Add support for va intrinsics for the XPLINK ABI.
Only the extended vararg variant, which uses a pointer to next
argument, is supported. The standard variant will build on this.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D120148
The tablegen lines that specify the XPLINK64 calling convention for promoting an f32 vararg to an f64 are effectively overwritten by the following tablegen line which bitcast an f64 vararg to an i64 (so that it can be used in the GPRs). It becomes a bitcast from f32 to i64.
Since we don't handle a bitcast for f32s this caused an assertion.
- This patch provides the initial implementation for lowering a call on z/OS according to the XPLINK64 calling convention
- A series of changes have been made to SystemZCallingConv.td to account for these additional XPLINK64 changes including adding a new helper function to shadow the stack along with allocation of a register wherever appropriate
- For the cases of copying a f64 to a gr64 and a f128 / 128-bit vector type to a gr64, a `CCBitConvertToType` has been added and has been bitcasted appropriately in the lowering phase
- Support for the ADA register (R5) will be provided in a later patch.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D111662
