Summary:
Port rL265480, rL264754, rL265997 and rL266252 to SystemZ, in order to enable the Swift port on the architecture. SwiftSelf and SwiftError are assigned to R10 and R9, respectively, which are normally callee-saved registers. For more information, see:
RFC: Implementing the Swift calling convention in LLVM and Clang
https://groups.google.com/forum/#!topic/llvm-dev/epDd2w93kZ0
Reviewers: kbarton, manmanren, rjmccall, uweigand
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D19414
llvm-svn: 267823
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
Recent mesa/llvmpipe crashes on SystemZ due to a failed assertion when
attempting to compile a routine with a return type of
{ <4 x float>, <4 x float>, <4 x float>, <4 x float> }
on a system without vector instruction support.
This is because after legalizing the vector type, we get a return value
consisting of 16 floats, which cannot all be returned in registers.
Usually, what should happen in this case is that the target's CanLowerReturn
routine rejects the return type, in which case SelectionDAG falls back to
implementing a structure return in memory via implicit reference.
However, the SystemZ target never actually implemented any CanLowerReturn
routine, and thus would accept any struct return type.
This patch fixes the crash by implementing CanLowerReturn. As a side effect,
this also handles fp128 return values, fixing a todo that was noted in
SystemZCallingConv.td.
llvm-svn: 244889
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
The architecture doesn't really have any native v4f32 operations except
v4f32->v2f64 and v2f64->v4f32 conversions, with only half of the v4f32
elements being used. Even so, using vector registers for <4 x float>
and scalarising individual operations is much better than generating
completely scalar code, since there's much less register pressure.
It's also more efficient to do v4f32 comparisons by extending to 2
v2f64s, comparing those, then packing the result.
This particularly helps with llvmpipe.
Based on a patch by Richard Sandiford.
llvm-svn: 236523
This adds ABI and CodeGen support for the v2f64 type, which is natively
supported by z13 instructions.
Based on a patch by Richard Sandiford.
llvm-svn: 236522
This the first of a series of patches to add CodeGen support exploiting
the instructions of the z13 vector facility. This patch adds support
for the native integer vector types (v16i8, v8i16, v4i32, v2i64).
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
(implemented in clang), 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: 236521
I'm about to add support for high-word operations, so it seemed better
for the low-word registers to have names like R0L rather than R0W.
No behavioral change intended.
llvm-svn: 191655
This adds the actual lib/Target/SystemZ target files necessary to
implement the SystemZ target. Note that at this point, the target
cannot yet be built since the configure bits are missing. Those
will be provided shortly by a follow-on patch.
This version of the patch incorporates feedback from reviews by
Chris Lattner and Anton Korobeynikov. Thanks to all reviewers!
Patch by Richard Sandiford.
llvm-svn: 181203
Bryan Chan