CFE produces it to indicate artificial locations.
c.f.: DWARF standard, Table 6.2:
line -- An unsigned integer indicating a source line number. Lines are numbered beginning at 1. The compiler may emit the value 0 in cases where an instruction cannot be attributed to any source line.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191471 91177308-0d34-0410-b5e6-96231b3b80d8
When generating code for shared libraries, even local calls may be
intercepted, so we need a nop after the call for the linker to fix up the
TOC. Test case adapted from the one provided in PR17354.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191440 91177308-0d34-0410-b5e6-96231b3b80d8
When asked to pad an irregular number of bytes, we should fill with
zeros. This is consistent with the behavior specified in the AIX
Assembler Language Reference as well as other LLVM and binutils
assemblers.
N.B. There is a small deviation from binutils' PPC assembler:
when handling pads which are greater than 4 bytes but not mod 4,
binutils will not emit any NOP sequences at all and only use zeros.
This may or may not be a bug but there is no excellent rationale as to
why that behavior is important to emulate. If that behavior is needed,
we can change writeNopData() to behave in the same way.
This fixes PR17352.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191426 91177308-0d34-0410-b5e6-96231b3b80d8
Encodings were checked against the Power ISA documents and double
checked against binutils.
This fixes PR17350.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191419 91177308-0d34-0410-b5e6-96231b3b80d8
This is the first set of instructions with a ".b" modifier thus we need to add the required code to disassemble a MSA128B register class.
Patch by Matheus Almeida
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191415 91177308-0d34-0410-b5e6-96231b3b80d8
In more detail, this patch adds the ability to parse, encode and decode MSA registers ($w0-$w31). The format of 2RF instructions (MipsMSAInstrFormat.td) was updated so that we could attach a test case to this patch i.e., the test case parses, encodes and decodes 2 MSA instructions. Following patches will add the remainder of the instructions.
Note that DecodeMSA128BRegisterClass is missing from MipsDisassembler.td because it's not yet required at this stage and having it would cause a compiler warning (unused function).
Patch by Matheus Almeida
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191412 91177308-0d34-0410-b5e6-96231b3b80d8
Generally, it is desirable to distribute (a + b) * c to a*c + b*c for
ARM with VMLx forwarding, where a, b and c are vectors.
However, for (a + b)*(a + b), distribution will result in one extra
instruction.
With distribution:
x = a + b (add)
y = a * x (mul)
z = y + b * y (mla)
Without distribution:
x = a + b (add)
z = x * x (mul)
This patch checks if a mul is a square of add/sub. If yes, skip
distribution.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191410 91177308-0d34-0410-b5e6-96231b3b80d8
(shl (zext (shr A, X)), X) => (zext (shl (shr A, X), X)).
The rule only triggers when there are no other uses of the
zext to avoid materializing more instructions.
This helps the DAGCombiner understand that the shl/shr
sequence can then be converted into an and instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191393 91177308-0d34-0410-b5e6-96231b3b80d8
Ideally, the machinel model is added at the time the instructions are
defined. But many instructions in X86InstrSSE.td still need a model.
Without this workaround the scheduler asserts because x86 already has
itinerary classes for these instructions, indicating they should be
modeled by the scheduler. Since we use the new machine model for other
instructions, it expects a new machine model for these too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191391 91177308-0d34-0410-b5e6-96231b3b80d8
Put them under a separate flag for experimentation. They are more likely to
interfere with loop vectorization which happens later in the pass pipeline.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191371 91177308-0d34-0410-b5e6-96231b3b80d8
Another patch to avoid duplication of encoding information. Things like
NILF, NILL and NILH are used as both 32-bit and 64-bit instructions.
Here the 64-bit versions are defined as aliases of the 32-bit ones.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191369 91177308-0d34-0410-b5e6-96231b3b80d8
The binutils assembler supports a mode called DOLLAR_DOT which treats
the dollar sign token as a reference to the current program counter if
the dollar sign doesn't precede a constant or identifier.
This commit adds a new MCAsmInfo flag stating whether or not a given
target supports this interpretation of the dollar sign token; by
default, this flag is not enabled.
Further, enable this flag for PPC. The system assembler for AIX and
binutils both support using the dollar sign in this manner.
This fixes PR17353.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191368 91177308-0d34-0410-b5e6-96231b3b80d8
Similar to r191364, but for calls. This patch also removes the shortening
of BRASL to BRAS within a TU. Doing that was a bit controversial internally,
since there's a strong expectation with the z assembler that WYWIWYG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191366 91177308-0d34-0410-b5e6-96231b3b80d8
Another patch to reduce the duplication of encoding information.
Rather than define separate patterns for truncating 64-bit stores,
use the 32-bit stores with a subreg. No behavioral changed intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191365 91177308-0d34-0410-b5e6-96231b3b80d8
This is the first of a few patches to reduce the dupliation of encoding
information. The return instruction is a normal BR in which one of the
registers is fixed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191364 91177308-0d34-0410-b5e6-96231b3b80d8
When loading immediates into a GR32, the port prefered LHI, followed by
LLILH or LLILL, followed by IILF. LHI and IILF are natural 32-bit
operations, but LLILH and LLILL also clear the upper 32 bits of the register.
This was represented as taking a 32-bit subreg of a 64-bit assignment.
Using subregs for something as simple as a move immediate was probably
a bad idea. Also, I have patches to add support for the high-word facility,
and we don't want something like LLILH and LLILL to stop the high word of
the same GPR from being used.
This patch therefore uses LHI and IILF to begin with and adds a late
machine-specific pass to use LLILH and LLILL if the other half of the
register is not live. The high-word patches extend this behavior to
IIHF, LLIHL and LLIHH.
No behavioral change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191363 91177308-0d34-0410-b5e6-96231b3b80d8
PEI inserts a save/restore sequence for the link register, according to the
information it gets from the MachineRegisterInfo.
MachineRegisterInfo is populated by the VirtRegMap pass.
This pass was not aware of noreturn calls and was registering the definitions of
these calls the same way as regular operations.
Modify VirtRegPass so that it does not set the isPhysRegUsed information for
registers only defined by noreturn calls.
The rational is that a noreturn call is the "last instruction" of the program
(if it returns the behavior is undefined), so everything that is defined by it
cannot be used and will not interfere with anything else. Therefore, it is
pointless to account for then.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191349 91177308-0d34-0410-b5e6-96231b3b80d8
This is being disabled because it is no longer needed for
performance. It is only used by postRAscheduler which is also planned
for removal, and it is implemented with an out-dated view of register
liveness. It consideres aliases instead of register units, assumes
valid kill flags, and assumes implicit uses on partial register
defs. Kill flags and implicit operands are error prone and impossible
to verify. We should gradually eliminate dependence on them in the
postRA phases.
Targets that still benefit from this should move to the MI
scheduler. If that doesn't solve the problem, then we should add a
hook to regalloc to optimize reload placement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191348 91177308-0d34-0410-b5e6-96231b3b80d8
This code isn't ready to deal with allocation functions where the return is not
the allocated pointer. The checks below will reject posix_memalign anyways.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191319 91177308-0d34-0410-b5e6-96231b3b80d8
