clang/test/C/C2x/n2900_n3011_2.c

   1 // RUN: %clang_cc1 -triple x86_64-unknown-unknown -std=c2x -verify -emit-llvm %s -o - | FileCheck %s
   2 // expected-no-diagnostics
   3
   4 struct S { int x, y; };
   5 struct T {
   6   int i;
   7   struct S s;
   8 };
   9
  10 // CHECK: @[[CONST_T1:.+]] = private unnamed_addr constant %struct.T { i32 1, %struct.S zeroinitializer }
  11 // CHECK: @[[CONST_T2:.+]] = private unnamed_addr constant %struct.T { i32 1, %struct.S { i32 2, i32 0 } }
  12
  13 void test_struct() {
  14   struct S s = {};
  15   // CHECK: define {{.*}} void @test_struct
  16   // CHECK-NEXT: entry:
  17   // CHECK-NEXT: %[[S:.+]] = alloca %struct.S
  18   // CHECK-NEXT: call void @llvm.memset.p0.i64({{.*}}%[[S]], i8 0, i64 8, i1 false)
  19 }
  20
  21 void test_var() {
  22   int i = {};
  23   // CHECK: define {{.*}} void @test_var
  24   // CHECK-NEXT: entry:
  25   // CHECK-NEXT: %[[I:.+]] = alloca i32
  26   // CHECK-NEXT: store i32 0, ptr %[[I]]
  27 }
  28
  29 void test_simple_compound_literal() {
  30   int j = (int){};
  31   // CHECK: define {{.*}} void @test_simple_compound_literal
  32   // CHECK-NEXT: entry:
  33   // CHECK-NEXT: %[[J:.+]] = alloca i32
  34   // CHECK-NEXT: %[[COMPOUND:.+]] = alloca i32
  35   // CHECK-NEXT: store i32 0, ptr %[[COMPOUND]]
  36   // CHECK-NEXT: %[[MEM:.+]] = load i32, ptr %[[COMPOUND]]
  37   // CHECK-NEXT: store i32 %[[MEM]], ptr %[[J]]
  38 }
  39
  40 void test_zero_size_array() {
  41   int unknown_size[] = {};
  42   // CHECK: define {{.*}} void @test_zero_size_array
  43   // CHECK-NEXT: entry:
  44   // CHECK-NEXT: %[[UNKNOWN:.+]] = alloca [0 x i32]
  45 }
  46
  47 void test_vla() {
  48   int num_elts = 12;
  49   int vla[num_elts] = {};
  50   // CHECK: define {{.*}} void @test_vla
  51   // CHECK-NEXT: entry:
  52   // CHECK-NEXT: %[[NUM_ELTS_PTR:.+]] = alloca i32
  53   // CHECK: %[[VLA_EXPR:.+]] = alloca i64
  54   // CHECK-NEXT: store i32 12, ptr %[[NUM_ELTS_PTR]]
  55   // CHECK-NEXT: %[[NUM_ELTS:.+]] = load i32, ptr %[[NUM_ELTS_PTR]]
  56   // CHECK-NEXT: %[[NUM_ELTS_EXT:.+]] = zext i32 %[[NUM_ELTS]] to i64
  57   // CHECK: %[[VLA:.+]] = alloca i32, i64 %[[NUM_ELTS_EXT]]
  58   // CHECK-NEXT: store i64 %[[NUM_ELTS_EXT]], ptr %[[VLA_EXPR]]
  59   // CHECK-NEXT: %[[BYTES_TO_COPY:.+]] = mul nuw i64 %[[NUM_ELTS_EXT]], 4
  60   // CHECK-NEXT: call void @llvm.memset.p0.i64(ptr {{.*}} %[[VLA]], i8 0, i64 %[[BYTES_TO_COPY]], i1 false)
  61 }
  62
  63 void test_zero_size_vla() {
  64   int num_elts = 0;
  65   int vla[num_elts] = {};
  66   // CHECK: define {{.*}} void @test_zero_size_vla
  67   // CHECK-NEXT: entry:
  68   // CHECK-NEXT: %[[NUM_ELTS_PTR:.+]] = alloca i32
  69   // CHECK: %[[VLA_EXPR:.+]] = alloca i64
  70   // CHECK-NEXT: store i32 0, ptr %[[NUM_ELTS_PTR]]
  71   // CHECK-NEXT: %[[NUM_ELTS:.+]] = load i32, ptr %[[NUM_ELTS_PTR]]
  72   // CHECK-NEXT: %[[NUM_ELTS_EXT:.+]] = zext i32 %[[NUM_ELTS]] to i64
  73   // CHECK: %[[VLA:.+]] = alloca i32, i64 %[[NUM_ELTS_EXT]]
  74   // CHECK-NEXT: store i64 %[[NUM_ELTS_EXT]], ptr %[[VLA_EXPR]]
  75   // CHECK-NEXT: %[[BYTES_TO_COPY:.+]] = mul nuw i64 %[[NUM_ELTS_EXT]], 4
  76   // CHECK-NEXT: call void @llvm.memset.p0.i64(ptr {{.*}} %[[VLA]], i8 0, i64 %[[BYTES_TO_COPY]], i1 false)
  77 }
  78
  79 void test_compound_literal_vla() {
  80   int num_elts = 12;
  81   int *compound_literal_vla = (int[num_elts]){};
  82   // CHECK: define {{.*}} void @test_compound_literal_vla
  83   // CHECK-NEXT: entry:
  84   // CHECK-NEXT: %[[NUM_ELTS_PTR:.+]] = alloca i32
  85   // CHECK-NEXT: %[[COMP_LIT_VLA:.+]] = alloca ptr
  86   // CHECK-NEXT: %[[COMP_LIT:.+]] = alloca i32
  87   // CHECK-NEXT: store i32 12, ptr %[[NUM_ELTS_PTR]]
  88   // CHECK-NEXT: %[[NUM_ELTS:.+]] = load i32, ptr %[[NUM_ELTS_PTR]]
  89   // CHECK-NEXT: %[[NUM_ELTS_EXT:.+]] = zext i32 %[[NUM_ELTS]] to i64
  90   // CHECK-NEXT: %[[BYTES_TO_COPY:.+]] = mul nuw i64 %[[NUM_ELTS_EXT]], 4
  91   // CHECK-NEXT: call void @llvm.memset.p0.i64(ptr {{.*}} %[[COMP_LIT]], i8 0, i64 %[[BYTES_TO_COPY]], i1 false)
  92   // CHECK-NEXT: store ptr %[[COMP_LIT]], ptr %[[COMP_LIT_VLA]]
  93 }
  94
  95 void test_nested_structs() {
  96   struct T t1 = { 1, {} };
  97   struct T t2 = { 1, { 2, {} } };
  98   struct T t3 = { (int){}, {} };
  99   // CHECK: define {{.*}} void @test_nested_structs
 100   // CHECK-NEXT: entry:
 101   // CHECK-NEXT: %[[T1:.+]] = alloca %struct.T
 102   // CHECK-NEXT: %[[T2:.+]] = alloca %struct.T
 103   // CHECK-NEXT: %[[T3:.+]] = alloca %struct.T
 104   // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr {{.*}} %[[T1]], ptr {{.*}} @[[CONST_T1]], i64 12, i1 false)
 105   // CHECK-NEXT: call void @llvm.memcpy.p0.p0.i64(ptr {{.*}} %[[T2]], ptr {{.*}} @[[CONST_T2]], i64 12, i1 false)
 106   // CHECK-NEXT: call void @llvm.memset.p0.i64(ptr {{.*}} %[[T3]], i8 0, i64 12, i1 false)
 107 }
 108
 109 void test_vla_of_nested_structs(int num_elts) {
 110   struct T t3[num_elts] = {};
 111   // CHECK: define {{.*}} void @test_vla_of_nested_structs(i32 noundef %[[NUM_ELTS_PARAM:.+]])
 112   // CHECK-NEXT: entry:
 113   // CHECK-NEXT: %[[NUM_ELTS_PTR:.+]] = alloca i32
 114   // CHECK: %[[VLA_EXPR:.+]] = alloca i64
 115   // CHECK-NEXT: store i32 %[[NUM_ELTS_PARAM]], ptr %[[NUM_ELTS_PTR]]
 116   // CHECK-NEXT: %[[NUM_ELTS_LOCAL:.+]] = load i32, ptr %[[NUM_ELTS_PTR]]
 117   // CHECK-NEXT: %[[NUM_ELTS_EXT:.+]] = zext i32 %[[NUM_ELTS_LOCAL]] to i64
 118   // CHECK: %[[VLA:.+]] = alloca %struct.T, i64 %[[NUM_ELTS_EXT]]
 119   // CHECK-NEXT: store i64 %[[NUM_ELTS_EXT]], ptr %[[VLA_EXPR]]
 120   // CHECK-NEXT: %[[COPY_BYTES:.+]] = mul nuw i64 %[[NUM_ELTS_EXT]], 12
 121   // CHECK-NEXT: call void @llvm.memset.p0.i64(ptr {{.*}} %[[VLA]], i8 0, i64 %[[COPY_BYTES]], i1 false)
 122 }