1 // RUN: %clang_cc1 -fcatch-undefined-behavior -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s 2 3 // CHECK: @_Z17reference_binding 4 void reference_binding(int *p) { 5 // C++ core issue 453: If an lvalue to which a reference is directly bound 6 // designates neither an existing object or function of an appropriate type, 7 // nor a region of storage of suitable size and alignment to contain an object 8 // of the reference's type, the behavior is undefined. 9 10 // CHECK: icmp ne {{.*}}, null 11 12 // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64 13 // CHECK-NEXT: icmp uge i64 %[[SIZE]], 4 14 15 // CHECK: %[[PTRINT:.*]] = ptrtoint 16 // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3 17 // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0 18 int &r = *p; 19 } 20 21 struct S { 22 double d; 23 int a, b; 24 virtual int f(); 25 }; 26 27 // CHECK: @_Z13member_access 28 void member_access(S *p) { 29 // (1) Check 'p' is appropriately sized and aligned for member access. 30 31 // FIXME: Check vptr is for 'S' or a class derived from 'S'. 32 33 // CHECK: icmp ne {{.*}}, null 34 35 // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64 36 // CHECK-NEXT: icmp uge i64 %[[SIZE]], 24 37 38 // CHECK: %[[PTRINT:.*]] = ptrtoint 39 // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 7 40 // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0 41 42 // (2) Check 'p->b' is appropriately sized and aligned for a load. 43 44 // FIXME: Suppress this in the trivial case of a member access, because we 45 // know we've just checked the member access expression itself. 46 47 // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64 48 // CHECK-NEXT: icmp uge i64 %[[SIZE]], 4 49 50 // CHECK: %[[PTRINT:.*]] = ptrtoint 51 // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 3 52 // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0 53 int k = p->b; 54 55 // (3) Check 'p' is appropriately sized and aligned for member function call. 56 57 // FIXME: Check vptr is for 'S' or a class derived from 'S'. 58 59 // CHECK: icmp ne {{.*}}, null 60 61 // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64 62 // CHECK-NEXT: icmp uge i64 %[[SIZE]], 24 63 64 // CHECK: %[[PTRINT:.*]] = ptrtoint 65 // CHECK-NEXT: %[[MISALIGN:.*]] = and i64 %[[PTRINT]], 7 66 // CHECK-NEXT: icmp eq i64 %[[MISALIGN]], 0 67 k = p->f(); 68 } 69 70 // CHECK: @_Z12lsh_overflow 71 int lsh_overflow(int a, int b) { 72 // CHECK: %[[INBOUNDS:.*]] = icmp ule i32 %[[RHS:.*]], 31 73 // CHECK-NEXT: br i1 %[[INBOUNDS]] 74 75 // CHECK: %[[SHIFTED_OUT_WIDTH:.*]] = sub nuw nsw i32 31, %[[RHS]] 76 // CHECK-NEXT: %[[SHIFTED_OUT:.*]] = lshr i32 %[[LHS:.*]], %[[SHIFTED_OUT_WIDTH]] 77 78 // This is present for C++11 but not for C: C++ core issue 1457 allows a '1' 79 // to be shifted into the sign bit, but not out of it. 80 // CHECK-NEXT: %[[SHIFTED_OUT_NOT_SIGN:.*]] = lshr i32 %[[SHIFTED_OUT]], 1 81 82 // CHECK-NEXT: %[[NO_OVERFLOW:.*]] = icmp eq i32 %[[SHIFTED_OUT_NOT_SIGN]], 0 83 // CHECK-NEXT: br i1 %[[NO_OVERFLOW]] 84 85 // CHECK: %[[RET:.*]] = shl i32 %[[LHS]], %[[RHS]] 86 // CHECK-NEXT: ret i32 %[[RET]] 87 return a << b; 88 } 89
