Pass aggregate arguments by value in NVPTX

[jpienaar]

Summary

Following the NVVM IR specifications, arguments of aggregate type should be passed on the stack without splitting (byval).

[eliben]

test/CodeGen/nvptx-abi.c

9

Makes sense to put a CHECK-LABEL here too?

[jpienaar]

Added CHECK-LABEL to myfunction

[jholewinski]

LGTM. Thanks!

[eliben]

Committed with a small test fix in r220854

Justin - thanks for the quick review

lib/CodeGen/TargetInfo.cpp

   if (const EnumType *EnumTy = Ty->getAs<EnumType>())
     Ty = EnumTy->getDecl()->getIntegerType();
 
+  // Return aggregates type as indirect by value
+  if (isAggregateTypeForABI(Ty))
+    return ABIArgInfo::getIndirect(0, /* byval */ true);
+
   return (Ty->isPromotableIntegerType() ?
           ABIArgInfo::getExtend() : ABIArgInfo::getDirect());
 }

test/CodeGen/nvptx-abi.c

   float x, y, z, w;
 } float4_t;
 
-float4_t my_function(void);
+float4_t my_function(void) {
+// CHECK-LABEL: @my_function
+// CHECK: define %struct.float4_s @my_function
+  float4_t t;
+  return t;
+};
 
-// CHECK-DAG: declare %struct.float4_s @my_function
-
 float bar(void) {
   float4_t ret;
-// CHECK-DAG: call %struct.float4_s @my_function
+// CHECK-LABEL: @bar
+// CHECK: call %struct.float4_s @my_function
   ret = my_function();
   return ret.x;
 }
+
+void foo(float4_t x) {
+// CHECK-LABEL: @foo
+// CHECK: %struct.float4_s* byval %x
+}
+
+void fooN(float4_t x, float4_t y, float4_t z) {
+// CHECK-LABEL: @fooN
+// CHECK: %struct.float4_s* byval %x
+// CHECK: %struct.float4_s* byval %y
+// CHECK: %struct.float4_s* byval %z
+}
+
+typedef struct nested_s {
+  unsigned long long x;
+  float z[64];
+  float4_t t;
+} nested_t;
+
+void baz(nested_t x) {
+// CHECK-LABEL: @baz
+// CHECK: %struct.nested_s* byval %x)
+}