[WebAssembly] Don't stackify calls past stack pointer modifications.

llvm-svn: 269843

[WebAssembly] Move register stackification and coloring to a late phase.

Move the register stackification and coloring passes to run very late, after
PEI, tail duplication, and most other passes. Th

[WebAssembly] Move register stackification and coloring to a late phase.

Move the register stackification and coloring passes to run very late, after
PEI, tail duplication, and most other passes. This means that all code emitted
and expanded by those passes is now exposed to these passes. This also
eliminates the need for prologue/epilogue code to be manually stackified,
which significantly simplifies the code.

This does require running LiveIntervals a second time. It's useful to think
of these late passes not as late optimization passes, but as a domain-specific
compression algorithm based on knowledge of liveness information. It's used to
compress the code after all conventional optimizations are complete, which is
why it uses LiveIntervals at a phase when actual optimization passes don't
typically need it.

Differential Revision: http://reviews.llvm.org/D20075

llvm-svn: 269012

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[WebAssembly] Don't emit epilogue code in the middle of stackified code.

llvm-svn: 268679

Change eliminateCallFramePseudoInstr() to return an iterator

This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous

Change eliminateCallFramePseudoInstr() to return an iterator

This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous
and/or next instruction.

It also greatly simplifies the calls to this function from Prolog-
EpilogInserter. Previously, that had a bunch of logic to resume iteration
after the call; now it just continues with the returned iterator.

Note that this changes the behaviour of PEI a little. Previously,
it attempted to re-visit the new instruction created by
eliminateCallFramePseudoInstr(). That code was added in r36625,
but I can't see any reason for it: the new instructions will obviously
not be pseudo instructions, they will not have FrameIndex operands,
and we have already accounted for the stack adjustment.

Differential Revision: http://reviews.llvm.org/D18627

llvm-svn: 265036

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[WebAssembly] Stackify code emitted by eliminateFrameIndex and SP writeback

Summary:
MRI::eliminateFrameIndex can emit several instructions to do address
calculations; these can usually be stackifie

[WebAssembly] Stackify code emitted by eliminateFrameIndex and SP writeback

Summary:
MRI::eliminateFrameIndex can emit several instructions to do address
calculations; these can usually be stackified. Because instructions with
FI operands can have subsequent operands which may be expression trees,
find the top of the leftmost tree and insert the code before it, to keep
the LIFO property.

Also use stackified registers when writing back the SP value to memory
in the epilog; it's unnecessary because SP will not be used after the
epilog, and it results in better code.

Differential Revision: http://reviews.llvm.org/D18234

llvm-svn: 263725

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[WebAssembly] Implement red zone for user stack

Implements a mostly-conventional redzone for the userspace
stack. Because we have unsigned load/store offsets we continue to use a
local SP subtracted

[WebAssembly] Implement red zone for user stack

Implements a mostly-conventional redzone for the userspace
stack. Because we have unsigned load/store offsets we continue to use a
local SP subtracted from the incoming SP but do not write it back to
memory.

Differential Revision: http://reviews.llvm.org/D17525

llvm-svn: 261662

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[WebAssembly] Fix writeback of stack pointer with dynamic alloca

Previously the stack pointer was only written back to memory in the
prolog. But this is wrong for dynamic allocas, for which
target-i

[WebAssembly] Fix writeback of stack pointer with dynamic alloca

Previously the stack pointer was only written back to memory in the
prolog. But this is wrong for dynamic allocas, for which
target-independent codegen handles SP updates after the prolog (and
possibly even in another BB). Instead update the SP global in
ADJCALLSTACKDOWN which is generated after the SP update sequence.
This will have further refinements when we add red zone support.

llvm-svn: 261579

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[WebAssembly] Write stack pointer back to memory when FP is used

The stack pointer is bumped when there is a frame pointer or when there
are static-size objects, but was only getting written back wh

[WebAssembly] Write stack pointer back to memory when FP is used

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

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[WebAssembly] Stackify function prologs and epilogs

The instructions are the same, but fewer locals are used.

Differential Revision: http://reviews.llvm.org/D17428

llvm-svn: 261452

[WebAssembly] Implement __builtin_frame_address.

Differential Revision: http://reviews.llvm.org/D17307

llvm-svn: 261032

[WebAssembly] Reformat WebAssemblyFrameLowering and WebAssemblyISelLowering

Reviewers: sunfish, jfb

Subscribers: jfb, dschuff

Differential Revision: http://reviews.llvm.org/D17156

llvm-svn: 260585

[WebAssembly] Address comments left over from r260421

llvm-svn: 260429

[WebAssembly] Switch varags calling convention to use a register

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 s

[WebAssembly] Switch varags calling convention to use a register

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

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WebAssembly NFC: fix build warning

WebAssemblyFrameLowering.cpp:158:44: warning: enumeral and non-enumeral type in conditional expression [enabled by default]

llvm-svn: 259303

[WebAssembly] Support frame pointer

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 s

[WebAssembly] Support frame pointer

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

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[WebAssembly] Omit no-op adds for non-mem uses of FrameIndex

Differential Revision: http://reviews.llvm.org/D16554

llvm-svn: 258872

[WebAssembly] Implement unaligned loads and stores.

Differential Revision: http://reviews.llvm.org/D16534

llvm-svn: 258779

[WebAssembly] Use the templated form of MachineFunction::getSubtarget(). NFC.

llvm-svn: 258126

[WebAssembly] Implement eliminateCallFramePseudo

Summary:
Implement eliminateCallFramePsuedo to handle ADJCALLSTACKUP/DOWN
pseudo-instructions. Add a test calling a vararg function which causes non-

[WebAssembly] Implement eliminateCallFramePseudo

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

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[WebAssembly] Implement prolog/epilog insertion and FrameIndex elimination

Summary:
Use the SP32 physical register as the base for FrameIndex
lowering. Update it and the __stack_pointer global var

[WebAssembly] Implement prolog/epilog insertion and FrameIndex elimination

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

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[WebAssembly] Minor clang-format and selected clang-tidy cleanups. NFC.

llvm-svn: 254267

[WebAssembly] Clean up several FIXME comments.

llvm-svn: 254079

[WebAssembly] Use the checked form of MachineFunction::getSubtarget. NFC.

llvm-svn: 245852

WebAssembly: basic bitcode → assembly CodeGen test

Summary:
Add a basic CodeGen bitcode test which (for now) only prints out the function name and nothing else. The current code merely implements th

WebAssembly: basic bitcode → assembly CodeGen test

Summary:
Add a basic CodeGen bitcode test which (for now) only prints out the function name and nothing else. The current code merely implements the basic needed for the test run to not crash / assert. Getting to that point required:

- Basic InstPrinter.
- Basic AsmPrinter.
- DiagnosticInfoUnsupported (not strictly required, but nice to have, duplicated from AMDGPU/BPF's ISelLowering).
- Some SP and register setup in WebAssemblyTargetLowering.
- Basic LowerFormalArguments.
- GenInstrInfo.
- Placeholder LowerFormalArguments.
- Placeholder CanLowerReturn and LowerReturn.
- Basic DAGToDAGISel::Select, which requiresGenDAGISel.inc as well as GET_INSTRINFO_ENUM with GenInstrInfo.inc.
- Remove WebAssemblyFrameLowering::determineCalleeSaves and rely on default.
- Implement WebAssemblyFrameLowering::hasFP, same as AArch64's implementation.

Follow-up patches will implement a real AsmPrinter, which will require adding MI opcodes specific to WebAssembly.

Reviewers: sunfish

Subscribers: aemerson, jfb, llvm-commits

Differential Revision: http://reviews.llvm.org/D11369

llvm-svn: 242939

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WebAssembly: fix build breakage.

Summary:
processFunctionBeforeCalleeSavedScan was renamed to determineCalleeSaves and now takes a BitVector parameter as of rL242165, reviewed in http://reviews.llvm

WebAssembly: fix build breakage.

Summary:
processFunctionBeforeCalleeSavedScan was renamed to determineCalleeSaves and now takes a BitVector parameter as of rL242165, reviewed in http://reviews.llvm.org/D10909

WebAssembly is still marked as experimental and therefore doesn't build by default. It does, however, grep by default! I notice that processFunctionBeforeCalleeSavedScan is still mentioned in a few comments and error messages, which I also fixed.

Reviewers: qcolombet, sunfish

Subscribers: jfb, dsanders, hfinkel, MatzeB, llvm-commits

Differential Revision: http://reviews.llvm.org/D11199

llvm-svn: 242242

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