This patch revamps the RegStackifier pass with a new tree traversal mechanism,
enabling three major new features:
- Stackification of values with multiple uses, using the result value of set_local
- More aggressive stackification of instructions with side effects
- Reordering operands in commutative instructions to enable more stackification.
llvm-svn: 259009
Summary:
Just does the simple allocation of a stack object and passes
a pointer to the callee.
Differential Revision: http://reviews.llvm.org/D16610
llvm-svn: 258989
The BPF and WebAssembly backends had identical code for emitting errors
for unsupported features, and AMDGPU had very similar code. This merges
them all into one DiagnosticInfo subclass, that can be used by any
backend.
There should be minimal functional changes here, but some AMDGPU tests
have been updated for the new format of errors (it used a slightly
different format to BPF and WebAssembly). The AMDGPU error messages will
now benefit from having precise source locations when debug info is
available.
The implementation of DiagnosticInfoUnsupported::print must be in
lib/Codegen rather than in the existing file in lib/IR/ to avoid
introducing a dependency from IR to CodeGen.
Differential Revision: http://reviews.llvm.org/D16590
llvm-svn: 258951
Summary:
This patch is provided in preparation for removing autoconf on 1/26. The proposal to remove autoconf on 1/26 was discussed on the llvm-dev thread here: http://lists.llvm.org/pipermail/llvm-dev/2016-January/093875.html
"I felt a great disturbance in the [build system], as if millions of [makefiles] suddenly cried out in terror and were suddenly silenced. I fear something [amazing] has happened."
- Obi Wan Kenobi
Reviewers: chandlerc, grosbach, bob.wilson, tstellarAMD, echristo, whitequark
Subscribers: chfast, simoncook, emaste, jholewinski, tberghammer, jfb, danalbert, srhines, arsenm, dschuff, jyknight, dsanders, joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D16471
llvm-svn: 258861
r258781 optimized memcpy/memmove/memcpy so the intrinsic call can return its first argument, but missed the frame index case. Teach it to ignore that case so C code doesn't assert out in these cases.
llvm-svn: 258851
These calls return their first argument, but because LLVM uses an intrinsic
with a void return type, they can't use the returned attribute. Generalize
the store results pass to optimize these calls too.
llvm-svn: 258781
Instructions can be DCE'd after the RegStackify pass. If the instruction which
would be the pop for what would be a push is removed, don't use a push.
llvm-svn: 258694
Previously it failed to add NumArgRegs to the offset and so clobbered an
already-used register. Now just start the numbering after the arg regs
and don't duplicate the add. Test coverage for this coming shortly with
the implementation of byval.
llvm-svn: 258597
Teach the register stackifier to rematerialize constants that have multiple
uses instead of leaving them in registers. In the WebAssembly encoding, it's
the same code size to materialize most constants as it is to read a value
from a register.
llvm-svn: 258142
WebAssembly's stack will never be executable by default, so it isn't
necessary to declare .note.GNU-stack sections to request a non-executable
stack.
Differential Revision: http://reviews.llvm.org/D15969
llvm-svn: 257962
A recent change introduced this assertion failure in some corner cases.
Repro:
mkdir /s/wasm/torture-out ; time /s/wasm/waterfall/src/compile_torture_tests.py --c /s/llvm/out/bin/clang --cxx /s/llvm/out/bin/clang++ --testsuite /s/gcc/gcc/testsuite --fails /s/llvm/llvm/lib/Target/WebAssembly/known_gcc_test_failures.txt --out /s/wasm/torture-out
Or look on the wasm integration bot:
https://build.chromium.org/p/client.wasm.llvm/console
llvm-svn: 257733
A request has been made to the official registry, but an official value is
not yet available. This patch uses a temporary value in order to support
development. When an official value is recieved, the value of EM_WEBASSEMBLY
will be updated.
llvm-svn: 257517
Refactor .param, .result, .local, and .endfunc, as directives, using the
proper MCTargetStreamer mechanism, rather than fake instructions.
llvm-svn: 257511
This patch changes the way labels are referenced. Instead of referencing the
basic-block label name (eg. .LBB0_0), instructions now just have an immediate
which indicates the depth in the control-flow stack to find a label to jump to.
This makes them much closer to what we expect to have in the binary encoding,
and avoids the problem of basic-block label names not being explicit in the
binary encoding.
Also, it terminates blocks and loops with end_block and end_loop instructions,
rather than basic-block label names, for similar reasons.
This will also fix problems where two constructs appear to have the same label,
because we no longer explicitly use labels, so consumers that need labels will
presumably create their own labels, and presumably they won't reuse labels
when they do.
This patch does make the code a little more awkward to read; as a partial
mitigation, this patch also introduces comments showing where the labels are,
and comments on each branch showing where it's branching to.
llvm-svn: 257505
Currently WebAssembly has two kinds of relocations; data addresses and
function addresses. This adds ELF relocations for them, as well as an
MC symbol kind to indicate which type of relocation is needed.
llvm-svn: 257416
Always expect tglobaladdr and texternalsym to be wrapped in
WebAssemblywrapper nodes. Also, split out a regPlusGA from regPlusImm so
that it can special-case global addresses, as they can be folded in more
cases.
Unfortunately this doesn't enable any new optimizations yet due to
SelectionDAG limitations. I'll be submitting changes to the SelectionDAG
infrastructure, along with tests, in a separate patch.
llvm-svn: 257394
.zero is confusing when used with two arguments. Documentation:
This directive emits SIZE 0-valued bytes. SIZE must be an absolute
expression. This directive is actually an alias for the '.skip'
directive so in can take an optional second argument of the value to
store in the bytes instead of zero. Using '.zero' in this way would be
confusing however.
Ref: https://sourceware.org/bugzilla/show_bug.cgi?id=18353
Hexagon and Sparc do the same, and it's all the same to WebAssembly so
let's pick the less confusing of the two.
llvm-svn: 257111
Previously we only supported putting the FI into memory operand offset
fields if there was nothing there already. Now combine them.
Differential Revision: http://reviews.llvm.org/D15941
llvm-svn: 257084
The MC assembler doesn't like using the empty string as a private label
prefix because then it treats all labels as private. This commit reverts
back to the default prefix, which is .L, which is common in ELF targets
and consistent with the LLVM name mangler.
llvm-svn: 257083
The first instruction in a block is what the rend() iterator points to, so
if it moves, we need to re-evaluate rend() so that we continue to iterate
through the rest of the instructions.
llvm-svn: 256953
Move RegStackify after coalescing and teach it to use LiveIntervals instead
of depending on SSA form. This avoids a problem where a register in a COPY
instruction is stackified and then subsequently coalesced with a register
that is not stackified.
This also puts it after the scheduler, which allows us to simplify the
EXPR_STACK constraint, as we no longer have instructions being reordered
after stackification and before coloring.
llvm-svn: 256402
This allows the AsmMatcherEmitter to properly tokenize the AsmStrings for
load and store instructions. This is a step towards asm parsing.
llvm-svn: 256166
This creates the initial infrastructure for writing ELF output files. It
doesn't yet have any implementation for encoding instructions.
Differential Revision: http://reviews.llvm.org/D15555
llvm-svn: 255869
Summary:
Implement eliminateCallFramePsuedo to handle ADJCALLSTACKUP/DOWN
pseudo-instructions. Add a test calling a vararg function which causes non-0
adjustments. This revealed an issue with RegisterCoalescer wherein it
eliminates a COPY from SP32 to a vreg but failes to update the live ranges
of EXPR_STACK, causing a machineinstr verifier failure (so this test
is commented out).
Also add a dynamic alloca test, which causes a callseq_end dag node with
a 0 (instead of undef) second argument to be generated. We currently fail to
select that, so adjust the ADJCALLSTACKUP tablegen code to handle it.
Differential Revision: http://reviews.llvm.org/D15587
llvm-svn: 255844
Add instruction patterns for matching load and store instructions with constant
offsets in addresses. The code is fairly redundant due to the need to replicate
everything between imm, tglobaldadr, and texternalsym, but this appears to be
common tablegen practice. The main alternative appears to be to introduce
matching functions with C++ code, but sticking with purely generated matchers
seems better for now.
Also note that this doesn't yet support offsets from getelementptr, which will
be the most common case; that will depend on a change in target-independent code
in order to set the NoUnsignedWrap flag, which I'll submit separately. Until
then, the testcase uses ptrtoint+add+inttoptr with a nuw on the add.
Also implement isLegalAddressingMode with an approximation of this.
Differential Revision: http://reviews.llvm.org/D15538
llvm-svn: 255681
Add return type information to call and call_indirect instructions. This
allows them to be disambiguated without knowledge of the callee.
Differential Revision: http://reviews.llvm.org/D15484
llvm-svn: 255565
Implement a new BLOCK scope placement algorithm which better handles
early-return blocks and early exists from nested scopes.
Differential Revision: http://reviews.llvm.org/D15368
llvm-svn: 255564
The WebAssemblyStoreResults pass runs before LiveVariables, so it doesn't
expect to have to keep dead flags up to date; check this with an assert.
llvm-svn: 255551
Many tests are now passing due to eliminateFrameIndex implementation and
the list needs to be re-triaged because it unblocks other failures, and
some previous failures are different. However I'm about to churn it more
by implementing more lowering, so will wait on that.
llvm-svn: 255396
Summary:
Use the SP32 physical register as the base for FrameIndex
lowering. Update it and the __stack_pointer global var in the prolog and
epilog. Extend the mapping of virtual registers to wasm locals to
include the physical registers.
Rather than modify the target-independent PrologEpilogInserter (which
asserts that there are no virtual registers left) include a
slightly-modified copy for Wasm that does not have this assertion and
only clears the virtual registers if scavenging was needed (which of
course it isn't for wasm).
Differential Revision: http://reviews.llvm.org/D15344
llvm-svn: 255392
Summary:
ADJCALLSTACK{DOWN,UP} (aka CALLSEQ_{START,END}) MIs are supposed to use
and def the stack pointer. Since they do not, all the nodes are being
eliminated by DeadMachineInstructionElim, so they aren't in the IR when
PrologEpilogInserter/eliminateCallFramePseudo needs them.
This change fixes that, but since RegStackify will not stackify across
them (and it runs early, before PEI), change LowerCall to only emit them
when the call frame size is > 0. That makes the current code work the
same way and makes code handled by D15344 also work the same way. We can
expand the condition beyond NumBytes > 0 in the future if needed.
Reviewers: sunfish, jfb
Subscribers: jfb, dschuff, llvm-commits
Differential Revision: http://reviews.llvm.org/D15459
llvm-svn: 255356
ISD::FCOPYSIGN permits its operands to have differing types, and DAGCombiner
uses this. Add some def : Pat rules to expand this out into an explicit
conversion and a normal copysign operation.
llvm-svn: 255220
Reinteroduce the code for moving ARGUMENTS back to the top of the basic block.
While the ARGUMENTS physical register prevents sinking and scheduling from
moving them, it does not appear to be sufficient to prevent SelectionDAG from
moving them down in the initial schedule. This patch introduces a patch that
moves them back to the top immediately after SelectionDAG runs.
This is still hopefully a temporary solution. http://reviews.llvm.org/D14750 is
one alternative, though the review has not been favorable, and proposed
alternatives are longer-term and have other downsides.
This fixes the main outstanding -verify-machineinstrs failures, so it adds
-verify-machineinstrs to several tests.
Differential Revision: http://reviews.llvm.org/D15377
llvm-svn: 255125
The bots are now running the torture tests properly. Bin all failures from the GCC C torture tests so that we can tackle failures and make the tree go red on regressions.
llvm-svn: 255111
This patch introduces a codegen-only instruction currently named br_unless,
which makes it convenient to implement ReverseBranchCondition and re-enable
the MachineBlockPlacement pass. Then in a late pass, it lowers br_unless
back into br_if.
Differential Revision: http://reviews.llvm.org/D14995
llvm-svn: 254826
Add physical register defs to instructions used from stackified
instructions to prevent them from being scheduled into the middle of
a stack sequence. This is a conservative measure which may be loosened
in the future.
Differential Revision: http://reviews.llvm.org/D15252
llvm-svn: 254811
This is just prototype for load/store for i32 types. I'll add them to
the rest of the types if we like this direction.
Differential Revision: http://reviews.llvm.org/D15197
llvm-svn: 254807
Full varargs support will depend on prologue/epilogue support, but this patch
gets us started with most of the basic infrastructure.
Differential Revision: http://reviews.llvm.org/D15231
llvm-svn: 254799
When a block has no terminator instructions, getFirstTerminator() returns
end(), which can't be used in dominance checks. Check dominance for phi
operands separately.
Also, remove some bits from WebAssemblyRegStackify.cpp that were causing
trouble on the same testcase; they were left behind from an earlier
experiment.
Differential Revision: http://reviews.llvm.org/D15210
llvm-svn: 254662
If virtual registers are created late, mappings to WebAssembly
registers need to be added explicitly. This patch adds a function
to do so and teaches WebAssemblyPeephole to use it. This fixes
an out-of-bounds access on the WARegs vector.
llvm-svn: 254094
Instead of trying to move ARGUMENT instructions back up to the top after
they've been scheduled or sunk down, use a fake physical register to
create a liveness constraint that prevents ARGUMENT instructions from
moving down in the first place. This is still not entirely ideal, however
it is more robust than letting them move and moving them back.
llvm-svn: 254084
With the '=' suffix now indicating which operands are output operands, it's
no longer as important to distinguish between a call's inputs and its outputs
using operand ordering, so we can go back to printing them in the normal order.
llvm-svn: 253925
This distinguishes input operands from output operands. This is something of
a syntactic experiment to see whether the mild amount of clutter this adds is
outweighed by the extra information it conveys to the reader.
llvm-svn: 253922
The current approach to using get_local and set_local is to use them
implicitly, as register uses and defs. Introduce new copy instructions
which are themselves no-ops except for the get_local and set_local
that they imply, so that we use get_local and set_local consistently.
llvm-svn: 253905
WebAssembly is currently using labels to end scopes, so for example a
loop scope looks like this:
BB0_0:
loop BB0_1
...
BB0_1:
with BB0_0 being the label of the first block not in the loop. This
requires that the label be printed even when it's only reachable via
fallthrough. To arrange this, insert a no-op LOOP_END instruction in
such cases at the end of the loop.
llvm-svn: 253901
Always starting blocks at the top of their containing loops works, but creates
unnecessarily deep nesting because it makes all blocks in a loop overlap.
Refine the BLOCK placement algorithm to start blocks at nearest common
dominating points instead, which significantly shrinks them and reduces
overlapping.
llvm-svn: 253876
WebAssembly does not have physical registers, so even if LLVM uses physical
registers like SP, they'll need to be lowered to virtual registers before
AsmPrinter time.
llvm-svn: 253644
coloring pass. Turn the logic into "look for an insert point and
then move things past the insert point".
No functional change intended.
llvm-svn: 253626
This also takes the push/pop syntax another step forward, introducing stack
slot numbers to make it easier to see how expressions are connected. For
example, the value pushed in $push7 is popped in $pop7.
And, this begins an experiment with making get_local and set_local implicit
when an operation directly uses or defines a register. This greatly reduces
clutter. If this experiment succeeds, it may make sense to do this for
const instructions as well.
And, this introduces more special code for ARGUMENTS; hopefully this code
will soon be obviated by proper support for live-in virtual registers.
llvm-svn: 253465
This was regressed in r252656 which wasn't quite NFC. Instead of using a
custom instruction as before, use a pattern to select CONST_I32 for the
global addrs.
Differential Revision: http://reviews.llvm.org/D14587
llvm-svn: 253276
Summary:
Previously return type information for a function was derived from
return dag nodes. But this didn't work for dags with != return node. So
instead compute it directly from the LLVM function as is done for imports.
Differential Revision: http://reviews.llvm.org/D14593
llvm-svn: 253251
Summary: This is to match the new version in the spec
Reviewers: sunfish
Subscribers: jfb, llvm-commits, dschuff
Differential Revision: http://reviews.llvm.org/D14519
llvm-svn: 253249
This arranges the types in the LLVM instruction names in the same order that
they appear in the WebAssembly opcode names, and eliminates
double-underscores.
llvm-svn: 252988
JF Bastien