This is a continuation of the __ptr32 support added here
https://github.com/llvm/llvm-project/commit/135fecd4441068667ef23f56098befd0c42f89f2

Differential Revision: https://reviews.llvm.org/D127328

- 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

This patch adds the XPLINK64 calling convention to the SystemZ
backend. It specifies and implements the argument passing and
return value conventions.

Reviewed By: uweigand

Differential Revision: https://reviews.llvm.org/D101010

Rename ELF specific variables, making it easier to add the XPLink
variables in future patches.

Reviewed By: abhina.sreeskantharajan, Kai

Differential Revision: https://reviews.llvm.org/D98199

Summary: This is a followup on D81196

Reviewers: courbet

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Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81278

This is a special calling convention to be used by the GHC compiler.

Author: Stefan Schulze Frielinghaus
Differential Revision: https://reviews.llvm.org/D69024

to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

According to the SystemZ ABI, 128-bit integer types should be
passed and returned via implicit reference.  However, this is
not currently implemented at the LLVM IR level for the i128
type.  This does not matter when compiling C/C++ code, since
clang will implement the implicit reference itself.

However, it turns out that when calling libgcc helper routines
operating on 128-bit integers, LLVM will use i128 argument and
return value types; the resulting code is not compatible with
the ABI used in libgcc, leading to crashes (see PR26559).

This should be simple to fix, except that i128 currently is not
even a legal type for the SystemZ back end.  Therefore, common
code will already split arguments and return values into multiple
parts.  The bulk of this patch therefore consists of detecting
such parts, and correctly handling passing via implicit reference
of a value split into multiple parts.  If at some time in the
future, i128 becomes a legal type, this code can be removed again.

This fixes PR26559.

llvm-svn: 261325

The ABI allows sub-128 vectors to be passed and returned in registers,
with the vector occupying the upper part of a register.  We therefore
want to legalize those types by widening the vector rather than promoting
the elements.

The patch includes some simple tests for sub-128 vectors and also tests
that we can recognize various pack sequences, some of which use sub-128
vectors as temporary results.  One of these forms is based on the pack
sequences generated by llvmpipe when no intrinsics are used.

Signed unpacks are recognized as BUILD_VECTORs whose elements are
individually sign-extended.  Unsigned unpacks can have the equivalent
form with zero extension, but they also occur as shuffles in which some
elements are zero.

Based on a patch by Richard Sandiford.

llvm-svn: 236525