// Function return values are passed exactly like function arguments, except a
// struct up to 32 bytes in size can be returned in registers.
-// Function arguments AND return values.
+// Function arguments AND most return values.
def CC_Sparc64 : CallingConv<[
// The frontend uses the inreg flag to indicate i32 and float arguments from
// structs. These arguments are not promoted to 64 bits, but they can still
CCCustom<"CC_Sparc64_Full">
]>;
+def RetCC_Sparc64 : CallingConv<[
+ // A single f32 return value always goes in %f0. The ABI doesn't specify what
+ // happens to multiple f32 return values outside a struct.
+ CCIfType<[f32], CCCustom<"CC_Sparc64_Half">>,
+
+ // Otherwise, return values are passed exactly like arguments.
+ CCDelegateTo<CC_Sparc64>
+]>;
+
// Callee-saved registers are handled by the register window mechanism.
def CSR : CalleeSavedRegs<(add)> {
let OtherPreserved = (add (sequence "I%u", 0, 7),