X86FloatingPoint keeps track of pending ST registers for an upcoming
inline asm instruction with fixed stack register constraints. It does
this by remembering which FP register holds the value that should appear
at a fixed stack position for the inline asm.
When that FP register is killed before the inline asm, make sure to
duplicate it to a scratch register, so the ST register still has a live
FP reference.
This could happen when the same FP register was copied to two ST
registers, or when a spill instruction is inserted between the ST copy
and the inline asm.
This fixes PR10602.
llvm-svn: 137050
recurrence, the initial values low bits can sometimes be ignored.
To take advantage of this, added FoldIVUser to IndVarSimplify to fold
an IV operand into a udiv/lshr if the operator doesn't affect the
result.
-indvars -disable-iv-rewrite now transforms
i = phi i4
i1 = i0 + 1
idx = i1 >> (2 or more)
i4 = i + 4
into
i = phi i4
idx = i0 >> ...
i4 = i + 4
llvm-svn: 137013
The local ranges created get to stay in the RS_New stage, just like for
local and region splitting.
This gives tryLocalSplit a bit more freedom the first time it sees one
of these new local ranges.
llvm-svn: 137001
Normally, we don't create a live range for a single instruction in a
basic block, the spiller does that anyway. However, when splitting a
live range that belongs to a proper register sub-class, inserting these
extra COPY instructions completely remove the constraints from the
remainder interval, and it may be allocated from the larger super-class.
The spiller will mop up these small live ranges if we end up spilling
anyway. It calls them snippets.
llvm-svn: 136989
More parsing support for indexed loads. Fix pre-indexed with writeback
parsing for register offsets and handle basic post-indexed offsets.
llvm-svn: 136982
Some instructions require restricted register classes, but most of the
time that doesn't affect register allocation. For example, some
instructions don't work with the stack pointer, but that is a reserved
register anyway.
Sometimes it matters, GR32_ABCD only has 4 allocatable registers. For
such a proper sub-class, the register allocator should try to enable
register class inflation since that makes more registers available for
allocation.
Make sure only legal super-classes are considered. For example, tGPR is
not a proper sub-class in Thumb mode, but in ARM mode it is.
llvm-svn: 136981
Refactor STR[B] pre and post indexed instructions to use addressing modes for
memory operands, which is necessary for assembly parsing and is more consistent
with the rest of the memory instruction definitions. Make some incremental
progress on refactoring away the mega-operand addrmode2 along the way, which
is nice.
llvm-svn: 136978
The old code would look at kills and defs in one pass over the
instruction operands, causing problems with this code:
%R0<def>, %CPSR<def,dead> = tLSLri %R5<kill>, 2, pred:14, pred:%noreg
%R0<def>, %CPSR<def,dead> = tADDrr %R4<kill>, %R0<kill>, pred:14, %pred:%noreg
The last instruction kills and redefines %R0, so it is still live after
the instruction.
This caused a register scavenger crash when compiling 483.xalancbmk for
armv6. I am not including a test case because it requires too much bad
luck to expose this old bug.
First you need to convince the register allocator to use %R0 twice on
the tADDrr instruction, then you have to convince BranchFolding to do
something that causes it to run the register scavenger on he bad block.
<rdar://problem/9898200>
llvm-svn: 136973
inlined variable, based on the discussion in PR10542.
This explodes the runtime of several passes down the pipeline due to
a large number of "copies" remaining live across a large function. This
only shows up with both debug and opt, but when it does it creates
a many-minute compile when self-hosting LLVM+Clang. There are several
other cases that show these types of regressions.
All of this is tracked in PR10542, and progress is being made on fixing
the issue. Once its addressed, the re-instated, but until then this
restores the performance for self-hosting and other opt+debug builds.
Devang, let me know if this causes any trouble, or impedes fixing it in
any way, and thanks for working on this!
llvm-svn: 136953
This is meant to be overriden by backends. Implement an override on PowerPC
which adjusts the offset by 2 for ha16/lo16 relocation kinds. This removes
a commented out hack and enables hello world to be compiled on PowerPC.
llvm-svn: 136905
Memory operand parsing is a bit haphazzard at the moment, in no small part
due to the even more haphazzard representations of memory operands in the .td
files. Start cleaning that all up, at least a bit.
The addressing modes in the .td files will be being simplified to not be
so monolithic, especially with regards to immediate vs. register offsets
and post-indexed addressing. addrmode3 is on its way with this patch, for
example.
This patch is foundational to enable going back to smaller incremental patches
for the individual memory referencing instructions themselves. It does just
enough to get the basics in place and handle the "make check" regression tests
we already have.
Follow-up work will be fleshing out the details and adding more robust test
cases for the individual instructions, starting with ARM mode and moving from
there into Thumb and Thumb2.
llvm-svn: 136845
LoopPassManager. The incremental update should be extremely cheap in
most cases and can be used in places where it's not feasible to
regenerate the entire loop forest.
- "Unloop" is a node in the loop tree whose last backedge has been removed.
- Perform reverse dataflow on the block inside Unloop to propagate the
nearest loop from the block's successors.
- For reducible CFG, each block in unloop is visited exactly
once. This is because unloop no longer has a backedge and blocks
within subloops don't change parents.
- Immediate subloops are summarized by the nearest loop reachable from
their exits or exits within nested subloops.
- At completion the unloop blocks each have a new parent loop, and
each immediate subloop has a new parent.
llvm-svn: 136844
It is possible to have multiple DBG_VALUEs for the same variable:
32L TEST32rr %vreg0<kill>, %vreg0, %EFLAGS<imp-def>; GR32:%vreg0
DBG_VALUE 2, 0, !"i"
DBG_VALUE %noreg, %0, !"i"
When that happens, keep the last one instead of the first.
llvm-svn: 136842
This helps generate better code in functions with high register
pressure.
The previous version of compact region splitting caused regressions
because the regions were a bit too large. A stronger negative bias
applied in r136832 fixed this problem.
llvm-svn: 136836
Apply twice the negative bias on transparent blocks when computing the
compact regions. This excludes loop backedges from the region when only
one of the loop blocks uses the register.
Previously, we would include the backedge in the region if the loop
preheader and the loop latch both used the register, but the loop header
didn't.
When both the header and latch blocks use the register, we still keep it
live on the backedge.
llvm-svn: 136832
- use SmallVectorImpl& for the function argument.
- ignore the operands on the GEP, even if they aren't constant! Much as we
pretend the malloc succeeds, we pretend that malloc + whatever-you-GEP'd-by
is not null. It's magic!
llvm-svn: 136757
Don't replace a gep/bitcast with 'undef' because that will form a "free(undef)"
which in turn means "unreachable". What we wanted was a no-op. Instead, analyze
the whole tree and look for all the instructions we need to delete first, then
delete them second, not relying on the use_list to stay consistent.
llvm-svn: 136752
This is either an invalid SlotIndex, or valno->def for the first value
defined inside the block. PHI values are not counted as defined inside
the block.
The FirstDef field will be used when estimating the cost of spilling
around a block.
llvm-svn: 136736
The PrefBoth constraint is used for blocks that ideally want a live-in
value both on the stack and in a register. This would be used by a block
that has a use before interference forces a spill.
Secondly, add the ChangesValue flag to BlockConstraint. This tells
SpillPlacement if a live-in value on the stack can be reused as a
live-out stack value for free. If the block redefines the virtual
register, a spill would be required for that.
This extra information will be used by SpillPlacement to more accurately
calculate spill costs when a value can exist both on the stack and in a
register.
The simplest example is a basic block that reads the virtual register,
but doesn't change its value. Spilling around such a block requires a
reload, but no spill in the block.
The spiller already knows this, but the spill placer doesn't. That can
sometimes lead to suboptimal regions.
llvm-svn: 136731
TableGen deps introduced in r136023. This completes the fixing that
dgregor started in r136621. Sorry for missing these the first time
around.
This should fix some of the random race-condition failures people are
still seeing with CMake.
llvm-svn: 136643
avoid returning early for v8i32 types, which would only be valid for
vector with all zeros. Also split the handling of zeros and ones into separate
checking logic since they are handled differently. This fixes PR10547
llvm-svn: 136642
them properly. Specifically, the disassembler clearly attempts to
initialiaze all TargetInfo, MCTargeDesc, AsmParser, and Disassembler
sublibraries of registered targets. This makes the CMakeLists accurately
reflect this intent in the code.
This should fix the last of the link errors that I have gotten reports
of on OS X, but if anyone continues to see link errors, continue to
pester me and I'll look into it.
llvm-svn: 136603
This adds the 'resume' instruction class, IR parsing, and bitcode reading and
writing. The 'resume' instruction resumes propagation of an existing (in-flight)
exception whose unwinding was interrupted with a 'landingpad' instruction (to be
added later).
llvm-svn: 136589
decide whether condition is likely to be true this way:
x == 0 -> false
x < 0 -> false
x <= 0 -> false
x != 0 -> true
x > 0 -> true
x >= 0 -> true
llvm-svn: 136583
This includes registers like EFLAGS and ST0-ST7. We don't check for
liveness issues in the verifier and scavenger because registers will
never be allocated from these classes.
While in SSA form, we do care about the liveness of unallocatable
unreserved registers. Liveness of EFLAGS and ST0 neds to be correct for
MachineDCE and MachineSinking.
llvm-svn: 136541
This flag is true from isel to register allocation when the machine
function is required to be in SSA form. The TwoAddressInstructionPass
and PHIElimination passes clear the flag.
The SSA flag wil be used by the machine code verifier to check for SSA
form, and eventually an assertion can enforce it in +Asserts builds.
This will catch the common target error of creating machine code with
multiple defs of a virtual register.
llvm-svn: 136532
Fix the instruction encoding for operands. Refactor mode to use explicit
instruction definitions per FIXME to be more consistent with loads/stores.
Fix disassembler accordingly. Add tests.
llvm-svn: 136509
for targets that don't have an MC-ized disassembler. I'm suspicious that
this shouldn't actually be happening, but hoping to fix the CMake build
on macs first, and investigate why second.
llvm-svn: 136508
Fill in the missing fixed bits and the register operand bits of the instruction
encoding. Refactor the definition to make the mode explicit, which is
consistent with how loads and stores are normally represented and makes
parsing much easier. Add parsing aliases for pseudo-instruction variants.
Update the disassembler for the new representations. Add tests for parsing and
encoding.
llvm-svn: 136479
screwy things by setting PWD != getcwd(). For example, some developers I know
will use this to control the value in gcc's DW_AT_comp_dir value in debug
output. With this patch, that trick will now work on clang too.
The only other effect of this change is that the static analysis will now
respect $PWD when reporting the directory of the files in its HTML output. I
think that's fine.
llvm-svn: 136459
working on x86 (at least for trivial testcases); other architectures will
need more work so that they actually emit the appropriate instructions for
orderings stricter than 'monotonic'. (As far as I can tell, the ARM, PPC,
Mips, and Alpha backends need such changes.)
llvm-svn: 136457
First off, only depend on the actual MC-ized disassemblers in the
targets, not all of the libraries those in turn depend on.
Second off, only depend on those MC-ized disassemblers for targets we're
building.
This should fix builds of fewer than all targets.
llvm-svn: 136455
This hidden llc option runs the machine code verifier after expanding
ARM pseudo-instructions, but before if-conversion.
The machine code verifier is much better at pointing out liveness errors
that can trip up the register scavenger.
llvm-svn: 136439
specified in the same file that the library itself is created. This is
more idiomatic for CMake builds, and also allows us to correctly specify
dependencies that are missed due to bugs in the GenLibDeps perl script,
or change from compiler to compiler. On Linux, this returns CMake to
a place where it can relably rebuild several targets of LLVM.
I have tried not to change the dependencies from the ones in the current
auto-generated file. The only places I've really diverged are in places
where I was seeing link failures, and added a dependency. The goal of
this patch is not to start changing the dependencies, merely to move
them into the correct location, and an explicit form that we can control
and change when necessary.
This also removes a serialization point in the build because we don't
have to scan all the libraries before we begin building various tools.
We no longer have a step of the build that regenerates a file inside the
source tree. A few other associated cleanups fall out of this.
This isn't really finished yet though. After talking to dgregor he urged
switching to a single CMake macro to construct libraries with both
sources and dependencies in the arguments. Migrating from the two macros
to that style will be a follow-up patch.
Also, llvm-config is still generated with GenLibDeps.pl, which means it
still has slightly buggy dependencies. The internal CMake
'llvm-config-like' macro uses the correct explicitly specified
dependencies however. A future patch will switch llvm-config generation
(when using CMake) to be based on these deps as well.
This may well break Windows. I'm getting a machine set up now to dig
into any failures there. If anyone can chime in with problems they see
or ideas of how to solve them for Windows, much appreciated.
llvm-svn: 136433
This generates the correct SDNodes for the landingpad instruction. It makes an
assumption that the result of the landingpad instruction has at least two
values. And that the first value is a pointer to the exception object and the
second value is the "selector."
llvm-svn: 136430
Add parsing support for BLX (immediate). Since the register operand version is
predicated and the label operand version is not, we have to use some special
handling to get the operand list right for matching.
llvm-svn: 136406
'atomicrmw' instructions, which allow representing all the current atomic
rmw intrinsics.
The allowed operands for these instructions are heavily restricted at the
moment; we can probably loosen it a bit, but supporting general
first-class types (where it makes sense) might get a bit complicated,
given how SelectionDAG works.
As an initial cut, these operations do not support specifying an alignment,
but it would be possible to add if we think it's useful. Specifying an
alignment lower than the natural alignment would be essentially
impossible to support on anything other than x86, but specifying a greater
alignment would be possible. I can't think of any useful optimizations which
would use that information, but maybe someone else has ideas.
Optimizer/codegen support coming soon.
llvm-svn: 136404
Code like that would only be produced by bugpoint, but we should still
handle it correctly.
When a register is defined by a REG_SEQUENCE of undefs, the register
itself is undef. Previously, we would create a register with uses but no
defs.
Fixes part of PR10520.
llvm-svn: 136401
Add parsing support that handles converting the lsb+width source into the
odd way we represent the instruction (an inverted bitfield mask).
llvm-svn: 136399
There are two conflicting strategies in play:
- Under high register pressure, we want to assign large live ranges
first. Smaller live ranges are easier to place afterwards.
- Live range splitting is guided by interference, so splitting should be
deferred until interference is as realistic as possible.
With the recent changes to the live range stages, and with compact
regions enabled, it is less traumatic to split a live range too early.
If some of the split products were too big, they can often be split
again.
By reversing the RS_Split order, we get this queue order:
1. Normal live ranges, large to small.
2. RS_Split live ranges, large to small.
The large-to-small order improves RAGreedy's puzzle solving skills under
high register pressure. It may cause a bit more iterated splitting, but
we handle that better now.
With this change, -compact-regions is mostly an improvement on SPEC.
llvm-svn: 136388
The new EH is more simple in many respects. Mainly, we don't have to worry about
the "llvm.eh.exception" and "llvm.eh.selector" calls being in weird places.
llvm-svn: 136339
LLVM*AsmPrinter.
GenLibDeps.pl fails to detect vtable references. As this is the only
referenced symbol from LLVM*Desc to LLVM*AsmPrinter on optimized
builds, the algorithm that creates the list of libraries to be linked
into tools doesn't know about the dependency and sometimes places the
libraries on the wrong order, yielding error messages like this:
../../lib/libLLVMARMDesc.a(ARMMCTargetDesc.cpp.o): In function
`llvm::ARMInstPrinter::ARMInstPrinter(llvm::MCAsmInfo const&)':
ARMMCTargetDesc.cpp:(.text._ZN4llvm14ARMInstPrinterC1ERKNS_9MCAsmInfoE
[llvm::ARMInstPrinter::ARMInstPrinter(llvm::MCAsmInfo
const&)]+0x2a): undefined reference to `vtable for
llvm::ARMInstPrinter'
llvm-svn: 136328
* InvokeInst: Get the landingpad instruction associated with this invoke.
* LandingPadInst: A method to reserve extra space for clauses.
llvm-svn: 136325
This takes the new 'resume' instruction and turns it into a direct jump to the
caller's landing pad code. The caller's landingpad instruction is merged with
the landingpad instructions of the callee. This is a bit rough and makes some
assumptions in how the code works. But it passes a simple test.
llvm-svn: 136313
If true and 'model' parameter is not an absolute path, a temp directory will be prepended.
Make it true by default to match current behaviour.
llvm-svn: 136310
This can happen in cases where TableGen generated asm matcher cannot check
whether a register operand is in the right register class. e.g. mem operands.
rdar://8204588
llvm-svn: 136292
llvm-mc gives an "invalid operand" error for instructions that take an unsigned
immediate which have the high bit set such as:
pblendw $0xc5, %xmm2, %xmm1
llvm-mc treats all x86 immediates as signed values and range checks them.
A small number of x86 instructions use the imm8 field as a set of bits.
This change only changes those instructions and where the high bit is not
ignored. The others remain unchanged.
llvm-svn: 136287
Encode the width operand as it encodes in the instruction, which simplifies
the disassembler and the encoder, by using the imm1_32 operand def. Add a
diagnostic for the context-sensitive constraint that the width must be in
the range [1,32-lsb].
llvm-svn: 136264
Refactor the rest of the extend instructions to not artificially distinguish
between a rotate of zero and a rotate of any other value. Replace the by-zero
versions with Pat<>'s for ISel.
llvm-svn: 136226
Refactor the SXTB, SXTH, SXTB16, UXTB, UXTH, and UXTB16 instructions to not
have an 'r' and an 'r_rot' version, but just a single version with a rotate
that can be zero. Use plain Pat<>'s for the ISel of the non-rotated version.
llvm-svn: 136225
usage of the shuffle bitmask. Both work in 128-bit lanes without
crossing, but in the former the mask of the high part is the same
used by the low part while in the later both lanes have independent
masks. Handle this properly and and add support for vpermilpd.
llvm-svn: 136200
When splitting global live ranges, it is now possible to split for
multiple destination intervals at once. Previously, we only had the main
and stack intervals.
Each edge bundle is assigned to a split candidate, and splitAroundRegion
will insert copies between the candidate intervals and the stack
interval as needed.
The multi-way splitting is used to split around compact regions when
enabled with -compact-regions. The best candidate register still gets
all the bundles it wants, but everything outside the main interval is
first split around compact regions before we create single-block
intervals.
Compact region splitting still causes some regressions, so it is not
enabled by default.
llvm-svn: 136186
These copies would coalesce easily, but the resulting value would be
defined by a deleted instruction. Now we also remove the undefined value
number from the destination register.
This fixes PR10503.
llvm-svn: 136174
On x86 we can't encode an immediate LHS of a sub directly. If the RHS comes from a XOR with a constant we can
fold the negation into the xor and add one to the immediate of the sub. Then we can turn the sub into an add,
which can be commuted and encoded efficiently.
This code is generated for __builtin_clz and friends.
llvm-svn: 136167
Allow the rot_imm operand to be optional. This sets the stage for refactoring
away the "rr" versions from the multiclasses and replacing them with Pat<>s.
llvm-svn: 136154
Start of cleaning this up a bit. First step is to remove the encoder hook by
storing the operand as the bits it'll actually encode to so it can just be
directly used. Map it to the assembly source values 8/16/24 when we print it.
llvm-svn: 136152
