CHECK-LABEL: @t6_nonsplat(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and <2 x i8> [[X:%.*]], <i8 15, i8 31>
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq <2 x i8> [[X_LOWBITS]], zeroinitializer
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i8> [[X]], <i8 16, i8 32>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i8> [[X_BIASED]], <i8 -16, i8 -32>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select <2 x i1> [[X_LOWBITS_ARE_ZERO]], <2 x i8> [[X]], <2 x i8> [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 31>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 0>
  %x.biased = add <2 x i8> %x, <i8 16, i8 32>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 -32>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}

; Even if the alignment (and masks) are splat, the bias could be non-splat
define <2 x i8> @t7_nonsplat_bias(<2 x i8> %x) {
; CHECK-LABEL: @t7_nonsplat_bias(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and <2 x i8> [[X:%.*]], <i8 15, i8 15>
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq <2 x i8> [[X_LOWBITS]], zeroinitializer
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i8> [[X]], <i8 15, i8 16>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i8> [[X_BIASED]], <i8 -16, i8 -16>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select <2 x i1> [[X_LOWBITS_ARE_ZERO]], <2 x i8> [[X]], <2 x i8> [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 15>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 0>
  %x.biased = add <2 x i8> %x, <i8 15, i8 16>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 -16>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}

; Splat-in-disguise vector tests
define <2 x i8> @t8_nonsplat_masked_by_poison_0b0001(<2 x i8> %x) {
; CHECK-LABEL: @t8_nonsplat_masked_by_poison_0b0001(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and <2 x i8> [[X:%.*]], <i8 15, i8 31>
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq <2 x i8> [[X_LOWBITS]], zeroinitializer
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i8> [[X]], <i8 16, i8 32>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i8> [[X_BIASED]], <i8 -16, i8 poison>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select <2 x i1> [[X_LOWBITS_ARE_ZERO]], <2 x i8> [[X]], <2 x i8> [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 31>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 0>
  %x.biased = add <2 x i8> %x, <i8 16, i8 32>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 poison>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}
define <2 x i8> @t8_nonsplat_masked_by_poison_0b0010(<2 x i8> %x) {
; CHECK-LABEL: @t8_nonsplat_masked_by_poison_0b0010(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and <2 x i8> [[X:%.*]], <i8 15, i8 31>
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq <2 x i8> [[X_LOWBITS]], zeroinitializer
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i8> [[X]], <i8 16, i8 poison>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i8> [[X_BIASED]], <i8 -16, i8 -32>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select <2 x i1> [[X_LOWBITS_ARE_ZERO]], <2 x i8> [[X]], <2 x i8> [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 31>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 0>
  %x.biased = add <2 x i8> %x, <i8 16, i8 poison>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 -32>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}
define <2 x i8> @t8_nonsplat_masked_by_poison_0b0100(<2 x i8> %x) {
; CHECK-LABEL: @t8_nonsplat_masked_by_poison_0b0100(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and <2 x i8> [[X:%.*]], <i8 15, i8 31>
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq <2 x i8> [[X_LOWBITS]], <i8 0, i8 poison>
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i8> [[X]], <i8 16, i8 32>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i8> [[X_BIASED]], <i8 -16, i8 -32>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select <2 x i1> [[X_LOWBITS_ARE_ZERO]], <2 x i8> [[X]], <2 x i8> [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 31>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 poison>
  %x.biased = add <2 x i8> %x, <i8 16, i8 32>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 -32>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}
define <2 x i8> @t8_nonsplat_masked_by_poison_0b1000(<2 x i8> %x) {
; CHECK-LABEL: @t8_nonsplat_masked_by_poison_0b1000(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and <2 x i8> [[X:%.*]], <i8 15, i8 poison>
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq <2 x i8> [[X_LOWBITS]], zeroinitializer
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i8> [[X]], <i8 16, i8 32>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i8> [[X_BIASED]], <i8 -16, i8 -32>
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select <2 x i1> [[X_LOWBITS_ARE_ZERO]], <2 x i8> [[X]], <2 x i8> [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret <2 x i8> [[X_ROUNDEDUP]]
;
  %x.lowbits = and <2 x i8> %x, <i8 15, i8 poison>
  %x.lowbits.are.zero = icmp eq <2 x i8> %x.lowbits, <i8 0, i8 0>
  %x.biased = add <2 x i8> %x, <i8 16, i8 32>
  %x.biased.highbits = and <2 x i8> %x.biased, <i8 -16, i8 -32>
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i8> %x, <2 x i8> %x.biased.highbits
  ret <2 x i8> %x.roundedup
}

; The X are different
define i8 @n9_wrong_x0(i8 %x.0, i8 %x.1) {
; CHECK-LABEL: @n9_wrong_x0(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X_0:%.*]], 15
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X_0]], -16
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X_1:%.*]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x.0, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x.0, 16
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x.1, i8 %x.biased.highbits
  ret i8 %x.roundedup
}
define i8 @n9_wrong_x1(i8 %x.0, i8 %x.1) {
; CHECK-LABEL: @n9_wrong_x1(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X_0:%.*]], 15
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X_1:%.*]], -16
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X_0]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x.0, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x.1, 16
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x.0, i8 %x.biased.highbits
  ret i8 %x.roundedup
}
define i8 @n9_wrong_x2(i8 %x.0, i8 %x.1) {
; CHECK-LABEL: @n9_wrong_x2(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X_1:%.*]], 15
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X_0:%.*]], -16
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X_0]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x.1, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x.0, 16
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x.0, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; Wrong low-bit mask
define i8 @n10_wrong_low_bit_mask(i8 %x) {
; CHECK-LABEL: @n10_wrong_low_bit_mask(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 31
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], -16
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 31
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x, 16
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; Wrong high-bit mask
define i8 @n11_wrong_high_bit_mask(i8 %x) {
; CHECK-LABEL: @n11_wrong_high_bit_mask(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 15
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    [[X_BIASED:%.*]] = add i8 [[X]], 16
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -32
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x, 16
  %x.biased.highbits = and i8 %x.biased, -32
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; Wrong bias
define i8 @n12_wrong_bias(i8 %x) {
; CHECK-LABEL: @n12_wrong_bias(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 15
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], -16
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 32
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x, 32
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; Wrong constants
define i8 @n13_wrong_constants_alignment_is_not_power_of_two(i8 %x) {
; CHECK-LABEL: @n13_wrong_constants_alignment_is_not_power_of_two(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 2
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    [[X_BIASED:%.*]] = add i8 [[X]], 3
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -3
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 2
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x, 3
  %x.biased.highbits = and i8 %x.biased, -3
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; Comparison is not with zero
define i8 @n14_wrong_comparison_constant(i8 %x) {
; CHECK-LABEL: @n14_wrong_comparison_constant(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 15
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 1
; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], -16
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 1
  %x.biased = add i8 %x, 16
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; Wrong comparison
define i8 @n15_wrong_comparison_predicate_and_constant(i8 %x) {
; CHECK-LABEL: @n15_wrong_comparison_predicate_and_constant(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 14
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], -16
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 15
  %x.lowbits.are.zero = icmp ult i8 %x.lowbits, 2
  %x.biased = add i8 %x, 16
  %x.biased.highbits = and i8 %x.biased, -16
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; %x.biased.highbits must not have other uses
define i8 @n16_oneuse(i8 %x) {
; CHECK-LABEL: @n16_oneuse(
; CHECK-NEXT:    [[X_LOWBITS:%.*]] = and i8 [[X:%.*]], 15
; CHECK-NEXT:    [[X_LOWBITS_ARE_ZERO:%.*]] = icmp eq i8 [[X_LOWBITS]], 0
; CHECK-NEXT:    [[TMP1:%.*]] = and i8 [[X]], -16
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = add i8 [[TMP1]], 16
; CHECK-NEXT:    call void @use.i8(i8 [[X_BIASED_HIGHBITS]])
; CHECK-NEXT:    [[X_ROUNDEDUP:%.*]] = select i1 [[X_LOWBITS_ARE_ZERO]], i8 [[X]], i8 [[X_BIASED_HIGHBITS]]
; CHECK-NEXT:    ret i8 [[X_ROUNDEDUP]]
;
  %x.lowbits = and i8 %x, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x, 16
  %x.biased.highbits = and i8 %x.biased, -16
  call void @use.i8(i8 %x.biased.highbits)
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; But if bias is equal to low-bit mask, then we *could* just replace %x.roundedup with %x.biased.highbits
define i8 @t17_oneuse(i8 %x) {
; CHECK-LABEL: @t17_oneuse(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add i8 [[X:%.*]], 15
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and i8 [[X_BIASED]], -16
; CHECK-NEXT:    call void @use.i8(i8 [[X_BIASED_HIGHBITS]])
; CHECK-NEXT:    ret i8 [[X_BIASED_HIGHBITS]]
;
  %x.lowbits = and i8 %x, 15
  %x.lowbits.are.zero = icmp eq i8 %x.lowbits, 0
  %x.biased = add i8 %x, 15
  %x.biased.highbits = and i8 %x.biased, -16
  call void @use.i8(i8 %x.biased.highbits)
  %x.roundedup = select i1 %x.lowbits.are.zero, i8 %x, i8 %x.biased.highbits
  ret i8 %x.roundedup
}

; Bias is equal to the alignment-1 (as opposed to alignment),
; so we can just replace %x.roundedup with %x.biased.highbits
define <2 x i4> @t18_replacement_0b0001(<2 x i4> %x) {
; CHECK-LABEL: @t18_replacement_0b0001(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i4> [[X:%.*]], <i4 3, i4 3>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i4> [[X_BIASED]], <i4 -4, i4 poison>
; CHECK-NEXT:    call void @use.v2i4(<2 x i4> [[X_BIASED_HIGHBITS]])
; CHECK-NEXT:    ret <2 x i4> [[X_BIASED_HIGHBITS]]
;
  %x.lowbits = and <2 x i4> %x, <i4 3, i4 3>
  %x.lowbits.are.zero = icmp eq <2 x i4> %x.lowbits, <i4 0, i4 0>
  %x.biased = add <2 x i4> %x, <i4 3, i4 3>
  %x.biased.highbits = and <2 x i4> %x.biased, <i4 -4, i4 poison>
  call void @use.v2i4(<2 x i4> %x.biased.highbits)
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i4> %x, <2 x i4> %x.biased.highbits
  ret <2 x i4> %x.roundedup
}
define <2 x i4> @t18_replacement_0b0010(<2 x i4> %x) {
; CHECK-LABEL: @t18_replacement_0b0010(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i4> [[X:%.*]], <i4 3, i4 poison>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i4> [[X_BIASED]], <i4 -4, i4 -4>
; CHECK-NEXT:    call void @use.v2i4(<2 x i4> [[X_BIASED_HIGHBITS]])
; CHECK-NEXT:    ret <2 x i4> [[X_BIASED_HIGHBITS]]
;
  %x.lowbits = and <2 x i4> %x, <i4 3, i4 3>
  %x.lowbits.are.zero = icmp eq <2 x i4> %x.lowbits, <i4 0, i4 0>
  %x.biased = add <2 x i4> %x, <i4 3, i4 poison>
  %x.biased.highbits = and <2 x i4> %x.biased, <i4 -4, i4 -4>
  call void @use.v2i4(<2 x i4> %x.biased.highbits)
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i4> %x, <2 x i4> %x.biased.highbits
  ret <2 x i4> %x.roundedup
}
define <2 x i4> @t18_replacement_0b0100(<2 x i4> %x) {
; CHECK-LABEL: @t18_replacement_0b0100(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i4> [[X:%.*]], <i4 3, i4 3>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i4> [[X_BIASED]], <i4 -4, i4 -4>
; CHECK-NEXT:    call void @use.v2i4(<2 x i4> [[X_BIASED_HIGHBITS]])
; CHECK-NEXT:    ret <2 x i4> [[X_BIASED_HIGHBITS]]
;
  %x.lowbits = and <2 x i4> %x, <i4 3, i4 3>
  %x.lowbits.are.zero = icmp eq <2 x i4> %x.lowbits, <i4 0, i4 poison>
  %x.biased = add <2 x i4> %x, <i4 3, i4 3>
  %x.biased.highbits = and <2 x i4> %x.biased, <i4 -4, i4 -4>
  call void @use.v2i4(<2 x i4> %x.biased.highbits)
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i4> %x, <2 x i4> %x.biased.highbits
  ret <2 x i4> %x.roundedup
}
define <2 x i4> @t18_replacement_0b1000(<2 x i4> %x) {
; CHECK-LABEL: @t18_replacement_0b1000(
; CHECK-NEXT:    [[X_BIASED:%.*]] = add <2 x i4> [[X:%.*]], <i4 3, i4 3>
; CHECK-NEXT:    [[X_BIASED_HIGHBITS:%.*]] = and <2 x i4> [[X_BIASED]], <i4 -4, i4 -4>
; CHECK-NEXT:    call void @use.v2i4(<2 x i4> [[X_BIASED_HIGHBITS]])
; CHECK-NEXT:    ret <2 x i4> [[X_BIASED_HIGHBITS]]
;
  %x.lowbits = and <2 x i4> %x, <i4 3, i4 poison>
  %x.lowbits.are.zero = icmp eq <2 x i4> %x.lowbits, <i4 0, i4 0>
  %x.biased = add <2 x i4> %x, <i4 3, i4 3>
  %x.biased.highbits = and <2 x i4> %x.biased, <i4 -4, i4 -4>
  call void @use.v2i4(<2 x i4> %x.biased.highbits)
  %x.roundedup = select <2 x i1> %x.lowbits.are.zero, <2 x i4> %x, <2 x i4> %x.biased.highbits
  ret <2 x i4> %x.roundedup
}