; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=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: ; b) (trunc ((x & (~(-1 << maskNbits))))) << shiftNbits ; simplify to: ; ((trunc(x)) << shiftNbits) & (~(-1 << (maskNbits+shiftNbits))) ; Simple tests. declare void @use32(i32) declare void @use64(i64) define i32 @t0_basic(i64 %x, i32 %nbits) { ; CHECK-LABEL: @t0_basic( ; CHECK-NEXT: [[T0:%.*]] = zext i32 [[NBITS:%.*]] to i64 ; CHECK-NEXT: [[T1:%.*]] = shl i64 -1, [[T0]] ; CHECK-NEXT: [[T2:%.*]] = xor i64 [[T1]], -1 ; CHECK-NEXT: [[T3:%.*]] = sub i32 32, [[NBITS]] ; CHECK-NEXT: [[T4:%.*]] = and i64 [[T2]], [[X:%.*]] ; CHECK-NEXT: call void @use32(i32 [[NBITS]]) ; CHECK-NEXT: call void @use64(i64 [[T0]]) ; CHECK-NEXT: call void @use64(i64 [[T1]]) ; CHECK-NEXT: call void @use64(i64 [[T2]]) ; CHECK-NEXT: call void @use32(i32 [[T3]]) ; CHECK-NEXT: call void @use64(i64 [[T4]]) ; CHECK-NEXT: [[TMP1:%.*]] = trunc i64 [[X]] to i32 ; CHECK-NEXT: [[T6:%.*]] = shl i32 [[TMP1]], [[T3]] ; CHECK-NEXT: ret i32 [[T6]] ; %t0 = zext i32 %nbits to i64 %t1 = shl i64 -1, %t0 %t2 = xor i64 %t1, -1 %t3 = sub i32 32, %nbits %t4 = and i64 %t2, %x call void @use32(i32 %nbits) call void @use64(i64 %t0) call void @use64(i64 %t1) call void @use64(i64 %t2) call void @use32(i32 %t3) call void @use64(i64 %t4) %t5 = trunc i64 %t4 to i32 %t6 = shl i32 %t5, %t3 ret i32 %t6 } ; Vectors declare void @use8xi32(<8 x i32>) declare void @use8xi64(<8 x i64>) define <8 x i32> @t1_vec_splat(<8 x i64> %x, <8 x i32> %nbits) { ; CHECK-LABEL: @t1_vec_splat( ; CHECK-NEXT: [[T0:%.*]] = zext <8 x i32> [[NBITS:%.*]] to <8 x i64> ; CHECK-NEXT: [[T1:%.*]] = shl <8 x i64> <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>, [[T0]] ; CHECK-NEXT: [[T2:%.*]] = xor <8 x i64> [[T1]], <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1> ; CHECK-NEXT: [[T3:%.*]] = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32>, [[NBITS]] ; CHECK-NEXT: [[T4:%.*]] = and <8 x i64> [[T2]], [[X:%.*]] ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[NBITS]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T0]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T1]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T2]]) ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T3]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T4]]) ; CHECK-NEXT: [[TMP1:%.*]] = trunc <8 x i64> [[X]] to <8 x i32> ; CHECK-NEXT: [[T6:%.*]] = shl <8 x i32> [[TMP1]], [[T3]] ; CHECK-NEXT: ret <8 x i32> [[T6]] ; %t0 = zext <8 x i32> %nbits to <8 x i64> %t1 = shl <8 x i64> <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>, %t0 %t2 = xor <8 x i64> %t1, <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1> %t3 = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 32>, %nbits %t4 = and <8 x i64> %t2, %x call void @use8xi32(<8 x i32> %nbits) call void @use8xi64(<8 x i64> %t0) call void @use8xi64(<8 x i64> %t1) call void @use8xi64(<8 x i64> %t2) call void @use8xi32(<8 x i32> %t3) call void @use8xi64(<8 x i64> %t4) %t5 = trunc <8 x i64> %t4 to <8 x i32> %t6 = shl <8 x i32> %t5, %t3 ret <8 x i32> %t6 } define <8 x i32> @t2_vec_splat_undef(<8 x i64> %x, <8 x i32> %nbits) { ; CHECK-LABEL: @t2_vec_splat_undef( ; CHECK-NEXT: [[T0:%.*]] = zext <8 x i32> [[NBITS:%.*]] to <8 x i64> ; CHECK-NEXT: [[T1:%.*]] = shl <8 x i64> <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 undef, i64 -1>, [[T0]] ; CHECK-NEXT: [[T2:%.*]] = xor <8 x i64> [[T1]], <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 undef, i64 -1> ; CHECK-NEXT: [[T3:%.*]] = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 undef, i32 32>, [[NBITS]] ; CHECK-NEXT: [[T4:%.*]] = and <8 x i64> [[T2]], [[X:%.*]] ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[NBITS]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T0]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T1]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T2]]) ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T3]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T4]]) ; CHECK-NEXT: [[TMP1:%.*]] = trunc <8 x i64> [[X]] to <8 x i32> ; CHECK-NEXT: [[T6:%.*]] = shl <8 x i32> [[TMP1]], [[T3]] ; CHECK-NEXT: ret <8 x i32> [[T6]] ; %t0 = zext <8 x i32> %nbits to <8 x i64> %t1 = shl <8 x i64> <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 undef, i64 -1>, %t0 %t2 = xor <8 x i64> %t1, <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 undef, i64 -1> %t3 = sub <8 x i32> <i32 32, i32 32, i32 32, i32 32, i32 32, i32 32, i32 undef, i32 32>, %nbits %t4 = and <8 x i64> %t2, %x call void @use8xi32(<8 x i32> %nbits) call void @use8xi64(<8 x i64> %t0) call void @use8xi64(<8 x i64> %t1) call void @use8xi64(<8 x i64> %t2) call void @use8xi32(<8 x i32> %t3) call void @use8xi64(<8 x i64> %t4) %t5 = trunc <8 x i64> %t4 to <8 x i32> %t6 = shl <8 x i32> %t5, %t3 ret <8 x i32> %t6 } define <8 x i32> @t3_vec_nonsplat(<8 x i64> %x, <8 x i32> %nbits) { ; CHECK-LABEL: @t3_vec_nonsplat( ; CHECK-NEXT: [[T0:%.*]] = add <8 x i32> [[NBITS:%.*]], <i32 -1, i32 0, i32 0, i32 1, i32 0, i32 0, i32 0, i32 0> ; CHECK-NEXT: [[T1:%.*]] = zext <8 x i32> [[T0]] to <8 x i64> ; CHECK-NEXT: [[T2:%.*]] = shl <8 x i64> <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>, [[T1]] ; CHECK-NEXT: [[T3:%.*]] = xor <8 x i64> [[T2]], <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1> ; CHECK-NEXT: [[T4:%.*]] = sub <8 x i32> <i32 33, i32 32, i32 33, i32 32, i32 32, i32 32, i32 32, i32 32>, [[NBITS]] ; CHECK-NEXT: [[T5:%.*]] = and <8 x i64> [[T3]], [[X:%.*]] ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T0]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T1]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T2]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T3]]) ; CHECK-NEXT: call void @use8xi32(<8 x i32> [[T4]]) ; CHECK-NEXT: call void @use8xi64(<8 x i64> [[T5]]) ; CHECK-NEXT: [[TMP1:%.*]] = trunc <8 x i64> [[X]] to <8 x i32> ; CHECK-NEXT: [[T7:%.*]] = shl <8 x i32> [[TMP1]], [[T4]] ; CHECK-NEXT: ret <8 x i32> [[T7]] ; %t0 = add <8 x i32> %nbits, <i32 -1, i32 0, i32 0, i32 1, i32 0, i32 0, i32 0, i32 0> %t1 = zext <8 x i32> %t0 to <8 x i64> %t2 = shl <8 x i64> <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>, %t1 ; shifting by nbits-1 %t3 = xor <8 x i64> %t2, <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1, i64 -1> %t4 = sub <8 x i32> <i32 33, i32 32, i32 33, i32 32, i32 32, i32 32, i32 32, i32 32>, %nbits %t5 = and <8 x i64> %t3, %x call void @use8xi32(<8 x i32> %t0) call void @use8xi64(<8 x i64> %t1) call void @use8xi64(<8 x i64> %t2) call void @use8xi64(<8 x i64> %t3) call void @use8xi32(<8 x i32> %t4) call void @use8xi64(<8 x i64> %t5) %t6 = trunc <8 x i64> %t5 to <8 x i32> %t7 = shl <8 x i32> %t6, %t4 ret <8 x i32> %t7 } ; -1 can be truncated. define i32 @t4_allones_trunc(i64 %x, i32 %nbits) { ; CHECK-LABEL: @t4_allones_trunc( ; CHECK-NEXT: [[T0:%.*]] = zext i32 [[NBITS:%.*]] to i64 ; CHECK-NEXT: [[T1:%.*]] = shl i64 -1, [[T0]] ; CHECK-NEXT: [[T2:%.*]] = xor i64 [[T1]], 4294967295 ; CHECK-NEXT: [[T3:%.*]] = sub i32 32, [[NBITS]] ; CHECK-NEXT: [[T4:%.*]] = and i64 [[T2]], [[X:%.*]] ; CHECK-NEXT: call void @use32(i32 [[NBITS]]) ; CHECK-NEXT: call void @use64(i64 [[T0]]) ; CHECK-NEXT: call void @use64(i64 [[T1]]) ; CHECK-NEXT: call void @use64(i64 [[T2]]) ; CHECK-NEXT: call void @use32(i32 [[T3]]) ; CHECK-NEXT: call void @use64(i64 [[T4]]) ; CHECK-NEXT: [[T5:%.*]] = trunc i64 [[T4]] to i32 ; CHECK-NEXT: [[T6:%.*]] = shl i32 [[T5]], [[T3]] ; CHECK-NEXT: ret i32 [[T6]] ; %t0 = zext i32 %nbits to i64 %t1 = shl i64 -1, %t0 %t2 = xor i64 %t1, 4294967295 %t3 = sub i32 32, %nbits %t4 = and i64 %t2, %x call void @use32(i32 %nbits) call void @use64(i64 %t0) call void @use64(i64 %t1) call void @use64(i64 %t2) call void @use32(i32 %t3) call void @use64(i64 %t4) %t5 = trunc i64 %t4 to i32 %t6 = shl i32 %t5, %t3 ret i32 %t6 } ; Extra uses define i32 @n5_extrause(i64 %x, i32 %nbits) { ; CHECK-LABEL: @n5_extrause( ; CHECK-NEXT: [[T0:%.*]] = zext i32 [[NBITS:%.*]] to i64 ; CHECK-NEXT: [[T1:%.*]] = shl i64 -1, [[T0]] ; CHECK-NEXT: [[T2:%.*]] = xor i64 [[T1]], -1 ; CHECK-NEXT: [[T3:%.*]] = sub i32 32, [[NBITS]] ; CHECK-NEXT: [[T4:%.*]] = and i64 [[T2]], [[X:%.*]] ; CHECK-NEXT: call void @use32(i32 [[NBITS]]) ; CHECK-NEXT: call void @use64(i64 [[T0]]) ; CHECK-NEXT: call void @use64(i64 [[T1]]) ; CHECK-NEXT: call void @use64(i64 [[T2]]) ; CHECK-NEXT: call void @use32(i32 [[T3]]) ; CHECK-NEXT: call void @use64(i64 [[T4]]) ; CHECK-NEXT: [[T5:%.*]] = trunc i64 [[T4]] to i32 ; CHECK-NEXT: call void @use32(i32 [[T5]]) ; CHECK-NEXT: [[T6:%.*]] = shl i32 [[T5]], [[T3]] ; CHECK-NEXT: ret i32 [[T6]] ; %t0 = zext i32 %nbits to i64 %t1 = shl i64 -1, %t0 %t2 = xor i64 %t1, -1 %t3 = sub i32 32, %nbits %t4 = and i64 %t2, %x call void @use32(i32 %nbits) call void @use64(i64 %t0) call void @use64(i64 %t1) call void @use64(i64 %t2) call void @use32(i32 %t3) call void @use64(i64 %t4) %t5 = trunc i64 %t4 to i32 call void @use32(i32 %t5) %t6 = shl i32 %t5, %t3 ret i32 %t6 }