clang/test/CodeGenCXX/builtin-bit-cast.cpp

   1 // RUN: %clang_cc1 -no-opaque-pointers -std=c++2a -S -emit-llvm -o - -disable-llvm-passes -triple x86_64-apple-macos10.14 %s | FileCheck %s
   2
   3 void test_scalar(int &oper) {
   4   // CHECK-LABEL: define{{.*}} void @_Z11test_scalarRi
   5   __builtin_bit_cast(float, oper);
   6
   7   // CHECK: [[OPER:%.*]] = alloca i32*
   8   // CHECK: [[REF:%.*]] = load i32*, i32**
   9   // CHECK-NEXT: [[CASTED:%.*]] = bitcast i32* [[REF]] to float*
  10   // CHECK-NEXT: load float, float* [[CASTED]]
  11 }
  12
  13 struct two_ints {
  14   int x;
  15   int y;
  16 };
  17
  18 unsigned long test_aggregate_to_scalar(two_ints &ti) {
  19   // CHECK-LABEL: define{{.*}} i64 @_Z24test_aggregate_to_scalarR8two_ints
  20   return __builtin_bit_cast(unsigned long, ti);
  21
  22   // CHECK: [[TI_ADDR:%.*]] = alloca %struct.two_ints*, align 8
  23   // CHECK: [[TI_LOAD:%.*]] = load %struct.two_ints*, %struct.two_ints** [[TI_ADDR]]
  24   // CHECK-NEXT: [[CASTED:%.*]] = bitcast %struct.two_ints* [[TI_LOAD]] to i64*
  25   // CHECK-NEXT: load i64, i64* [[CASTED]]
  26 }
  27
  28 struct two_floats {
  29   float x;
  30   float y;
  31 };
  32
  33 two_floats test_aggregate_record(two_ints& ti) {
  34   // CHECK-LABEL: define{{.*}} <2 x float> @_Z21test_aggregate_recordR8two_int
  35    return __builtin_bit_cast(two_floats, ti);
  36
  37   // CHECK: [[RETVAL:%.*]] = alloca %struct.two_floats, align 4
  38   // CHECK: [[TI:%.*]] = alloca %struct.two_ints*, align 8
  39
  40   // CHECK: [[LOAD_TI:%.*]] = load %struct.two_ints*, %struct.two_ints** [[TI]]
  41   // CHECK: [[MEMCPY_SRC:%.*]] = bitcast %struct.two_ints* [[LOAD_TI]] to i8*
  42   // CHECK: [[MEMCPY_DST:%.*]] = bitcast %struct.two_floats* [[RETVAL]] to i8*
  43   // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 [[MEMCPY_DST]], i8* align 4 [[MEMCPY_SRC]]
  44 }
  45
  46 two_floats test_aggregate_array(int (&ary)[2]) {
  47   // CHECK-LABEL: define{{.*}} <2 x float> @_Z20test_aggregate_arrayRA2_i
  48   return __builtin_bit_cast(two_floats, ary);
  49
  50   // CHECK: [[RETVAL:%.*]] = alloca %struct.two_floats, align 4
  51   // CHECK: [[ARY:%.*]] = alloca [2 x i32]*, align 8
  52
  53   // CHECK: [[LOAD_ARY:%.*]] = load [2 x i32]*, [2 x i32]** [[ARY]]
  54   // CHECK: [[MEMCPY_SRC:%.*]] = bitcast [2 x i32]* [[LOAD_ARY]] to i8*
  55   // CHECK: [[MEMCPY_DST:%.*]] = bitcast %struct.two_floats* [[RETVAL]] to i8*
  56   // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 [[MEMCPY_DST]], i8* align 4 [[MEMCPY_SRC]]
  57 }
  58
  59 two_ints test_scalar_to_aggregate(unsigned long ul) {
  60   // CHECK-LABEL: define{{.*}} i64 @_Z24test_scalar_to_aggregatem
  61   return __builtin_bit_cast(two_ints, ul);
  62
  63   // CHECK: [[TI:%.*]] = alloca %struct.two_ints, align 4
  64   // CHECK: [[TITMP:%.*]] = bitcast %struct.two_ints* [[TI]] to i8*
  65   // CHECK-NEXT: call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 [[TITMP]]
  66 }
  67
  68 unsigned long test_complex(_Complex unsigned &cu) {
  69   // CHECK-LABEL: define{{.*}} i64 @_Z12test_complexRCj
  70   return __builtin_bit_cast(unsigned long, cu);
  71
  72   // CHECK: [[REF_ALLOCA:%.*]] = alloca { i32, i32 }*, align 8
  73   // CHECK-NEXT: store { i32, i32 }* {{.*}}, { i32, i32 }** [[REF_ALLOCA]]
  74   // CHECK-NEXT: [[REF:%.*]] = load { i32, i32 }*, { i32, i32 }** [[REF_ALLOCA]]
  75   // CHECK-NEXT: [[CASTED:%.*]] = bitcast { i32, i32 }* [[REF]] to i64*
  76   // CHECK-NEXT: load i64, i64* [[CASTED]], align 4
  77 }
  78
  79 _Complex unsigned test_to_complex(unsigned long &ul) {
  80   // CHECK-LABEL: define{{.*}} i64 @_Z15test_to_complexRm
  81
  82   return __builtin_bit_cast(_Complex unsigned, ul);
  83
  84   // CHECK: [[REF:%.*]] = alloca i64*
  85   // CHECK: [[LOAD_REF:%.*]] = load i64*, i64** [[REF]]
  86   // CHECK: [[CASTED:%.*]] = bitcast i64* [[LOAD_REF]] to { i32, i32 }*
  87 }
  88
  89 unsigned long test_array(int (&ary)[2]) {
  90   // CHECK-LABEL: define{{.*}} i64 @_Z10test_arrayRA2_i
  91   return __builtin_bit_cast(unsigned long, ary);
  92
  93   // CHECK: [[REF_ALLOCA:%.*]] = alloca [2 x i32]*
  94   // CHECK: [[LOAD_REF:%.*]] = load [2 x i32]*, [2 x i32]** [[REF_ALLOCA]]
  95   // CHECK: [[CASTED:%.*]] = bitcast [2 x i32]* [[LOAD_REF]] to i64*
  96   // CHECK: load i64, i64* [[CASTED]], align 4
  97 }
  98
  99 two_ints test_rvalue_aggregate() {
 100   // CHECK-LABEL: define{{.*}} i64 @_Z21test_rvalue_aggregate
 101   return __builtin_bit_cast(two_ints, 42ul);
 102
 103   // CHECK: [[TI:%.*]] = alloca %struct.two_ints, align 4
 104   // CHECK: [[CASTED:%.*]] = bitcast %struct.two_ints* [[TI]] to i8*
 105   // CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* align 4 [[CASTED]]
 106 }