LivePhysRegs: addLiveOuts() can skip addPristines() in ret block
Drive-by improvement: We would 1) add CSRs, 2) remove callee saved CSRs
and 3) add all CSRs again for the return block. Just adding CSRs once
obviously gives the same results.
VirtRegMap: Replace some identity copies with KILL instructions.
An identity COPY like this:
%AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.
Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).
Avoid implicit conversions from MachineInstrBundleIIterator to
MachineInstr* in the MSP430 backend by preferring MachineInstr& over
MachineInstr* when a pointer isn't nullable.
[InstCombine] don't form select from bitcasted logic ops if bitcasts have >1 use
This isn't a sure thing (are 2 extra bitcasts less expensive than a logic op?),
but we'll try to err on the conservative side by going with the case that has
less IR instructions.
Note: This question came up in http://reviews.llvm.org/D22114 , but this part is
independent of that patch proposal, so I'm making this small change ahead of that
one.
Avoid implicit conversions from MachineInstrBundleIterator to
MachineInstr* in the NVPTX backend, mainly by preferring MachineInstr&
over MachineInstr* when a pointer isn't nullable and using range-based
for loops.
There was one piece of questionable code in
NVPTXInstrInfo::AnalyzeBranch, where a condition checked a pointer
converted from an iterator for nullptr. Since this case is impossible
(moreover, the code above guarantees that the iterator is valid), I
removed the check when I changed the pointer to a reference.
Despite that case, there should be no functionality change here.
Wei Mi [Fri, 8 Jul 2016 21:08:09 +0000 (21:08 +0000)]
Allow dead insts to be kept in DeadRemat only when they are rematerializable.
Because isReallyTriviallyReMaterializableGeneric puts many limits on
rematerializable instructions, this fix can prevent instructions with
tied virtual operands and instructions with virtual register uses from
being kept in DeadRemat, so as to workaround the live interval consistency
problem for the dummy instructions kept in DeadRemat.
But we still need to fix the live interval consistency problem. This patch
is just a short time relieve. PR28464 has been filed as a reminder.
Avoid implicit conversions from MachineInstrBundleInstr to MachineInstr*
in the AArch64 backend, mainly by preferring MachineInstr& over
MachineInstr* when a pointer isn't nullable.
Remove remaining implicit conversions from MachineInstrBundleIterator to
MachineInstr* from the ARM backend. In most cases, I made them less attractive
by preferring MachineInstr& or using a ranged-based for loop.
Once all the backends are fixed I'll make the operator explicit so that this
doesn't bitrot back.
Remove remaining implicit conversions from MachineInstrBundleIterator to
MachineInstr* from the AMDGPU backend. In most cases, I made them less
attractive by preferring MachineInstr& or using a ranged-based for loop.
Once all the backends are fixed I'll make the operator explicit so that
this doesn't bitrot back.
Change a while loop that was checking for nullptr on an
iterator-to-pointer conversion to an infinite for loop. Now it's clear
that the condition doesn't terminate.
The only change in behaviour is if an invalid iterator (holding nullptr)
was passed into AMDGPUCFGStructurizer::reversePredicateSetter. There
are only two callers, and they both dereference the iterator before
sending it in, so rather than adding an early return to avoid the loop
I've just asserted (using a static_cast, to avoid an implicit conversion
to pointer).
Stop using an implicit conversion from the return of
MachineBasicBlock::getFirstTerminator to MachineInstr*. In two cases,
directly dereference to a MachineInstr& since later code assumes it's
valid. In a third case, change to an iterator since later code checks
against MachineBasicBlock::end.
Although the fix for the third case avoids undefined behaviour, I expect
this doesn't cause a functionality change in practice (since the basic
block already has a terminator).
CodeGen: Avoid iterator conversions in TwoAddressInstructionPass, NFC
Mostly through preferring MachineInstr&, avoid implicit conversions from
iterator to pointer.
Although this may bitrot (since there are other uses blocking me from
removing the implicit operator), this removes the last of the implicit
conversions from MachineInstrBundleIterator to MachineInstr* in the
LLVMCodeGen build target.
Since these are named nvvm_* rather than nvptx_*, we also need to
update getArchTypePrefix. It's a bit unusual for getArchTypePrefix not
to match the backend name, but I think this fits the intent of the
function in this case.
David Majnemer [Fri, 8 Jul 2016 16:39:00 +0000 (16:39 +0000)]
[CodeGen, TargetPassConfig] Remove a race from createRegAllocPass
The createRegAllocPass reads and writes to a global variable 'Registry'
via calls to getDefault and setDefault. Run this under a call_once to
avoid races.
Chris Dewhurst [Fri, 8 Jul 2016 15:33:56 +0000 (15:33 +0000)]
[Sparc] Leon errata fix passes.
Errata fixes for various errata in different versions of the Leon variants of the Sparc 32 bit processor.
The nature of the errata are listed in the comments preceding the errata fix passes. Relevant unit tests are implemented for each of these.
Note: Running clang-format has changed a few other lines too, unrelated to the implemented errata fixes. These have been left in as this keeps the code formatting consistent.
Anna Thomas [Fri, 8 Jul 2016 15:18:56 +0000 (15:18 +0000)]
InstCombine rule to fold truncs whose value is available
We can fold truncs whose operand feeds from a load, if the trunc value
is available through a prior load/store.
This change is from: http://reviews.llvm.org/D21246, which folded the
trunc but missed the bitcast or ptrtoint/inttoptr required in the RAUW
call, when the load type didnt match the prior load/store type.
Simon Pilgrim [Fri, 8 Jul 2016 13:28:34 +0000 (13:28 +0000)]
[X86][SSE] Improve constant folding tests for CVTSD/CVTSS/CVTTSD/CVTTSS
As discussed on D22106, improve the testing for constant folding sse scalar conversion intrinsics to ensure we are correctly handling special/out of range cases
Code size optimisation: don't expand a div to a mul and and a shift sequence.
As a result, the urem instruction will not be expanded to a sequence of umull,
lsrs, muls and sub instructions, but just a call to __aeabi_uidivmod.
Simon Pilgrim [Fri, 8 Jul 2016 10:39:12 +0000 (10:39 +0000)]
[X86][SSE] Accept any shuffle mask that is all zeroes
Until we have a better way to extract constants through bitcasted build vectors (and how to handle undefs of partial lanes etc.) at least accept build vectors that are all zeroes.
Mehdi Amini [Fri, 8 Jul 2016 01:13:41 +0000 (01:13 +0000)]
Add an assertion for the value enumerator (bitcode writer) NFC
I have an LTO snapshot (for which I don't have sources) that can't
be read back by LLVM. It seems the writer emitted broken bitcode
and this assertions aims at catching such cases.
ARM: support high registers in __builtin_longjmp on WoA
Windows on ARM uses a pure thumb-2 environment. This means that it can select a
high register when doing a __builtin_longjmp. We would use a tLDRi which would
truncate the register to a low register. Use a t2LDRi12 to get the full
register file access. Tweak the code to just load into PC, as that is an
interworking branch on all supported cores anyways.
Jacques Pienaar [Thu, 7 Jul 2016 23:36:04 +0000 (23:36 +0000)]
[lanai] Use peephole optimizer to generate more conditional ALU operations.
Summary:
* Similiar to the ARM backend yse the peephole optimizer to generate more conditional ALU operations;
* Add predicated type with default always true to RR instructions in LanaiInstrInfo.td;
* Move LanaiSetflagAluCombiner into optimizeCompare;
* The ASM parser can currently only handle explicitly specified CC, so specify ".t" (true) where needed in the ASM test;
* Remove unused MachineOperand flags;
xorl + setcc is generally the preferred sequence due to the partial register
stall setcc + movzbl suffers from. As a bonus, it also encodes one byte smaller.
This fixes PR28146.
The original commit tried inserting an 8bit-subreg into a GR32 (not GR32_ABCD)
which was not appreciated by fast regalloc on 32-bit.
GCOVProfiler::emitProfileArcs() can create many variables with names
starting with "__llvm_gcov_ctr", so llvm appends a numeric suffix to
most of them. Teach tsan about this.
projects / llvm / log