Commit Graph

132 Commits

Author SHA1 Message Date
Rafael Espindola
d8ee23f34c Add back commits r219835 and a fixed version of r219829.
The only difference from r219829 is using

getOrCreateSectionSymbol(*ELFSec)

instead of

GetOrCreateSymbol(ELFSec->getSectionName())

in ELFObjectWriter which causes us to use the correct section symbol even if
we have multiple sections with the same name.

Original messages:

r219829:
Correctly handle references to section symbols.

When processing assembly like

.long .text

we were creating a new undefined symbol .text. GAS on the other hand would
handle that as a reference to the .text section.

This patch implements that by creating the section symbols earlier so that
they are visible during asm parsing.

The patch also updates llvm-readobj to print the symbol number in the relocation
dump so that the test can differentiate between two sections with the same name.

r219835:
Allow forward references to section symbols.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220021 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-17 01:48:58 +00:00
Rafael Espindola
70a1be3f76 Revert commit r219835 and r219829.
Revert "Correctly handle references to section symbols."
Revert "Allow forward references to section symbols."

Rui found a regression I am debugging.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220010 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-17 01:06:02 +00:00
Rafael Espindola
ad04f5db82 Correctly handle references to section symbols.
When processing assembly like

.long .text

we were creating a new undefined symbol .text. GAS on the other hand would
handle that as a reference to the .text section.

This patch implements that by creating the section symbols earlier so that
they are visible during asm parsing.

The patch also updates llvm-readobj to print the symbol number in the relocation
dump so that the test can differentiate between two sections with the same name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219829 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 18:55:30 +00:00
Derek Schuff
279b5504a3 [MC] Make bundle alignment mode setting idempotent and support nested bundles
Summary:
Currently an error is thrown if bundle alignment mode is set more than once
per module (either via the API or the .bundle_align_mode directive). This
change allows setting it multiple times as long as the alignment doesn't
change.

Also nested bundle_lock groups are currently not allowed. This change allows
them, with the effect that the group stays open until all nests are exited,
and if any of the bundle_lock directives has the align_to_end flag, the
group becomes align_to_end.

These changes make the bundle aligment simpler to use in the compiler, and
also better match the corresponding support in GNU as.

Reviewers: jvoung, eliben

Differential Revision: http://reviews.llvm.org/D5801

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 17:10:04 +00:00
Rafael Espindola
90ce9f70e2 Simplify handling of --noexecstack by using getNonexecutableStackSection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219799 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 16:12:52 +00:00
Rafael Espindola
4186005edc Print a=b as an assignment.
In assembly the expression a=b is parsed as an assignment, so it should be
printed as one.

This remove a truly horrible hack for producing a label with "a=.". It would
be used by codegen but would never be reached by the asm parser. Sorry I
missed this when it was first committed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211639 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-24 22:45:16 +00:00
Rafael Espindola
044302d718 Remove an always true argument.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208557 91177308-0d34-0410-b5e6-96231b3b80d8
2014-05-12 13:30:10 +00:00
Rafael Espindola
14a1490eb8 Make getOrCreateSymbolData non virtual.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207367 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-27 17:23:37 +00:00
Kevin Enderby
29c96f133e Fix the assembler to print a better relocatable expression error
diagnostic that includes location information.

Currently if one has this assembly:

	.quad (0x1234 + (4 * SOME_VALUE))

where SOME_VALUE is undefined ones gets the less than
useful error message with no location information:

% clang -c x.s
clang -cc1as: fatal error: error in backend: expected relocatable expression

With this fix one now gets a more useful error message
with location information:

% clang -c x.s 
x.s:5:8: error: expected relocatable expression
 .quad (0x1234 + (4 * SOME_VALUE))
       ^

To do this I plumbed the SMLoc through the MCObjectStreamer
EmitValue() and EmitValueImpl() interfaces so it could be used
when creating the MCFixup.

rdar://12391022


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206906 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-22 17:27:29 +00:00
Craig Topper
4266ae8067 [C++11] More 'nullptr' conversion or in some cases just using a boolean check instead of comparing to nullptr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206129 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-13 04:57:38 +00:00
Zoran Jovanovic
b71fd20f2d Mark alias symbols as microMIPS if necessary. Differential Revision: http://llvm-reviews.chandlerc.com/D3080
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204323 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-20 09:44:49 +00:00
Rafael Espindola
0a70f9b3b9 Look through variables when computing relocations.
Given

bar = foo + 4
	.long bar

MC would eat the 4. GNU as includes it in the relocation. The rule seems to be
that a variable that defines a symbol is used in the relocation and one that
does not define a symbol is evaluated and the result included in the relocation.

Fixing this unfortunately required some other changes:

* Since the variable is now evaluated, it would prevent the ELF writer from
  noticing the weakref marker the elf streamer uses. This patch then replaces
  that with a VariantKind in MCSymbolRefExpr.

* Using VariantKind then requires us to look past other VariantKind to see

	.weakref	bar,foo
	call	bar@PLT

  doing this also fixes

	zed = foo +2
	call zed@PLT

  so that is a good thing.

* Looking past VariantKind means that the relocation selection has to use
  the fixup instead of the target.

This is a reboot of the previous fixes for MC. I will watch the sanitizer
buildbot and wait for a build before adding back the previous fixes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204294 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-20 02:12:01 +00:00
Rafael Espindola
fc5436c951 Always print the implicit .text at the start of an asm file.
Before llvm-mc would print it, but llc was assuming that it would produce
another section changing directive before one was needed. That assumption is
false with inline asm.

Fixes PR19049.

Another option would be to always create the section, but in the asm printer
avoid printing sections changes during initialization. That would work, but
* We do use the fact that llvm-mc prints it in testing. The tests can be changed
  if needed.
* A quick poll on IRC suggest that most developers prefer the implicit .text to
  be printed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203001 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-05 20:09:15 +00:00
Rafael Espindola
506eb6df35 Use the default values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200781 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-04 18:34:04 +00:00
David Woodhouse
2ddea4b44d Explictly pass MCSubtargetInfo to MCCodeEmitter::EncodeInstruction()
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200348 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-28 23:13:07 +00:00
David Woodhouse
d5d381b762 Modify MCObjectStreamer EmitInstTo* interface
Add MCSubtargetInfo parameter
virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &);
virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo &);

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200346 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-28 23:12:49 +00:00
Rafael Espindola
aa75693ea4 Construct the MCStreamer before constructing the MCTargetStreamer.
This has a few advantages:
* Only targets that use a MCTargetStreamer have to worry about it.
* There is never a MCTargetStreamer without a MCStreamer, so we can use a
  reference.
* A MCTargetStreamer can talk to the MCStreamer in its constructor.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200129 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-26 06:06:37 +00:00
Rafael Espindola
a1f7c26cc8 Simplify the logic for deciding when to initialize the sections.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199971 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 03:54:40 +00:00
Rafael Espindola
5950c6fa48 Inline functions that are only called once.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199965 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-24 02:18:40 +00:00
Rafael Espindola
3a89110b6e InitToTextSection is redundant with InitSections. Remove it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199955 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-23 23:14:14 +00:00
Rafael Espindola
e0fd567df0 Remove duplicated info on what .text, .data and .bss look like.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199951 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-23 22:49:25 +00:00
Chandler Carruth
974a445bd9 Re-sort all of the includes with ./utils/sort_includes.py so that
subsequent changes are easier to review. About to fix some layering
issues, and wanted to separate out the necessary churn.

Also comment and sink the include of "Windows.h" in three .inc files to
match the usage in Memory.inc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198685 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-07 11:48:04 +00:00
David Peixotto
0fc8c68b11 Add support for parsing ARM symbol variants on ELF targets
ARM symbol variants are written with parens instead of @ like this:

  .word __GLOBAL_I_a(target1)

This commit adds support for parsing these symbol variants in
expressions. We introduce a new flag to MCAsmInfo that indicates the
parser should use parens to parse the symbol variant. The expression
parser is modified to look for symbol variants using parens instead
of @ when the corresponding MCAsmInfo flag is true.

The MCAsmInfo parens flag is enabled only for ARM on ELF.

By adding this flag to MCAsmInfo, we are able to get rid of
redundant ARM-specific symbol variants and use the generic variants
instead (e.g. VK_GOT instead of VK_ARM_GOT). We use the new
UseParensForSymbolVariant attribute in MCAsmInfo to correctly print
the symbol variants for arm.

To achive this we need to keep a handle to the MCAsmInfo in the
MCSymbolRefExpr class that we can check when printing the symbol
variant.

Updated Tests:
  Changed case of symbol variant to match the generic kind.
  test/CodeGen/ARM/tls-models.ll
  test/CodeGen/ARM/tls1.ll
  test/CodeGen/ARM/tls2.ll
  test/CodeGen/Thumb2/tls1.ll
  test/CodeGen/Thumb2/tls2.ll

PR18080


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196424 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-04 22:43:20 +00:00
David Peixotto
1edc33b924 ARM integrated assembler generates incorrect nop opcode
This patch fixes a bug in the assembler that was causing bad code to
be emitted.  When switching modes in an assembly file (e.g. arm to
thumb mode) we would always emit the opcode from the original mode.

Consider this small example:

$ cat align.s
.code 16
foo:
  add r0, r0
.align 3
  add r0, r0

$ llvm-mc -triple armv7-none-linux align.s -filetype=obj -o t.o
$ llvm-objdump -triple thumbv7 -d t.o
Disassembly of section .text:
foo:
       0:       00 44         add     r0, r0
       2:       00 f0 20 e3   blx #4195904
       6:       00 00         movs    r0, r0
       8:       00 44         add     r0, r0

This shows that we have actually emitted an arm nop (e320f000)
instead of a thumb nop. Unfortunately, this encodes to a thumb
branch which causes bad things to happen when compiling assembly
code with align directives.

The fix is to notify the ARMAsmBackend when we switch mode. The
MCMachOStreamer was already doing this correctly. This patch makes
the same change for the MCElfStreamer.

There is still a bug in the way nops are emitted for alignment
because the MCAlignment fragment does not store the correct mode.
The ARMAsmBackend will emit nops for the last mode it knew about. In
the example above, we still generate an arm nop if we add a `.code
32` to the end of the file.

PR18019


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195677 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-25 19:11:13 +00:00
Joerg Sonnenberger
72580780a9 Move the STT_FILE symbols out of the normal symbol table processing for
ELF. They can overlap with the other symbols, e.g. if a source file
"foo.c" contains a function "foo" with a static variable "c".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193569 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-29 01:06:17 +00:00
Rafael Espindola
c7ce3e4f42 Move .ident handling to MCStreamer.
No functionality change, but exposes the API so that codegen can use it too.

Patch by Katya Romanova.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192757 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-16 01:05:45 +00:00
Rafael Espindola
320296a4cf Add a MCTargetStreamer interface.
This patch fixes an old FIXME by creating a MCTargetStreamer interface
and moving the target specific functions for ARM, Mips and PPC to it.

The ARM streamer is still declared in a common place because it is
used from lib/CodeGen/ARMException.cpp, but the Mips and PPC are
completely hidden in the corresponding Target directories.

I will send an email to llvmdev with instructions on how to use this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192181 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-08 13:08:17 +00:00
Richard Mitton
5cc319a42a Added support for generate DWARF .debug_aranges sections automatically.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191052 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-19 23:21:01 +00:00
Bill Wendling
da11df0c22 Call generateCompactUnwindEncodings() right before we need to output the frame information.
There are more than one paths to where the frame information is emitted. Place
the call to generateCompactUnwindEncodings() into the method which outputs the
frame information, thus ensuring that the encoding is there for every path. This
involved threading the MCAsmBackend object through to this method.

<rdar://problem/13623355>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190335 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-09 19:48:37 +00:00
Saleem Abdulrasool
1c9cd021c8 [CodeGen] prevent abnormal on invalid attributes
Currently, when an invalid attribute is encountered on processing a .s file,
clang will abort due to llvm_unreachable.  Invalid user input should not cause
an abnormal termination of the compiler.  Change the interface to return a
boolean to indicate the failure as a first step towards improving hanlding of
malformed user input to clang.

Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188047 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-09 01:52:03 +00:00
Ulrich Weigand
7a34599db0 [PowerPC] Revert r185476 and fix up TLS variant kinds
In the commit message to r185476 I wrote:

>The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
>correspond exactly to the generic modifiers VK_TLSGD and VK_TLSLD.
>This causes some confusion with the asm parser, since VK_PPC_TLSGD
>is output as @tlsgd, which is then read back in as VK_TLSGD.
>
>To avoid this confusion, this patch removes the PowerPC-specific
>modifiers and uses the generic modifiers throughout.  (The only
>drawback is that the generic modifiers are printed in upper case
>while the usual convention on PowerPC is to use lower-case modifiers.
>But this is just a cosmetic issue.)

This was unfortunately incorrect, there is is fact another,
serious drawback to using the default VK_TLSLD/VK_TLSGD
variant kinds: using these causes ELFObjectWriter::RelocNeedsGOT
to return true, which in turn causes the ELFObjectWriter to emit
an undefined reference to _GLOBAL_OFFSET_TABLE_.

This is a problem on powerpc64, because it uses the TOC instead
of the GOT, and the linker does not provide _GLOBAL_OFFSET_TABLE_,
so the symbol remains undefined.  This means shared libraries
using TLS built with the integrated assembler are currently
broken.

While the whole RelocNeedsGOT / _GLOBAL_OFFSET_TABLE_ situation
probably ought to be properly fixed at some point, for now I'm
simply reverting the r185476 commit.  Now this in turn exposes
the breakage of handling @tlsgd/@tlsld in the asm parser that
this check-in was originally intended to fix.

To avoid this regression, I'm also adding a different fix for
this problem: while common code now parses @tlsgd as VK_TLSGD,
a special hack in the asm parser translates this code to the
platform-specific VK_PPC_TLSGD that the back-end now expects.
While this is not really pretty, it's self-contained and
shouldn't hurt anything else for now.  One the underlying
problem is fixed, this hack can be reverted again.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185945 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-09 16:41:09 +00:00
Ulrich Weigand
58fc1f52ce [PowerPC] Remove VK_PPC_TLSGD and VK_PPC_TLSLD
The PowerPC-specific modifiers VK_PPC_TLSGD and VK_PPC_TLSLD
correspond exactly to the generic modifiers VK_TLSGD and VK_TLSLD.
This causes some confusion with the asm parser, since VK_PPC_TLSGD
is output as @tlsgd, which is then read back in as VK_TLSGD.

To avoid this confusion, this patch removes the PowerPC-specific
modifiers and uses the generic modifiers throughout.  (The only
drawback is that the generic modifiers are printed in upper case
while the usual convention on PowerPC is to use lower-case modifiers.
But this is just a cosmetic issue.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185476 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-02 21:29:06 +00:00
Rafael Espindola
a3863ea2da Remove address spaces from MC.
This is dead code since PIC16 was removed in 2010. The result was an odd mix,
where some parts would carefully pass it along and others would assert it was
zero (most of the object streamer for example).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185436 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-02 15:49:13 +00:00
Ulrich Weigand
228e0afcfd [PowerPC] Add support for TLS data relocations
This adds support for TLS data relocations and modifiers:
       .quad target@dtpmod
       .quad target@tprel
       .quad target@dtprel
Currently exploited by the asm parser only.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185394 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-01 23:33:29 +00:00
Ulrich Weigand
cab0a19338 [PowerPC] Support various tls-related modifiers
The current code base only supports the minimum set of tls-related
relocations and @modifiers that are necessary to support compiler-
generated code.  This patch extends this to the full set defined
in the ABI (and supported by the GNU assembler) for the benefit
of the assembler parser.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184551 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-21 14:44:15 +00:00
Ulrich Weigand
92cfa61c50 [PowerPC] Rename some more VK_PPC_ enums
This renames more VK_PPC_ enums, to make them more closely reflect
the @modifier string they represent.  This also prepares for adding
a bunch of new VK_PPC_ enums in upcoming patches.

For consistency, some MO_ flags related to VK_PPC_ enums are
likewise renamed.

No change in behaviour.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184547 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-21 14:42:20 +00:00
Peter Collingbourne
df39be6cb4 Add support for subsections to the ELF assembler. Fixes PR8717.
Differential Revision: http://llvm-reviews.chandlerc.com/D598

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179725 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-17 21:18:16 +00:00
Peter Collingbourne
01a7b5c43e Use a scheme closer to that of GNU as when deciding the type of a
symbol with multiple .type declarations.

Differential Revision: http://llvm-reviews.chandlerc.com/D607

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179184 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-10 16:52:15 +00:00
Nick Lewycky
462bba39c2 We need a shndx if the number of sections breaks SHN_LORESERVE. This condition
for choosing to emit a shndx was simply testing the wrong variable.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176762 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-09 09:31:44 +00:00
Bill Schmidt
3a42989d3d Fix PR15359.
The PowerPC TLS relocation types were not previously added to the
necessary list in MCELFStreamer::fixSymbolsInTLSFixups().  Now they are!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176094 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-26 16:41:03 +00:00
Jack Carter
77afbdce53 ELF symbol table field st_other support,
excluding visibility bits.

Generic STO handling at the Target level.

The st_other field of the ELF symbol table is one
byte in size. The first 2 bytes are used for generic
visibility and are currently handled by llvm.

The other six bits are processor specific and need 
to be set at the target level.

A couple of notes:

The new static methods for accessing and setting the "other"
flags in include/llvm/MC/MCELF.h match the style guide
and not the other methods in the file. I don't like the
inconsistency, but feel I should follow the prescribed 
lowerUpper() convention.

STO_ value definitions are not specified in gnu land as 
consistently as the STT_ and STB_ fields. Probably because
the latter were defined in a standards doc and the former
defined partially in code. I have stuck with the full byte
definition of the flags.

Contributer: Zoran Jovanovic




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175561 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-19 21:57:35 +00:00
Derek Schuff
67144e37ba If bundle alignment is enabled, do not add data to a fragment with instructions
With bundle alignment, instructions all get their own MCFragments
(unless they are in a bundle-locked group). For instructions with
fixups, this is an MCDataFragment. Emitting actual data (e.g. for
.long) attempts to re-use MCDataFragments, which we don't want int
this case since it leads to fragments which exceed the bundle size.
So, don't reuse them in this case.
Also adds a test and fixes some formatting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175316 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-15 22:50:52 +00:00
Tim Northover
72062f5744 Add AArch64 as an experimental target.
This patch adds support for AArch64 (ARM's 64-bit architecture) to
LLVM in the "experimental" category. Currently, it won't be built
unless requested explicitly.

This initial commit should have support for:
    + Assembly of all scalar (i.e. non-NEON, non-Crypto) instructions
      (except the late addition CRC instructions).
    + CodeGen features required for C++03 and C99.
    + Compilation for the "small" memory model: code+static data <
      4GB.
    + Absolute and position-independent code.
    + GNU-style (i.e. "__thread") TLS.
    + Debugging information.

The principal omission, currently, is performance tuning.

This patch excludes the NEON support also reviewed due to an outbreak of
batshit insanity in our legal department. That will be committed soon bringing
the changes to precisely what has been approved.

Further reviews would be gratefully received.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174054 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 12:12:40 +00:00
Eli Bendersky
9ccb76998f Optimize the memory usage of MC bundling, by creating a new type of fragment
into which we can emit single instructions without fixups (which is most
instructions). This is an optimization required because MCDataFragment
is prety large (240 bytes on x64), with no change in functionality.

For large programs, this reduces memory usage overhead required for bundling
by 40%.

To make the code as palatable as possible, the MCEncodedFragment interface was
further fragmented (no pun intended) and MCEncodedFragmentWithFixups is used
as the interface to work against when the user expects fixups. MCDataFragment
and MCRelaxableFragment implement this interface, while the new
MCCompactEncodedInstFragment implements MCEncodeFragment.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172572 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-15 23:22:09 +00:00
Eli Bendersky
030f63a397 Expose an InitToTextSection through MCStreamer.
The aim of this patch is to fix the following piece of code in the
platform-independent AsmParser:

void AsmParser::CheckForValidSection() {
  if (!ParsingInlineAsm && !getStreamer().getCurrentSection()) {
    TokError("expected section directive before assembly directive");
    Out.SwitchSection(Ctx.getMachOSection(
                        "__TEXT", "__text",
                        MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
                        0, SectionKind::getText()));
  }
}

This was added for the "-n" option of llvm-mc.

The proposed fix adds another virtual method to MCStreamer, called
InitToTextSection. Conceptually, it's similar to the existing
InitSections which initializes all common sections and switches to
text. The new method is implemented by each platform streamer in a way
that it sees fit. So AsmParser can now do this:

void AsmParser::CheckForValidSection() {
  if (!ParsingInlineAsm && !getStreamer().getCurrentSection()) {
    TokError("expected section directive before assembly directive");
    Out.InitToTextSection();
  }
}

Which is much more reasonable.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172450 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-14 19:04:57 +00:00
Eric Christopher
1ced208be9 Last in the series of removing unnecessary '0' arguments for
address space. Reordered the EmitULEB128IntValue arguments to
make this easier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171949 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-09 03:52:05 +00:00
Eli Bendersky
251040bc18 Renamed MCInstFragment to MCRelaxableFragment and added some comments.
No change in functionality.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171822 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-08 00:22:56 +00:00
Eli Bendersky
6c1d4972cf Add the align_to_end option to .bundle_lock in the MC implementation of aligned
bundling. The document describing this feature and the implementation has also
been updated:

https://sites.google.com/a/chromium.org/dev/nativeclient/pnacl/aligned-bundling-support-in-llvm


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171797 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 21:51:08 +00:00
Eli Bendersky
4766ef41b3 Aligned bundling support. Following the discussion here:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-December/056754.html

The proposal and implementation are fully documented here:
https://sites.google.com/a/chromium.org/dev/nativeclient/pnacl/aligned-bundling-support-in-llvm

Tests will follow shortly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170718 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-20 19:05:53 +00:00
Reed Kotler
2c3a4641a7 This patch is needed to make c++ exceptions work for mips16.
Mips16 is really a processor decoding mode (ala thumb 1) and in the same
program, mips16 and mips32 functions can exist and can call each other.

If a jal type instruction encounters an address with the lower bit set, then
the processor switches to mips16 mode (if it is not already in it). If the
lower bit is not set, then it switches to mips32 mode.

The linker knows which functions are mips16 and which are mips32.
When relocation is performed on code labels, this lower order bit is
set if the code label is a mips16 code label.

In general this works just fine, however when creating exception handling
tables and dwarf, there are cases where you don't want this lower order
bit added in.

This has been traditionally distinguished in gas assembly source by using a
different syntax for the label.

lab1:      ; this will cause the lower order bit to be added
lab2=.     ; this will not cause the lower order bit to be added

In some cases, it does not matter because in dwarf and debug tables
the difference of two labels is used and in that case the lower order
bits subtract each other out.

To fix this, I have added to mcstreamer the notion of a debuglabel.
The default is for label and debug label to be the same. So calling
EmitLabel and EmitDebugLabel produce the same result.

For various reasons, there is only one set of labels that needs to be
modified for the mips exceptions to work. These are the "$eh_func_beginXXX" 
labels.

Mips overrides the debug label suffix from ":" to "=." .

This initial patch fixes exceptions. More changes most likely
will be needed to DwarfCFException to make all of this work
for actual debugging. These changes will be to emit debug labels in some
places where a simple label is emitted now.

Some historical discussion on this from gcc can be found at:
http://gcc.gnu.org/ml/gcc-patches/2008-08/msg00623.html
http://gcc.gnu.org/ml/gcc-patches/2008-11/msg01273.html 



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170279 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-16 04:00:45 +00:00