This is part of fixing the instruction predicates for MIPS.
Reviewers: atanasyan, abeserminji
Differential Revision: https://reviews.llvm.org/D44212
llvm-svn: 327409
For the MIPS O32 ABI, the current call lowering logic naively lowers each
call, creating the reserved argument area to hold the argument spill areas for
$a0..$a3 and the outgoing parameter area if one is required at each call site.
In the case of a sufficently large byval argument, a call to memcpy is used
to write the start+16..end of the argument into the outgoing parameter area.
This is done within the CALLSEQ_START..CALLSEQ_END of the callee. The CALLSEQ
nodes are responsible for performing the necessary stack adjustments.
Since the O32/N32/N64 MIPS ABIs do not have a red-zone and writing below the
stack pointer and reading the values back is unpredictable, the call to memcpy
cannot be hoisted out of the callee's CALLSEQ nodes.
However, for the O32 ABI requires the reserved argument area for functions
which have parameters. The naive lowering of calls will then create nested
CALLSEQ sequences. For N32 and N64 these nodes are also created, but with
zero stack adjustments as those ABIs do not have a reserved argument area.
This patch addresses the correctness issue by recognizing the special case
of lowering a byval argument that uses memcpy. By recognizing that the
incoming chain already has a CALLSEQ_START node on it when calling memcpy,
the CALLSEQ nodes are not created. For the N32 and N64 ABIs, this is not an
issue, as no stack adjustment has to be performed.
For the O32 ABI, the correctness reasoning is different. In the case of a
sufficently large byval argument, registers a0..a3 are going to be used for
the callee's arguments, mandating the creation of the reserved argument area.
The call to memcpy in the naive case will also create its own reserved
argument area. However, since the reserved argument area consists of undefined
values, both calls can use the same reserved argument area.
Reviewers: abeserminji, atanasyan
Differential Revision: https://reviews.llvm.org/D44296
llvm-svn: 327388
This simplifies tagging instructions with the correct ISA and ASE, albeit making
instruction definitions a bit more verbose.
Reviewers: atanasyan, abeserminji
Differential Revision: https://reviews.llvm.org/D44299
llvm-svn: 327265
These instructions are defined as taking a GPR register and a
coprocessor register for ISAs up to MIPS32. MIPS32 extended the
definition to allow a selector--a value from 0 to 32--to access
another register.
These instructions are now internally defined as being MIPS-I
instructions, but are rejected for pre-MIPS32 ISA's if they have
an explicit selector which is non-zero. This deviates slightly from
GAS's behaviour which rejects assembly instructions with an
explicit selector for pre-MIPS32 ISAs.
E.g:
mfc0 $4, $5, 0
is rejected by GAS for MIPS-I to MIPS-V but will be accepted
with this patch for MIPS-I to MIPS-V.
Reviewers: atanasyan
Differential Revision: https://reviews.llvm.org/D41662
llvm-svn: 326890
Emulated TLS is enabled by llc flag -emulated-tls,
which is passed by clang driver.
When llc is called explicitly or from other drivers like LTO,
missing -emulated-tls flag would generate wrong TLS code for targets
that supports only this mode.
Now use useEmulatedTLS() instead of Options.EmulatedTLS to decide whether
emulated TLS code should be generated.
Unit tests are modified to run with and without the -emulated-tls flag.
Differential Revision: https://reviews.llvm.org/D42999
llvm-svn: 326341
The MIPS backend has inconsistent usage of instruction predicates
for assembly and code generation. The issue arises from supporting three
encodings, two (MIPS and microMIPS) of which have a near 1:1 instruction
mapping across ISA revisions and a third encoding with a more restricted
set of instructions (MIPS16e).
To enforce consistent usage, each of the ISA_* adjectives has (or will
have) the relevant encoding attached to it along the relevant ISA revision
where the instruction is defined.
Each instruction, pattern or alias will then have the correct ISA adjective
attached to it, and the base instruction description classes will have any
predicates relating to ISA encoding or revision removed.
Pseudo instructions will also be guarded for the encoding or ABI that they are
supported in.
Finally, the hasStandardEncoding() / inMicroMipsMode() / inMips16Mode() methods
of MipsSubtarget will be changed such that only one can be true at any one time.
The result of this is that code generation and assembly will produce the
correct encoding up front, while code generated from pseudo instructions
and other inserted sequences of instructions will be able to rely on the mapping
tables to produce the correct encoding. This should fix numerous bugs where
the result 'happens' to be correct but has edge cases where microMIPS and MIPS
have subtle differences (e.g. microMIPSR6 using 'j', 'jal' instructions.)
This patch starts the process by changing most of the ISA adjectives to make
use of the EncodingPredicate member of PredicateControl. Follow on patches
will annotate instructions with their correct ISA adjective and eliminate
the usage of "let Predicates = [..]", "let AdditionalPredicates = [..]" and
"isCodeGenOnly = 1" in the cases where it was used to control instruction
availability.
Contributions from Nitesh Jain.
Reviewers: atanasyan
Differential Revision: https://reviews.llvm.org/D41434
llvm-svn: 326322
Summary:
Add a target option AllowRegisterRenaming that is used to opt in to
post-register-allocation renaming of registers. This is set to 0 by
default, which causes the hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq
fields of all opcodes to be set to 1, causing
MachineOperand::isRenamable to always return false.
Set the AllowRegisterRenaming flag to 1 for all in-tree targets that
have lit tests that were effected by enabling COPY forwarding in
MachineCopyPropagation (AArch64, AMDGPU, ARM, Hexagon, Mips, PowerPC,
RISCV, Sparc, SystemZ and X86).
Add some more comments describing the semantics of the
MachineOperand::isRenamable function and how it is set and maintained.
Change isRenamable to check the operand's opcode
hasExtraSrcRegAllocReq/hasExtraDstRegAllocReq bit directly instead of
relying on it being consistently reflected in the IsRenamable bit
setting.
Clear the IsRenamable bit when changing an operand's register value.
Remove target code that was clearing the IsRenamable bit when changing
registers/opcodes now that this is done conservatively by default.
Change setting of hasExtraSrcRegAllocReq in AMDGPU target to be done in
one place covering all opcodes that have constant pipe read limit
restrictions.
Reviewers: qcolombet, MatzeB
Subscribers: aemerson, arsenm, jyknight, mcrosier, sdardis, nhaehnle, javed.absar, tpr, arichardson, kristof.beyls, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, niosHD, escha, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D43042
llvm-svn: 325931
Add GlobalISel infrastructure up to the point where we can select a ret
void.
Patch by Petar Avramovic.
Differential Revision: https://reviews.llvm.org/D43583
llvm-svn: 325888
Enable multiple COPY hints to eliminate more COPYs during register allocation.
Note that this is something all targets should do, see
https://reviews.llvm.org/D38128.
Review: Simon Dardis
llvm-svn: 325870
There were no memory dependencies made between stores generated
when lowering formal arguments and loads generated when
call lowering byVal arguments which made the Post-RA scheduler
place a load before a matching store.
Make the fixed object stored to mutable so that the load
instructions can have their memory dependencies added
Set the frame object as isAliased which clears the underlying
objects vector in ScheduleDAGInstrs::buildSchedGraph().
This results in addition of all stores as dependenies for loads.
This problem appeared when passing a byVal parameter
coupled with a fastcc function call.
Differential Revision: https://reviews.llvm.org/D37515
llvm-svn: 325782
This patch provides mitigation for CVE-2017-5715, Spectre variant two,
which affects the P5600 and P6600. It implements the LLVM part of
-mindirect-jump=hazard. It is _not_ enabled by default for the P5600.
The migitation strategy suggested by MIPS for these processors is to use
hazard barrier instructions. 'jalr.hb' and 'jr.hb' are hazard
barrier variants of the 'jalr' and 'jr' instructions respectively.
These instructions impede the execution of instruction stream until
architecturally defined hazards (changes to the instruction stream,
privileged registers which may affect execution) are cleared. These
instructions in MIPS' designs are not speculated past.
These instructions are used with the attribute +use-indirect-jump-hazard
when branching indirectly and for indirect function calls.
These instructions are defined by the MIPS32R2 ISA, so this mitigation
method is not compatible with processors which implement an earlier
revision of the MIPS ISA.
Performance benchmarking of this option with -fpic and lld using
-z hazardplt shows a difference of overall 10%~ time increase
for the LLVM testsuite. Certain benchmarks such as methcall show a
substantially larger increase in time due to their nature.
Reviewers: atanasyan, zoran.jovanovic
Differential Revision: https://reviews.llvm.org/D43486
llvm-svn: 325653
An upcoming patch D41434, changes the ordering of the matcher table
for assembly. This patch corrects the definition of the normal MIPS
cvt.d.w not to be available in microMIPS.
llvm-svn: 325589
These instructions conflict with their full length variants
for the purposes of FastISel as they cannot be distingushed
based on the number and type of operands and predicates.
Reviewers: atanasyan
Differential Revision: https://reviews.llvm.org/D41285
llvm-svn: 325341
In case of correct using of the 'l' constraint llvm now generates valid
code; otherwise it shows an error message. Initially these triggers an
assertion.
This commit is the same as r324869 with fixed the test's file name.
llvm-svn: 324885
In case of correct using of the 'l' constraint llvm now generates valid
code; otherwise it shows an error message. Initially these triggers an
assertion.
llvm-svn: 324869
Instructions affected:
mthc1, mfhc1, add.d, sub.d, mul.d, div.d,
mov.d, neg.d, cvt.w.d, cvt.d.s, cvt.d.w, cvt.s.d
These instructions are now defined for
microMIPS32r3 + microMIPS32r6 in MicroMipsInstrFPU.td
since they shared their encoding with those already defined
in microMIPS32r6InstrInfo.td and have been therefore
removed from the latter file.
Some instructions present in MicroMipsInstrFPU.td which
did not have both AFGR64 and FGR64 variants defined have
been altered to do so.
Differential revision: https://reviews.llvm.org/D42738
llvm-svn: 324584
Both operand codes now work the same way in case of register or memory
operands. It print high-order or low-order word in a double-word
register or memory location.
llvm-svn: 324476
This patch includes EVA instructions in the Std2MicroMips mapping
tables, which is required for direct object emission.
Differential Revision: https://reviews.llvm.org/D41771
llvm-svn: 323958
PR36061 showed that during the expansion of ISD::FPOWI, that there
was an incorrect zero extension of the integer argument which for
MIPS64 would then give incorrect results. Address this with the
existing mechanism for correcting sign extensions.
This resolves PR36061.
Thanks to James Cowgill for reporting the issue!
Reviewers: atanasyan, hfinkel
Differential Revision: https://reviews.llvm.org/D42537
llvm-svn: 323781
Previously some targets printed their own message at the start of Select to indicate what they were selecting. For the targets that didn't, it means there was no print of the root node before any custom handling in the target executed. So if the target did something custom and never called SelectNodeCommon, no print would be made. For the targets that did print a message in Select, if they didn't custom handle a node SelectNodeCommon would reprint the root node before walking the isel table.
It seems better to just print the message before the call to Select so all targets behave the same. And then remove the root node printing from SelectNodeCommon and just leave a message that says we're starting the table search.
There were also some oddities in blank line behavior. Usually due to a \n after a call to SelectionDAGNode::dump which already inserted a new line.
llvm-svn: 323551
- Alter abs for micromips to have both AFGR64 and FGR64
variants, same as sqrt
- Remove sqrt and abs from MicroMips32r6InstrInfo.td,
use micromips FGR64 variants
- Restrict non-micromips abs/sqrt with NotInMicroMips
predicate
Differential revision: https://reviews.llvm.org/D41439
llvm-svn: 323184
Dsp and dspr2 require MIPS revision 2, while msa requires revision 5. Adding
warnings for cases when these flags are used with earlier revision.
Patch by Milos Stojanovic.
Differential Revision: https://reviews.llvm.org/D40490
llvm-svn: 323131
Currently it's not possible to access MCSubtargetInfo from a TgtMCAsmBackend.
D20830 threaded an MCSubtargetInfo reference through
MCAsmBackend::relaxInstruction, but this isn't the only function that would
benefit from access. This patch removes the Triple and CPUString arguments
from createMCAsmBackend and replaces them with MCSubtargetInfo.
This patch just changes the interface without making any intentional
functional changes. Once in, several cleanups are possible:
* Get rid of the awkward MCSubtargetInfo handling in ARMAsmBackend
* Support 16-bit instructions when valid in MipsAsmBackend::writeNopData
* Get rid of the CPU string parsing in X86AsmBackend and just use a SubtargetFeature for HasNopl
* Emit 16-bit nops in RISCVAsmBackend::writeNopData if the compressed instruction set extension is enabled (see D41221)
This change initially exposed PR35686, which has since been resolved in r321026.
Differential Revision: https://reviews.llvm.org/D41349
llvm-svn: 321692
Initially, if the `c` constraint applied to the wrong data type that
causes LLVM to assert. This commit replaces the assert by an error
message.
llvm-svn: 321565
Re-land r321234. It had to be reverted because it broke the shared
library build. The shared library build broke because there was a
missing LLVMBuild dependency from lib/Passes (which calls
TargetMachine::getTargetIRAnalysis) to lib/Target. As far as I can
tell, this problem was always there but was somehow masked
before (perhaps because TargetMachine::getTargetIRAnalysis was a
virtual function).
Original commit message:
This makes the TargetMachine interface a bit simpler. We still need
the std::function in TargetIRAnalysis to avoid having to add a
dependency from Analysis to Target.
See discussion:
http://lists.llvm.org/pipermail/llvm-dev/2017-December/119749.html
I avoided adding all of the backend owners to this review since the
change is simple, but let me know if you feel differently about this.
Reviewers: echristo, MatzeB, hfinkel
Reviewed By: hfinkel
Subscribers: jholewinski, jfb, arsenm, dschuff, mcrosier, sdardis, nemanjai, nhaehnle, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, llvm-commits
Differential Revision: https://reviews.llvm.org/D41464
llvm-svn: 321375
Summary:
This makes the TargetMachine interface a bit simpler. We still need
the std::function in TargetIRAnalysis to avoid having to add a
dependency from Analysis to Target.
See discussion:
http://lists.llvm.org/pipermail/llvm-dev/2017-December/119749.html
I avoided adding all of the backend owners to this review since the
change is simple, but let me know if you feel differently about this.
Reviewers: echristo, MatzeB, hfinkel
Reviewed By: hfinkel
Subscribers: jholewinski, jfb, arsenm, dschuff, mcrosier, sdardis, nemanjai, nhaehnle, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, llvm-commits
Differential Revision: https://reviews.llvm.org/D41464
llvm-svn: 321234
This instruction is encoded as zero, so we have handle that case when checking
for unimplemented opcodes when producing the encoding for an instruction.
llvm-svn: 321066
Fix an off by one error in the bounds checking for 'dinsu' and update
the ranges in the test comments so that they are accurate.
This version has the correct commit message.
Reviewers: atanasyan
Differential Revision: https://reviews.llvm.org/D41183
llvm-svn: 320991
Fix an off by one error in the bounds checking for 'dinsu' and update
the ranges in the test comments so that they are accurate.
Reviewers: atanasyan
https://reviews.llvm.org/D41183
llvm-svn: 320974
