test/Transforms/InstCombine/shift-amount-reassociation-in-bittest-with-truncation-lshr.ll

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

; Given pattern:
;   icmp eq/ne (and ((x shift Q), (y oppositeshift K))), 0
; we should move shifts to the same hand of 'and', i.e. e.g. rewrite as
;   icmp eq/ne (and (((x shift Q) shift K), y)), 0
; We are only interested in opposite logical shifts here.
; We still can handle the case where there is a truncation between a shift
; and an 'and', thought the legality check isn't obvious.

;-------------------------------------------------------------------------------
; Basic scalar tests
;-------------------------------------------------------------------------------

; This fold can't be performed for fully variable %x and %y
define i1 @n0(i32 %x, i64 %y, i32 %len) {
; CHECK-LABEL: @n0(
; CHECK-NEXT:    [[T0:%.*]] = sub i32 32, [[LEN:%.*]]
; CHECK-NEXT:    [[T1:%.*]] = shl i32 [[X:%.*]], [[T0]]
; CHECK-NEXT:    [[T2:%.*]] = add i32 [[LEN]], -16
; CHECK-NEXT:    [[T2_WIDE:%.*]] = zext i32 [[T2]] to i64
; CHECK-NEXT:    [[T3:%.*]] = lshr i64 [[Y:%.*]], [[T2_WIDE]]
; CHECK-NEXT:    [[T3_TRUNC:%.*]] = trunc i64 [[T3]] to i32
; CHECK-NEXT:    [[T4:%.*]] = and i32 [[T1]], [[T3_TRUNC]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i32 [[T4]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 32, %len
  %t1 = shl i32 %x, %t0
  %t2 = add i32 %len, -16
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 %y, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}

; However we can fold if %x/%y are constants that pass extra legality check.

; New shift amount would be 16, %x has 16 leading zeros - can fold.
define i1 @t1(i64 %y, i32 %len) {
; CHECK-LABEL: @t1(
; CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[Y:%.*]], 4294901760
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i64 [[TMP1]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 32, %len
  %t1 = shl i32 65535, %t0
  %t2 = add i32 %len, -16
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 %y, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}
; Note that we indeed look at leading zeros!
define i1 @t1_single_bit(i64 %y, i32 %len) {
; CHECK-LABEL: @t1_single_bit(
; CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[Y:%.*]], 2147483648
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i64 [[TMP1]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 32, %len
  %t1 = shl i32 32768, %t0
  %t2 = add i32 %len, -16
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 %y, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}
; New shift amount would be 16, %x has 15 leading zeros - can not fold.
define i1 @n2(i64 %y, i32 %len) {
; CHECK-LABEL: @n2(
; CHECK-NEXT:    [[T0:%.*]] = sub i32 32, [[LEN:%.*]]
; CHECK-NEXT:    [[T1:%.*]] = shl i32 131071, [[T0]]
; CHECK-NEXT:    [[T2:%.*]] = add i32 [[LEN]], -16
; CHECK-NEXT:    [[T2_WIDE:%.*]] = zext i32 [[T2]] to i64
; CHECK-NEXT:    [[T3:%.*]] = lshr i64 [[Y:%.*]], [[T2_WIDE]]
; CHECK-NEXT:    [[T3_TRUNC:%.*]] = trunc i64 [[T3]] to i32
; CHECK-NEXT:    [[T4:%.*]] = and i32 [[T1]], [[T3_TRUNC]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i32 [[T4]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 32, %len
  %t1 = shl i32 131071, %t0
  %t2 = add i32 %len, -16
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 %y, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}

; New shift amount would be 16, %y has 47 leading zeros - can fold.
define i1 @t3(i32 %x, i32 %len) {
; CHECK-LABEL: @t3(
; CHECK-NEXT:    [[TMP1:%.*]] = and i32 [[X:%.*]], 1
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i32 [[TMP1]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 32, %len
  %t1 = shl i32 %x, %t0
  %t2 = add i32 %len, -16
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 131071, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}
; Note that we indeed look at leading zeros!
define i1 @t3_singlebit(i32 %x, i32 %len) {
; CHECK-LABEL: @t3_singlebit(
; CHECK-NEXT:    [[TMP1:%.*]] = and i32 [[X:%.*]], 1
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i32 [[TMP1]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 32, %len
  %t1 = shl i32 %x, %t0
  %t2 = add i32 %len, -16
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 65536, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}
; New shift amount would be 16, %y has 48 leading zeros - can not fold.
define i1 @n4(i32 %x, i32 %len) {
; CHECK-LABEL: @n4(
; CHECK-NEXT:    [[T0:%.*]] = sub i32 32, [[LEN:%.*]]
; CHECK-NEXT:    [[T1:%.*]] = shl i32 [[X:%.*]], [[T0]]
; CHECK-NEXT:    [[T2:%.*]] = add i32 [[LEN]], -16
; CHECK-NEXT:    [[T2_WIDE:%.*]] = zext i32 [[T2]] to i64
; CHECK-NEXT:    [[T3:%.*]] = lshr i64 262143, [[T2_WIDE]]
; CHECK-NEXT:    [[T3_TRUNC:%.*]] = trunc i64 [[T3]] to i32
; CHECK-NEXT:    [[T4:%.*]] = and i32 [[T1]], [[T3_TRUNC]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i32 [[T4]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 32, %len
  %t1 = shl i32 %x, %t0
  %t2 = add i32 %len, -16
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 262143, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}

; While we could still deal with arbitrary values if KnownBits can answer
; the question, it isn't obvious it's worth it, so let's not for now.

;-------------------------------------------------------------------------------
; Vector tests
;-------------------------------------------------------------------------------

; New shift amount would be 16, minimal count of leading zeros in %x is 16. Ok.
define <2 x i1> @t5_vec(<2 x i64> %y, <2 x i32> %len) {
; CHECK-LABEL: @t5_vec(
; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i64> [[Y:%.*]], <i64 16, i64 16>
; CHECK-NEXT:    [[TMP2:%.*]] = and <2 x i64> [[TMP1]], <i64 65535, i64 32767>
; CHECK-NEXT:    [[T5:%.*]] = icmp ne <2 x i64> [[TMP2]], zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[T5]]
;
  %t0 = sub <2 x i32> <i32 32, i32 32>, %len
  %t1 = shl <2 x i32> <i32 65535, i32 32767>, %t0
  %t2 = add <2 x i32> %len, <i32 -16, i32 -16>
  %t2_wide = zext <2 x i32> %t2 to <2 x i64>
  %t3 = lshr <2 x i64> %y, %t2_wide
  %t3_trunc = trunc <2 x i64> %t3 to <2 x i32>
  %t4 = and <2 x i32> %t1, %t3_trunc
  %t5 = icmp ne <2 x i32> %t4, <i32 0, i32 0>
  ret <2 x i1> %t5
}
; New shift amount would be 16, minimal count of leading zeros in %x is 15, not ok to fold.
define <2 x i1> @n6_vec(<2 x i64> %y, <2 x i32> %len) {
; CHECK-LABEL: @n6_vec(
; CHECK-NEXT:    [[T0:%.*]] = sub <2 x i32> <i32 32, i32 32>, [[LEN:%.*]]
; CHECK-NEXT:    [[T1:%.*]] = shl <2 x i32> <i32 65535, i32 131071>, [[T0]]
; CHECK-NEXT:    [[T2:%.*]] = add <2 x i32> [[LEN]], <i32 -16, i32 -16>
; CHECK-NEXT:    [[T2_WIDE:%.*]] = zext <2 x i32> [[T2]] to <2 x i64>
; CHECK-NEXT:    [[T3:%.*]] = lshr <2 x i64> [[Y:%.*]], [[T2_WIDE]]
; CHECK-NEXT:    [[T3_TRUNC:%.*]] = trunc <2 x i64> [[T3]] to <2 x i32>
; CHECK-NEXT:    [[T4:%.*]] = and <2 x i32> [[T1]], [[T3_TRUNC]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne <2 x i32> [[T4]], zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[T5]]
;
  %t0 = sub <2 x i32> <i32 32, i32 32>, %len
  %t1 = shl <2 x i32> <i32 65535, i32 131071>, %t0
  %t2 = add <2 x i32> %len, <i32 -16, i32 -16>
  %t2_wide = zext <2 x i32> %t2 to <2 x i64>
  %t3 = lshr <2 x i64> %y, %t2_wide
  %t3_trunc = trunc <2 x i64> %t3 to <2 x i32>
  %t4 = and <2 x i32> %t1, %t3_trunc
  %t5 = icmp ne <2 x i32> %t4, <i32 0, i32 0>
  ret <2 x i1> %t5
}

; New shift amount would be 16, minimal count of leading zeros in %x is 47. Ok.
define <2 x i1> @t7_vec(<2 x i32> %x, <2 x i32> %len) {
; CHECK-LABEL: @t7_vec(
; CHECK-NEXT:    [[TMP1:%.*]] = and <2 x i32> [[X:%.*]], <i32 1, i32 0>
; CHECK-NEXT:    [[T5:%.*]] = icmp ne <2 x i32> [[TMP1]], zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[T5]]
;
  %t0 = sub <2 x i32> <i32 32, i32 32>, %len
  %t1 = shl <2 x i32> %x, %t0
  %t2 = add <2 x i32> %len, <i32 -16, i32 -16>
  %t2_wide = zext <2 x i32> %t2 to <2 x i64>
  %t3 = lshr <2 x i64> <i64 131071, i64 65535>, %t2_wide
  %t3_trunc = trunc <2 x i64> %t3 to <2 x i32>
  %t4 = and <2 x i32> %t1, %t3_trunc
  %t5 = icmp ne <2 x i32> %t4, <i32 0, i32 0>
  ret <2 x i1> %t5
}
; New shift amount would be 16, minimal count of leading zeros in %x is 48, not ok to fold.
define <2 x i1> @n8_vec(<2 x i32> %x, <2 x i32> %len) {
; CHECK-LABEL: @n8_vec(
; CHECK-NEXT:    [[T0:%.*]] = sub <2 x i32> <i32 32, i32 32>, [[LEN:%.*]]
; CHECK-NEXT:    [[T1:%.*]] = shl <2 x i32> [[X:%.*]], [[T0]]
; CHECK-NEXT:    [[T2:%.*]] = add <2 x i32> [[LEN]], <i32 -16, i32 -16>
; CHECK-NEXT:    [[T2_WIDE:%.*]] = zext <2 x i32> [[T2]] to <2 x i64>
; CHECK-NEXT:    [[T3:%.*]] = lshr <2 x i64> <i64 131071, i64 262143>, [[T2_WIDE]]
; CHECK-NEXT:    [[T3_TRUNC:%.*]] = trunc <2 x i64> [[T3]] to <2 x i32>
; CHECK-NEXT:    [[T4:%.*]] = and <2 x i32> [[T1]], [[T3_TRUNC]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne <2 x i32> [[T4]], zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[T5]]
;
  %t0 = sub <2 x i32> <i32 32, i32 32>, %len
  %t1 = shl <2 x i32> %x, %t0
  %t2 = add <2 x i32> %len, <i32 -16, i32 -16>
  %t2_wide = zext <2 x i32> %t2 to <2 x i64>
  %t3 = lshr <2 x i64> <i64 131071, i64 262143>, %t2_wide
  %t3_trunc = trunc <2 x i64> %t3 to <2 x i32>
  %t4 = and <2 x i32> %t1, %t3_trunc
  %t5 = icmp ne <2 x i32> %t4, <i32 0, i32 0>
  ret <2 x i1> %t5
}

;-------------------------------------------------------------------------------

; Ok if the final shift amount is exactly one less than widest bit width.
define i1 @t9_highest_bit(i32 %x, i64 %y, i32 %len) {
; CHECK-LABEL: @t9_highest_bit(
; CHECK-NEXT:    [[TMP1:%.*]] = zext i32 [[X:%.*]] to i64
; CHECK-NEXT:    [[TMP2:%.*]] = lshr i64 [[Y:%.*]], 63
; CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP2]], [[TMP1]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i64 [[TMP3]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 64, %len
  %t1 = shl i32 %x, %t0
  %t2 = add i32 %len, -1
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 %y, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}
; Not highest bit.
define i1 @t10_almost_highest_bit(i32 %x, i64 %y, i32 %len) {
; CHECK-LABEL: @t10_almost_highest_bit(
; CHECK-NEXT:    [[T0:%.*]] = sub i32 64, [[LEN:%.*]]
; CHECK-NEXT:    [[T1:%.*]] = shl i32 [[X:%.*]], [[T0]]
; CHECK-NEXT:    [[T2:%.*]] = add i32 [[LEN]], -2
; CHECK-NEXT:    [[T2_WIDE:%.*]] = zext i32 [[T2]] to i64
; CHECK-NEXT:    [[T3:%.*]] = lshr i64 [[Y:%.*]], [[T2_WIDE]]
; CHECK-NEXT:    [[T3_TRUNC:%.*]] = trunc i64 [[T3]] to i32
; CHECK-NEXT:    [[T4:%.*]] = and i32 [[T1]], [[T3_TRUNC]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i32 [[T4]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 64, %len
  %t1 = shl i32 %x, %t0
  %t2 = add i32 %len, -2
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 %y, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}

; Ok if the final shift amount is zero.
define i1 @t11_no_shift(i32 %x, i64 %y, i32 %len) {
; CHECK-LABEL: @t11_no_shift(
; CHECK-NEXT:    [[TMP1:%.*]] = zext i32 [[X:%.*]] to i64
; CHECK-NEXT:    [[TMP2:%.*]] = and i64 [[TMP1]], [[Y:%.*]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i64 [[TMP2]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 64, %len
  %t1 = shl i32 %x, %t0
  %t2 = add i32 %len, -64
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 %y, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}
; Not zero-shift.
define i1 @t10_shift_by_one(i32 %x, i64 %y, i32 %len) {
; CHECK-LABEL: @t10_shift_by_one(
; CHECK-NEXT:    [[T0:%.*]] = sub i32 64, [[LEN:%.*]]
; CHECK-NEXT:    [[T1:%.*]] = shl i32 [[X:%.*]], [[T0]]
; CHECK-NEXT:    [[T2:%.*]] = add i32 [[LEN]], -63
; CHECK-NEXT:    [[T2_WIDE:%.*]] = zext i32 [[T2]] to i64
; CHECK-NEXT:    [[T3:%.*]] = lshr i64 [[Y:%.*]], [[T2_WIDE]]
; CHECK-NEXT:    [[T3_TRUNC:%.*]] = trunc i64 [[T3]] to i32
; CHECK-NEXT:    [[T4:%.*]] = and i32 [[T1]], [[T3_TRUNC]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i32 [[T4]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 64, %len
  %t1 = shl i32 %x, %t0
  %t2 = add i32 %len, -63
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 %y, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}

; A mix of those conditions is ok.
define <2 x i1> @t11_zero_and_almost_bitwidth(<2 x i32> %x, <2 x i64> %y, <2 x i32> %len) {
; CHECK-LABEL: @t11_zero_and_almost_bitwidth(
; CHECK-NEXT:    [[T0:%.*]] = sub <2 x i32> <i32 64, i32 64>, [[LEN:%.*]]
; CHECK-NEXT:    [[T1:%.*]] = shl <2 x i32> [[X:%.*]], [[T0]]
; CHECK-NEXT:    [[T2:%.*]] = add <2 x i32> [[LEN]], <i32 -1, i32 -64>
; CHECK-NEXT:    [[T2_WIDE:%.*]] = zext <2 x i32> [[T2]] to <2 x i64>
; CHECK-NEXT:    [[T3:%.*]] = lshr <2 x i64> [[Y:%.*]], [[T2_WIDE]]
; CHECK-NEXT:    [[T3_TRUNC:%.*]] = trunc <2 x i64> [[T3]] to <2 x i32>
; CHECK-NEXT:    [[T4:%.*]] = and <2 x i32> [[T1]], [[T3_TRUNC]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne <2 x i32> [[T4]], zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[T5]]
;
  %t0 = sub <2 x i32> <i32 64, i32 64>, %len
  %t1 = shl <2 x i32> %x, %t0
  %t2 = add <2 x i32> %len, <i32 -1, i32 -64>
  %t2_wide = zext <2 x i32> %t2 to <2 x i64>
  %t3 = lshr <2 x i64> %y, %t2_wide
  %t3_trunc = trunc <2 x i64> %t3 to <2 x i32>
  %t4 = and <2 x i32> %t1, %t3_trunc
  %t5 = icmp ne <2 x i32> %t4, <i32 0, i32 0>
  ret <2 x i1> %t5
}
define <2 x i1> @n12_bad(<2 x i32> %x, <2 x i64> %y, <2 x i32> %len) {
; CHECK-LABEL: @n12_bad(
; CHECK-NEXT:    [[T0:%.*]] = sub <2 x i32> <i32 64, i32 64>, [[LEN:%.*]]
; CHECK-NEXT:    [[T1:%.*]] = shl <2 x i32> [[X:%.*]], [[T0]]
; CHECK-NEXT:    [[T2:%.*]] = add <2 x i32> [[LEN]], <i32 -2, i32 -64>
; CHECK-NEXT:    [[T2_WIDE:%.*]] = zext <2 x i32> [[T2]] to <2 x i64>
; CHECK-NEXT:    [[T3:%.*]] = lshr <2 x i64> [[Y:%.*]], [[T2_WIDE]]
; CHECK-NEXT:    [[T3_TRUNC:%.*]] = trunc <2 x i64> [[T3]] to <2 x i32>
; CHECK-NEXT:    [[T4:%.*]] = and <2 x i32> [[T1]], [[T3_TRUNC]]
; CHECK-NEXT:    [[T5:%.*]] = icmp ne <2 x i32> [[T4]], zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[T5]]
;
  %t0 = sub <2 x i32> <i32 64, i32 64>, %len
  %t1 = shl <2 x i32> %x, %t0
  %t2 = add <2 x i32> %len, <i32 -2, i32 -64>
  %t2_wide = zext <2 x i32> %t2 to <2 x i64>
  %t3 = lshr <2 x i64> %y, %t2_wide
  %t3_trunc = trunc <2 x i64> %t3 to <2 x i32>
  %t4 = and <2 x i32> %t1, %t3_trunc
  %t5 = icmp ne <2 x i32> %t4, <i32 0, i32 0>
  ret <2 x i1> %t5
}

;------------------------------------------------------------------------------;

; Ok if one of the values being shifted is 1
define i1 @t13_x_is_one(i64 %y, i32 %len) {
; CHECK-LABEL: @t13_x_is_one(
; CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[Y:%.*]], 65536
; CHECK-NEXT:    [[T5:%.*]] = icmp ne i64 [[TMP1]], 0
; CHECK-NEXT:    ret i1 [[T5]]
;
  %t0 = sub i32 32, %len
  %t1 = shl i32 1, %t0
  %t2 = add i32 %len, -16
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 %y, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}
define i1 @t14_x_is_one(i32 %x, i32 %len) {
; CHECK-LABEL: @t14_x_is_one(
; CHECK-NEXT:    ret i1 false
;
  %t0 = sub i32 32, %len
  %t1 = shl i32 %x, %t0
  %t2 = add i32 %len, -16
  %t2_wide = zext i32 %t2 to i64
  %t3 = lshr i64 1, %t2_wide
  %t3_trunc = trunc i64 %t3 to i32
  %t4 = and i32 %t1, %t3_trunc
  %t5 = icmp ne i32 %t4, 0
  ret i1 %t5
}

define <2 x i1> @t15_vec_x_is_one_or_zero(<2 x i64> %y, <2 x i32> %len) {
; CHECK-LABEL: @t15_vec_x_is_one_or_zero(
; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i64> [[Y:%.*]], <i64 48, i64 48>
; CHECK-NEXT:    [[TMP2:%.*]] = and <2 x i64> [[TMP1]], <i64 1, i64 0>
; CHECK-NEXT:    [[T5:%.*]] = icmp ne <2 x i64> [[TMP2]], zeroinitializer
; CHECK-NEXT:    ret <2 x i1> [[T5]]
;
  %t0 = sub <2 x i32> <i32 64, i32 64>, %len
  %t1 = shl <2 x i32> <i32 1, i32 0>, %t0
  %t2 = add <2 x i32> %len, <i32 -16, i32 -16>
  %t2_wide = zext <2 x i32> %t2 to <2 x i64>
  %t3 = lshr <2 x i64> %y, %t2_wide
  %t3_trunc = trunc <2 x i64> %t3 to <2 x i32>
  %t4 = and <2 x i32> %t1, %t3_trunc
  %t5 = icmp ne <2 x i32> %t4, <i32 0, i32 0>
  ret <2 x i1> %t5
}
define <2 x i1> @t16_vec_y_is_one_or_zero(<2 x i32> %x, <2 x i32> %len) {
; CHECK-LABEL: @t16_vec_y_is_one_or_zero(
; CHECK-NEXT:    ret <2 x i1> zeroinitializer
;
  %t0 = sub <2 x i32> <i32 64, i32 64>, %len
  %t1 = shl <2 x i32> %x, %t0
  %t2 = add <2 x i32> %len, <i32 -16, i32 -16>
  %t2_wide = zext <2 x i32> %t2 to <2 x i64>
  %t3 = lshr <2 x i64> <i64 1, i64 0>, %t2_wide
  %t3_trunc = trunc <2 x i64> %t3 to <2 x i32>
  %t4 = and <2 x i32> %t1, %t3_trunc
  %t5 = icmp ne <2 x i32> %t4, <i32 0, i32 0>
  ret <2 x i1> %t5
}

;------------------------------------------------------------------------------;

; All other tests - extra uses, etc are already covered in
; shift-amount-reassociation-in-bittest-with-truncation-shl.ll and
; shift-amount-reassociation-in-bittest.ll

; And that's the main motivational pattern:
define i1 @rawspeed_signbit(i64 %storage, i32 %nbits) {
; CHECK-LABEL: @rawspeed_signbit(
; CHECK-NEXT:    [[ISBITUNSET:%.*]] = icmp sgt i64 [[STORAGE:%.*]], -1
; CHECK-NEXT:    ret i1 [[ISBITUNSET]]
;
  %skipnbits = sub nsw i32 64, %nbits
  %skipnbitswide = zext i32 %skipnbits to i64
  %datawide = lshr i64 %storage, %skipnbitswide
  %data = trunc i64 %datawide to i32
  %nbitsminusone = add nsw i32 %nbits, -1
  %bitmask = shl i32 1, %nbitsminusone
  %bitmasked = and i32 %bitmask, %data
  %isbitunset = icmp eq i32 %bitmasked, 0
  ret i1 %isbitunset
}