test/Transforms/InstCombine/lshr.ll

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

target datalayout = "e-m:e-i64:64-n8:16:32:64"

declare i32 @llvm.bswap.i32(i32)
declare i128 @llvm.bswap.i128(i128)
declare <2 x i64> @llvm.bswap.v2i64(<2 x i64>)
declare i32 @llvm.cttz.i32(i32, i1) nounwind readnone
declare i32 @llvm.ctlz.i32(i32, i1) nounwind readnone
declare i32 @llvm.ctpop.i32(i32) nounwind readnone
declare <2 x i8> @llvm.cttz.v2i8(<2 x i8>, i1) nounwind readnone
declare <2 x i8> @llvm.ctlz.v2i8(<2 x i8>, i1) nounwind readnone
declare <2 x i8> @llvm.ctpop.v2i8(<2 x i8>) nounwind readnone

declare void @use(i32)
declare void @usevec(<3 x i14>)

define i32 @lshr_ctlz_zero_is_not_undef(i32 %x) {
; CHECK-LABEL: @lshr_ctlz_zero_is_not_undef(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i32 [[X:%.*]], 0
; CHECK-NEXT:    [[SH:%.*]] = zext i1 [[TMP1]] to i32
; CHECK-NEXT:    ret i32 [[SH]]
;
  %ct = call i32 @llvm.ctlz.i32(i32 %x, i1 false)
  %sh = lshr i32 %ct, 5
  ret i32 %sh
}

define i32 @lshr_cttz_zero_is_not_undef(i32 %x) {
; CHECK-LABEL: @lshr_cttz_zero_is_not_undef(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i32 [[X:%.*]], 0
; CHECK-NEXT:    [[SH:%.*]] = zext i1 [[TMP1]] to i32
; CHECK-NEXT:    ret i32 [[SH]]
;
  %ct = call i32 @llvm.cttz.i32(i32 %x, i1 false)
  %sh = lshr i32 %ct, 5
  ret i32 %sh
}

define i32 @lshr_ctpop(i32 %x) {
; CHECK-LABEL: @lshr_ctpop(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i32 [[X:%.*]], -1
; CHECK-NEXT:    [[SH:%.*]] = zext i1 [[TMP1]] to i32
; CHECK-NEXT:    ret i32 [[SH]]
;
  %ct = call i32 @llvm.ctpop.i32(i32 %x)
  %sh = lshr i32 %ct, 5
  ret i32 %sh
}

define <2 x i8> @lshr_ctlz_zero_is_not_undef_splat_vec(<2 x i8> %x) {
; CHECK-LABEL: @lshr_ctlz_zero_is_not_undef_splat_vec(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq <2 x i8> [[X:%.*]], zeroinitializer
; CHECK-NEXT:    [[SH:%.*]] = zext <2 x i1> [[TMP1]] to <2 x i8>
; CHECK-NEXT:    ret <2 x i8> [[SH]]
;
  %ct = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %x, i1 false)
  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
  ret <2 x i8> %sh
}

define <2 x i8> @lshr_cttz_zero_is_not_undef_splat_vec(<2 x i8> %x) {
; CHECK-LABEL: @lshr_cttz_zero_is_not_undef_splat_vec(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq <2 x i8> [[X:%.*]], zeroinitializer
; CHECK-NEXT:    [[SH:%.*]] = zext <2 x i1> [[TMP1]] to <2 x i8>
; CHECK-NEXT:    ret <2 x i8> [[SH]]
;
  %ct = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> %x, i1 false)
  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
  ret <2 x i8> %sh
}

define <2 x i8> @lshr_ctpop_splat_vec(<2 x i8> %x) {
; CHECK-LABEL: @lshr_ctpop_splat_vec(
; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq <2 x i8> [[X:%.*]], <i8 -1, i8 -1>
; CHECK-NEXT:    [[SH:%.*]] = zext <2 x i1> [[TMP1]] to <2 x i8>
; CHECK-NEXT:    ret <2 x i8> [[SH]]
;
  %ct = call <2 x i8> @llvm.ctpop.v2i8(<2 x i8> %x)
  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
  ret <2 x i8> %sh
}

define i32 @lshr_ctlz_zero_is_undef(i32 %x) {
; CHECK-LABEL: @lshr_ctlz_zero_is_undef(
; CHECK-NEXT:    ret i32 0
;
  %ct = call i32 @llvm.ctlz.i32(i32 %x, i1 true)
  %sh = lshr i32 %ct, 5
  ret i32 %sh
}

define i32 @lshr_cttz_zero_is_undef(i32 %x) {
; CHECK-LABEL: @lshr_cttz_zero_is_undef(
; CHECK-NEXT:    ret i32 0
;
  %ct = call i32 @llvm.cttz.i32(i32 %x, i1 true)
  %sh = lshr i32 %ct, 5
  ret i32 %sh
}

define <2 x i8> @lshr_ctlz_zero_is_undef_splat_vec(<2 x i8> %x) {
; CHECK-LABEL: @lshr_ctlz_zero_is_undef_splat_vec(
; CHECK-NEXT:    ret <2 x i8> zeroinitializer
;
  %ct = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %x, i1 true)
  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
  ret <2 x i8> %sh
}

define i8 @lshr_ctlz_zero_is_undef_vec(<2 x i8> %x) {
; CHECK-LABEL: @lshr_ctlz_zero_is_undef_vec(
; CHECK-NEXT:    ret i8 0
;
  %ct = call <2 x i8> @llvm.ctlz.v2i8(<2 x i8> %x, i1 true)
  %sh = lshr <2 x i8> %ct, <i8 3, i8 0>
  %ex = extractelement <2 x i8> %sh, i32 0
  ret i8 %ex
}

define <2 x i8> @lshr_cttz_zero_is_undef_splat_vec(<2 x i8> %x) {
; CHECK-LABEL: @lshr_cttz_zero_is_undef_splat_vec(
; CHECK-NEXT:    ret <2 x i8> zeroinitializer
;
  %ct = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> %x, i1 true)
  %sh = lshr <2 x i8> %ct, <i8 3, i8 3>
  ret <2 x i8> %sh
}

define i8 @lshr_cttz_zero_is_undef_vec(<2 x i8> %x) {
; CHECK-LABEL: @lshr_cttz_zero_is_undef_vec(
; CHECK-NEXT:    ret i8 0
;
  %ct = call <2 x i8> @llvm.cttz.v2i8(<2 x i8> %x, i1 true)
  %sh = lshr <2 x i8> %ct, <i8 3, i8 0>
  %ex = extractelement <2 x i8> %sh, i32 0
  ret i8 %ex
}


define i8 @lshr_exact(i8 %x) {
; CHECK-LABEL: @lshr_exact(
; CHECK-NEXT:    [[TMP1:%.*]] = add i8 [[X:%.*]], 1
; CHECK-NEXT:    [[LSHR:%.*]] = and i8 [[TMP1]], 63
; CHECK-NEXT:    ret i8 [[LSHR]]
;
  %shl = shl i8 %x, 2
  %add = add i8 %shl, 4
  %lshr = lshr i8 %add, 2
  ret i8 %lshr
}

define <2 x i8> @lshr_exact_splat_vec(<2 x i8> %x) {
; CHECK-LABEL: @lshr_exact_splat_vec(
; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i8> [[X:%.*]], <i8 1, i8 1>
; CHECK-NEXT:    [[LSHR:%.*]] = and <2 x i8> [[TMP1]], <i8 63, i8 63>
; CHECK-NEXT:    ret <2 x i8> [[LSHR]]
;
  %shl = shl <2 x i8> %x, <i8 2, i8 2>
  %add = add <2 x i8> %shl, <i8 4, i8 4>
  %lshr = lshr <2 x i8> %add, <i8 2, i8 2>
  ret <2 x i8> %lshr
}

define i8 @shl_add(i8 %x, i8 %y) {
; CHECK-LABEL: @shl_add(
; CHECK-NEXT:    [[TMP1:%.*]] = lshr i8 [[Y:%.*]], 2
; CHECK-NEXT:    [[TMP2:%.*]] = add i8 [[TMP1]], [[X:%.*]]
; CHECK-NEXT:    [[R:%.*]] = and i8 [[TMP2]], 63
; CHECK-NEXT:    ret i8 [[R]]
;
  %l = shl i8 %x, 2
  %a = add i8 %l, %y
  %r = lshr i8 %a, 2
  ret i8 %r
}

define <2 x i8> @shl_add_commute_vec(<2 x i8> %x, <2 x i8> %py) {
; CHECK-LABEL: @shl_add_commute_vec(
; CHECK-NEXT:    [[Y:%.*]] = mul <2 x i8> [[PY:%.*]], [[PY]]
; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i8> [[Y]], <i8 3, i8 3>
; CHECK-NEXT:    [[TMP2:%.*]] = add <2 x i8> [[TMP1]], [[X:%.*]]
; CHECK-NEXT:    [[R:%.*]] = and <2 x i8> [[TMP2]], <i8 31, i8 31>
; CHECK-NEXT:    ret <2 x i8> [[R]]
;
  %y = mul <2 x i8> %py, %py ; thwart complexity-based canonicalization
  %l = shl <2 x i8> %x, <i8 3, i8 3>
  %a = add <2 x i8> %y, %l
  %r = lshr <2 x i8> %a, <i8 3, i8 3>
  ret <2 x i8> %r
}

define i32 @shl_add_use1(i32 %x, i32 %y) {
; CHECK-LABEL: @shl_add_use1(
; CHECK-NEXT:    [[L:%.*]] = shl i32 [[X:%.*]], 2
; CHECK-NEXT:    call void @use(i32 [[L]])
; CHECK-NEXT:    [[A:%.*]] = add i32 [[L]], [[Y:%.*]]
; CHECK-NEXT:    [[R:%.*]] = lshr i32 [[A]], 2
; CHECK-NEXT:    ret i32 [[R]]
;
  %l = shl i32 %x, 2
  call void @use(i32 %l)
  %a = add i32 %l, %y
  %r = lshr i32 %a, 2
  ret i32 %r
}

define i32 @shl_add_use2(i32 %x, i32 %y) {
; CHECK-LABEL: @shl_add_use2(
; CHECK-NEXT:    [[L:%.*]] = shl i32 [[X:%.*]], 2
; CHECK-NEXT:    [[A:%.*]] = add i32 [[L]], [[Y:%.*]]
; CHECK-NEXT:    call void @use(i32 [[A]])
; CHECK-NEXT:    [[R:%.*]] = lshr i32 [[A]], 2
; CHECK-NEXT:    ret i32 [[R]]
;
  %l = shl i32 %x, 2
  %a = add i32 %l, %y
  call void @use(i32 %a)
  %r = lshr i32 %a, 2
  ret i32 %r
}

define i16 @bool_zext(i1 %x) {
; CHECK-LABEL: @bool_zext(
; CHECK-NEXT:    [[HIBIT:%.*]] = zext i1 [[X:%.*]] to i16
; CHECK-NEXT:    ret i16 [[HIBIT]]
;
  %sext = sext i1 %x to i16
  %hibit = lshr i16 %sext, 15
  ret i16 %hibit
}

define i32 @bool_zext_use(i1 %x) {
; CHECK-LABEL: @bool_zext_use(
; CHECK-NEXT:    [[SEXT:%.*]] = sext i1 [[X:%.*]] to i32
; CHECK-NEXT:    call void @use(i32 [[SEXT]])
; CHECK-NEXT:    [[HIBIT:%.*]] = zext i1 [[X]] to i32
; CHECK-NEXT:    ret i32 [[HIBIT]]
;
  %sext = sext i1 %x to i32
  call void @use(i32 %sext)
  %hibit = lshr i32 %sext, 31
  ret i32 %hibit
}

define <2 x i8> @bool_zext_splat(<2 x i1> %x) {
; CHECK-LABEL: @bool_zext_splat(
; CHECK-NEXT:    [[HIBIT:%.*]] = zext <2 x i1> [[X:%.*]] to <2 x i8>
; CHECK-NEXT:    ret <2 x i8> [[HIBIT]]
;
  %sext = sext <2 x i1> %x to <2 x i8>
  %hibit = lshr <2 x i8> %sext, <i8 7, i8 7>
  ret <2 x i8> %hibit
}

define i32 @smear_sign_and_widen(i8 %x) {
; CHECK-LABEL: @smear_sign_and_widen(
; CHECK-NEXT:    [[TMP1:%.*]] = ashr i8 [[X:%.*]], 7
; CHECK-NEXT:    [[HIBIT:%.*]] = zext i8 [[TMP1]] to i32
; CHECK-NEXT:    ret i32 [[HIBIT]]
;
  %sext = sext i8 %x to i32
  %hibit = lshr i32 %sext, 24
  ret i32 %hibit
}

define i16 @smear_sign_and_widen_should_not_change_type(i4 %x) {
; CHECK-LABEL: @smear_sign_and_widen_should_not_change_type(
; CHECK-NEXT:    [[SEXT:%.*]] = sext i4 [[X:%.*]] to i16
; CHECK-NEXT:    [[HIBIT:%.*]] = lshr i16 [[SEXT]], 12
; CHECK-NEXT:    ret i16 [[HIBIT]]
;
  %sext = sext i4 %x to i16
  %hibit = lshr i16 %sext, 12
  ret i16 %hibit
}

define <2 x i8> @smear_sign_and_widen_splat(<2 x i6> %x) {
; CHECK-LABEL: @smear_sign_and_widen_splat(
; CHECK-NEXT:    [[TMP1:%.*]] = ashr <2 x i6> [[X:%.*]], <i6 2, i6 2>
; CHECK-NEXT:    [[HIBIT:%.*]] = zext <2 x i6> [[TMP1]] to <2 x i8>
; CHECK-NEXT:    ret <2 x i8> [[HIBIT]]
;
  %sext = sext <2 x i6> %x to <2 x i8>
  %hibit = lshr <2 x i8> %sext, <i8 2, i8 2>
  ret <2 x i8> %hibit
}

define i18 @fake_sext(i3 %x) {
; CHECK-LABEL: @fake_sext(
; CHECK-NEXT:    [[TMP1:%.*]] = lshr i3 [[X:%.*]], 2
; CHECK-NEXT:    [[SH:%.*]] = zext i3 [[TMP1]] to i18
; CHECK-NEXT:    ret i18 [[SH]]
;
  %sext = sext i3 %x to i18
  %sh = lshr i18 %sext, 17
  ret i18 %sh
}

; Avoid the transform if it would change the shift from a legal to illegal type.

define i32 @fake_sext_but_should_not_change_type(i3 %x) {
; CHECK-LABEL: @fake_sext_but_should_not_change_type(
; CHECK-NEXT:    [[SEXT:%.*]] = sext i3 [[X:%.*]] to i32
; CHECK-NEXT:    [[SH:%.*]] = lshr i32 [[SEXT]], 31
; CHECK-NEXT:    ret i32 [[SH]]
;
  %sext = sext i3 %x to i32
  %sh = lshr i32 %sext, 31
  ret i32 %sh
}

define <2 x i8> @fake_sext_splat(<2 x i3> %x) {
; CHECK-LABEL: @fake_sext_splat(
; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i3> [[X:%.*]], <i3 2, i3 2>
; CHECK-NEXT:    [[SH:%.*]] = zext <2 x i3> [[TMP1]] to <2 x i8>
; CHECK-NEXT:    ret <2 x i8> [[SH]]
;
  %sext = sext <2 x i3> %x to <2 x i8>
  %sh = lshr <2 x i8> %sext, <i8 7, i8 7>
  ret <2 x i8> %sh
}

; Use a narrow shift: lshr (zext iM X to iN), C --> zext (lshr X, C) to iN

define <2 x i32> @narrow_lshr_constant(<2 x i8> %x, <2 x i8> %y) {
; CHECK-LABEL: @narrow_lshr_constant(
; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i8> [[X:%.*]], <i8 3, i8 3>
; CHECK-NEXT:    [[SH:%.*]] = zext <2 x i8> [[TMP1]] to <2 x i32>
; CHECK-NEXT:    ret <2 x i32> [[SH]]
;
  %zx = zext <2 x i8> %x to <2 x i32>
  %sh = lshr <2 x i32> %zx, <i32 3, i32 3>
  ret <2 x i32> %sh
}

define i32 @mul_splat_fold(i32 %x) {
; CHECK-LABEL: @mul_splat_fold(
; CHECK-NEXT:    [[T:%.*]] = and i32 [[X:%.*]], 65535
; CHECK-NEXT:    ret i32 [[T]]
;
  %m = mul nuw i32 %x, 65537
  %t = lshr i32 %m, 16
  ret i32 %t
}

; Vector type, extra use, weird types are all ok.

define <3 x i14> @mul_splat_fold_vec(<3 x i14> %x) {
; CHECK-LABEL: @mul_splat_fold_vec(
; CHECK-NEXT:    [[M:%.*]] = mul nuw <3 x i14> [[X:%.*]], <i14 129, i14 129, i14 129>
; CHECK-NEXT:    call void @usevec(<3 x i14> [[M]])
; CHECK-NEXT:    [[T:%.*]] = and <3 x i14> [[X]], <i14 127, i14 127, i14 127>
; CHECK-NEXT:    ret <3 x i14> [[T]]
;
  %m = mul nuw <3 x i14> %x, <i14 129, i14 129, i14 129>
  call void @usevec(<3 x i14> %m)
  %t = lshr <3 x i14> %m, <i14 7, i14 7, i14 7>
  ret <3 x i14> %t
}

; Negative test

define i32 @mul_splat_fold_wrong_mul_const(i32 %x) {
; CHECK-LABEL: @mul_splat_fold_wrong_mul_const(
; CHECK-NEXT:    [[M:%.*]] = mul nuw i32 [[X:%.*]], 65538
; CHECK-NEXT:    [[T:%.*]] = lshr i32 [[M]], 16
; CHECK-NEXT:    ret i32 [[T]]
;
  %m = mul nuw i32 %x, 65538
  %t = lshr i32 %m, 16
  ret i32 %t
}

; Negative test

define i32 @mul_splat_fold_wrong_lshr_const(i32 %x) {
; CHECK-LABEL: @mul_splat_fold_wrong_lshr_const(
; CHECK-NEXT:    [[M:%.*]] = mul nuw i32 [[X:%.*]], 65537
; CHECK-NEXT:    [[T:%.*]] = lshr i32 [[M]], 15
; CHECK-NEXT:    ret i32 [[T]]
;
  %m = mul nuw i32 %x, 65537
  %t = lshr i32 %m, 15
  ret i32 %t
}

; Negative test

define i32 @mul_splat_fold_no_nuw(i32 %x) {
; CHECK-LABEL: @mul_splat_fold_no_nuw(
; CHECK-NEXT:    [[M:%.*]] = mul nsw i32 [[X:%.*]], 65537
; CHECK-NEXT:    [[T:%.*]] = lshr i32 [[M]], 16
; CHECK-NEXT:    ret i32 [[T]]
;
  %m = mul nsw i32 %x, 65537
  %t = lshr i32 %m, 16
  ret i32 %t
}

; Negative test (but simplifies before we reach the mul_splat transform)- need more than 2 bits

define i2 @mul_splat_fold_too_narrow(i2 %x) {
; CHECK-LABEL: @mul_splat_fold_too_narrow(
; CHECK-NEXT:    ret i2 [[X:%.*]]
;
  %m = mul nuw i2 %x, 2
  %t = lshr i2 %m, 1
  ret i2 %t
}

define i32 @negative_and_odd(i32 %x) {
; CHECK-LABEL: @negative_and_odd(
; CHECK-NEXT:    [[TMP1:%.*]] = lshr i32 [[X:%.*]], 31
; CHECK-NEXT:    [[R:%.*]] = and i32 [[TMP1]], [[X]]
; CHECK-NEXT:    ret i32 [[R]]
;
  %s = srem i32 %x, 2
  %r = lshr i32 %s, 31
  ret i32 %r
}

define <2 x i7> @negative_and_odd_vec(<2 x i7> %x) {
; CHECK-LABEL: @negative_and_odd_vec(
; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i7> [[X:%.*]], <i7 6, i7 6>
; CHECK-NEXT:    [[R:%.*]] = and <2 x i7> [[TMP1]], [[X]]
; CHECK-NEXT:    ret <2 x i7> [[R]]
;
  %s = srem <2 x i7> %x, <i7 2, i7 2>
  %r = lshr <2 x i7> %s, <i7 6, i7 6>
  ret <2 x i7> %r
}

; Negative test - this is still worth trying to avoid srem?

define i32 @negative_and_odd_uses(i32 %x, i32* %p) {
; CHECK-LABEL: @negative_and_odd_uses(
; CHECK-NEXT:    [[S:%.*]] = srem i32 [[X:%.*]], 2
; CHECK-NEXT:    store i32 [[S]], i32* [[P:%.*]], align 4
; CHECK-NEXT:    [[R:%.*]] = lshr i32 [[S]], 31
; CHECK-NEXT:    ret i32 [[R]]
;
  %s = srem i32 %x, 2
  store i32 %s, i32* %p
  %r = lshr i32 %s, 31
  ret i32 %r
}

; Negative test - wrong divisor

define i32 @srem3(i32 %x) {
; CHECK-LABEL: @srem3(
; CHECK-NEXT:    [[S:%.*]] = srem i32 [[X:%.*]], 3
; CHECK-NEXT:    [[R:%.*]] = lshr i32 [[S]], 31
; CHECK-NEXT:    ret i32 [[R]]
;
  %s = srem i32 %x, 3
  %r = lshr i32 %s, 31
  ret i32 %r
}

; Negative test - wrong shift amount

define i32 @srem2_lshr30(i32 %x) {
; CHECK-LABEL: @srem2_lshr30(
; CHECK-NEXT:    [[S:%.*]] = srem i32 [[X:%.*]], 2
; CHECK-NEXT:    [[R:%.*]] = lshr i32 [[S]], 30
; CHECK-NEXT:    ret i32 [[R]]
;
  %s = srem i32 %x, 2
  %r = lshr i32 %s, 30
  ret i32 %r
}

define i12 @trunc_sandwich(i32 %x) {
; CHECK-LABEL: @trunc_sandwich(
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr i32 [[X:%.*]], 30
; CHECK-NEXT:    [[R1:%.*]] = trunc i32 [[SUM_SHIFT]] to i12
; CHECK-NEXT:    ret i12 [[R1]]
;
  %sh = lshr i32 %x, 28
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 2
  ret i12 %r
}

define <2 x i12> @trunc_sandwich_splat_vec(<2 x i32> %x) {
; CHECK-LABEL: @trunc_sandwich_splat_vec(
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr <2 x i32> [[X:%.*]], <i32 30, i32 30>
; CHECK-NEXT:    [[R1:%.*]] = trunc <2 x i32> [[SUM_SHIFT]] to <2 x i12>
; CHECK-NEXT:    ret <2 x i12> [[R1]]
;
  %sh = lshr <2 x i32> %x, <i32 22, i32 22>
  %tr = trunc <2 x i32> %sh to <2 x i12>
  %r = lshr <2 x i12> %tr, <i12 8, i12 8>
  ret <2 x i12> %r
}

define i12 @trunc_sandwich_min_shift1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_min_shift1(
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr i32 [[X:%.*]], 21
; CHECK-NEXT:    [[R1:%.*]] = trunc i32 [[SUM_SHIFT]] to i12
; CHECK-NEXT:    ret i12 [[R1]]
;
  %sh = lshr i32 %x, 20
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 1
  ret i12 %r
}

define i12 @trunc_sandwich_small_shift1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_small_shift1(
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr i32 [[X:%.*]], 20
; CHECK-NEXT:    [[R1:%.*]] = trunc i32 [[SUM_SHIFT]] to i12
; CHECK-NEXT:    [[R:%.*]] = and i12 [[R1]], 2047
; CHECK-NEXT:    ret i12 [[R]]
;
  %sh = lshr i32 %x, 19
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 1
  ret i12 %r
}

define i12 @trunc_sandwich_max_sum_shift(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_max_sum_shift(
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr i32 [[X:%.*]], 31
; CHECK-NEXT:    [[R1:%.*]] = trunc i32 [[SUM_SHIFT]] to i12
; CHECK-NEXT:    ret i12 [[R1]]
;
  %sh = lshr i32 %x, 20
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 11
  ret i12 %r
}

define i12 @trunc_sandwich_max_sum_shift2(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_max_sum_shift2(
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr i32 [[X:%.*]], 31
; CHECK-NEXT:    [[R1:%.*]] = trunc i32 [[SUM_SHIFT]] to i12
; CHECK-NEXT:    ret i12 [[R1]]
;
  %sh = lshr i32 %x, 30
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 1
  ret i12 %r
}

define i12 @trunc_sandwich_big_sum_shift1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_big_sum_shift1(
; CHECK-NEXT:    ret i12 0
;
  %sh = lshr i32 %x, 21
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 11
  ret i12 %r
}

define i12 @trunc_sandwich_big_sum_shift2(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_big_sum_shift2(
; CHECK-NEXT:    ret i12 0
;
  %sh = lshr i32 %x, 31
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 1
  ret i12 %r
}

define i12 @trunc_sandwich_use1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_use1(
; CHECK-NEXT:    [[SH:%.*]] = lshr i32 [[X:%.*]], 28
; CHECK-NEXT:    call void @use(i32 [[SH]])
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr i32 [[X]], 30
; CHECK-NEXT:    [[R1:%.*]] = trunc i32 [[SUM_SHIFT]] to i12
; CHECK-NEXT:    ret i12 [[R1]]
;
  %sh = lshr i32 %x, 28
  call void @use(i32 %sh)
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 2
  ret i12 %r
}

define <3 x i9> @trunc_sandwich_splat_vec_use1(<3 x i14> %x) {
; CHECK-LABEL: @trunc_sandwich_splat_vec_use1(
; CHECK-NEXT:    [[SH:%.*]] = lshr <3 x i14> [[X:%.*]], <i14 6, i14 6, i14 6>
; CHECK-NEXT:    call void @usevec(<3 x i14> [[SH]])
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr <3 x i14> [[X]], <i14 11, i14 11, i14 11>
; CHECK-NEXT:    [[R1:%.*]] = trunc <3 x i14> [[SUM_SHIFT]] to <3 x i9>
; CHECK-NEXT:    ret <3 x i9> [[R1]]
;
  %sh = lshr <3 x i14> %x, <i14 6, i14 6, i14 6>
  call void @usevec(<3 x i14> %sh)
  %tr = trunc <3 x i14> %sh to <3 x i9>
  %r = lshr <3 x i9> %tr, <i9 5, i9 5, i9 5>
  ret <3 x i9> %r
}

define i12 @trunc_sandwich_min_shift1_use1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_min_shift1_use1(
; CHECK-NEXT:    [[SH:%.*]] = lshr i32 [[X:%.*]], 20
; CHECK-NEXT:    call void @use(i32 [[SH]])
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr i32 [[X]], 21
; CHECK-NEXT:    [[R1:%.*]] = trunc i32 [[SUM_SHIFT]] to i12
; CHECK-NEXT:    ret i12 [[R1]]
;
  %sh = lshr i32 %x, 20
  call void @use(i32 %sh)
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 1
  ret i12 %r
}

; negative test - trunc is bigger than first shift

define i12 @trunc_sandwich_small_shift1_use1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_small_shift1_use1(
; CHECK-NEXT:    [[SH:%.*]] = lshr i32 [[X:%.*]], 19
; CHECK-NEXT:    call void @use(i32 [[SH]])
; CHECK-NEXT:    [[TR:%.*]] = trunc i32 [[SH]] to i12
; CHECK-NEXT:    [[R:%.*]] = lshr i12 [[TR]], 1
; CHECK-NEXT:    ret i12 [[R]]
;
  %sh = lshr i32 %x, 19
  call void @use(i32 %sh)
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 1
  ret i12 %r
}

define i12 @trunc_sandwich_max_sum_shift_use1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_max_sum_shift_use1(
; CHECK-NEXT:    [[SH:%.*]] = lshr i32 [[X:%.*]], 20
; CHECK-NEXT:    call void @use(i32 [[SH]])
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr i32 [[X]], 31
; CHECK-NEXT:    [[R1:%.*]] = trunc i32 [[SUM_SHIFT]] to i12
; CHECK-NEXT:    ret i12 [[R1]]
;
  %sh = lshr i32 %x, 20
  call void @use(i32 %sh)
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 11
  ret i12 %r
}

define i12 @trunc_sandwich_max_sum_shift2_use1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_max_sum_shift2_use1(
; CHECK-NEXT:    [[SH:%.*]] = lshr i32 [[X:%.*]], 30
; CHECK-NEXT:    call void @use(i32 [[SH]])
; CHECK-NEXT:    [[SUM_SHIFT:%.*]] = lshr i32 [[X]], 31
; CHECK-NEXT:    [[R1:%.*]] = trunc i32 [[SUM_SHIFT]] to i12
; CHECK-NEXT:    ret i12 [[R1]]
;
  %sh = lshr i32 %x, 30
  call void @use(i32 %sh)
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 1
  ret i12 %r
}

; negative test - but overshift is simplified to zero by another fold

define i12 @trunc_sandwich_big_sum_shift1_use1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_big_sum_shift1_use1(
; CHECK-NEXT:    [[SH:%.*]] = lshr i32 [[X:%.*]], 21
; CHECK-NEXT:    call void @use(i32 [[SH]])
; CHECK-NEXT:    ret i12 0
;
  %sh = lshr i32 %x, 21
  call void @use(i32 %sh)
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 11
  ret i12 %r
}

; negative test - but overshift is simplified to zero by another fold

define i12 @trunc_sandwich_big_sum_shift2_use1(i32 %x) {
; CHECK-LABEL: @trunc_sandwich_big_sum_shift2_use1(
; CHECK-NEXT:    [[SH:%.*]] = lshr i32 [[X:%.*]], 31
; CHECK-NEXT:    call void @use(i32 [[SH]])
; CHECK-NEXT:    ret i12 0
;
  %sh = lshr i32 %x, 31
  call void @use(i32 %sh)
  %tr = trunc i32 %sh to i12
  %r = lshr i12 %tr, 1
  ret i12 %r
}

define i16 @lshr_sext_i1_to_i16(i1 %a) {
; CHECK-LABEL: @lshr_sext_i1_to_i16(
; CHECK-NEXT:    [[LSHR:%.*]] = select i1 [[A:%.*]], i16 4095, i16 0
; CHECK-NEXT:    ret i16 [[LSHR]]
;
  %sext = sext i1 %a to i16
  %lshr = lshr i16 %sext, 4
  ret i16 %lshr
}

define i128 @lshr_sext_i1_to_i128(i1 %a) {
; CHECK-LABEL: @lshr_sext_i1_to_i128(
; CHECK-NEXT:    [[LSHR:%.*]] = select i1 [[A:%.*]], i128 77371252455336267181195263, i128 0
; CHECK-NEXT:    ret i128 [[LSHR]]
;
  %sext = sext i1 %a to i128
  %lshr = lshr i128 %sext, 42
  ret i128 %lshr
}

define i32 @lshr_sext_i1_to_i32_use(i1 %a) {
; CHECK-LABEL: @lshr_sext_i1_to_i32_use(
; CHECK-NEXT:    [[SEXT:%.*]] = sext i1 [[A:%.*]] to i32
; CHECK-NEXT:    call void @use(i32 [[SEXT]])
; CHECK-NEXT:    [[LSHR:%.*]] = select i1 [[A]], i32 262143, i32 0
; CHECK-NEXT:    ret i32 [[LSHR]]
;
  %sext = sext i1 %a to i32
  call void @use(i32 %sext)
  %lshr = lshr i32 %sext, 14
  ret i32 %lshr
}

define <3 x i14> @lshr_sext_i1_to_i14_splat_vec_use1(<3 x i1> %a) {
; CHECK-LABEL: @lshr_sext_i1_to_i14_splat_vec_use1(
; CHECK-NEXT:    [[SEXT:%.*]] = sext <3 x i1> [[A:%.*]] to <3 x i14>
; CHECK-NEXT:    call void @usevec(<3 x i14> [[SEXT]])
; CHECK-NEXT:    [[LSHR:%.*]] = select <3 x i1> [[A]], <3 x i14> <i14 1023, i14 1023, i14 1023>, <3 x i14> zeroinitializer
; CHECK-NEXT:    ret <3 x i14> [[LSHR]]
;
  %sext = sext <3 x i1> %a to <3 x i14>
  call void @usevec(<3 x i14> %sext)
  %lshr = lshr <3 x i14> %sext, <i14 4, i14 4, i14 4>
  ret <3 x i14> %lshr
}

define i1 @icmp_ule(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_ule(
; CHECK-NEXT:    ret i1 true
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp ule i32 %x.shifted, %x
  ret i1 %cmp
}

define i1 @icmp_ult(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_ult(
; CHECK-NEXT:    [[X_SHIFTED:%.*]] = lshr i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[X_SHIFTED]], [[X]]
; CHECK-NEXT:    ret i1 [[CMP]]
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp ult i32 %x.shifted, %x
  ret i1 %cmp
}

define i1 @icmp_eq(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_eq(
; CHECK-NEXT:    [[X_SHIFTED:%.*]] = lshr i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[X_SHIFTED]], [[X]]
; CHECK-NEXT:    ret i1 [[CMP]]
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp eq i32 %x.shifted, %x
  ret i1 %cmp
}

define i1 @icmp_ne(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_ne(
; CHECK-NEXT:    [[X_SHIFTED:%.*]] = lshr i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i32 [[X_SHIFTED]], [[X]]
; CHECK-NEXT:    ret i1 [[CMP]]
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp ne i32 %x.shifted, %x
  ret i1 %cmp
}

define i1 @icmp_ugt(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_ugt(
; CHECK-NEXT:    ret i1 false
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp ugt i32 %x.shifted, %x
  ret i1 %cmp
}

define i1 @icmp_uge(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_uge(
; CHECK-NEXT:    [[X_SHIFTED:%.*]] = lshr i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp uge i32 [[X_SHIFTED]], [[X]]
; CHECK-NEXT:    ret i1 [[CMP]]
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp uge i32 %x.shifted, %x
  ret i1 %cmp
}

define i1 @icmp_sle(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_sle(
; CHECK-NEXT:    [[X_SHIFTED:%.*]] = lshr i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i32 [[X_SHIFTED]], [[X]]
; CHECK-NEXT:    ret i1 [[CMP]]
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp sle i32 %x.shifted, %x
  ret i1 %cmp
}

define i1 @icmp_slt(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_slt(
; CHECK-NEXT:    [[X_SHIFTED:%.*]] = lshr i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 [[X_SHIFTED]], [[X]]
; CHECK-NEXT:    ret i1 [[CMP]]
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp slt i32 %x.shifted, %x
  ret i1 %cmp
}

define i1 @icmp_sgt(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_sgt(
; CHECK-NEXT:    [[X_SHIFTED:%.*]] = lshr i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[X_SHIFTED]], [[X]]
; CHECK-NEXT:    ret i1 [[CMP]]
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp sgt i32 %x.shifted, %x
  ret i1 %cmp
}

define i1 @icmp_sge(i32 %x, i32 %y) {
; CHECK-LABEL: @icmp_sge(
; CHECK-NEXT:    [[X_SHIFTED:%.*]] = lshr i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i32 [[X_SHIFTED]], [[X]]
; CHECK-NEXT:    ret i1 [[CMP]]
;
  %x.shifted = lshr i32 %x, %y
  %cmp = icmp sge i32 %x.shifted, %x
  ret i1 %cmp
}

define i32 @narrow_bswap(i16 %x) {
; CHECK-LABEL: @narrow_bswap(
; CHECK-NEXT:    [[TMP1:%.*]] = call i16 @llvm.bswap.i16(i16 [[X:%.*]])
; CHECK-NEXT:    [[S:%.*]] = zext i16 [[TMP1]] to i32
; CHECK-NEXT:    ret i32 [[S]]
;
  %z = zext i16 %x to i32
  %b = call i32 @llvm.bswap.i32(i32 %z)
  %s = lshr i32 %b, 16
  ret i32 %s
}

define i128 @narrow_bswap_extra_wide(i16 %x) {
; CHECK-LABEL: @narrow_bswap_extra_wide(
; CHECK-NEXT:    [[TMP1:%.*]] = call i16 @llvm.bswap.i16(i16 [[X:%.*]])
; CHECK-NEXT:    [[S:%.*]] = zext i16 [[TMP1]] to i128
; CHECK-NEXT:    ret i128 [[S]]
;
  %z = zext i16 %x to i128
  %b = call i128 @llvm.bswap.i128(i128 %z)
  %s = lshr i128 %b, 112
  ret i128 %s
}

define i32 @narrow_bswap_undershift(i16 %x) {
; CHECK-LABEL: @narrow_bswap_undershift(
; CHECK-NEXT:    [[TMP1:%.*]] = call i16 @llvm.bswap.i16(i16 [[X:%.*]])
; CHECK-NEXT:    [[TMP2:%.*]] = zext i16 [[TMP1]] to i32
; CHECK-NEXT:    [[S:%.*]] = shl nuw nsw i32 [[TMP2]], 7
; CHECK-NEXT:    ret i32 [[S]]
;
  %z = zext i16 %x to i32
  %b = call i32 @llvm.bswap.i32(i32 %z)
  %s = lshr i32 %b, 9
  ret i32 %s
}

define <2 x i64> @narrow_bswap_splat(<2 x i16> %x) {
; CHECK-LABEL: @narrow_bswap_splat(
; CHECK-NEXT:    [[TMP1:%.*]] = call <2 x i16> @llvm.bswap.v2i16(<2 x i16> [[X:%.*]])
; CHECK-NEXT:    [[S:%.*]] = zext <2 x i16> [[TMP1]] to <2 x i64>
; CHECK-NEXT:    ret <2 x i64> [[S]]
;
  %z = zext <2 x i16> %x to <2 x i64>
  %b = call <2 x i64> @llvm.bswap.v2i64(<2 x i64> %z)
  %s = lshr <2 x i64> %b, <i64 48, i64 48>
  ret <2 x i64> %s
}

; TODO: poison/undef in the shift amount is ok to propagate.

define <2 x i64> @narrow_bswap_splat_poison_elt(<2 x i16> %x) {
; CHECK-LABEL: @narrow_bswap_splat_poison_elt(
; CHECK-NEXT:    [[Z:%.*]] = zext <2 x i16> [[X:%.*]] to <2 x i64>
; CHECK-NEXT:    [[B:%.*]] = call <2 x i64> @llvm.bswap.v2i64(<2 x i64> [[Z]])
; CHECK-NEXT:    [[S:%.*]] = lshr <2 x i64> [[B]], <i64 48, i64 poison>
; CHECK-NEXT:    ret <2 x i64> [[S]]
;
  %z = zext <2 x i16> %x to <2 x i64>
  %b = call <2 x i64> @llvm.bswap.v2i64(<2 x i64> %z)
  %s = lshr <2 x i64> %b, <i64 48, i64 poison>
  ret <2 x i64> %s
}

define <2 x i64> @narrow_bswap_overshift(<2 x i32> %x) {
; CHECK-LABEL: @narrow_bswap_overshift(
; CHECK-NEXT:    [[TMP1:%.*]] = call <2 x i32> @llvm.bswap.v2i32(<2 x i32> [[X:%.*]])
; CHECK-NEXT:    [[TMP2:%.*]] = lshr <2 x i32> [[TMP1]], <i32 16, i32 16>
; CHECK-NEXT:    [[S:%.*]] = zext <2 x i32> [[TMP2]] to <2 x i64>
; CHECK-NEXT:    ret <2 x i64> [[S]]
;
  %z = zext <2 x i32> %x to <2 x i64>
  %b = call <2 x i64> @llvm.bswap.v2i64(<2 x i64> %z)
  %s = lshr <2 x i64> %b, <i64 48, i64 48>
  ret <2 x i64> %s
}

define i128 @narrow_bswap_overshift2(i96 %x) {
; CHECK-LABEL: @narrow_bswap_overshift2(
; CHECK-NEXT:    [[TMP1:%.*]] = call i96 @llvm.bswap.i96(i96 [[X:%.*]])
; CHECK-NEXT:    [[TMP2:%.*]] = lshr i96 [[TMP1]], 29
; CHECK-NEXT:    [[S:%.*]] = zext i96 [[TMP2]] to i128
; CHECK-NEXT:    ret i128 [[S]]
;
  %z = zext i96 %x to i128
  %b = call i128 @llvm.bswap.i128(i128 %z)
  %s = lshr i128 %b, 61
  ret i128 %s
}

; negative test - can't make a bswap with an odd number of bytes

define i32 @not_narrow_bswap(i24 %x) {
; CHECK-LABEL: @not_narrow_bswap(
; CHECK-NEXT:    [[Z:%.*]] = zext i24 [[X:%.*]] to i32
; CHECK-NEXT:    [[B:%.*]] = call i32 @llvm.bswap.i32(i32 [[Z]])
; CHECK-NEXT:    [[R:%.*]] = lshr exact i32 [[B]], 8
; CHECK-NEXT:    ret i32 [[R]]
;
  %z = zext i24 %x to i32
  %b = call i32 @llvm.bswap.i32(i32 %z)
  %r = lshr i32 %b, 8
  ret i32 %r
}