; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt -S -passes=instcombine < %s | FileCheck %s ; Check if a value can be deduced as a power of 2, allowing urem optimization. ; i.e. A urem B = A & (B - 1) if B is a power of 2. define i64 @known_power_of_two_urem_phi(i64 %size, i1 %cmp, i1 %cmp1) { ; CHECK-LABEL: @known_power_of_two_urem_phi( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[CMP:%.*]], label [[COND_TRUE:%.*]], label [[COND_END:%.*]] ; CHECK: cond.true: ; CHECK-NEXT: br i1 [[CMP1:%.*]], label [[COND_TRUE_TRUE:%.*]], label [[COND_TRUE_FALSE:%.*]] ; CHECK: cond.true.true: ; CHECK-NEXT: br label [[COND_TRUE_END:%.*]] ; CHECK: cond.true.false: ; CHECK-NEXT: br label [[COND_TRUE_END]] ; CHECK: cond.true.end: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ 1, [[COND_TRUE_TRUE]] ], [ 3, [[COND_TRUE_FALSE]] ] ; CHECK-NEXT: br label [[COND_END]] ; CHECK: cond.end: ; CHECK-NEXT: [[PHI1:%.*]] = phi i64 [ 4095, [[ENTRY:%.*]] ], [ [[PHI]], [[COND_TRUE_END]] ] ; CHECK-NEXT: [[UREM:%.*]] = and i64 [[SIZE:%.*]], [[PHI1]] ; CHECK-NEXT: ret i64 [[UREM]] ; entry: br i1 %cmp, label %cond.true, label %cond.end cond.true: br i1 %cmp1, label %cond.true.true, label %cond.true.false cond.true.true: br label %cond.true.end cond.true.false: br label %cond.true.end cond.true.end: %phi = phi i64 [ 2, %cond.true.true ], [ 4, %cond.true.false ] br label %cond.end cond.end: %phi1 = phi i64 [ 4096, %entry ], [ %phi, %cond.true.end ] %urem = urem i64 %size, %phi1 ret i64 %urem } define i64 @known_power_of_two_urem_nested_expr(i64 %size, i1 %cmp, i1 %cmp1, i64 %0) { ; CHECK-LABEL: @known_power_of_two_urem_nested_expr( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[CMP:%.*]], label [[COND_TRUE:%.*]], label [[COND_FALSE:%.*]] ; CHECK: cond.true: ; CHECK-NEXT: [[TMP1:%.*]] = shl nuw i64 1, [[TMP0:%.*]] ; CHECK-NEXT: br label [[COND_END:%.*]] ; CHECK: cond.false: ; CHECK-NEXT: [[SELECT:%.*]] = select i1 [[CMP1:%.*]], i64 2, i64 8 ; CHECK-NEXT: br label [[COND_END]] ; CHECK: cond.end: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ [[SELECT]], [[COND_FALSE]] ], [ [[TMP1]], [[COND_TRUE]] ], [ [[PHI]], [[COND_END]] ] ; CHECK-NEXT: [[TMP2:%.*]] = add i64 [[PHI]], -1 ; CHECK-NEXT: [[UREM:%.*]] = and i64 [[SIZE:%.*]], [[TMP2]] ; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i64 [[UREM]], 10 ; CHECK-NEXT: br i1 [[CMP2]], label [[COND_END]], label [[END:%.*]] ; CHECK: end: ; CHECK-NEXT: ret i64 [[UREM]] ; entry: br i1 %cmp, label %cond.true, label %cond.false cond.true: %1 = shl nuw i64 1, %0 br label %cond.end cond.false: %select = select i1 %cmp1, i64 2, i64 8 br label %cond.end cond.end: %phi = phi i64 [ %select, %cond.false ], [ %1, %cond.true ], [ %phi, %cond.end ] %2 = phi i64 [ %size, %cond.false ], [ %size, %cond.true ], [ %0, %cond.end ] %urem = urem i64 %size, %phi %cmp2 = icmp ult i64 %urem, 10 br i1 %cmp2, label %cond.end, label %end end: ret i64 %urem } define i64 @known_power_of_two_urem_negative(i64 %size, i1 %cmp, i64 %0) { ; urem is not replaced if not all operands are power of 2. ; ; CHECK-LABEL: @known_power_of_two_urem_negative( ; CHECK-NEXT: entry: ; CHECK-NEXT: br i1 [[CMP:%.*]], label [[COND_TRUE:%.*]], label [[COND_END:%.*]] ; CHECK: cond.true: ; CHECK-NEXT: br label [[COND_END]] ; CHECK: cond.end: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ 4, [[ENTRY:%.*]] ], [ [[TMP0:%.*]], [[COND_TRUE]] ] ; CHECK-NEXT: [[UREM:%.*]] = urem i64 [[SIZE:%.*]], [[PHI]] ; CHECK-NEXT: ret i64 [[UREM]] ; entry: br i1 %cmp, label %cond.true, label %cond.end cond.true: br label %cond.end cond.end: %phi = phi i64 [ 4, %entry ], [ %0, %cond.true ] %urem = urem i64 %size, %phi ret i64 %urem } define i64 @known_power_of_two_urem_loop_mul(i64 %size, i64 %a) { ; CHECK-LABEL: @known_power_of_two_urem_loop_mul( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[START:%.*]] = shl nuw i64 1, [[A:%.*]] ; CHECK-NEXT: br label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ [[START]], [[ENTRY:%.*]] ], [ [[I:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[SUM:%.*]] = phi i64 [ 0, [[ENTRY]] ], [ [[ADD:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[PHI]], -1 ; CHECK-NEXT: [[UREM:%.*]] = and i64 [[SIZE:%.*]], [[TMP0]] ; CHECK-NEXT: [[ADD]] = add nuw i64 [[SUM]], [[UREM]] ; CHECK-NEXT: [[I]] = shl nuw i64 [[PHI]], 2 ; CHECK-NEXT: [[ICMP:%.*]] = icmp ult i64 [[PHI]], 25000000 ; CHECK-NEXT: br i1 [[ICMP]], label [[FOR_BODY]], label [[FOR_END:%.*]] ; CHECK: for.end: ; CHECK-NEXT: ret i64 [[SUM]] ; entry: %start = shl nuw i64 1, %a br label %for.body for.body: %phi = phi i64 [ %start, %entry ], [ %i, %for.body ] %sum = phi i64 [ 0, %entry ], [ %add, %for.body ] %urem = urem i64 %size, %phi %add = add nuw i64 %sum, %urem %i = mul nuw i64 %phi, 4 %icmp = icmp ult i64 %i, 100000000 br i1 %icmp, label %for.body, label %for.end for.end: %r = phi i64 [ %sum, %for.body ] ret i64 %r } define i64 @known_power_of_two_urem_loop_mul_negative(i64 %size, i64 %a) { ; Cannot deduce induction variable is a power of 2 if it is multiplied by 3. ; ; CHECK-LABEL: @known_power_of_two_urem_loop_mul_negative( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[START:%.*]] = shl nuw i64 1, [[A:%.*]] ; CHECK-NEXT: br label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ [[START]], [[ENTRY:%.*]] ], [ [[I:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[SUM:%.*]] = phi i64 [ 0, [[ENTRY]] ], [ [[ADD:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[UREM:%.*]] = urem i64 [[SIZE:%.*]], [[PHI]] ; CHECK-NEXT: [[ADD]] = add nuw i64 [[SUM]], [[UREM]] ; CHECK-NEXT: [[I]] = mul nuw i64 [[PHI]], 3 ; CHECK-NEXT: [[ICMP:%.*]] = icmp ult i64 [[PHI]], 33333334 ; CHECK-NEXT: br i1 [[ICMP]], label [[FOR_BODY]], label [[FOR_END:%.*]] ; CHECK: for.end: ; CHECK-NEXT: ret i64 [[SUM]] ; entry: %start = shl nuw i64 1, %a br label %for.body for.body: %phi = phi i64 [ %start, %entry ], [ %i, %for.body ] %sum = phi i64 [ 0, %entry ], [ %add, %for.body ] %urem = urem i64 %size, %phi %add = add nuw i64 %sum, %urem %i = mul nuw i64 %phi, 3 %icmp = icmp ult i64 %i, 100000000 br i1 %icmp, label %for.body, label %for.end for.end: %r = phi i64 [ %sum, %for.body ] ret i64 %r } define i64 @known_power_of_two_urem_loop_shl(i64 %size, i64 %a) { ; CHECK-LABEL: @known_power_of_two_urem_loop_shl( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[START:%.*]] = shl nuw i64 1, [[A:%.*]] ; CHECK-NEXT: br label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ [[START]], [[ENTRY:%.*]] ], [ [[I:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[SUM:%.*]] = phi i64 [ 0, [[ENTRY]] ], [ [[ADD:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[PHI]], -1 ; CHECK-NEXT: [[UREM:%.*]] = and i64 [[SIZE:%.*]], [[TMP0]] ; CHECK-NEXT: [[ADD]] = add nuw i64 [[SUM]], [[UREM]] ; CHECK-NEXT: [[I]] = shl nuw i64 [[PHI]], 1 ; CHECK-NEXT: [[ICMP:%.*]] = icmp ult i64 [[PHI]], 50000000 ; CHECK-NEXT: br i1 [[ICMP]], label [[FOR_BODY]], label [[FOR_END:%.*]] ; CHECK: for.end: ; CHECK-NEXT: ret i64 [[SUM]] ; entry: %start = shl nuw i64 1, %a br label %for.body for.body: %phi = phi i64 [ %start, %entry ], [ %i, %for.body ] %sum = phi i64 [ 0, %entry ], [ %add, %for.body ] %urem = urem i64 %size, %phi %add = add nuw i64 %sum, %urem %i = shl nuw i64 %phi, 1 %icmp = icmp ult i64 %i, 100000000 br i1 %icmp, label %for.body, label %for.end for.end: %r = phi i64 [ %sum, %for.body ] ret i64 %r } define i64 @known_power_of_two_urem_loop_lshr(i64 %size, i64 %a) { ; CHECK-LABEL: @known_power_of_two_urem_loop_lshr( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[START:%.*]] = shl nuw i64 1, [[A:%.*]] ; CHECK-NEXT: br label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ [[START]], [[ENTRY:%.*]] ], [ [[I:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[SUM:%.*]] = phi i64 [ 0, [[ENTRY]] ], [ [[ADD:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[PHI]], -1 ; CHECK-NEXT: [[UREM:%.*]] = and i64 [[SIZE:%.*]], [[TMP0]] ; CHECK-NEXT: [[ADD]] = add nuw i64 [[SUM]], [[UREM]] ; CHECK-NEXT: [[I]] = lshr i64 [[PHI]], 1 ; CHECK-NEXT: [[ICMP_NOT:%.*]] = icmp eq i64 [[I]], 0 ; CHECK-NEXT: br i1 [[ICMP_NOT]], label [[FOR_END:%.*]], label [[FOR_BODY]] ; CHECK: for.end: ; CHECK-NEXT: ret i64 [[SUM]] ; entry: %start = shl nuw i64 1, %a br label %for.body for.body: %phi = phi i64 [ %start, %entry ], [ %i, %for.body ] %sum = phi i64 [ 0, %entry ], [ %add, %for.body ] %urem = urem i64 %size, %phi %add = add nuw i64 %sum, %urem %i = lshr i64 %phi, 1 %icmp = icmp ugt i64 %i, 0 br i1 %icmp, label %for.body, label %for.end for.end: %r = phi i64 [ %sum, %for.body ] ret i64 %r } define i64 @known_power_of_two_urem_loop_ashr(i64 %size, i64 %a) { ; CHECK-LABEL: @known_power_of_two_urem_loop_ashr( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ 4096, [[ENTRY:%.*]] ], [ [[I:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[SUM:%.*]] = phi i64 [ 0, [[ENTRY]] ], [ [[ADD:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[TMP0:%.*]] = add nsw i64 [[PHI]], -1 ; CHECK-NEXT: [[UREM:%.*]] = and i64 [[SIZE:%.*]], [[TMP0]] ; CHECK-NEXT: [[ADD]] = add nsw i64 [[SUM]], [[UREM]] ; CHECK-NEXT: [[I]] = lshr i64 [[PHI]], [[A:%.*]] ; CHECK-NEXT: [[ICMP_NOT:%.*]] = icmp eq i64 [[I]], 0 ; CHECK-NEXT: br i1 [[ICMP_NOT]], label [[FOR_END:%.*]], label [[FOR_BODY]] ; CHECK: for.end: ; CHECK-NEXT: ret i64 [[SUM]] ; entry: br label %for.body for.body: %phi = phi i64 [ 4096, %entry ], [ %i, %for.body ] %sum = phi i64 [ 0, %entry ], [ %add, %for.body ] %urem = urem i64 %size, %phi %add = add nsw i64 %sum, %urem %i = ashr i64 %phi, %a %icmp = icmp ugt i64 %i, 0 br i1 %icmp, label %for.body, label %for.end for.end: %r = phi i64 [ %sum, %for.body ] ret i64 %r } define i64 @known_power_of_two_urem_loop_ashr_negative(i64 %size, i64 %a) { ; Cannot deduce induction variable is a power of 2 for ashr if its starting ; value is equal to sign bit ; ; CHECK-LABEL: @known_power_of_two_urem_loop_ashr_negative( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: br i1 true, label [[FOR_BODY]], label [[FOR_END:%.*]] ; CHECK: for.end: ; CHECK-NEXT: ret i64 poison ; entry: br label %for.body for.body: %phi = phi i64 [ u0x8000000000000000, %entry ], [ %i, %for.body ] %sum = phi i64 [ 0, %entry ], [ %add, %for.body ] %urem = urem i64 %size, %phi %add = add nsw i64 %sum, %urem %i = ashr i64 %phi, %a %icmp = icmp ugt i64 %i, 1 br i1 %icmp, label %for.body, label %for.end for.end: %r = phi i64 [ %sum, %for.body ] ret i64 %r } define i64 @known_power_of_two_urem_loop_ashr_negative_2(i64 %size, i64 %a) { ; Cannot deduce induction variable is a power of 2 for ashr if its starting ; value may equal to sign bit. ; ; CHECK-LABEL: @known_power_of_two_urem_loop_ashr_negative_2( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[START:%.*]] = shl nuw i64 1, [[A:%.*]] ; CHECK-NEXT: br label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ [[START]], [[ENTRY:%.*]] ], [ [[I:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[SUM:%.*]] = phi i64 [ 0, [[ENTRY]] ], [ [[ADD:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[UREM:%.*]] = urem i64 [[SIZE:%.*]], [[PHI]] ; CHECK-NEXT: [[ADD]] = add nsw i64 [[SUM]], [[UREM]] ; CHECK-NEXT: [[I]] = ashr i64 [[PHI]], 2 ; CHECK-NEXT: [[ICMP_NOT:%.*]] = icmp eq i64 [[I]], 0 ; CHECK-NEXT: br i1 [[ICMP_NOT]], label [[FOR_END:%.*]], label [[FOR_BODY]] ; CHECK: for.end: ; CHECK-NEXT: ret i64 [[SUM]] ; entry: %start = shl nuw i64 1, %a br label %for.body for.body: %phi = phi i64 [ %start, %entry ], [ %i, %for.body ] %sum = phi i64 [ 0, %entry ], [ %add, %for.body ] %urem = urem i64 %size, %phi %add = add nsw i64 %sum, %urem %i = ashr i64 %phi, 2 %icmp = icmp ugt i64 %i, 0 br i1 %icmp, label %for.body, label %for.end for.end: %r = phi i64 [ %sum, %for.body ] ret i64 %r } define i64 @known_power_of_two_urem_loop_negative(i64 %size, i64 %a) { ; Cannot deduce induction variable is a power of 2 if the recurrence is not one ; of the valid arithmetic operations. ; ; CHECK-LABEL: @known_power_of_two_urem_loop_negative( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[START:%.*]] = shl nuw i64 1, [[A:%.*]] ; CHECK-NEXT: br label [[FOR_BODY:%.*]] ; CHECK: for.body: ; CHECK-NEXT: [[PHI:%.*]] = phi i64 [ [[START]], [[ENTRY:%.*]] ], [ [[I:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[SUM:%.*]] = phi i64 [ 0, [[ENTRY]] ], [ [[ADD:%.*]], [[FOR_BODY]] ] ; CHECK-NEXT: [[UREM:%.*]] = urem i64 [[SIZE:%.*]], [[PHI]] ; CHECK-NEXT: [[ADD]] = add nuw i64 [[SUM]], [[UREM]] ; CHECK-NEXT: [[I]] = add nuw i64 [[PHI]], 1 ; CHECK-NEXT: [[ICMP:%.*]] = icmp ugt i64 [[PHI]], 1 ; CHECK-NEXT: br i1 [[ICMP]], label [[FOR_BODY]], label [[FOR_END:%.*]] ; CHECK: for.end: ; CHECK-NEXT: ret i64 [[SUM]] ; entry: %start = shl nuw i64 1, %a br label %for.body for.body: %phi = phi i64 [ %start, %entry ], [ %i, %for.body ] %sum = phi i64 [ 0, %entry ], [ %add, %for.body ] %urem = urem i64 %size, %phi %add = add nuw i64 %sum, %urem %i = add nuw i64 %phi, 1 %icmp = icmp ugt i64 %i, 2 br i1 %icmp, label %for.body, label %for.end for.end: %r = phi i64 [ %sum, %for.body ] ret i64 %r } ; https://alive2.llvm.org/ce/z/3QfEHm define i8 @known_power_of_two_rust_next_power_of_two(i8 %x, i8 %y) { ; CHECK-LABEL: @known_power_of_two_rust_next_power_of_two( ; CHECK-NEXT: [[TMP1:%.*]] = add i8 [[X:%.*]], -1 ; CHECK-NEXT: [[TMP2:%.*]] = tail call range(i8 0, 9) i8 @llvm.ctlz.i8(i8 [[TMP1]], i1 true) ; CHECK-NEXT: [[TMP3:%.*]] = lshr i8 -1, [[TMP2]] ; CHECK-NEXT: [[TMP4:%.*]] = icmp ugt i8 [[X]], 1 ; CHECK-NEXT: [[TMP5:%.*]] = select i1 [[TMP4]], i8 [[TMP3]], i8 0 ; CHECK-NEXT: [[R:%.*]] = and i8 [[Y:%.*]], [[TMP5]] ; CHECK-NEXT: ret i8 [[R]] ; %2 = add i8 %x, -1 %3 = tail call i8 @llvm.ctlz.i8(i8 %2, i1 true) %4 = lshr i8 -1, %3 %5 = add i8 %4, 1 %6 = icmp ugt i8 %x, 1 %p = select i1 %6, i8 %5, i8 1 ; Rust's implementation of `%p = next_power_of_two(%x)` %r = urem i8 %y, %p ret i8 %r } define i8 @known_power_of_two_lshr_add_one_allow_zero(i8 %x, i8 %y) { ; CHECK-LABEL: @known_power_of_two_lshr_add_one_allow_zero( ; CHECK-NEXT: [[TMP1:%.*]] = lshr i8 -1, [[X:%.*]] ; CHECK-NEXT: [[R:%.*]] = and i8 [[Y:%.*]], [[TMP1]] ; CHECK-NEXT: ret i8 [[R]] ; %4 = lshr i8 -1, %x %p = add i8 %4, 1 ; Note: y % p --> y & (p - 1) allows p == 0 %r = urem i8 %y, %p ret i8 %r } define i1 @known_power_of_two_lshr_add_one_nuw_deny_zero(i8 %x, i8 %y) { ; CHECK-LABEL: @known_power_of_two_lshr_add_one_nuw_deny_zero( ; CHECK-NEXT: [[TMP1:%.*]] = lshr i8 -1, [[X:%.*]] ; CHECK-NEXT: [[TMP2:%.*]] = sub i8 -2, [[TMP1]] ; CHECK-NEXT: [[TMP3:%.*]] = or i8 [[Y:%.*]], [[TMP2]] ; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[TMP3]], -1 ; CHECK-NEXT: ret i1 [[R]] ; %4 = lshr i8 -1, %x %p = add nuw i8 %4, 1 ; Note: A & B_Pow2 != B_Pow2 --> A & B_Pow2 == 0 requires B_Pow2 != 0 %and = and i8 %p, %y %r = icmp ne i8 %and, %p ret i1 %r } define i1 @negative_known_power_of_two_lshr_add_one_deny_zero(i8 %x, i8 %y) { ; CHECK-LABEL: @negative_known_power_of_two_lshr_add_one_deny_zero( ; CHECK-NEXT: [[TMP1:%.*]] = lshr i8 -1, [[X:%.*]] ; CHECK-NEXT: [[TMP2:%.*]] = sub i8 -2, [[TMP1]] ; CHECK-NEXT: [[TMP3:%.*]] = or i8 [[Y:%.*]], [[TMP2]] ; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[TMP3]], -1 ; CHECK-NEXT: ret i1 [[R]] ; %4 = lshr i8 -1, %x %p = add i8 %4, 1 ; Note: A & B_Pow2 != B_Pow2 --> A & B_Pow2 == 0 requires B_Pow2 != 0 %and = and i8 %p, %y %r = icmp ne i8 %and, %p ret i1 %r } define i1 @negative_known_power_of_two_lshr_add_one_nsw_deny_zero(i8 %x, i8 %y) { ; CHECK-LABEL: @negative_known_power_of_two_lshr_add_one_nsw_deny_zero( ; CHECK-NEXT: [[TMP1:%.*]] = lshr i8 -1, [[X:%.*]] ; CHECK-NEXT: [[TMP2:%.*]] = sub i8 -2, [[TMP1]] ; CHECK-NEXT: [[TMP3:%.*]] = or i8 [[Y:%.*]], [[TMP2]] ; CHECK-NEXT: [[R:%.*]] = icmp ne i8 [[TMP3]], -1 ; CHECK-NEXT: ret i1 [[R]] ; %4 = lshr i8 -1, %x %p = add nsw i8 %4, 1 ; Note: A & B_Pow2 != B_Pow2 --> A & B_Pow2 == 0 requires B_Pow2 != 0 %and = and i8 %p, %y %r = icmp ne i8 %and, %p ret i1 %r } define i8 @known_power_of_two_lshr_add_negative_1(i8 %x, i8 %y) { ; CHECK-LABEL: @known_power_of_two_lshr_add_negative_1( ; CHECK-NEXT: [[TMP1:%.*]] = lshr i8 -2, [[X:%.*]] ; CHECK-NEXT: [[P:%.*]] = add nuw i8 [[TMP1]], 1 ; CHECK-NEXT: [[R:%.*]] = urem i8 [[Y:%.*]], [[P]] ; CHECK-NEXT: ret i8 [[R]] ; %4 = lshr i8 -2, %x %p = add i8 %4, 1 %r = urem i8 %y, %p ret i8 %r } define i8 @known_power_of_two_lshr_add_negative_2(i8 %x, i8 %y) { ; CHECK-LABEL: @known_power_of_two_lshr_add_negative_2( ; CHECK-NEXT: [[TMP1:%.*]] = lshr i8 -1, [[X:%.*]] ; CHECK-NEXT: [[P:%.*]] = add nsw i8 [[TMP1]], -1 ; CHECK-NEXT: [[R:%.*]] = urem i8 [[Y:%.*]], [[P]] ; CHECK-NEXT: ret i8 [[R]] ; %4 = lshr i8 -1, %x %p = add i8 %4, -1 %r = urem i8 %y, %p ret i8 %r }