[clang][PowerPC][NFC] Add base test case for PPC64 VAArg aggregate smaller than a slot

[tingwang]

Summary

Add base test case for https://reviews.llvm.org/D133338.

[tingwang]

Rebase on opaque-pointers test case changes && Gentle ping.

[tingwang]

Add test case according to comment.

[shchenz]

LGTM

clang/test/CodeGen/PowerPC/ppc64-align-struct.c

 // RUN: %clang_cc1 -target-feature +altivec -triple powerpc64-unknown-linux-gnu -emit-llvm -o - %s | FileCheck %s
 
 #include <stdarg.h>
 
 struct test1 { int x; int y; };
 struct test2 { int x; int y; } __attribute__((aligned (16)));
 struct test3 { int x; int y; } __attribute__((aligned (32)));
 struct test4 { int x; int y; int z; };
 struct test5 { int x[17]; };
 struct test6 { int x[17]; } __attribute__((aligned (16)));
 struct test7 { int x[17]; } __attribute__((aligned (32)));
+struct test8 { char x; };
+struct test9 { _Complex char x; };
 
 // CHECK: define{{.*}} void @test1(i32 noundef signext %x, i64 %y.coerce)
 void test1 (int x, struct test1 y)
 {
 }
 
 // CHECK: define{{.*}} void @test2(i32 noundef signext %x, [1 x i128] %y.coerce)
 void test2 (int x, struct test2 y)

 // This case requires run-time realignment of the incoming struct
 // CHECK-LABEL: define{{.*}} void @test7(i32 noundef signext %x, ptr noundef byval(%struct.test7) align 16 %0)
 // CHECK: %y = alloca %struct.test7, align 32
 // CHECK: call void @llvm.memcpy.p0.p0.i64
 void test7 (int x, struct test7 y)
 {
 }
 
+// CHECK: define{{.*}} void @test8(i32 noundef signext %x, i8 %y.coerce)
+void test8 (int x, struct test8 y)
+{
+}
+
+// CHECK: define{{.*}} void @test9(i32 noundef signext %x, i16 %y.coerce)
+void test9 (int x, struct test9 y)
+{
+}
+
 // CHECK: define{{.*}} void @test1va(ptr noalias sret(%struct.test1) align 4 %[[AGG_RESULT:.*]], i32 noundef signext %x, ...)
 // CHECK: %[[CUR:[^ ]+]] = load ptr, ptr %ap
 // CHECK: %[[NEXT:[^ ]+]] = getelementptr inbounds i8, ptr %[[CUR]], i64 8
 // CHECK: store ptr %[[NEXT]], ptr %ap
 // CHECK: call void @llvm.memcpy.p0.p0.i64(ptr align 4 %[[AGG_RESULT]], ptr align 8 %[[CUR]], i64 8, i1 false)
 struct test1 test1va (int x, ...)
 {
   struct test1 y;
struct test4 test4va (int x, ...)
   struct test4 y;
   va_list ap;
   va_start(ap, x);
   y = va_arg (ap, struct test4);
   va_end(ap);
   return y;
 }
 
+// Error pattern will be fixed in https://reviews.llvm.org/D133338
+// CHECK: define{{.*}} void @test8va(ptr noalias sret(%struct.test8) align 1 %[[AGG_RESULT:.*]], i32 noundef signext %x, ...)
+// CHECK: %[[CUR:[^ ]+]] = load ptr, ptr %ap
+// CHECK: %[[NEXT:[^ ]+]] = getelementptr inbounds i8, ptr %[[CUR]], i64 8
+// CHECK: store ptr %[[NEXT]], ptr %ap
+// CHECK: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %[[AGG_RESULT]], ptr align 8 %[[CUR]], i64 1, i1 false)
+struct test8 test8va (int x, ...)
+{
+  struct test8 y;
+  va_list ap;
+  va_start(ap, x);
+  y = va_arg (ap, struct test8);
+  va_end(ap);
+  return y;
+}
+
+// Error pattern will be fixed in https://reviews.llvm.org/D133338
+// CHECK: define{{.*}} void @test9va(ptr noalias sret(%struct.test9) align 1 %[[AGG_RESULT:.*]], i32 noundef signext %x, ...)
+// CHECK: %[[CUR:[^ ]+]] = load ptr, ptr %ap
+// CHECK: %[[NEXT:[^ ]+]] = getelementptr inbounds i8, ptr %[[CUR]], i64 8
+// CHECK: store ptr %[[NEXT]], ptr %ap
+// CHECK: call void @llvm.memcpy.p0.p0.i64(ptr align 1 %[[AGG_RESULT]], ptr align 8 %[[CUR]], i64 2, i1 false)
+struct test9 test9va (int x, ...)
+{
+  struct test9 y;
+  va_list ap;
+  va_start(ap, x);
+  y = va_arg (ap, struct test9);
+  va_end(ap);
+  return y;
+}
+
 // CHECK: define{{.*}} void @testva_longdouble(ptr noalias sret(%struct.test_longdouble) align 16 %[[AGG_RESULT:.*]], i32 noundef signext %x, ...)
 // CHECK: %[[CUR:[^ ]+]] = load ptr, ptr %ap
 // CHECK: %[[NEXT:[^ ]+]] = getelementptr inbounds i8, ptr %[[CUR]], i64 16
 // CHECK: store ptr %[[NEXT]], ptr %ap
 // CHECK: call void @llvm.memcpy.p0.p0.i64(ptr align 16 %[[AGG_RESULT]], ptr align 8 %[[CUR]], i64 16, i1 false)
 struct test_longdouble { long double x; };
 struct test_longdouble testva_longdouble (int x, ...)
 {