Commit Graph

330 Commits

Author SHA1 Message Date
Derek Schuff
ed1cb75099 Revert "[WebAssemby] Support main functions with alternate signatures."
This reverts commit 959e37e669.
That commit doesn't handle the case where main is declared rather than defined,
in particular the even-more special case where main is a prototypeless
declaration (which is of course the one actually used by musl currently).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320121 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-08 00:39:54 +00:00
Dan Gohman
959e37e669 [WebAssemby] Support main functions with alternate signatures.
WebAssembly requires caller and callee signatures to match, so the usual
C runtime trick of calling main and having it just work regardless of
whether main is defined as '()' or '(int argc, char *argv[])' doesn't
work. Extend the FixFunctionBitcasts pass to rewrite main to use the
latter form.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320041 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-07 13:49:27 +00:00
Dan Gohman
113753f1f6 [WebAssembly] Don't try to emit size information for unsized types
Patch by John Sully!

Fixes PR35164.

Differential Revision: https://reviews.llvm.org/D39519


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319991 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-07 00:14:30 +00:00
Dan Gohman
73135b400e [WebAssembly] Remove WASM_STACK_POINTER.
WASM_STACK_POINTER and the .stack_pointer directive are no longer needed
now that the stack pointer global is an import.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319956 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-06 20:56:40 +00:00
Dan Gohman
f07a1d491b [WebAssembly] Implement WASM_STACK_POINTER.
Use the .stack_pointer directive to implement WASM_STACK_POINTER for
specifying a global variable to be the stack pointer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319797 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-05 17:23:43 +00:00
Dan Gohman
314790b9d8 [WebAssembly] Don't emit .import_global for the wasm target.
.import_global is used by the ELF-based target and not needed by the wasm
target.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319796 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-05 17:21:57 +00:00
Francis Visoiu Mistrih
ca0df55065 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319665 91177308-0d34-0410-b5e6-96231b3b80d8
2017-12-04 17:18:51 +00:00
Dan Gohman
5155d5128a [WebAssembly] Revert r319186 "Support bitcasted function addresses with varargs."
The patch broke Emscripten's EM_ASM macros, which utiltize unprototyped
functions.

See https://bugs.llvm.org/show_bug.cgi?id=35385 for details.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319452 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-30 18:16:49 +00:00
Francis Visoiu Mistrih
7384652668 [CodeGen] Print "%vreg0" as "%0" in both MIR and debug output
As part of the unification of the debug format and the MIR format, avoid
printing "vreg" for virtual registers (which is one of the current MIR
possibilities).

Basically:

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/%vreg([0-9]+)/%\1/g"
* grep -nr '%vreg' . and fix if needed
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E "s/ vreg([0-9]+)/ %\1/g"
* grep -nr 'vreg[0-9]\+' . and fix if needed

Differential Revision: https://reviews.llvm.org/D40420

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319427 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-30 12:12:19 +00:00
Dan Gohman
685c102164 [WebAssembly] Fix fptoui lowering bounds
To fully avoid trapping on wasm, fptoui needs a second check to ensure that
the operand isn't below the supported range.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319354 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-29 20:20:11 +00:00
Dan Gohman
7005517f42 [WebAssembly] Support bitcasted function addresses with varargs.
Generalize FixFunctionBitcasts to handle varargs functions. This in
particular fixes the case where clang bitcasts away a varargs when
calling a K&R-style function.

This avoids interacting with tricky ABI details because it operates
at the LLVM IR level before varargs ABI details are exposed.

This fixes PR35385.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319186 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-28 17:15:03 +00:00
Dan Gohman
8aaa99a506 [WebAssembly] Handle errors better in fast-isel.
Fast-isel routines need to bail out in the case that fast-isel
fails on the operands.

This fixes https://bugs.llvm.org/show_bug.cgi?id=35064


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319144 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-28 05:36:42 +00:00
Dan Gohman
9f86840c1c [WebAssembly] Fix trapping behavior in fptosi/fptoui.
This adds code to protect WebAssembly's `trunc_s` family of opcodes
from values outside their domain. Even though such conversions have
full undefined behavior in C/C++, LLVM IR's `fptosi` and `fptoui` do
not, and only return undef.

This also implements the proposed non-trapping float-to-int conversion
feature and uses that instead when available.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319128 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-28 01:13:40 +00:00
Dan Gohman
9b78b26b27 [WebAssembly] Update cfg-stackify.ll to remove the workaround added in r318288.
Remove -switch-peel-threshold=100 and update the expected results in test10
in cfg-stackify.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318338 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-15 21:38:33 +00:00
Ilya Biryukov
571bd4540f Workaround CodeGen/WebAssembly/cfg-stackify.ll failure after r318202
By disabling the introduced optimization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318288 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-15 10:50:43 +00:00
Ilya Biryukov
3656d83960 Use input redirection in WebAssembly/comdat.ll test.
To match how the other tests do it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318153 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-14 14:26:42 +00:00
Sam Clegg
336b4883e2 [WebAssembly] Explicily disable comdat support for wasm output
For now at least.  We clearly need some kind of comdat or
linkonce_odr support for wasm but currently COMDAT is not
supported.

Disable COMDAT support in the same way we do the Mach-O.  This
also causes clang not to generated COMDATs.

Differential Revision: https://reviews.llvm.org/D39873

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318123 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-14 00:49:16 +00:00
Jatin Bhateja
be808009ac [WebAssembly] Fix stack offsets of return values from call lowering.
Summary: Fixes PR35220

Reviewers: vadimcn, alexcrichton

Reviewed By: alexcrichton

Subscribers: pepyakin, alexcrichton, jfb, dschuff, sbc100, jgravelle-google, llvm-commits, aheejin

Differential Revision: https://reviews.llvm.org/D39866

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317895 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-10 16:26:04 +00:00
Dan Gohman
94964bb756 [WebAssembly] Add a test for inline-asm "m" constraints.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317711 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-08 19:37:24 +00:00
Dan Gohman
40486d7dcf [WebAssembly] Call signExtend to get sign extended register
Patch by Jatin Bhateja!

Differential Revision: https://reviews.llvm.org/D39529


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317710 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-08 19:24:21 +00:00
Dan Gohman
8e0d3d4cd7 [WebAssembly] Revise the strategy for inline asm.
Previously, an "r" constraint would mean the compiler provides a value
on WebAssembly's operand stack. This was tricky to use properly,
particularly since it isn't possible to declare a new local from within
an inline asm string.

With this patch, "r" provides the value in a WebAssembly local, and the
local index is provided to the inline asm string. This requires inline
asm to use get_local and set_local to read the register. This does
potentially result in larger code size, however inline asm should
hopefully be quite rare in WebAssembly.

This also means that the "m" constraint can no longer be supported, as
WebAssembly has nothing like a "memory operand" that includes an
implicit get_local.

This fixes PR34599 for the wasm32-unknown-unknown-wasm target (though
not for the ELF target).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317707 91177308-0d34-0410-b5e6-96231b3b80d8
2017-11-08 19:18:08 +00:00
Jacob Gravelle
8e46b87a2e [WebAssembly] Narrow the scope of WebAssemblyFixFunctionBitcasts
Summary:
The pass to fix function bitcasts generates thunks for functions that
are called directly with a mismatching signature. It was also generating
thunks in cases where the function was address-taken, causing aliasing
problems in otherwise valid cases.
This patch tightens the restrictions for when the pass runs.

Reviewers: sunfish, dschuff

Subscribers: jfb, sbc100, llvm-commits, aheejin

Differential Revision: https://reviews.llvm.org/D38640

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315326 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-10 16:20:18 +00:00
Derek Schuff
365cb32dfe [WebAssembly] Add the rest of the atomic loads
Add extending loads and constant offset patterns
A bit more refactoring of the tablegen to make the patterns fairly nice and
uniform between the regular and atomic loads.

Differential Revision: https://reviews.llvm.org/D38523

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315022 91177308-0d34-0410-b5e6-96231b3b80d8
2017-10-05 21:18:42 +00:00
Derek Schuff
c1e866c7f1 [WebAssembly] Add sign extend instructions from atomics proposal
Select them from ISD::SIGN_EXTEND_INREG

Differential Revision: https://reviews.llvm.org/D37603

remove spurious change

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313101 91177308-0d34-0410-b5e6-96231b3b80d8
2017-09-13 00:29:06 +00:00
Derek Schuff
1bfa7682dc [WebAssembly] Refactor load ISel tablegen patterns into classes
Not all of these will be able to be used by atomics because tablegen, but it
still seems like a good change by itself.

Differential Revision: https://reviews.llvm.org/D37345

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312287 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-31 21:51:48 +00:00
Derek Schuff
3e170f0a06 [WebAssembly] Add target feature for atomics
Summary:
This tracks the WebAssembly threads feature proposal at
https://github.com/WebAssembly/threads/blob/master/proposals/threads/Overview.md

Differential Revision: https://reviews.llvm.org/D37300

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312145 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-30 18:07:45 +00:00
Adrian Prantl
69e607f200 Canonicalize the representation of empty an expression in DIGlobalVariableExpression
This change simplifies code that has to deal with
DIGlobalVariableExpression and mirrors how we treat DIExpressions in
debug info intrinsics. Before this change there were two ways of
representing empty expressions on globals, a nullptr and an empty
!DIExpression().

If someone needs to upgrade out-of-tree testcases:
  perl -pi -e 's/(!DIGlobalVariableExpression\(var: ![0-9]*)\)/\1, expr: !DIExpression())/g' <MYTEST.ll>
will catch 95%.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312144 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-30 18:06:51 +00:00
Jacob Gravelle
73e192592e [WebAssembly] FastISel : Bail to SelectionDAG for constexpr calls
Summary: Currently FastISel lowers constexpr calls as indirect calls.
We'd like those to direct calls, and falling back to SelectionDAGISel
handles that.

Reviewers: dschuff, sunfish

Subscribers: jfb, sbc100, llvm-commits, aheejin

Differential Revision: https://reviews.llvm.org/D37073

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311693 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-24 19:53:44 +00:00
Derek Schuff
9689681e1b [WebAssembly] Remove infinite loop from reg-stackify test
r310940 exposed reverse-unreachable code to some optimizers,
which caused some of the code in this test to be sunk, changing
the input to the pass and breaking the exptectations.

Since that change is irrelevant to this particular test, this change
just adds an exit node to work around the problem; the
test should really be more robust (or be an MIR test?) but this preserves
the existing test intent.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310981 91177308-0d34-0410-b5e6-96231b3b80d8
2017-08-16 00:49:44 +00:00
Chandler Carruth
c89b1f0456 Revert r308273 to reinstate part of r308100.
That part was reverted because the underlying change necessitating it
(r308025) was reverted in r308271.

Nirav re-landed r308025 again in r308350, so re-landing this fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308418 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-19 04:15:30 +00:00
Chandler Carruth
1ad46660b4 Revert part of r308100 since the cause (r308025) was also reverted.
The commit r308100 updated WebAssembly tests for r308025. In one case it
merely made the test more resilient but in another case it made
a substantive update. Because r308025 was reverted in r308271, these
changes to the test also need to be reverted. They should be folded into
the recommit of r308025 when it is ready.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308273 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-18 08:20:50 +00:00
Chandler Carruth
49ca68c80a [wasm] Update two tests for r308025 which causes scheduling changes due
to the newly improved AA information.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@308100 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-15 15:44:36 +00:00
Vadim Chugunov
a671f7f9d2 Fix libcall expansion creating DAG nodes with invalid type post type legalization.
If we are lowering a libcall after legalization, we'll split the return type into a pair of legal values.

Patch by Jatin Bhateja and Eli Friedman.

Differential Revision: https://reviews.llvm.org/D34240



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307207 91177308-0d34-0410-b5e6-96231b3b80d8
2017-07-05 22:01:49 +00:00
Heejin Ahn
f21a6b7f6b [WebAssembly] Add support for exception handling instructions
Summary:
This adds backend support for throw, rethrow, try, and try_end instructions.
This needs the corresponding clang builtin support:
https://reviews.llvm.org/D34783
This follows the Wasm exception handling proposal in
https://github.com/WebAssembly/exception-handling/blob/master/proposals/Exceptions.md

Reviewers: sunfish, dschuff

Reviewed By: dschuff

Subscribers: jfb, sbc100, jgravelle-google

Differential Revision: https://reviews.llvm.org/D34826

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306774 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-30 00:43:15 +00:00
Jacob Gravelle
3f3e2c4f63 [WebAssembly] WebAssemblyFastISel getelementptr variable index support
Summary:
Previously -fast-isel getelementptr would constant-fold non-constant i8
load/stores.

Reviewers: sunfish

Subscribers: jfb, dschuff, sbc100, llvm-commits

Differential Revision: https://reviews.llvm.org/D34044

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306060 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-22 21:26:08 +00:00
Sam Clegg
46016f24b4 [WebAssembly] Use __stack_pointer global when writing wasm binary
This ensures that symbolic relocations are generated for stack
pointer manipulations.

These relocations are of type R_WEBASSEMBLY_GLOBAL_INDEX_LEB.
This change also adds support for reading relocations of this
type in WasmObjectFile.cpp.

Since its a globally imported symbol this does mean that
the get_global/set_global instruction won't be valid until
the objects are linked that global used in no longer an
imported global.

Differential Revision: https://reviews.llvm.org/D34172

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305616 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-16 23:59:10 +00:00
Benjamin Kramer
0666890a33 [wasm] Fix test after r304117.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304164 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-29 16:32:52 +00:00
Jacob Gravelle
fee2961b5a [WebAssembly] Fix WebAssemblyOptimizeReturned after r300367
Summary:
Refactoring changed paramHasAttr(1 + i) to paramHasAttr(0), fix that to
paramHasAttr(i).
Add more tests to WebAssemblyOptimizeReturned that catch that
regression.

Reviewers: dschuff

Subscribers: jfb, sbc100, llvm-commits

Differential Revision: https://reviews.llvm.org/D32136

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300502 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-17 21:40:28 +00:00
Dan Gohman
24efa5d42e [WebAssembly] Convert the remaining unit tests to the new wasm-object-file target.
To facilitate this, add a new hidden command-line option to disable
the explicit-locals pass. That causes llc to emit invalid code that doesn't
have all locals converted to get_local/set_local, however it simplifies
testwriting in many cases.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296540 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-28 23:37:04 +00:00
Dan Gohman
8f5a7d69cc [WebAssembly] Add support for using a wasm global for the stack pointer.
This replaces the __stack_pointer variable which was allocated in linear
memory.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296201 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-24 23:46:05 +00:00
Dan Gohman
53ff96ab08 [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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296190 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-24 23:18:00 +00:00
Dan Gohman
3d2ef31552 [WebAssembly] Handle f16 in fast-isel.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296172 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-24 21:05:35 +00:00
Dan Gohman
61ce026358 [WebAssembly] Configure codegen to legalize f16 values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295850 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-22 16:28:00 +00:00
Kyle Butt
a466b368fe Codegen: Make chains from trellis-shaped CFGs
Lay out trellis-shaped CFGs optimally.
A trellis of the shape below:

  A     B
  |\   /|
  | \ / |
  |  X  |
  | / \ |
  |/   \|
  C     D

would be laid out A; B->C ; D by the current layout algorithm. Now we identify
trellises and lay them out either A->C; B->D or A->D; B->C. This scales with an
increasing number of predecessors. A trellis is a a group of 2 or more
predecessor blocks that all have the same successors.

because of this we can tail duplicate to extend existing trellises.

As an example consider the following CFG:

    B   D   F   H
   / \ / \ / \ / \
  A---C---E---G---Ret

Where A,C,E,G are all small (Currently 2 instructions).

The CFG preserving layout is then A,B,C,D,E,F,G,H,Ret.

The current code will copy C into B, E into D and G into F and yield the layout
A,C,B(C),E,D(E),F(G),G,H,ret

define void @straight_test(i32 %tag) {
entry:
  br label %test1
test1: ; A
  %tagbit1 = and i32 %tag, 1
  %tagbit1eq0 = icmp eq i32 %tagbit1, 0
  br i1 %tagbit1eq0, label %test2, label %optional1
optional1: ; B
  call void @a()
  br label %test2
test2: ; C
  %tagbit2 = and i32 %tag, 2
  %tagbit2eq0 = icmp eq i32 %tagbit2, 0
  br i1 %tagbit2eq0, label %test3, label %optional2
optional2: ; D
  call void @b()
  br label %test3
test3: ; E
  %tagbit3 = and i32 %tag, 4
  %tagbit3eq0 = icmp eq i32 %tagbit3, 0
  br i1 %tagbit3eq0, label %test4, label %optional3
optional3: ; F
  call void @c()
  br label %test4
test4: ; G
  %tagbit4 = and i32 %tag, 8
  %tagbit4eq0 = icmp eq i32 %tagbit4, 0
  br i1 %tagbit4eq0, label %exit, label %optional4
optional4: ; H
  call void @d()
  br label %exit
exit:
  ret void
}

here is the layout after D27742:
straight_test:                          # @straight_test
; ... Prologue elided
; BB#0:                                 # %entry ; A (merged with test1)
; ... More prologue elided
	mr 30, 3
	andi. 3, 30, 1
	bc 12, 1, .LBB0_2
; BB#1:                                 # %test2 ; C
	rlwinm. 3, 30, 0, 30, 30
	beq	 0, .LBB0_3
	b .LBB0_4
.LBB0_2:                                # %optional1 ; B (copy of C)
	bl a
	nop
	rlwinm. 3, 30, 0, 30, 30
	bne	 0, .LBB0_4
.LBB0_3:                                # %test3 ; E
	rlwinm. 3, 30, 0, 29, 29
	beq	 0, .LBB0_5
	b .LBB0_6
.LBB0_4:                                # %optional2 ; D (copy of E)
	bl b
	nop
	rlwinm. 3, 30, 0, 29, 29
	bne	 0, .LBB0_6
.LBB0_5:                                # %test4 ; G
	rlwinm. 3, 30, 0, 28, 28
	beq	 0, .LBB0_8
	b .LBB0_7
.LBB0_6:                                # %optional3 ; F (copy of G)
	bl c
	nop
	rlwinm. 3, 30, 0, 28, 28
	beq	 0, .LBB0_8
.LBB0_7:                                # %optional4 ; H
	bl d
	nop
.LBB0_8:                                # %exit ; Ret
	ld 30, 96(1)                    # 8-byte Folded Reload
	addi 1, 1, 112
	ld 0, 16(1)
	mtlr 0
	blr

The tail-duplication has produced some benefit, but it has also produced a
trellis which is not laid out optimally. With this patch, we improve the layouts
of such trellises, and decrease the cost calculation for tail-duplication
accordingly.

This patch produces the layout A,C,E,G,B,D,F,H,Ret. This layout does have
back edges, which is a negative, but it has a bigger compensating
positive, which is that it handles the case where there are long strings
of skipped blocks much better than the original layout. Both layouts
handle runs of executed blocks equally well. Branch prediction also
improves if there is any correlation between subsequent optional blocks.

Here is the resulting concrete layout:

straight_test:                          # @straight_test
; BB#0:                                 # %entry ; A (merged with test1)
	mr 30, 3
	andi. 3, 30, 1
	bc 12, 1, .LBB0_4
; BB#1:                                 # %test2 ; C
	rlwinm. 3, 30, 0, 30, 30
	bne	 0, .LBB0_5
.LBB0_2:                                # %test3 ; E
	rlwinm. 3, 30, 0, 29, 29
	bne	 0, .LBB0_6
.LBB0_3:                                # %test4 ; G
	rlwinm. 3, 30, 0, 28, 28
	bne	 0, .LBB0_7
	b .LBB0_8
.LBB0_4:                                # %optional1 ; B (Copy of C)
	bl a
	nop
	rlwinm. 3, 30, 0, 30, 30
	beq	 0, .LBB0_2
.LBB0_5:                                # %optional2 ; D (Copy of E)
	bl b
	nop
	rlwinm. 3, 30, 0, 29, 29
	beq	 0, .LBB0_3
.LBB0_6:                                # %optional3 ; F (Copy of G)
	bl c
	nop
	rlwinm. 3, 30, 0, 28, 28
	beq	 0, .LBB0_8
.LBB0_7:                                # %optional4 ; H
	bl d
	nop
.LBB0_8:                                # %exit

Differential Revision: https://reviews.llvm.org/D28522

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@295223 91177308-0d34-0410-b5e6-96231b3b80d8
2017-02-15 19:49:14 +00:00
Kyle Butt
5818a513ae CodeGen: Allow small copyable blocks to "break" the CFG.
When choosing the best successor for a block, ordinarily we would have preferred
a block that preserves the CFG unless there is a strong probability the other
direction. For small blocks that can be duplicated we now skip that requirement
as well, subject to some simple frequency calculations.

Differential Revision: https://reviews.llvm.org/D28583

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293716 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-31 23:48:32 +00:00
Dan Gohman
0d4e33d211 [WebAssembly] Don't create bitcast-wrappers for varargs.
WebAssembly varargs functions use a significantly different ABI than
non-varargs functions, and the current code in
WebAssemblyFixFunctionBitcasts doesn't handle that difference. For now,
just avoid creating wrapper functions in the presence of varargs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292645 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-20 20:50:29 +00:00
Dan Gohman
97c35d16c6 [WebAssembly] Update grow_memory's return type.
The grow_memory instruction now returns the previous memory size. Add the
return type to the LLVM intrinsic.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292322 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-18 01:02:45 +00:00
Kyle Butt
0aa7497cd7 Revert "CodeGen: Allow small copyable blocks to "break" the CFG."
This reverts commit ada6595a52.

This needs a simple probability check because there are some cases where it is
not profitable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291695 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-11 19:55:19 +00:00
Kyle Butt
ada6595a52 CodeGen: Allow small copyable blocks to "break" the CFG.
When choosing the best successor for a block, ordinarily we would have preferred
a block that preserves the CFG unless there is a strong probability the other
direction. For small blocks that can be duplicated we now skip that requirement
as well.

Differential revision: https://reviews.llvm.org/D27742

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291609 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-10 23:04:30 +00:00
Derek Schuff
aca5f1663a [WebAssembly] Only RAUW a constant once in FixFunctionBitcasts
When we collect 2 uses of a function in FindUses and then RAUW when we
visit the first, we end up visiting the wrapper (because the second was
RAUW'd).  We still want to use RAUW instead of just Use->set() because
it has special handling for Constants, so this patch just ensures that
only one use of each constant is added to the work list.

Differential Revision: https://reviews.llvm.org/D28504

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291603 91177308-0d34-0410-b5e6-96231b3b80d8
2017-01-10 21:59:53 +00:00