LLVM converts adds into ors when it can prove that the operands don't share
any non-zero bits. Teach address folding to recognize or instructions with
constant operands with this property that can be folded into addresses as
if they were adds.
llvm-svn: 261562
The stack pointer is bumped when there is a frame pointer or when there
are static-size objects, but was only getting written back when there
were static-size objects.
llvm-svn: 261453
While we still do want reducible control flow, the RequiresStructuredCFG
flag imposes more strict structure constraints than WebAssembly wants.
Unsetting this flag enables critical edge splitting and tail merging.
Also, disable TailDuplication explicitly, as it doesn't support virtual
registers, and was previously only disabled by the RequiresStructuredCFG
flag.
llvm-svn: 261190
These passes are optimizations, and should be disabled when not
optimizing.
Also create an MCCodeGenInfo so the opt level is correctly plumbed to
the backend pass manager.
Also remove the command line flag for disabling register coloring;
running llc with -O0 should now be useful for debugging, so it's not
necessary.
Differential Revision: http://reviews.llvm.org/D17327
llvm-svn: 261176
This fixes very slow compilation on
test/CodeGen/Generic/2010-11-04-BigByval.ll . Note that MaxStoresPerMemcpy
and friends are not yet carefully tuned so the cutoff point is currently
somewhat arbitrary. However, it's important that there be a cutoff point
so that we don't emit unbounded quantities of loads and stores.
llvm-svn: 261050
The register stackifier currently checks for intervening stores (and
loads that may alias them) but doesn't account for the fact that the
instruction being moved may affect intervening loads.
Differential Revision: http://reviews.llvm.org/D17298
llvm-svn: 261014
CopyToReg nodes don't support FrameIndex operands. Other targets select
the FI to some LEA-like instruction, but since we don't have that, we
need to insert some kind of instruction that can take an FI operand and
produces a value usable by CopyToReg (i.e. in a vreg). So insert a dummy
copy_local between Op and its FI operand. This results in a redundant
copy which we should optimize away later (maybe in the post-FI-lowering
peephole pass).
Differential Revision: http://reviews.llvm.org/D17213
llvm-svn: 260987
WebAssembly doesn't require full RPO; topological sorting is sufficient and
can preserve more of the MachineBlockPlacement ordering. Unfortunately, this
still depends a lot on heuristics, because while we use the
MachineBlockPlacement ordering as a guide, we can't use it in places where
it isn't topologically ordered. This area will require further attention.
llvm-svn: 260978
This avoids some complications updating LiveIntervals to be aware of the new
register lifetimes, because we can just compute new intervals from scratch
rather than describe how the old ones have been changed.
llvm-svn: 260971
Instead of passing varargs directly on the user stack, allocate a buffer in
the caller's stack frame and pass a pointer to it. This simplifies the C
ABI (e.g. non-C callers of C functions do not need to use C's user stack if
they have their own mechanism) and allows further optimizations in the future
(e.g. fewer functions may need to use the stack).
Differential Revision: http://reviews.llvm.org/D17048
llvm-svn: 260421
Re-commit of r258951 after fixing layering violation.
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.
llvm-svn: 259498
Previously the code assumed all uses of FI on loads and stores were as
addresses. This checks whether the use is the address or a value and
handles the latter case as it does for non-memory instructions.
llvm-svn: 259306
The previous code was incorrect (can't getReg a frameindex). We could instead optimize it to reduce tree height, but I'm not sure that's worthwhile yet because we then try to eliminate the frameindex.
This patch also fixes frame index elimination for operations which may load or store: it used to assume the base was operand 2 and immediate offset operand 1. That's not true for stores, where they're 4 and 3.
llvm-svn: 259305
Refine the test for whether an instruction is in an expression tree so that
it detects when one tree ends and another begins, so we can place a block
at that point, rather than continuing to find the first instruction not in
a tree at all.
llvm-svn: 259294
Add support for frame pointer use in prolog/epilog.
Supports dynamic allocas but not yet over-aligned locals.
Target-independend CG generates SP updates, but we still need to write
back the SP value to memory when necessary.
llvm-svn: 259220
Re-commit of r258951 after fixing layering violation.
The related LLVM patch adds a backend diagnostic type for reporting
unsupported features, this adds a printer for them to clang.
In the case where debug location information is not available, I've
changed the printer to report the location as the first line of the
function, rather than the closing brace, as the latter does not give the
user any information. This also affects optimisation remarks.
Differential Revision: http://reviews.llvm.org/D16590
llvm-svn: 259035
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
Dan Gohman