clang/test/CodeGenCXX/virtual-base-cast.cpp

   1 // RUN: %clang_cc1 -emit-llvm %s -o - -triple i686-pc-linux-gnu | FileCheck %s
   2 // RUN: %clang_cc1 -emit-llvm %s -o - -triple i686-pc-win32 | FileCheck -check-prefix MSVC %s
   3
   4 struct A { int a; virtual int aa(); };
   5 struct B { int b; virtual int bb(); };
   6 struct C : virtual A, virtual B { int c; virtual int aa(); virtual int bb(); };
   7 struct AA { int a; virtual int aa(); };
   8 struct BB { int b; virtual int bb(); };
   9 struct CC : AA, BB { virtual int aa(); virtual int bb(); virtual int cc(); };
  10 struct D : virtual C, virtual CC { int e; };
  11
  12 D* x;
  13
  14 A* a() { return x; }
  15 // CHECK: @_Z1av() [[NUW:#[0-9]+]]
  16 // CHECK: [[VBASEOFFSETPTRA:%[a-zA-Z0-9\.]+]] = getelementptr i8, ptr {{.*}}, i64 -16
  17 // CHECK: load i32, ptr [[VBASEOFFSETPTRA]]
  18 // CHECK: }
  19
  20 // MSVC: @"?a@@YAPAUA@@XZ"() [[NUW:#[0-9]+]] {
  21 // MSVC:   %[[vbptr_off:.*]] = getelementptr inbounds i8, ptr {{.*}}, i32 0
  22 // MSVC:   %[[vbtable:.*]] = load ptr, ptr %[[vbptr_off]]
  23 // MSVC:   %[[entry:.*]] = getelementptr inbounds i32, ptr {{.*}}, i32 1
  24 // MSVC:   %[[offset:.*]] = load i32, ptr %[[entry]]
  25 // MSVC:   add nsw i32 0, %[[offset]]
  26 // MSVC: }
  27
  28 B* b() { return x; }
  29 // CHECK: @_Z1bv() [[NUW]]
  30 // CHECK: [[VBASEOFFSETPTRA:%[a-zA-Z0-9\.]+]] = getelementptr i8, ptr {{.*}}, i64 -20
  31 // CHECK: load i32, ptr [[VBASEOFFSETPTRA]]
  32 // CHECK: }
  33
  34 // Same as 'a' except we use a different vbtable offset.
  35 // MSVC: @"?b@@YAPAUB@@XZ"() [[NUW:#[0-9]+]] {
  36 // MSVC:   %[[vbptr_off:.*]] = getelementptr inbounds i8, ptr {{.*}}, i32 0
  37 // MSVC:   %[[vbtable:.*]] = load ptr, ptr %[[vbptr_off]]
  38 // MSVC:   %[[entry:.*]] = getelementptr inbounds i32, ptr {{.*}}, i32 2
  39 // MSVC:   %[[offset:.*]] = load i32, ptr %[[entry]]
  40 // MSVC:   add nsw i32 0, %[[offset]]
  41 // MSVC: }
  42
  43
  44 BB* c() { return x; }
  45 // CHECK: @_Z1cv() [[NUW]]
  46 // CHECK: [[VBASEOFFSETPTRC:%[a-zA-Z0-9\.]+]] = getelementptr i8, ptr {{.*}}, i64 -24
  47 // CHECK: [[VBASEOFFSETC:%[a-zA-Z0-9\.]+]] = load i32, ptr [[VBASEOFFSETPTRC]]
  48 // CHECK: add i32 [[VBASEOFFSETC]], 8
  49 // CHECK: }
  50
  51 // Same as 'a' except we use a different vbtable offset.
  52 // MSVC: @"?c@@YAPAUBB@@XZ"() [[NUW:#[0-9]+]] {
  53 // MSVC:   %[[vbptr_off:.*]] = getelementptr inbounds i8, ptr {{.*}}, i32 0
  54 // MSVC:   %[[vbtable:.*]] = load ptr, ptr %[[vbptr_off]]
  55 // MSVC:   %[[entry:.*]] = getelementptr inbounds i32, ptr {{.*}}, i32 4
  56 // MSVC:   %[[offset:.*]] = load i32, ptr %[[entry]]
  57 // MSVC:   add nsw i32 0, %[[offset]]
  58 // MSVC: }
  59
  60 // Put the vbptr at a non-zero offset inside a non-virtual base.
  61 struct E { int e; };
  62 struct F : E, D { int f; };
  63
  64 F* y;
  65
  66 BB* d() { return y; }
  67
  68 // Same as 'c' except the vbptr offset is 4, changing the initial GEP and the
  69 // final add.
  70 // MSVC: @"?d@@YAPAUBB@@XZ"() [[NUW:#[0-9]+]] {
  71 // MSVC:   %[[vbptr_off:.*]] = getelementptr inbounds i8, ptr {{.*}}, i32 4
  72 // MSVC:   %[[vbtable:.*]] = load ptr, ptr %[[vbptr_off]]
  73 // MSVC:   %[[entry:.*]] = getelementptr inbounds i32, ptr {{.*}}, i32 4
  74 // MSVC:   %[[offset:.*]] = load i32, ptr %[[entry]]
  75 // MSVC:   add nsw i32 4, %[[offset]]
  76 // MSVC: }
  77
  78 // CHECK: attributes [[NUW]] = { mustprogress noinline nounwind{{.*}} }