1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4 2; RUN: opt -passes=bdce %s -S | FileCheck %s 3 4; The 'nuw' on the subtract allows us to deduce that %setbit is not demanded. 5; But if we change that value to '0', then the 'nuw' is no longer valid. If we don't 6; remove the 'nuw', another pass (-instcombine) may make a transform based on an 7; that incorrect assumption and we can miscompile: 8; https://bugs.llvm.org/show_bug.cgi?id=33695 9 10define i1 @PR33695(i1 %b, i8 %x) { 11; CHECK-LABEL: define i1 @PR33695( 12; CHECK-SAME: i1 [[B:%.*]], i8 [[X:%.*]]) { 13; CHECK-NEXT: [[LITTLE_NUMBER:%.*]] = zext i1 [[B]] to i8 14; CHECK-NEXT: [[BIG_NUMBER:%.*]] = shl i8 0, 1 15; CHECK-NEXT: [[SUB:%.*]] = sub i8 [[BIG_NUMBER]], [[LITTLE_NUMBER]] 16; CHECK-NEXT: [[TRUNC:%.*]] = trunc i8 [[SUB]] to i1 17; CHECK-NEXT: ret i1 [[TRUNC]] 18; 19 %setbit = or i8 %x, 64 20 %little_number = zext i1 %b to i8 21 %big_number = shl i8 %setbit, 1 22 %sub = sub nuw i8 %big_number, %little_number 23 %trunc = trunc i8 %sub to i1 24 ret i1 %trunc 25} 26 27; Similar to above, but now with more no-wrap. 28; https://bugs.llvm.org/show_bug.cgi?id=34037 29 30define i64 @PR34037(i64 %m, i32 %r, i64 %j, i1 %b, i32 %k, i64 %p) { 31; CHECK-LABEL: define i64 @PR34037( 32; CHECK-SAME: i64 [[M:%.*]], i32 [[R:%.*]], i64 [[J:%.*]], i1 [[B:%.*]], i32 [[K:%.*]], i64 [[P:%.*]]) { 33; CHECK-NEXT: [[SHL:%.*]] = shl i64 0, 29 34; CHECK-NEXT: [[CONV1:%.*]] = select i1 [[B]], i64 7, i64 0 35; CHECK-NEXT: [[SUB:%.*]] = sub i64 [[SHL]], [[CONV1]] 36; CHECK-NEXT: [[CONV2:%.*]] = zext i32 [[K]] to i64 37; CHECK-NEXT: [[MUL:%.*]] = mul i64 [[SUB]], [[CONV2]] 38; CHECK-NEXT: [[CONV4:%.*]] = and i64 [[P]], 65535 39; CHECK-NEXT: [[AND5:%.*]] = and i64 [[MUL]], [[CONV4]] 40; CHECK-NEXT: ret i64 [[AND5]] 41; 42 %conv = zext i32 %r to i64 43 %and = and i64 %m, %conv 44 %neg = xor i64 %and, 34359738367 45 %or = or i64 %j, %neg 46 %shl = shl i64 %or, 29 47 %conv1 = select i1 %b, i64 7, i64 0 48 %sub = sub nuw nsw i64 %shl, %conv1 49 %conv2 = zext i32 %k to i64 50 %mul = mul nsw i64 %sub, %conv2 51 %conv4 = and i64 %p, 65535 52 %and5 = and i64 %mul, %conv4 53 ret i64 %and5 54} 55 56; This is a manufactured example based on the 1st test to prove that the 57; assumption-killing algorithm stops at the call. Ie, it does not remove 58; nsw/nuw from the 'add' because a call demands all bits of its argument. 59 60declare i1 @foo(i1) 61 62define i1 @poison_on_call_user_is_ok(i1 %b, i8 %x) { 63; CHECK-LABEL: define i1 @poison_on_call_user_is_ok( 64; CHECK-SAME: i1 [[B:%.*]], i8 [[X:%.*]]) { 65; CHECK-NEXT: [[LITTLE_NUMBER:%.*]] = zext i1 [[B]] to i8 66; CHECK-NEXT: [[BIG_NUMBER:%.*]] = shl i8 0, 1 67; CHECK-NEXT: [[SUB:%.*]] = sub i8 [[BIG_NUMBER]], [[LITTLE_NUMBER]] 68; CHECK-NEXT: [[TRUNC:%.*]] = trunc i8 [[SUB]] to i1 69; CHECK-NEXT: [[CALL_RESULT:%.*]] = call i1 @foo(i1 [[TRUNC]]) 70; CHECK-NEXT: [[ADD:%.*]] = add nuw nsw i1 [[CALL_RESULT]], true 71; CHECK-NEXT: [[MUL:%.*]] = mul i1 [[TRUNC]], [[ADD]] 72; CHECK-NEXT: ret i1 [[MUL]] 73; 74 %setbit = or i8 %x, 64 75 %little_number = zext i1 %b to i8 76 %big_number = shl i8 %setbit, 1 77 %sub = sub nuw i8 %big_number, %little_number 78 %trunc = trunc i8 %sub to i1 79 %call_result = call i1 @foo(i1 %trunc) 80 %add = add nsw nuw i1 %call_result, 1 81 %mul = mul i1 %trunc, %add 82 ret i1 %mul 83} 84 85 86; We were asserting that all users of a trivialized integer-type instruction were 87; also integer-typed, but that's too strong. The alloca has a pointer-type result. 88 89define void @PR34179(ptr %a) { 90; CHECK-LABEL: define void @PR34179( 91; CHECK-SAME: ptr [[A:%.*]]) { 92; CHECK-NEXT: [[T0:%.*]] = load volatile i32, ptr [[A]], align 4 93; CHECK-NEXT: ret void 94; 95 %t0 = load volatile i32, ptr %a 96 %vla = alloca i32, i32 %t0 97 ret void 98} 99 100define i64 @disjoint(i64 %x) { 101; CHECK-LABEL: define i64 @disjoint( 102; CHECK-SAME: i64 [[X:%.*]]) { 103; CHECK-NEXT: [[OR:%.*]] = or i64 [[X]], -2 104; CHECK-NEXT: ret i64 [[OR]] 105; 106 %and = and i64 %x, 1 107 %or = or disjoint i64 %and, -2 108 ret i64 %or 109} 110 111define i32 @disjoint_indirect(i64 %x) { 112; CHECK-LABEL: define i32 @disjoint_indirect( 113; CHECK-SAME: i64 [[X:%.*]]) { 114; CHECK-NEXT: [[TRUNC:%.*]] = trunc i64 [[X]] to i32 115; CHECK-NEXT: [[OR:%.*]] = or i32 [[TRUNC]], -2 116; CHECK-NEXT: ret i32 [[OR]] 117; 118 %and = and i64 %x, 1 119 %trunc = trunc i64 %and to i32 120 %or = or disjoint i32 %trunc, -2 121 ret i32 %or 122} 123 124define i32 @range(i32 %x) { 125; CHECK-LABEL: define i32 @range( 126; CHECK-SAME: i32 [[X:%.*]]) { 127; CHECK-NEXT: [[UMIN:%.*]] = call i32 @llvm.umin.i32(i32 [[X]], i32 100) 128; CHECK-NEXT: [[AND:%.*]] = and i32 [[UMIN]], -2 129; CHECK-NEXT: ret i32 [[AND]] 130; 131 %or = or i32 %x, 1 132 %umin = call i32 @llvm.umin.i32(i32 %or, i32 100), !range !{i32 1, i32 101} 133 %and = and i32 %umin, -2 134 ret i32 %and 135} 136