Commit Graph

179 Commits

Author SHA1 Message Date
Rafael Espindola dbaf0498a9 Revert "Centralize the information about which object format we are using."
This reverts commit r245047.

It was failing on the darwin bots. The problem was that when running

./bin/llc -march=msp430

llc gets to

  if (TheTriple.getTriple().empty())
    TheTriple.setTriple(sys::getDefaultTargetTriple());

Which means that we go with an arch of msp430 but a triple of
x86_64-apple-darwin14.4.0 which fails badly.

That code has to be updated to select a triple based on the value of
march, but that is not a trivial fix.

llvm-svn: 245062
2015-08-14 15:48:41 +00:00
Rafael Espindola 90eb70c8a7 Centralize the information about which object format we are using.
Other than some places that were handling unknown as ELF, this should
have no change. The test updates are because we were detecting
arm-coff or x86_64-win64-coff as ELF targets before.

It is not clear if the enum should live on the Triple. At least now it lives
in a single location and should be easier to move somewhere else.

llvm-svn: 245047
2015-08-14 13:31:17 +00:00
Daniel Jasper 41de8027b1 Revert r240302 ("Bring r240130 back.").
This causes errors like:

  ld: error: blah.o: requires dynamic R_X86_64_PC32 reloc against '' which
  may overflow at runtime; recompile with -fPIC
  blah.cc:function f(): error: undefined reference to ''
  blah.o:g(): error: undefined reference to ''

I have not yet come up with an appropriate reproduction.

llvm-svn: 240394
2015-06-23 11:31:32 +00:00
Rafael Espindola 2d6bae2e09 Bring r240130 back.
Now that pr23900 is fixed, we can bring it back with no changes.

Original message:

Make all temporary symbols unnamed.

What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.

Some of these symbols still show up in the symbol table, but we can just
make them unnamed.

In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.

Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.

llvm-svn: 240302
2015-06-22 17:52:52 +00:00
Nico Weber 67e715ff7d Revert 240130, it caused crashes (repro in PR23900).
llvm-svn: 240193
2015-06-19 23:43:47 +00:00
Rafael Espindola 284a750c5f Make all temporary symbols unnamed.
What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.

Some of these symbols still show up in the symbol table, but we can just
make them unnamed.

In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.

Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.

llvm-svn: 240130
2015-06-19 12:16:55 +00:00
Rafael Espindola f27fa2bb9d Use named temporaries for directional labels.
Directional labels can show up in symbol tables (and we have a llvm-mc test for
that). Given that, we need to make sure they are named.

With that out of the way, use setUseNamesOnTempLabels in llvm-mc so that it
too benefits from the memory saving.

llvm-svn: 239914
2015-06-17 16:26:47 +00:00
Pete Cooper 234b875690 Allocate space for MCSymbol::Name only if required.
Similarly to User which allocates a number of Use's prior to the this pointer,
allocate space for the Name* for MCSymbol only when we need a name.

Given that an MCSymbol is 48-bytes on 64-bit systems, this saves a decent % of space.

Given the verify_uselistorder test case with debug info and llc, 50k symbols have names
out of 700k so this optimises for the common case of temporary unnamed symbols.

Reviewed by David Blaikie.

llvm-svn: 239423
2015-06-09 18:36:13 +00:00
Pete Cooper eb012fa761 Add MCSymbolMachO which will be used to hide the MCSymbolMachO flags.
Reviewed by Rafael Espíndola.

llvm-svn: 239315
2015-06-08 17:17:23 +00:00
Pete Cooper ad9f9c3517 Add MCSymbolCOFF class and use it to get and set the COFF type field.
Reviewed by Rafael Espíndola.

llvm-svn: 239312
2015-06-08 17:17:12 +00:00
Pete Cooper a3ab3841c0 Change MCSymbol IsELF to an enum to support future MCSymbolCOFF and MCSymbolMachO.
Reviewed by Rafael Espíndola.

llvm-svn: 239311
2015-06-08 17:17:09 +00:00
Rafael Espindola 3e9e72a56b Clarify when we can avoid creating names for temp symbols.
Some temporary symbols are created by MC itself. These symbols are never used
for lookup and are never included in the object symbol table, so we can
avoid creating a name for them.

Other temporaries are created by CodeGen or by the user by explicitly asking
for a name starting with .L (or L on MachO).

These temporaries behave like regular symbols, we just try to avoid including
them in the object symbol table, but sometimes they end up there:

const char *foo() {
  return "abc" + 3;
}

will have a relocation pointing to a .L symbol.

It just so happens that almost all MC created temporary has the AlwaysAddSuffix
option and CodeGen/user created ones don't.

One interesting future optimization would be to use unnamed symbols for
all temporaries, but that would require use an st_name of 0 or
having the object writer create the names if a symbol does end up in the
symbol table.

No testcase since this just avoid creating a few extra names for MC created
temporaries.

llvm-svn: 238887
2015-06-02 22:52:13 +00:00
Rafael Espindola 0ccf9b71f3 Pass a MCSymbolELF to a few ELF only functions. NFC.
llvm-svn: 238868
2015-06-02 21:30:13 +00:00
Rafael Espindola a869576008 Create a MCSymbolELF.
This create a MCSymbolELF class and moves SymbolSize since only ELF
needs a size expression.

This reduces the size of MCSymbol from 56 to 48 bytes.

llvm-svn: 238801
2015-06-02 00:25:12 +00:00
Benjamin Kramer 412c4dbbd9 [MC] Simplify code. No functionality change intended.
llvm-svn: 238676
2015-05-31 18:49:28 +00:00
Rafael Espindola ed34d58c09 Move MCSection destruction to MCContext::reset.
Fixes the leaks when running llc.

Also found by an asan bot.

llvm-svn: 238167
2015-05-26 01:52:19 +00:00
Rafael Espindola 24d285d31b Call the destructors of the MCSections.
They now contain the fragments. If we don't call the destructors the
fragments leak.

Found by an asan bot.

llvm-svn: 238161
2015-05-26 00:32:28 +00:00
Duncan P. N. Exon Smith 03656162a3 MC: Shave a pointer off of MCSymbol::Name
Shave a pointer off of `MCSymbolName` by storing `StringMapEntry<bool>*`
instead of `StringRef`.  This brings `sizeof(MCSymbol)` down to 64 on
64-bit platforms, a nice round number.  My profile showed memory
dropping from 914 MB down to 908 MB, roughly 0.7%.  Other than memory
usage, no functionality change here.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 238005
2015-05-22 06:04:42 +00:00
Rafael Espindola 0709a7bd1a Move alignment from MCSectionData to MCSection.
This starts merging MCSection and MCSectionData.

There are a few issues with the current split between MCSection and
MCSectionData.

* It optimizes the the not as important case. We want the production
of .o files to be really fast, but the split puts the information used
for .o emission in a separate data structure.

* The ELF/COFF/MachO hierarchy is not represented in MCSectionData,
leading to some ad-hoc ways to represent the various flags.

* It makes it harder to remember where each item is.

The attached patch starts merging the two by moving the alignment from
MCSectionData to MCSection.

Most of the patch is actually just dropping 'const', since
MCSectionData is mutable, but MCSection was not.

llvm-svn: 237936
2015-05-21 19:20:38 +00:00
Rafael Espindola e2fdf8d60e Avoid unnecessary section switching. NFC.
llvm-svn: 237913
2015-05-21 17:00:40 +00:00
Rafael Espindola e07467901b Remove yet another method of creating begin and end symbol for sections.
I missed this one when first unifying how we handle begin and end symbols.

llvm-svn: 237912
2015-05-21 16:52:32 +00:00
Reid Kleckner 2632f0df48 [WinEH] Store pointers to the LSDA in the exception registration object
We aren't yet emitting the LSDA yet, so this will still fail to
assemble.

llvm-svn: 237852
2015-05-20 23:08:04 +00:00
Jim Grosbach 008359ae4a MC: clang-format MCContext. NFC.
llvm-svn: 237595
2015-05-18 18:43:23 +00:00
Jim Grosbach 6f482000e9 MC: Clean up method names in MCContext.
The naming was a mish-mash of old and new style. Update to be consistent
with the new. NFC.

llvm-svn: 237594
2015-05-18 18:43:14 +00:00
Duncan P. N. Exon Smith c177fec93f MC: Skip names of temporary symbols in object streamer
Don't create names for temporary symbols when using an object streamer.
The names never make it to the output anyway.  From the starting point
of r236629, my heap profile says this drops peak memory usage from 1100
MB to 1058 MB for CodeGen of `verify-uselistorder`, a savings of almost
4% on peak memory, and removes `StringMap<bool, BumpPtrAllocator...>`
from the profile entirely.

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 236642
2015-05-06 21:34:34 +00:00
Rafael Espindola 55a3afb418 Remove the GroupMapTy DenseMap. NFC.
Instead use the Group symbol of MCSectionELF.

llvm-svn: 236033
2015-04-28 21:07:28 +00:00
Matt Arsenault 9897e03b11 Revert accidentally committed "MC: Allow targets to stop symbol name quoting"
llvm-svn: 235672
2015-04-23 23:34:51 +00:00
Matt Arsenault 0bad85de10 MC: Allow targets to stop symbol name quoting
Currently symbol names are printed in quotes if it contains something
outside of the arbitrary set of characters that isAcceptableChar tests
for. On somem targets, it is never OK to print a symbol name in quotes
so allow targets to opt out of this behavior.

llvm-svn: 235670
2015-04-23 23:34:05 +00:00
Rafael Espindola 61e8ce36be Store the sh_link of ARM_EXIDX directly in MCSectionELF.
This avoids some pretty horrible and broken name based section handling.

llvm-svn: 234142
2015-04-06 04:25:18 +00:00
Rafael Espindola b73b70ebff Simplify mapping from relocation sections to relocated sections.
Just store the section in MCSectionELF. This avoids multiple hash lookups.

This will also be used by ARM_EXIDX.

llvm-svn: 234139
2015-04-06 03:09:30 +00:00
Rafael Espindola 972d55851a Don't mix overload and default values.
It makes it hard to see which one is being called.

llvm-svn: 234100
2015-04-04 18:16:01 +00:00
Rafael Espindola 8ca44f0b5c Implement unique sections with an unique ID.
This allows the compiler/assembly programmer to switch back to a
section. This in turn fixes the bootstrap failure on powerpc (tested
on gcc110) without changing the ppc codegen at all.

I will try to cleanup the various getELFSection overloads in a  followup patch.
Just using a default argument now would lead to ambiguities.

llvm-svn: 234099
2015-04-04 18:02:01 +00:00
David Majnemer a225a19dd0 [WinEH] Generate .xdata for catch handlers
This lets us catch exceptions in simple cases.

N.B. Things that do not work include (but are not limited to):
- Throwing from within a catch handler.
- Catching an object with a named catch parameter.
- 'CatchHigh' is fictitious, we aren't sure of its purpose.
- We aren't entirely efficient with regards to the number of EH states
  that we generate.
- IP-to-State tables are sensitive to the order of emission.

llvm-svn: 233767
2015-03-31 22:35:44 +00:00
Rafael Espindola d3ac79b3b4 Save a std::string.
The group names are always symbol names, so we can use a StringRef.

llvm-svn: 233545
2015-03-30 13:59:06 +00:00
Rafael Espindola c9d069222e Special case the creation of relocation sections.
These sections are never looked up and we know when have to create them. Use
that to save adding them to the regular map and avoid a symbol->string->symbol
conversion for the group symbol.

This also makes the implementation independent of the details of how unique
sections are implemented.

llvm-svn: 233539
2015-03-30 13:39:16 +00:00
Rafael Espindola 44d5057e38 Add two small structs for readability in place of std::pair and std::tuple. NFC.
llvm-svn: 233422
2015-03-27 21:34:24 +00:00
Rafael Espindola 9ab09237dc Centralize the handling of unique ids for temporary labels.
Before this patch code wanting to create temporary labels for a given entity
(function, cu, exception range, etc) had to keep its own counter to have stable
symbol names.

createTempSymbol would still add a suffix to make sure a new symbol was always
returned, but it kept a single counter. Because of that, if we were to use
just createTempSymbol("cu_begin"), the label could change from cu_begin42 to
cu_begin43 because some other code started using temporary labels.

Simplify this by just keeping one counter per prefix and removing the various
specialized counters.

llvm-svn: 232535
2015-03-17 20:07:06 +00:00
Yaron Keren d7c546c935 Remove LookupSymbol(StringRef) and optimize LookupSymbol(Twine).
Same as MakeArgString in r232465, keep only LookupSymbol(Twine)
while making sure it handles the StringRef like cases efficiently
using twine::toStringRef.

llvm-svn: 232517
2015-03-17 18:55:30 +00:00
Yaron Keren 1ee89fc432 Teach Twine to support SmallString.
Enable removing .str() member calls for these frequent cases. 

 http://reviews.llvm.org/D6372

llvm-svn: 232465
2015-03-17 09:51:17 +00:00
Rafael Espindola 6b9998b3eb Create symbols marking the start of a section earlier.
This lets us pass the symbol to the constructor and avoid the mutable field.

This also opens the way for outputting the symbol only when needed, instead
of outputting them at the start of the file.

llvm-svn: 231859
2015-03-10 22:00:25 +00:00
Rafael Espindola 6ed58a2d91 clang-format code that is about to change.
llvm-svn: 231848
2015-03-10 21:16:18 +00:00
Reid Kleckner cfb9ce53c1 Replace llvm.frameallocate with llvm.frameescape
Turns out it's pretty straightforward and simplifies the implementation.

Reviewers: andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D8051

llvm-svn: 231386
2015-03-05 18:26:34 +00:00
Pete Cooper ef21bd444d Remove MCStreamer.h include from MCContext.h and explictly include it where necessary. NFC
llvm-svn: 231193
2015-03-04 01:24:11 +00:00
Rafael Espindola 629cdbae94 Centralize handling of the eh_begin and eh_end labels.
This removes a bit of duplicated code and more importantly, remembers the
labels so that they don't need to be looked up by name.

This in turn allows for any name to be used and avoids a crash if the name
we wanted was already taken.

llvm-svn: 230772
2015-02-27 18:18:39 +00:00
Rafael Espindola 68fa249cb5 Add r228980 back.
Add support for having multiple sections with the same name and comdat.

Using this in combination with -ffunction-sections allows LLVM to output a .o
file with mulitple sections named .text. This saves space by avoiding long
unique names of the form .text.<C++ mangled name>.

llvm-svn: 229541
2015-02-17 20:48:01 +00:00
Chandler Carruth d99f427e31 Revert a series of commits starting at r228886 which is triggering some
regressions for LLDB on Linux. Rafael indicated on lldb-dev that we
should just go ahead and revert these but that he wasn't at a computer.
The patches backed out are as follows:

r228980: Add support for having multiple sections with the name and ...
r228889: Invert the section relocation map.
r228888: Use the existing SymbolTableIndex intsead of doing a lookup.
r228886: Create the Section -> Rel Section map when it is first needed.

These patches look pretty nice to me, so hoping its not too hard to get
them re-instated. =D

llvm-svn: 229080
2015-02-13 07:52:39 +00:00
Rafael Espindola b6a812ebb1 Add support for having multiple sections with the same name and comdat.
Using this in combination with -ffunction-sections allows LLVM to output a .o
file with mulitple sections named .text. This saves space by avoiding long
unique names of the form .text.<C++ mangled name>.

llvm-svn: 228980
2015-02-12 23:29:51 +00:00
Rafael Espindola ba31e27f0a Compute the ELF SectionKind from the flags.
Any code creating an MCSectionELF knows ELF and already provides the flags.

SectionKind is an abstraction used by common code that uses a plain
MCSection.

Use the flags to compute the SectionKind. This removes a lot of
guessing and boilerplate from the MCSectionELF construction.

llvm-svn: 227476
2015-01-29 17:33:21 +00:00
Reid Kleckner e9b8931873 Add the llvm.frameallocate and llvm.recoverframeallocation intrinsics
These intrinsics allow multiple functions to share a single stack
allocation from one function's call frame. The function with the
allocation may only perform one allocation, and it must be in the entry
block.

Functions accessing the allocation call llvm.recoverframeallocation with
the function whose frame they are accessing and a frame pointer from an
active call frame of that function.

These intrinsics are very difficult to inline correctly, so the
intention is that they be introduced rarely, or at least very late
during EH preparation.

Reviewers: echristo, andrew.w.kaylor

Differential Revision: http://reviews.llvm.org/D6493

llvm-svn: 225746
2015-01-13 00:48:10 +00:00
David Blaikie 5106ce7897 Remove StringMap::GetOrCreateValue in favor of StringMap::insert
Having two ways to do this doesn't seem terribly helpful and
consistently using the insert version (which we already has) seems like
it'll make the code easier to understand to anyone working with standard
data structures. (I also updated many references to the Entry's
key and value to use first() and second instead of getKey{Data,Length,}
and get/setValue - for similar consistency)

Also removes the GetOrCreateValue functions so there's less surface area
to StringMap to fix/improve/change/accommodate move semantics, etc.

llvm-svn: 222319
2014-11-19 05:49:42 +00:00