clang/test/CodeGen/AArch64/pure-scalable-args-empty-union.c

   1 // RUN: %clang_cc1        -O3 -triple aarch64 -target-feature +sve -mvscale-min=1 -mvscale-max=1 -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK-C
   2 // RUN: %clang_cc1 -x c++ -O3 -triple aarch64 -target-feature +sve -mvscale-min=1 -mvscale-max=1 -emit-llvm -o - %s | FileCheck %s --check-prefixes=CHECK-CXX
   3
   4 typedef __SVFloat32_t fvec32 __attribute__((arm_sve_vector_bits(128)));
   5
   6 // PST containing an empty union: when compiled as C pass it in registers,
   7 // when compiled as C++ - in memory.
   8 typedef struct {
   9   fvec32 x[4];
  10   union {} u;
  11 } S0;
  12
  13 #ifdef __cplusplus
  14 extern "C"
  15 #endif
  16 void use0(S0);
  17
  18 void f0(S0 *p) {
  19   use0(*p);
  20 }
  21 // CHECK-C:   declare void @use0(<vscale x 4 x float>, <vscale x 4 x float>, <vscale x 4 x float>, <vscale x 4 x float>)
  22 // CHECK-CXX: declare void @use0(ptr noundef)
  23
  24 #ifdef __cplusplus
  25
  26 // PST containing an empty union with `[[no_unique_address]]`` - pass in registers.
  27 typedef struct {
  28    fvec32 x[4];
  29    [[no_unique_address]]
  30    union {} u;
  31 } S1;
  32
  33 extern "C" void use1(S1);
  34 void f1(S1 *p) {
  35   use1(*p);
  36 }
  37 // CHECK-CXX: declare void @use1(<vscale x 4 x float>, <vscale x 4 x float>, <vscale x 4 x float>, <vscale x 4 x float>)
  38
  39 #endif // __cplusplus