clang/test/CodeGen/mcu-struct-return.c

   1 // RUN: %clang_cc1 -triple i386-pc-elfiamcu -emit-llvm %s -o - | FileCheck %s
   2
   3 // Structure that is more than 8 byte.
   4 struct Big {
   5   double a[10];
   6 };
   7
   8 // Empty union with zero size must be returned as void.
   9 union U1 {
  10 } u1;
  11
  12 // Too large union (80 bytes) must be returned via memory.
  13 union U2 {
  14   struct Big b;
  15 } u2;
  16
  17 // Must be returned in register.
  18 union U3 {
  19   int x;
  20 } u3;
  21
  22 // Empty struct with zero size, must be returned as void.
  23 struct S1 {
  24 } s1;
  25
  26 // Must be returend in register.
  27 struct S2 {
  28   int x;
  29 } s2;
  30
  31 // CHECK: [[UNION1_TYPE:%.+]] = type {}
  32 // CHECK: [[UNION2_TYPE:%.+]] = type { [[STRUCT_TYPE:%.+]] }
  33 // CHECK: [[STRUCT_TYPE]] = type { [10 x double] }
  34 // CHECK: [[UNION3_TYPE:%.+]] = type { i32 }
  35 // CHECK: [[STRUCT1_TYPE:%.+]] = type {}
  36 // CHECK: [[STRUCT2_TYPE:%.+]] = type { i32 }
  37
  38 union U1 foo1(void) { return u1; }
  39 union U2 foo2(void) { return u2; }
  40 union U3 foo3(void) { return u3; }
  41 struct S1 bar1(void) { return s1; }
  42 struct S2 bar2(void) { return s2; }
  43 struct S1 bar3(union U1 u) { return s1; }
  44 // CHECK: define{{.*}} void @foo1()
  45 // CHECK: define{{.*}} void @foo2(ptr dead_on_unwind noalias writable sret([[UNION2_TYPE]]) align 4 %{{.+}})
  46 // CHECK: define{{.*}} i32 @foo3()
  47 // CHECK: define{{.*}} void @bar1()
  48 // CHECK: define{{.*}} i32 @bar2()
  49 // CHECK: define{{.*}} void @bar3()
  50
  51 void run(void) {
  52   union U1 x1 = foo1();
  53   union U2 x2 = foo2();
  54   union U3 x3 = foo3();
  55   struct S1 y1 = bar1();
  56   struct S2 y2 = bar2();
  57   struct S1 y3 = bar3(x1);
  58
  59   // CHECK: [[X1:%.+]] = alloca [[UNION1_TYPE]]
  60   // CHECK: [[X2:%.+]] = alloca [[UNION2_TYPE]]
  61   // CHECK: [[X3:%.+]] = alloca [[UNION3_TYPE]]
  62   // CHECK: [[Y1:%.+]] = alloca [[STRUCT1_TYPE]]
  63   // CHECK: [[Y2:%.+]] = alloca [[STRUCT2_TYPE]]
  64   // CHECK: call void @foo1()
  65   // CHECK: call void @foo2(ptr dead_on_unwind writable sret([[UNION2_TYPE]]) align 4 [[X2]])
  66   // CHECK: {{.+}} = call i32 @foo3()
  67   // CHECK: call void @bar1()
  68   // CHECK: {{.+}} = call i32 @bar2()
  69   // CHECK: call void @bar3()
  70 }