[clang][CodeGen] Use memory type representation in `va_arg`

[jansvoboda11]

Summary

Some types (e.g. _Bool) have different scalar and memory representations. CodeGen for va_arg didn't take this into account, leading to an assertion failures with different types.

This patch makes sure we use memory representation for va_arg.

[jansvoboda11]

Should we add tests for other targets besides arm64?

clang/test/CodeGen/arm64-arguments.c

203

Not sure what to check here. Currently, we're just verifying the compiler doesn't crash.

[jansvoboda11]

Add proper check

[ahatanak]

LGTM

clang/test/CodeGen/arm64-arguments.c

203

If CreateStore is crashing, you can check the store instruction is being emitted with the correct type.

clang/lib/CodeGen/TargetInfo.cpp

if (AI.isIndirect()) {
     assert(!AI.getPaddingType() &&
            "Unexpected PaddingType seen in arginfo in generic VAArg emitter!");
     assert(!AI.getDirectOffset() &&
            "Unexpected DirectOffset seen in arginfo in generic VAArg emitter!");
     assert(!AI.getCoerceToType() &&
            "Unexpected CoerceToType seen in arginfo in generic VAArg emitter!");
 
     Address Temp = CGF.CreateMemTemp(Ty, "varet");
-    Val = CGF.Builder.CreateVAArg(VAListAddr.getPointer(), CGF.ConvertType(Ty));
+    Val = CGF.Builder.CreateVAArg(VAListAddr.getPointer(),
+                                  CGF.ConvertTypeForMem(Ty));
     CGF.Builder.CreateStore(Val, Temp);
     return Temp;
   }
 }
 
 /// DefaultABIInfo - The default implementation for ABI specific
 /// details. This implementation provides information which results in
 /// self-consistent and sensible LLVM IR generation, but does not

clang/test/CodeGen/arm64-arguments.c

double t2(int i, ...) {
     __builtin_va_list ap;
     __builtin_va_start(ap, i);
     // CHECK-NOT: add i32 %{{.*}} 7
     // CHECK-NOT: and i32 %{{.*}} -8
     double ll = __builtin_va_arg(ap, double);
     __builtin_va_end(ap);
     return ll;
 }
+_Bool t3(int i, ...) {
+  // CHECK: t3
+  __builtin_va_list ap;
+  __builtin_va_start(ap, i);
+  // CHECK:      %0 = va_arg {{.*}}* %ap, i8
+  // CHECK-NEXT: store i8 %0, i8* %varet, align 1
+  _Bool b = __builtin_va_arg(ap, _Bool);
+  __builtin_va_end(ap);
+  return b;
+}
 
 #include <arm_neon.h>
 
 // Homogeneous Vector Aggregate as return type and argument type.
 // CHECK: define{{.*}} %struct.int8x16x2_t @f0_0(<16 x i8> noundef %{{.*}}, <16 x i8> noundef %{{.*}})
 int8x16x2_t f0_0(int8x16_t a0, int8x16_t a1) {
   return vzipq_s8(a0, a1);
 }