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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
declare void @use6(i6)
declare void @use8(i8)
define i6 @trunc_lshr(i8 %x) {
; CHECK-LABEL: @trunc_lshr(
; CHECK-NEXT: [[TMP1:%.*]] = trunc i8 [[X:%.*]] to i6
; CHECK-NEXT: [[TMP2:%.*]] = lshr i6 [[TMP1]], 2
; CHECK-NEXT: [[R:%.*]] = and i6 [[TMP2]], 14
; CHECK-NEXT: ret i6 [[R]]
;
%s = lshr i8 %x, 2
%t = trunc i8 %s to i6
%r = and i6 %t, 14
ret i6 %r
}
; The 'and' is eliminated.
define i6 @trunc_lshr_exact_mask(i8 %x) {
; CHECK-LABEL: @trunc_lshr_exact_mask(
; CHECK-NEXT: [[TMP1:%.*]] = trunc i8 [[X:%.*]] to i6
; CHECK-NEXT: [[TMP2:%.*]] = lshr i6 [[TMP1]], 2
; CHECK-NEXT: ret i6 [[TMP2]]
;
%s = lshr i8 %x, 2
%t = trunc i8 %s to i6
%r = and i6 %t, 15
ret i6 %r
}
; negative test - a high bit of x is in the result
define i6 @trunc_lshr_big_mask(i8 %x) {
; CHECK-LABEL: @trunc_lshr_big_mask(
; CHECK-NEXT: [[S:%.*]] = lshr i8 [[X:%.*]], 2
; CHECK-NEXT: [[T:%.*]] = trunc i8 [[S]] to i6
; CHECK-NEXT: [[R:%.*]] = and i6 [[T]], 31
; CHECK-NEXT: ret i6 [[R]]
;
%s = lshr i8 %x, 2
%t = trunc i8 %s to i6
%r = and i6 %t, 31
ret i6 %r
}
; negative test - too many uses
define i6 @trunc_lshr_use1(i8 %x) {
; CHECK-LABEL: @trunc_lshr_use1(
; CHECK-NEXT: [[S:%.*]] = lshr i8 [[X:%.*]], 2
; CHECK-NEXT: call void @use8(i8 [[S]])
; CHECK-NEXT: [[T:%.*]] = trunc i8 [[S]] to i6
; CHECK-NEXT: [[R:%.*]] = and i6 [[T]], 15
; CHECK-NEXT: ret i6 [[R]]
;
%s = lshr i8 %x, 2
call void @use8(i8 %s)
%t = trunc i8 %s to i6
%r = and i6 %t, 15
ret i6 %r
}
; negative test - too many uses
define i6 @trunc_lshr_use2(i8 %x) {
; CHECK-LABEL: @trunc_lshr_use2(
; CHECK-NEXT: [[S:%.*]] = lshr i8 [[X:%.*]], 2
; CHECK-NEXT: [[T:%.*]] = trunc i8 [[S]] to i6
; CHECK-NEXT: call void @use6(i6 [[T]])
; CHECK-NEXT: [[R:%.*]] = and i6 [[T]], 15
; CHECK-NEXT: ret i6 [[R]]
;
%s = lshr i8 %x, 2
%t = trunc i8 %s to i6
call void @use6(i6 %t)
%r = and i6 %t, 15
ret i6 %r
}
; Splat vectors are ok.
define <2 x i7> @trunc_lshr_vec_splat(<2 x i16> %x) {
; CHECK-LABEL: @trunc_lshr_vec_splat(
; CHECK-NEXT: [[TMP1:%.*]] = trunc <2 x i16> [[X:%.*]] to <2 x i7>
; CHECK-NEXT: [[TMP2:%.*]] = lshr <2 x i7> [[TMP1]], <i7 5, i7 5>
; CHECK-NEXT: [[R:%.*]] = and <2 x i7> [[TMP2]], <i7 1, i7 1>
; CHECK-NEXT: ret <2 x i7> [[R]]
;
%s = lshr <2 x i16> %x, <i16 5, i16 5>
%t = trunc <2 x i16> %s to <2 x i7>
%r = and <2 x i7> %t, <i7 1, i7 1>
ret <2 x i7> %r
}
; The 'and' is eliminated.
define <2 x i7> @trunc_lshr_vec_splat_exact_mask(<2 x i16> %x) {
; CHECK-LABEL: @trunc_lshr_vec_splat_exact_mask(
; CHECK-NEXT: [[TMP1:%.*]] = trunc <2 x i16> [[X:%.*]] to <2 x i7>
; CHECK-NEXT: [[TMP2:%.*]] = lshr <2 x i7> [[TMP1]], <i7 6, i7 6>
; CHECK-NEXT: ret <2 x i7> [[TMP2]]
;
%s = lshr <2 x i16> %x, <i16 6, i16 6>
%t = trunc <2 x i16> %s to <2 x i7>
%r = and <2 x i7> %t, <i7 1, i7 1>
ret <2 x i7> %r
}
; negative test - the shift is too big for the narrow type
define <2 x i7> @trunc_lshr_big_shift(<2 x i16> %x) {
; CHECK-LABEL: @trunc_lshr_big_shift(
; CHECK-NEXT: [[S:%.*]] = lshr <2 x i16> [[X:%.*]], <i16 7, i16 7>
; CHECK-NEXT: [[T:%.*]] = trunc <2 x i16> [[S]] to <2 x i7>
; CHECK-NEXT: [[R:%.*]] = and <2 x i7> [[T]], <i7 1, i7 1>
; CHECK-NEXT: ret <2 x i7> [[R]]
;
%s = lshr <2 x i16> %x, <i16 7, i16 7>
%t = trunc <2 x i16> %s to <2 x i7>
%r = and <2 x i7> %t, <i7 1, i7 1>
ret <2 x i7> %r
}
; High bits could also be set rather than cleared.
define i6 @or_trunc_lshr(i8 %x) {
; CHECK-LABEL: @or_trunc_lshr(
; CHECK-NEXT: [[TMP1:%.*]] = trunc i8 [[X:%.*]] to i6
; CHECK-NEXT: [[TMP2:%.*]] = lshr i6 [[TMP1]], 1
; CHECK-NEXT: [[R:%.*]] = or i6 [[TMP2]], -32
; CHECK-NEXT: ret i6 [[R]]
;
%s = lshr i8 %x, 1
%t = trunc i8 %s to i6
%r = or i6 %t, 32 ; 0b100000
ret i6 %r
}
define i6 @or_trunc_lshr_more(i8 %x) {
; CHECK-LABEL: @or_trunc_lshr_more(
; CHECK-NEXT: [[TMP1:%.*]] = trunc i8 [[X:%.*]] to i6
; CHECK-NEXT: [[TMP2:%.*]] = lshr i6 [[TMP1]], 4
; CHECK-NEXT: [[R:%.*]] = or i6 [[TMP2]], -4
; CHECK-NEXT: ret i6 [[R]]
;
%s = lshr i8 %x, 4
%t = trunc i8 %s to i6
%r = or i6 %t, 60 ; 0b111100
ret i6 %r
}
; negative test - need all high bits to be undemanded
define i6 @or_trunc_lshr_small_mask(i8 %x) {
; CHECK-LABEL: @or_trunc_lshr_small_mask(
; CHECK-NEXT: [[S:%.*]] = lshr i8 [[X:%.*]], 4
; CHECK-NEXT: [[T:%.*]] = trunc i8 [[S]] to i6
; CHECK-NEXT: [[R:%.*]] = or i6 [[T]], -8
; CHECK-NEXT: ret i6 [[R]]
;
%s = lshr i8 %x, 4
%t = trunc i8 %s to i6
%r = or i6 %t, 56 ; 0b111000
ret i6 %r
}
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