| ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py |
| ; RUN: opt < %s -instcombine -S | FileCheck %s |
| |
| ; If we have some pattern that leaves only some low bits set, and then performs |
| ; left-shift of those bits, we can combine those two shifts into a shift+mask. |
| |
| ; There are many variants to this pattern: |
| ; d) (x & ((-1 << maskNbits) >> maskNbits)) << shiftNbits |
| ; simplify to: |
| ; (x << shiftNbits) & (-1 >> ((-(maskNbits+shiftNbits))+32)) |
| |
| ; Simple tests. |
| |
| declare void @use32(i32) |
| |
| define i32 @t0_basic(i32 %x, i32 %nbits) { |
| ; CHECK-LABEL: @t0_basic( |
| ; CHECK-NEXT: [[T0:%.*]] = shl i32 -1, [[NBITS:%.*]] |
| ; CHECK-NEXT: [[T1:%.*]] = lshr i32 [[T0]], [[NBITS]] |
| ; CHECK-NEXT: [[T3:%.*]] = add i32 [[NBITS]], -1 |
| ; CHECK-NEXT: call void @use32(i32 [[T0]]) |
| ; CHECK-NEXT: call void @use32(i32 [[T1]]) |
| ; CHECK-NEXT: call void @use32(i32 [[T3]]) |
| ; CHECK-NEXT: [[TMP1:%.*]] = shl i32 [[X:%.*]], [[T3]] |
| ; CHECK-NEXT: [[T4:%.*]] = and i32 [[TMP1]], 2147483647 |
| ; CHECK-NEXT: ret i32 [[T4]] |
| ; |
| %t0 = shl i32 -1, %nbits |
| %t1 = lshr i32 %t0, %nbits |
| %t2 = and i32 %t1, %x |
| %t3 = add i32 %nbits, -1 |
| call void @use32(i32 %t0) |
| call void @use32(i32 %t1) |
| call void @use32(i32 %t3) |
| %t4 = shl i32 %t2, %t3 ; shift is smaller than mask |
| ret i32 %t4 |
| } |
| |
| ; Vectors |
| |
| declare void @use8xi32(<8 x i32>) |
| |
| define <8 x i32> @t2_vec_splat(<8 x i32> %x, <8 x i32> %nbits) { |
| ; CHECK-LABEL: @t2_vec_splat( |
| ; CHECK-NEXT: [[T0:%.*]] = shl <8 x i32> <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1>, [[NBITS:%.*]] |
| ; CHECK-NEXT: [[T1:%.*]] = lshr <8 x i32> [[T0]], [[NBITS]] |
| ; CHECK-NEXT: [[T3:%.*]] = add <8 x i32> [[NBITS]], <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1> |
| ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T0]]) |
| ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T1]]) |
| ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T3]]) |
| ; CHECK-NEXT: [[TMP1:%.*]] = shl <8 x i32> [[X:%.*]], [[T3]] |
| ; CHECK-NEXT: [[T4:%.*]] = and <8 x i32> [[TMP1]], <i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647> |
| ; CHECK-NEXT: ret <8 x i32> [[T4]] |
| ; |
| %t0 = shl <8 x i32> <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1>, %nbits |
| %t1 = lshr <8 x i32> %t0, %nbits |
| %t2 = and <8 x i32> %t1, %x |
| %t3 = add <8 x i32> %nbits, <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1> |
| call void @use8xi32(<8 x i32> %t0) |
| call void @use8xi32(<8 x i32> %t1) |
| call void @use8xi32(<8 x i32> %t3) |
| %t4 = shl <8 x i32> %t2, %t3 ; shift is smaller than mask |
| ret <8 x i32> %t4 |
| } |
| |
| define <8 x i32> @t2_vec_splat_undef(<8 x i32> %x, <8 x i32> %nbits) { |
| ; CHECK-LABEL: @t2_vec_splat_undef( |
| ; CHECK-NEXT: [[T0:%.*]] = shl <8 x i32> <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 undef, i32 -1>, [[NBITS:%.*]] |
| ; CHECK-NEXT: [[T1:%.*]] = lshr <8 x i32> [[T0]], [[NBITS]] |
| ; CHECK-NEXT: [[T3:%.*]] = add <8 x i32> [[NBITS]], <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 undef, i32 -1> |
| ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T0]]) |
| ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T1]]) |
| ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T3]]) |
| ; CHECK-NEXT: [[TMP1:%.*]] = shl <8 x i32> [[X:%.*]], [[T3]] |
| ; CHECK-NEXT: [[T4:%.*]] = and <8 x i32> [[TMP1]], <i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 2147483647, i32 poison, i32 2147483647> |
| ; CHECK-NEXT: ret <8 x i32> [[T4]] |
| ; |
| %t0 = shl <8 x i32> <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 undef, i32 -1>, %nbits |
| %t1 = lshr <8 x i32> %t0, %nbits |
| %t2 = and <8 x i32> %t1, %x |
| %t3 = add <8 x i32> %nbits, <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 undef, i32 -1> |
| call void @use8xi32(<8 x i32> %t0) |
| call void @use8xi32(<8 x i32> %t1) |
| call void @use8xi32(<8 x i32> %t3) |
| %t4 = shl <8 x i32> %t2, %t3 ; shift is smaller than mask |
| ret <8 x i32> %t4 |
| } |
| |
| define <8 x i32> @t2_vec_nonsplat(<8 x i32> %x, <8 x i32> %nbits) { |
| ; CHECK-LABEL: @t2_vec_nonsplat( |
| ; CHECK-NEXT: [[T0:%.*]] = shl <8 x i32> <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1>, [[NBITS:%.*]] |
| ; CHECK-NEXT: [[T1:%.*]] = lshr <8 x i32> [[T0]], [[NBITS]] |
| ; CHECK-NEXT: [[T3:%.*]] = add <8 x i32> [[NBITS]], <i32 -32, i32 -31, i32 -1, i32 0, i32 1, i32 31, i32 32, i32 33> |
| ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T0]]) |
| ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T1]]) |
| ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T3]]) |
| ; CHECK-NEXT: [[TMP1:%.*]] = shl <8 x i32> [[X:%.*]], [[T3]] |
| ; CHECK-NEXT: [[T4:%.*]] = and <8 x i32> [[TMP1]], <i32 poison, i32 1, i32 2147483647, i32 -1, i32 -1, i32 -1, i32 -1, i32 poison> |
| ; CHECK-NEXT: ret <8 x i32> [[T4]] |
| ; |
| %t0 = shl <8 x i32> <i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1, i32 -1>, %nbits |
| %t1 = lshr <8 x i32> %t0, %nbits |
| %t2 = and <8 x i32> %t1, %x |
| %t3 = add <8 x i32> %nbits, <i32 -32, i32 -31, i32 -1, i32 0, i32 1, i32 31, i32 32, i32 33> |
| call void @use8xi32(<8 x i32> %t0) |
| call void @use8xi32(<8 x i32> %t1) |
| call void @use8xi32(<8 x i32> %t3) |
| %t4 = shl <8 x i32> %t2, %t3 ; shift is smaller than mask |
| ret <8 x i32> %t4 |
| } |
| |
| ; Extra uses. |
| |
| define i32 @n3_extrause(i32 %x, i32 %nbits) { |
| ; CHECK-LABEL: @n3_extrause( |
| ; CHECK-NEXT: [[T0:%.*]] = shl i32 -1, [[NBITS:%.*]] |
| ; CHECK-NEXT: [[T1:%.*]] = lshr i32 [[T0]], [[NBITS]] |
| ; CHECK-NEXT: [[T2:%.*]] = and i32 [[T1]], [[X:%.*]] |
| ; CHECK-NEXT: [[T3:%.*]] = add i32 [[NBITS]], -1 |
| ; CHECK-NEXT: call void @use32(i32 [[T0]]) |
| ; CHECK-NEXT: call void @use32(i32 [[T1]]) |
| ; CHECK-NEXT: call void @use32(i32 [[T2]]) |
| ; CHECK-NEXT: call void @use32(i32 [[T3]]) |
| ; CHECK-NEXT: [[T4:%.*]] = shl i32 [[T2]], [[T3]] |
| ; CHECK-NEXT: ret i32 [[T4]] |
| ; |
| %t0 = shl i32 -1, %nbits |
| %t1 = lshr i32 %t0, %nbits |
| %t2 = and i32 %t1, %x |
| %t3 = add i32 %nbits, -1 |
| call void @use32(i32 %t0) |
| call void @use32(i32 %t1) |
| call void @use32(i32 %t2) ; BAD |
| call void @use32(i32 %t3) |
| %t4 = shl i32 %t2, %t3 ; shift is smaller than mask |
| ret i32 %t4 |
| } |