Commit Graph

56 Commits

Author SHA1 Message Date
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 4491d0d337 Put jump tables in distinct sections if -ffunction-sections is used.
A small regression in r230411 was that we were basing the decision on
-fdata-sections.

llvm-svn: 230707
2015-02-26 23:55:11 +00:00
Rafael Espindola df19519800 Add r228939 back with a fix.
The problem in the original patch was not switching back to .text after printing
an eh table.

Original message:

On ELF, put PIC jump tables in a non executable section.

Fixes PR22558.

llvm-svn: 229586
2015-02-17 23:34:51 +00:00
Rafael Espindola 8c77768609 Add a test showing the problem in r228939.
If an EH table is printed in between the function and the jump table we would
fail to switch back to the text section to print the jump table.

llvm-svn: 229580
2015-02-17 23:21:46 +00:00
Matthias Braun 33cc10724d Revert "On ELF, put PIC jump tables in a non executable section."
This reverts commit r228939.

The commit broke something in the output of exception handling tables on
darwin x86-64.

llvm-svn: 229203
2015-02-14 01:16:54 +00:00
Rafael Espindola 203c5b9f39 On ELF, put PIC jump tables in a non executable section.
Fixes PR22558.

llvm-svn: 228939
2015-02-12 17:46:49 +00:00
Rafael Espindola 29786d4c16 Put each jump table in an independent section if the function is too.
This allows the linker to GC both, fixing pr22557.

llvm-svn: 228937
2015-02-12 17:16:46 +00:00
David Majnemer 5614ea9aae MC: Emit COFF section flags in the "proper" order
COFF section flags are not idempotent:
  'rd' will make a read-write section because 'd' implies write
  'dr' will make a read-only section because 'r' disables write

llvm-svn: 228490
2015-02-07 08:26:40 +00:00
Rafael Espindola fad3901095 Don't create multiple mergeable sections with -fdata-sections.
ELF has support for sections that can be split into fixed size or
null terminated entities.

Since these sections can be split by the linker, it is not necessary
to split them in codegen.

This reduces the combined .o size in a llvm+clang build from
202,394,570 to 173,819,098 bytes.

The time for linking clang with gold (on a VM, on a laptop) goes
from 2.250089985 to 1.383001792 seconds.

The flip side is the size of rodata in clang goes from 10,926,785
to 10,929,345 bytes.

The increase seems to be because of http://sourceware.org/bugzilla/show_bug.cgi?id=17902.

llvm-svn: 227431
2015-01-29 12:43:28 +00:00
Rafael Espindola 12ca34f53f Bring r226038 back.
No change in this commit, but clang was changed to also produce trivial comdats when
needed.

Original message:

Don't create new comdats in CodeGen.

This patch stops the implicit creation of comdats during codegen.

Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.

llvm-svn: 226467
2015-01-19 15:16:06 +00:00
Timur Iskhodzhanov 60b721363c Revert r226242 - Revert Revert Don't create new comdats in CodeGen
This breaks AddressSanitizer (ninja check-asan) on Windows

llvm-svn: 226251
2015-01-16 08:38:45 +00:00
Rafael Espindola 67a79e72f5 Revert "Revert Don't create new comdats in CodeGen"
This reverts commit r226173, adding r226038 back.

No change in this commit, but clang was changed to also produce trivial comdats for
costructors, destructors and vtables when needed.

Original message:

Don't create new comdats in CodeGen.

This patch stops the implicit creation of comdats during codegen.

Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.

llvm-svn: 226242
2015-01-16 02:22:55 +00:00
Timur Iskhodzhanov f5adf13fac Revert Don't create new comdats in CodeGen
It breaks AddressSanitizer on Windows.

llvm-svn: 226173
2015-01-15 16:14:34 +00:00
Rafael Espindola fad1639a12 Don't create new comdats in CodeGen.
This patch stops the implicit creation of comdats during codegen.

Clang now sets the comdat explicitly when it is required. With this patch clang and gcc
now produce the same result in pr19848.

llvm-svn: 226038
2015-01-14 20:55:48 +00:00
Rafael Espindola b43d51de95 On MachO, don't put non-private constants in mergeable sections.
On MachO, putting a symbol that doesn't start with a 'L' or 'l' in one of the
__TEXT,__literal* sections prevents the linker from merging the context of the
section.

Since private GVs are the ones the get mangled to start with 'L' or 'l', we now
only put those on the __TEXT,__literal* sections.

llvm-svn: 216682
2014-08-28 20:13:31 +00:00
Eric Christopher 2feed5fd68 Move the function and data section flags into the options struct and
make the functions to set them non-static.
Move and rename the llvm specific backend options to avoid conflicting
with the clang option.

Paired with a backend commit to update.

llvm-svn: 209238
2014-05-20 21:25:34 +00:00
Saleem Abdulrasool 11049a0fef MC: honour IMAGE_SCN_CNT_INITIALIZED_DATA
Emit the flag to indicate to the assembler that a section contains data if there
is pre-populated data present.

llvm-svn: 207028
2014-04-23 21:29:34 +00:00
David Majnemer 273bff4713 WinCOFF: Add support for -fdata-sections
This is a pretty straight forward translation for COFF, we just need to
stick the data in a COMDAT section marked as
IMAGE_COMDAT_SELECT_NODUPLICATES.

N.B. We must be careful to avoid sticking entities with private linkage
in COMDAT groups.  COFF is pretty hostile to the renaming of entities so
we must be careful to disallow GlobalVariables with unstable names.

llvm-svn: 204703
2014-03-25 06:14:26 +00:00
David Majnemer 9338984f57 WinCOFF: Add support for -ffunction-sections
This is a pretty straight forward translation for COFF, we just need to
stick the function in a COMDAT section marked as
IMAGE_COMDAT_SELECT_NODUPLICATES.

llvm-svn: 204565
2014-03-23 17:47:39 +00:00
Rafael Espindola daeafb4c2a Add back r201608, r201622, r201624 and r201625
r201608 made llvm corretly handle private globals with MachO. r201622 fixed
a bug in it and r201624 and r201625 were changes for using private linkage,
assuming that llvm would do the right thing.

They all got reverted because r201608 introduced a crash in LTO. This patch
includes a fix for that. The issue was that TargetLoweringObjectFile now has
to be initialized before we can mangle names of private globals. This is
trivially true during the normal codegen pipeline (the asm printer does it),
but LTO has to do it manually.

llvm-svn: 201700
2014-02-19 17:23:20 +00:00
Daniel Jasper 7e198ad862 Revert r201622 and r201608.
This causes the LLVMgold plugin to segfault. More information on the
replies to r201608.

llvm-svn: 201669
2014-02-19 12:26:01 +00:00
Rafael Espindola b9ea63c551 Avoid an infinite cycle with private linkage and -f{data|function}-sections.
When outputting an object we check its section to find its name, but when
looking for the section with -ffunction-section we look for the symbol name.

Break the loop by requesting a name with the private prefix when constructing
the section name. This matches the behavior before r201608.

llvm-svn: 201622
2014-02-19 01:28:30 +00:00
Rafael Espindola 1f3de49f37 Use __literal16. It has been supported by the linker since 2005.
llvm-svn: 201365
2014-02-13 23:16:11 +00:00
Rafael Espindola fdc88137f4 Remove AllowQuotesInName and friends from MCAsmInfo.
Accepting quotes is a property of an assembler, not of an object file. For
example, ELF can support any names for sections and symbols, but the gnu
assembler only accepts quotes in some contexts and llvm-mc in a few more.

LLVM should not produce different symbols based on a guess about which assembler
will be reading the code it is printing.

llvm-svn: 194575
2013-11-13 14:01:59 +00:00
Arnold Schwaighofer c31c2de18b Revert "Reapply r185872 now that the address sanitizer has been changed to support this."
This reverts commit r187939. It broke an O0 build of a spec benchmark.

llvm-svn: 188012
2013-08-08 21:04:16 +00:00
Bill Wendling b80f9791e4 Reapply r185872 now that the address sanitizer has been changed to support this.
Original commit message:

Stop emitting weak symbols into the "coal" sections.

The Mach-O linker has been able to support the weak-def bit on any symbol for
quite a while now. The compiler however continued to place these symbols into a
"coal" section, which required the linker to map them back to the base section
name.

Replace the sections like this:

  __TEXT/__textcoal_nt   instead use  __TEXT/__text
  __TEXT/__const_coal    instead use  __TEXT/__const
  __DATA/__datacoal_nt   instead use  __DATA/__data

<rdar://problem/14265330>

llvm-svn: 187939
2013-08-07 23:42:09 +00:00
Alexander Potapenko 8d2d79d05f Revert r185872 - "Stop emitting weak symbols into the "coal" sections"
This patch broke `make check-asan` on Mac, causing ld warnings like the following one:

ld: warning: direct access in __GLOBAL__I_a to global weak symbol
___asan_mapping_scale means the weak symbol cannot be overridden at
runtime. This was likely caused by different translation units being
compiled with different visibility settings.

The resulting test binaries crashed with incorrect ASan warnings.

llvm-svn: 185923
2013-07-09 10:00:16 +00:00
Bill Wendling 0176708e85 Stop emitting weak symbols into the "coal" sections.
The Mach-O linker has been able to support the weak-def bit on any symbol for
quite a while now. The compiler however continued to place these symbols into a
"coal" section, which required the linker to map them back to the base section
name.

Replace the sections like this:

  __TEXT/__textcoal_nt   instead use  __TEXT/__text
  __TEXT/__const_coal    instead use  __TEXT/__const
  __DATA/__datacoal_nt   instead use  __DATA/__data

<rdar://problem/14265330>

llvm-svn: 185872
2013-07-08 21:34:52 +00:00
Evan Cheng ccf243d56b Fix an obvious typo that's preventing x86 (32-bit) from using .literal16.
llvm-svn: 135535
2011-07-19 23:14:32 +00:00
Joerg Sonnenberger 62f759791a Be nice to Xcore and the XMOS assembler and avoid quoting section names
that contain only letters, digits and the characters "_" and ".".

llvm-svn: 127028
2011-03-04 20:03:14 +00:00
Joerg Sonnenberger 852ab890b5 Bug#9033: For the ELF assembler output, always quote the section name.
llvm-svn: 126963
2011-03-03 22:31:08 +00:00
Rafael Espindola 70d8015063 Switch llvm to using comdats. For now always use groups with a single
section.

llvm-svn: 125526
2011-02-14 22:23:49 +00:00
Rafael Espindola ec517cdf24 Update tests.
llvm-svn: 123591
2011-01-16 18:02:57 +00:00
Chris Lattner 34bfab0ad5 two changes:
1) nuke ConstDataCoalSection, which is dead.
2) revise my previous patch for rdar://8018335,
  which was completely wrong.  Specifically, it doesn't 
  make sense to mark __TEXT,__const_coal as PURE_INSTRUCTIONS,
  because it is for readonly data.  templates (it turns out)
  go to const_coal_nt.  The real fix for rdar://8018335 was
  to give ConstTextCoalSection a section kind of ReadOnly 
  instead of Text.

llvm-svn: 112496
2010-08-30 18:12:35 +00:00
Chris Lattner 60b131654b fix the definitions of ConstTextCoalSection/ConstDataCoalSection
to keep "Text" in sync with the "pure instructions" section attribute.
Lack of this attribute was preventing the assembler from emitting
multibyte noops instructions for templates (and inlines, and other
coalesced stuff) and was causing the assembler to mismatch .o files.

This fixes rdar://8018335

llvm-svn: 108461
2010-07-15 21:22:00 +00:00
Chris Lattner 64d43d80be round zero-byte .zerofill directives up to 1 byte. This
should fix some "g++.dg-struct-layout-1" failures, 
rdar://7886017

llvm-svn: 102421
2010-04-27 07:41:44 +00:00
Chris Lattner 5b212a31a2 add llvm codegen support for -ffunction-sections and -fdata-sections,
patch by Sylvere Teissier!

llvm-svn: 101106
2010-04-13 00:36:43 +00:00
Dan Gohman 4bd755419f Revert the recent alignment changes. They're broken for -Os because,
in particular, they end up aligning strings at 16-byte boundaries, and
there's no way for GlobalOpt to check OptForSize.

llvm-svn: 100172
2010-04-02 03:04:37 +00:00
Dan Gohman ffb9c71174 Update this test for the new preferred alignment heuristics.
llvm-svn: 100165
2010-04-02 01:24:08 +00:00
Charles Davis 8545afe0b0 Don't emit global symbols into the (__TEXT,__ustring) section on Darwin. This
is a workaround for <rdar://problem/7672401/> (which I filed).

This let's us build Wine on Darwin, and it gets the Qt build there a little bit
further (so Doug says).

llvm-svn: 97845
2010-03-05 22:28:45 +00:00
Chris Lattner 68eeb5ec9c emit .ascii and .asciz through MCStreamer.
llvm-svn: 94282
2010-01-23 04:54:10 +00:00
Chris Lattner a986aa33eb fix a significant difference between llvm and gcc on ELF systems:
GCC would put weak zero initialized mutable data in the .bss section,
we would put it into a crasy '.gnu.linkonce.b.test,"aw",@nobits' 
section.  Fixing this will allow simplifications next up.

llvm-svn: 93844
2010-01-19 03:06:01 +00:00
Chris Lattner 024734e0f0 there is no need to emit a .section above .comm on linux.
llvm-svn: 93842
2010-01-19 02:46:56 +00:00
Dan Gohman 40503396da Eliminate more uses of llvm-as and llvm-dis.
llvm-svn: 81290
2009-09-08 23:54:48 +00:00
Dan Gohman ef3d457126 Various AsmWriter output cleanups. Use WriteAsOperand instead of
PrintUnmangledNameSafely.

llvm-svn: 78878
2009-08-13 01:36:44 +00:00
Chris Lattner cb307a27bf Make the big switch: Change MCSectionMachO to represent a section *semantically*
instead of syntactically as a string.  This means that it keeps track of the 
segment, section, flags, etc directly and asmprints them in the right format.
This also includes parsing and validation support for llvm-mc and 
"attribute(section)", so we should now start getting errors about invalid 
section attributes from the compiler instead of the assembler on darwin.

Still todo: 
1) Uniquing of darwin mcsections
2) Move all the Darwin stuff out to MCSectionMachO.[cpp|h]
3) there are a few FIXMEs, for example what is the syntax to get the
   S_GB_ZEROFILL segment type?

llvm-svn: 78547
2009-08-10 01:39:42 +00:00
Chris Lattner f222054df7 enhance codegen to put 16-bit character strings into the
__TEXT,__ustring section on darwin.

llvm-svn: 78068
2009-08-04 16:27:13 +00:00
Chris Lattner 81bbf443fe Add support emiting for 2/4 byte mergable strings to the ".rodata.str*"
section on ELF targets.

llvm-svn: 78066
2009-08-04 16:13:09 +00:00
Chris Lattner fc0264a38e fix PR4650: we only track sizes for certain objects, so only put something
into the mergable section if it is one of our special cases.  This could
obviously be improved, but this is the minimal fix and restores us to the
previous behavior.

llvm-svn: 77679
2009-07-31 16:17:13 +00:00
Chris Lattner c5397abb52 fix PR4584 with a trivial patch now that the pieces are in place.
llvm-svn: 77434
2009-07-29 05:20:33 +00:00