| ; 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 |
| } |