Commit Graph

2 Commits

Author SHA1 Message Date
Ulrich Weigand 66ff51b4ea [SystemZ] Add support for z13 and its vector facility
This patch adds support for the z13 architecture type.  For compatibility
with GCC, a pair of options -mvx / -mno-vx can be used to selectively
enable/disable use of the vector facility.

When the vector facility is present, we default to the new vector ABI.
This is characterized by two major differences:
- Vector types are passed/returned in vector registers
  (except for unnamed arguments of a variable-argument list function).
- Vector types are at most 8-byte aligned.

The reason for the choice of 8-byte vector alignment is that the hardware
is able to efficiently load vectors at 8-byte alignment, and the ABI only
guarantees 8-byte alignment of the stack pointer, so requiring any higher
alignment for vectors would require dynamic stack re-alignment code.

However, for compatibility with old code that may use vector types, when
*not* using the vector facility, the old alignment rules (vector types
are naturally aligned) remain in use.

These alignment rules are not only implemented at the C language level,
but also at the LLVM IR level.  This is done by selecting a different
DataLayout string depending on whether the vector ABI is in effect or not.

Based on a patch by Richard Sandiford.

llvm-svn: 236531
2015-05-05 19:35:52 +00:00
Ulrich Weigand 3a610ebf1e [SystemZ] Support transactional execution on zEC12
The zEC12 provides the transactional-execution facility.  This is exposed
to users via a set of builtin routines on other compilers.  This patch
adds clang support to enable those builtins.  In partciular, the patch:

- enables the transactional-execution feature by default on zEC12
- allows to override presence of that feature via the -mhtm/-mno-htm options
- adds a predefined macro __HTM__ if the feature is enabled
- adds support for the transactional-execution GCC builtins
- adds Sema checking to verify the __builtin_tabort abort code
- adds the s390intrin.h header file (for GCC compatibility)
- adds s390 sections to the htmintrin.h and htmxlintrin.h header files

Since this is first use of target-specific intrinsics on the platform,
the patch creates the include/clang/Basic/BuiltinsSystemZ.def file and
hooks it up in TargetBuiltins.h and lib/Basic/Targets.cpp.

An associated LLVM patch adds the required LLVM IR intrinsics.

For reference, the transactional-execution instructions are documented
in the z/Architecture Principles of Operation for the zEC12:
http://publibfp.boulder.ibm.com/cgi-bin/bookmgr/download/DZ9ZR009.pdf
The associated builtins are documented in the GCC manual:
http://gcc.gnu.org/onlinedocs/gcc/S_002f390-System-z-Built-in-Functions.html
The htmxlintrin.h intrinsics provided for compatibility with the IBM XL
compiler are documented in the "z/OS XL C/C++ Programming Guide".

llvm-svn: 233804
2015-04-01 12:54:25 +00:00