133 Commits

Author SHA1 Message Date
Wouter van Oortmerssen
f7cc5288f6 [WebAssembly] Added default stack-only instruction mode for MC.
Summary:
Moved Explicit Locals pass to last.
Made that pass obligatory.
Made it convert from register to stack based instructions, and removed the registers.
Fixes to related code that was expecting register based instructions.
Added the correct testing flag to all tests, depending on what the
format they were expecting so far.
Translated one test to stack format as example: reg-stackify-stack.ll

tested:
llvm-lit -v `find test -name WebAssembly`
unittests/MC/*

Reviewers: dschuff, sunfish

Subscribers: sbc100, jgravelle-google, eraman, aheejin, llvm-commits

Differential Revision: https://reviews.llvm.org/D49160

llvm-svn: 338164
2018-07-27 20:56:43 +00:00
Sam Clegg
5c92980d35 [WebAssembly] Remove ELF file support.
This support was partial and temporary.  Now that we have
wasm object file support its no longer needed.

Differential Revision: https://reviews.llvm.org/D48744

llvm-svn: 337222
2018-07-16 23:09:29 +00:00
Sam Clegg
eb883aa8d1 [WebAssembly] Add pass to infer prototypes for prototype-less functions
See https://bugs.llvm.org/show_bug.cgi?id=35385

Differential Revision: https://reviews.llvm.org/D48471

llvm-svn: 336759
2018-07-11 04:29:36 +00:00
Heejin Ahn
75b74e2ab2 [WebAssembly] Add WebAssemblyException information analysis
Summary:
A WebAssemblyException object contains BBs that belong to a 'catch' part
of the try-catch-end structure. Because CFGSort requires all the BBs
within a catch part to be sorted together as it does for loops, this
pass calculates the nesting structure of catch part of exceptions in a
function. Now this assumes the use of Windows EH instructions.

Reviewers: dschuff, majnemer

Subscribers: jfb, mgorny, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D44134

llvm-svn: 335439
2018-06-25 01:20:21 +00:00
Heejin Ahn
eb5b2cac1c [WebAssembly] Add WebAssemblyLateEHPrepare pass
Summary:
Add WebAssemblyLateEHPrepare pass that does several small jobs for
exception handling. This runs before CFGSort, and is different from
WasmEHPrepare pass that runs before ISel, even though the names are
similar.

Reviewers: dschuff, majnemer

Subscribers: sbc100, jgravelle-google, sunfish, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D46803

llvm-svn: 335438
2018-06-25 01:07:11 +00:00
Heejin Ahn
d3615c630c [WebAssembly] Support instruction selection for catching exceptions
Summary:
This lowers exception catching-related instructions:
1. Lowers `wasm.catch` intrinsic to `catch` instruction
2. Removes `catchpad` and `cleanuppad` instructions; they are not
necessary after isel phase. (`MachineBasicBlock::isEHFuncletEntry()` or
`MachineBasicBlock::isEHPad()` can be used instead.)
3. Lowers `catchret` and `cleanupret` instructions to pseudo `catchret`
and `cleanupret` instructions in isel, which will be replaced with other
instructions in `WebAssemblyExceptionPrepare` pass.
4. Adds 'WebAssemblyExceptionPrepare` pass, which is for running various
transformation for EH. Currently this pass only replaces `catchret` and
`cleanupret` instructions into appropriate wasm instructions to make
this patch successfully run until the end.

Currently this does not handle lowering of intrinsics related to LSDA
info generation (`wasm.landingpad.index` and `wasm.lsda`), because they
cannot be tested without implementing `EHStreamer`'s wasm-specific
handlers. They are marked as TODO, which is needed to make isel pass.
Also this does not generate `try` and `end_try` markers yet, which will
be handled in later patches.

This patch is based on the first wasm EH proposal.
(https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md)

Reviewers: dschuff, majnemer

Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D44090

llvm-svn: 333705
2018-05-31 22:25:54 +00:00
Adrian Prantl
076a6683eb Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Jun Bum Lim
38fea091d2 [CodeGen]Add NoVRegs property on PostRASink and ShrinkWrap
Summary:
This change declare that PostRAMachineSinking and ShrinkWrap require NoVRegs
property, so now the MachineFunctionPass can enforce this check.
These passes are disabled in NVPTX & WebAssembly.

Reviewers: dschuff, jlebar, tra, jgravelle-google, MatzeB, sebpop, thegameg, mcrosier

Reviewed By: dschuff, thegameg

Subscribers: jholewinski, jfb, sbc100, aheejin, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D45183

llvm-svn: 329095
2018-04-03 18:17:34 +00:00
Jacob Gravelle
39f4890682 [WebAssembly] Register wasm passes with the PassRegistry
Summary:
This exposes WebAssembly passes for use on the command line (as
arguments to -print-before and the like).

Reviewers: dschuff, sunfish

Subscribers: MatzeB, jfb, sbc100, llvm-commits, aheejin

Differential Revision: https://reviews.llvm.org/D45103

llvm-svn: 328901
2018-03-30 20:36:58 +00:00
David Blaikie
2efa3f569e Transforms: Introduce Transforms/Utils.h rather than spreading the declarations amongst Scalar.h and IPO.h
Fixes layering - Transforms/Utils shouldn't depend on including a Scalar
or IPO header, because Scalar and IPO depend on Utils.

llvm-svn: 328717
2018-03-28 17:44:36 +00:00
Derek Schuff
40971abb82 [WebAssembly] Strip threadlocal attribute from globals in single thread mode
The default thread model for wasm is single, and in this mode thread-local
global variables can be lowered identically to non-thread-local variables.

Differential Revision: https://reviews.llvm.org/D44703

llvm-svn: 328049
2018-03-20 22:01:32 +00:00
Heejin Ahn
b8d1671df9 [WebAssembly] Add exception handling option and feature
Summary:
Add a llc command line option and WebAssembly architecture feature for
exception handling.

Reviewers: dschuff

Subscribers: jfb, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D43683

llvm-svn: 326004
2018-02-24 00:40:50 +00:00
Sanjoy Das
df40ece177 (Re-landing) Expose a TargetMachine::getTargetTransformInfo function
Re-land r321234.  It had to be reverted because it broke the shared
library build.  The shared library build broke because there was a
missing LLVMBuild dependency from lib/Passes (which calls
TargetMachine::getTargetIRAnalysis) to lib/Target.  As far as I can
tell, this problem was always there but was somehow masked
before (perhaps because TargetMachine::getTargetIRAnalysis was a
virtual function).

Original commit message:

This makes the TargetMachine interface a bit simpler.  We still need
the std::function in TargetIRAnalysis to avoid having to add a
dependency from Analysis to Target.

See discussion:
http://lists.llvm.org/pipermail/llvm-dev/2017-December/119749.html

I avoided adding all of the backend owners to this review since the
change is simple, but let me know if you feel differently about this.

Reviewers: echristo, MatzeB, hfinkel

Reviewed By: hfinkel

Subscribers: jholewinski, jfb, arsenm, dschuff, mcrosier, sdardis, nemanjai, nhaehnle, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, llvm-commits

Differential Revision: https://reviews.llvm.org/D41464

llvm-svn: 321375
2017-12-22 18:21:59 +00:00
Sanjoy Das
259bcf37bc Revert "Expose a TargetMachine::getTargetTransformInfo function"
This reverts commit r321234.  It breaks the -DBUILD_SHARED_LIBS=ON build.

llvm-svn: 321243
2017-12-21 02:34:39 +00:00
Sanjoy Das
90359bc4d6 Expose a TargetMachine::getTargetTransformInfo function
Summary:
This makes the TargetMachine interface a bit simpler.  We still need
the std::function in TargetIRAnalysis to avoid having to add a
dependency from Analysis to Target.

See discussion:
http://lists.llvm.org/pipermail/llvm-dev/2017-December/119749.html

I avoided adding all of the backend owners to this review since the
change is simple, but let me know if you feel differently about this.

Reviewers: echristo, MatzeB, hfinkel

Reviewed By: hfinkel

Subscribers: jholewinski, jfb, arsenm, dschuff, mcrosier, sdardis, nemanjai, nhaehnle, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, llvm-commits

Differential Revision: https://reviews.llvm.org/D41464

llvm-svn: 321234
2017-12-21 01:06:58 +00:00
Sam Clegg
3b48c1eb32 [WebAssembly] Implement @llvm.global_ctors and @llvm.global_dtors
Summary:
- lowers @llvm.global_dtors by adding @llvm.global_ctors
  functions which register the destructors with `__cxa_atexit`.
- impements @llvm.global_ctors with wasm start functions and linker metadata

See [here](https://github.com/WebAssembly/tool-conventions/issues/25) for more background.

Subscribers: jfb, dschuff, mgorny, jgravelle-google, aheejin, sunfish

Differential Revision: https://reviews.llvm.org/D41211

llvm-svn: 320774
2017-12-15 00:17:10 +00:00
Matthias Braun
6cdc04a20c Revert "TargetMachine: Merge TargetMachine and LLVMTargetMachine"
Reverting to investigate layering effects of MCJIT not linking
libCodeGen but using TargetMachine::getNameWithPrefix() breaking the
lldb bots.

This reverts commit r315633.

llvm-svn: 315637
2017-10-12 22:57:28 +00:00
Matthias Braun
e1c491ab05 TargetMachine: Merge TargetMachine and LLVMTargetMachine
Merge LLVMTargetMachine into TargetMachine.

- There is no in-tree target anymore that just implements TargetMachine
  but not LLVMTargetMachine.
- It should still be possible to stub out all the various functions in
  case a target does not want to use lib/CodeGen
- This simplifies the code and avoids methods ending up in the wrong
  interface.

Differential Revision: https://reviews.llvm.org/D38489

llvm-svn: 315633
2017-10-12 22:28:54 +00:00
Daniel Jasper
e889874f2c Fix WebAssembly target after r309911.
llvm-svn: 309922
2017-08-03 05:15:53 +00:00
Chandler Carruth
eb66b33867 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Matthias Braun
7b8d690af1 TargetPassConfig: Keep a reference to an LLVMTargetMachine; NFC
TargetPassConfig is not useful for targets that do not use the CodeGen
library, so we may just as well store a pointer to an
LLVMTargetMachine instead of just to a TargetMachine.

While at it, also change the constructor to take a reference instead of a
pointer as the TM must not be nullptr.

llvm-svn: 304247
2017-05-30 21:36:41 +00:00
Francis Visoiu Mistrih
5f6c901f02 [LegacyPassManager] Remove TargetMachine constructors
This provides a new way to access the TargetMachine through
TargetPassConfig, as a dependency.

The patterns replaced here are:

* Passes handling a null TargetMachine call
  `getAnalysisIfAvailable<TargetPassConfig>`.

* Passes not handling a null TargetMachine
  `addRequired<TargetPassConfig>` and call
  `getAnalysis<TargetPassConfig>`.

* MachineFunctionPasses now use MF.getTarget().

* Remove all the TargetMachine constructors.
* Remove INITIALIZE_TM_PASS.

This fixes a crash when running `llc -start-before prologepilog`.

PEI needs StackProtector, which gets constructed without a TargetMachine
by the pass manager. The StackProtector pass doesn't handle the case
where there is no TargetMachine, so it segfaults.

Related to PR30324.

Differential Revision: https://reviews.llvm.org/D33222

llvm-svn: 303360
2017-05-18 17:21:13 +00:00
Dan Gohman
f2e8848268 [WebAssembly] Split CFG-sorting into its own pass. NFC.
CFG sorting was already an independent algorithm from block/loop insertion;
this change makes it more convenient to debug.

llvm-svn: 296399
2017-02-27 22:38:58 +00:00
Dan Gohman
d6675baf7a [WebAssembly] Basic support for Wasm object file encoding.
With the "wasm32-unknown-unknown-wasm" triple, this allows writing out
simple wasm object files, and is another step in a larger series toward
migrating from ELF to general wasm object support. Note that this code
and the binary format itself is still experimental.

llvm-svn: 296190
2017-02-24 23:18:00 +00:00
Dan Gohman
da00194d3c [WebAssembly] Add skeleton MC support for the Wasm container format
This just adds the basic skeleton for supporting a new object file format.
All of the actual encoding will be implemented in followup patches.

Differential Revision: https://reviews.llvm.org/D26722

llvm-svn: 295803
2017-02-22 01:23:18 +00:00
Dan Gohman
8d46f8cefc [WebAssembly] Add a pass to create wrappers for function bitcasts.
WebAssembly requires caller and callee signatures to match exactly. In LLVM,
there are a variety of circumstances where signatures may be mismatched in
practice, and one can bitcast a function address to another type to call it
as that type. This patch adds a pass which replaces bitcasted function
addresses with wrappers to replace the bitcasts.

This doesn't catch everything, but it does match many common cases.

llvm-svn: 291315
2017-01-07 00:34:54 +00:00
Dan Gohman
205bc689ab [WebAssembly] Eliminate an ad-hoc command-line argument.
Use the target triple to determine whether to run the explicit-locals
pass, rather than using a separate command-line argument.

llvm-svn: 288602
2016-12-03 23:00:12 +00:00
Dan Gohman
a62715a542 [WebAssembly] Add an option to make get_local/set_local explicit.
This patch adds a pass, controlled by an option and off by default for
now, for making implicit get_local/set_local explicit. This simplifies
emitting wasm with MC.

Differential Revision: https://reviews.llvm.org/D25836

llvm-svn: 285009
2016-10-24 19:49:43 +00:00
Derek Schuff
8f7a717a1c [WebAssembly] Fix for 0xc call_indirect changes
Summary:
Need to reorder the operands to have the callee as the last argument.
Adds a pseudo-instruction, and a pass to lower it into a real
call_indirect.

This is the first of two options for how to fix the problem.

Reviewers: dschuff, sunfish

Subscribers: jfb, beanz, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D25708

llvm-svn: 284840
2016-10-21 16:38:07 +00:00
Mehdi Amini
fa86e5fee9 Move the global variables representing each Target behind accessor function
This avoids "static initialization order fiasco"

Differential Revision: https://reviews.llvm.org/D25412

llvm-svn: 283702
2016-10-09 23:00:34 +00:00
Dan Gohman
aef2568ce0 [WebAssembly] Update to more stack-machine-oriented terminology.
WebAssembly has officially switched from being an AST to being a stack
machine. Update various bits of terminology and README.md entries
accordingly.

llvm-svn: 283154
2016-10-03 22:43:53 +00:00
Heejin Ahn
b74a4abac9 [WebAssembly] Add asm.js-style setjmp/longjmp handling for wasm (reland r280302)
Summary: This patch adds asm.js-style setjmp/longjmp handling support for WebAssembly. It also uses JavaScript's try and catch mechanism.

Reviewers: jpp, dschuff

Subscribers: jfb, dschuff

Differential Revision: https://reviews.llvm.org/D24121

llvm-svn: 280415
2016-09-01 21:05:15 +00:00
Heejin Ahn
829e0caa72 Revert "Add asm.js-style setjmp/longjmp handling for wasm"
This reverts commit r280302, it broke the integration tests.

llvm-svn: 280329
2016-09-01 00:44:37 +00:00
Heejin Ahn
fb2e9ff982 Add asm.js-style setjmp/longjmp handling for wasm
Summary: This patch adds asm.js-style setjmp/longjmp handling support for WebAssembly. It also uses JavaScript's try and catch mechanism.

Reviewers: jpp, dschuff

Subscribers: jfb, dschuff

Differential Revision: https://reviews.llvm.org/D23928

llvm-svn: 280302
2016-08-31 22:40:34 +00:00
Matthias Braun
923da8d677 MachineFunctionProperties/MIRParser: Rename AllVRegsAllocated->NoVRegs, compute it
Rename AllVRegsAllocated to NoVRegs. This avoids the connotation of
running after register and simply describes that no vregs are used in
a machine function. With that we can simply compute the property and do
not need to dump/parse it in .mir files.

Differential Revision: http://reviews.llvm.org/D23850

llvm-svn: 279698
2016-08-25 01:27:13 +00:00
Derek Schuff
8347d72571 [WebAssembly] Refactor WebAssemblyLowerEmscriptenException pass for setjmp/longjmp
This patch changes the code structure of
WebAssemblyLowerEmscriptenException pass to support both exception
handling and setjmp/longjmp. It also changes the name of the pass and
the source file.

1. Change the file/pass name to WebAssemblyLowerEmscriptenExceptions ->
WebAssemblyLowerEmscriptenEHSjLj to make it clear that it supports both
EH and SjLj
2. List function / global variable names at the top so they
can be changed easily
3. Some cosmetic changes

Patch by Heejin Ahn

Differential Revision: https://reviews.llvm.org/D23588

llvm-svn: 279075
2016-08-18 15:27:25 +00:00
Derek Schuff
4212b80989 [WebAssembly] Fix bugs in WebAssemblyLowerEmscriptenExceptions pass
* Delete extra '_' prefixes from JS library function names. fixImports()
  function in JS glue code deals with this for wasm.
* Change command-line option names in order to be consistent with
  asm.js.
* Add missing lowering code for llvm.eh.typeid.for intrinsics
* Delete commas in mangled function names
* Fix a function argument attributes bug. Because we add the pointer to
  the original callee as the first argument of invoke wrapper, all
  argument attribute indices have to be incremented by one.

Patch by Heejin Ahn

Differential Revision: https://reviews.llvm.org/D23258

llvm-svn: 278081
2016-08-09 00:29:55 +00:00
Derek Schuff
87e99c4f9c [WebAssembly] Add asm.js-style exception handling support
Summary: This patch includes asm.js-style exception handling support for
WebAssembly. The WebAssembly MVP does not have any support for
unwinding or non-local control flow. In order to support C++ exceptions,
emscripten currently uses JavaScript exceptions along with some support
code (written in JavaScript) that is bundled by emscripten with the
generated code.
This scheme lowers exception-related instructions for wasm such that
wasm modules can be compatible with emscripten's existing scheme and
share the support code.

Patch by Heejin Ahn

Differential Revision: https://reviews.llvm.org/D22958

llvm-svn: 277391
2016-08-01 21:34:04 +00:00
Dan Gohman
920c7d7490 [WebAssembly] Optimize away return instructions using fallthroughs.
This saves a small amount of code size, and is a first small step toward
passing values on the stack across block boundaries.

Differential Review: http://reviews.llvm.org/D20450

llvm-svn: 270294
2016-05-21 00:21:56 +00:00
Dan Gohman
bb2c8e5fad [WebAssembly] Update WebAssembly target for r269988.
llvm-svn: 270017
2016-05-19 03:00:05 +00:00
Derek Schuff
6435e10dbd Factor PrologEpilogInserter around spilling, frame finalization, and scavenging
PrologEpilogInserter has these 3 phases, which are related, but not
all of them are needed by all targets. This patch reorganizes PEI's
varous functions around those phases for more clear separation. It also
introduces a new TargetMachine hook, usesPhysRegsForPEI, which is true
for non-virtual targets. When it is true, all the phases operate as
before, and PEI requires the AllVRegsAllocated property on
MachineFunctions. Otherwise, CSR spilling and scavenging are skipped and
only prolog/epilog insertion/frame finalization is done.

Differential Revision: http://reviews.llvm.org/D18366

llvm-svn: 269750
2016-05-17 08:49:59 +00:00
Dan Gohman
13d15dbc40 [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
2016-05-10 04:24:02 +00:00
Matthias Braun
556abb392a CodeGen: Move TargetPassConfig from Passes.h to an own header; NFC
Many files include Passes.h but only a fraction needs to know about the
TargetPassConfig class. Move it into an own header. Also rename
Passes.cpp to TargetPassConfig.cpp while we are at it.

llvm-svn: 269011
2016-05-10 03:21:59 +00:00
Sanjoy Das
7e1b5ea5d3 Disable the PatchableFunction pass for NVPTX & Wasm
PatchableFunction requires AllVRegsAllocated that these targets don't
provide.

llvm-svn: 266720
2016-04-19 06:24:58 +00:00
Mehdi Amini
9ff867f98c [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Derek Schuff
07872afb5b [WebAssembly] Remove duplicate disabling of passes
Also put all the disabled passes together

llvm-svn: 264684
2016-03-28 22:52:20 +00:00
Derek Schuff
9f833b6097 Introduce MachineFunctionProperties and the AllVRegsAllocated property
MachineFunctionProperties represents a set of properties that a MachineFunction
can have at particular points in time. Existing examples of this idea are
MachineRegisterInfo::isSSA() and MachineRegisterInfo::tracksLiveness() which
will eventually be switched to use this mechanism.
This change introduces the AllVRegsAllocated property; i.e. the property that
all virtual registers have been allocated and there are no VReg operands
left.

With this mechanism, passes can declare that they require a particular property
to be set, or that they set or clear properties by implementing e.g.
MachineFunctionPass::getRequiredProperties(). The MachineFunctionPass base class
verifies that the requirements are met, and handles the setting and clearing
based on the delcarations. Passes can also directly query and update the current
properties of the MF if they want to have conditional behavior.

This change annotates the target-independent post-regalloc passes; future
changes will also annotate target-specific ones.

Reviewers: qcolombet, hfinkel

Differential Revision: http://reviews.llvm.org/D18421

llvm-svn: 264593
2016-03-28 17:05:30 +00:00
Dan Gohman
639ae6b08b [WebAssembly] Implement irreducible control flow.
This implements a very simple conservative transformation that doesn't
require more than linear code size growth. There's room for much more
optimization in this space.

llvm-svn: 262982
2016-03-09 02:01:14 +00:00
Dan Gohman
eb0777680f [WebAssembly] Re-enable the TailDuplicate pass.
llvm-svn: 261566
2016-02-22 20:47:12 +00:00
Dan Gohman
32f3e081a8 [WebAssembly] Don't use setRequiresStructuredCFG(true).
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
2016-02-18 06:32:53 +00:00