We currently force symbols to be globals in .thumb_set. The intent
seems to be that given
.thumb_set foo, bar
we emit an undefined symbol to bar if it is never defined. The side
effect is that we mark bar as global, even if it is defined, which gas
does not.
Producing an undefined reference to bar is a general difference from MC and gas.
For example, given
a = b
gas will produce an undefined reference to b, MC will not. I would be surprised
if any code depends on this, but it it does, we should fix the general
difference, not special case .thumb_set.
llvm-svn: 207757
This patch centralizes the handling of the thumb bit around
MCStreamer::isThumbFunc and makes isThumbFunc handle aliases.
This fixes a corner case, but the main advantage is having just one
way to check if a MCSymbol is thumb or not. This should still be
refactored to be ARM only, but at least now it is just one predicate
that has to be refactored instead of 3 (isThumbFunc,
ELF_Other_ThumbFunc, and SF_ThumbFunc).
llvm-svn: 207522
Only the object streamers need to track if a symbol should be marked thumb or
not. This ports the ELF case. The COFF case is not ported since it is currently
not working for some other reason (I will report a bug).
llvm-svn: 207366
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
llvm-svn: 206906
This commit moves getSLEB128Size() and getULEB128Size() from
MCAsmInfo to LEB128.h and removes some copy-and-paste code.
Besides, this commit also adds some unit tests for the LEB128
functions.
llvm-svn: 201937
This patch fixes the ldr-pseudo implementation to work when used in
inline assembly. The fix is to move arm assembler constant pools
from the ARMAsmParser class to the ARMTargetStreamer class.
Previously we kept the assembler generated constant pools in the
ARMAsmParser object. This does not work for inline assembly because
a new parser object is created for each blob of inline assembly.
This patch moves the constant pools to the ARMTargetStreamer class
so that the constant pool will remain alive for the entire code
generation process.
An ARMTargetStreamer class is now required for the arm backend.
There was no existing implementation for MachO, only Asm and ELF.
Instead of creating an empty MachO subclass, we decided to make the
ARMTargetStreamer a non-abstract class and provide default
(llvm_unreachable) implementations for the non constant-pool related
methods.
Differential Revision: http://llvm-reviews.chandlerc.com/D2638
llvm-svn: 200777
The .object_arch directive indicates an alternative architecture to be specified
in the object file. The directive does *not* effect the enabled feature bits
for the object file generation. This is particularly useful when the code
performs runtime detection and would like to indicate a lower architecture as
the requirements than the actual instructions used.
llvm-svn: 200451
.movsp is an ARM unwinding directive that indicates to the unwinder that a
register contains an offset from the current stack pointer. If the offset is
unspecified, it defaults to zero.
llvm-svn: 200449
This enhances the ARMAsmParser to handle .tlsdescseq directives. This is a
slightly special relocation. We must be able to generate them, but not consume
them in assembly. The relocation is meant to assist the linker in generating a
TLS descriptor sequence. The ELF target streamer is enhanced to append
additional fixups into the current segment and that is used to emit the new
R_ARM_TLS_DESCSEQ relocations.
llvm-svn: 200448
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.
llvm-svn: 200129
There is no inline asm in a .s file. Therefore, there should be no logic to
handle it in the streamer. Inline asm only exists in bitcode files, so the
logic can live in the (long misnamed) AsmPrinter class.
llvm-svn: 200011
This patch restores the ARM mode if the user's inline assembly
does not. In the object streamer, it ensures that instructions
following the inline assembly are encoded correctly and that
correct mapping symbols are emitted. For the asm streamer, it
emits a .arm or .thumb directive.
This patch does not ensure that the inline assembly contains
the ADR instruction to switch modes at runtime.
The problem we need to solve is code like this:
int foo(int a, int b) {
int r = a + b;
asm volatile(
".align 2 \n"
".arm \n"
"add r0,r0,r0 \n"
: : "r"(r));
return r+1;
}
If we compile this function in thumb mode then the inline assembly
will switch to arm mode. We need to make sure that we switch back to
thumb mode after emitting the inline assembly or we will incorrectly
encode the instructions that follow (i.e. the assembly instructions
for return r+1).
Based on patch by David Peixotto
Change-Id: Ib57f6d2d78a22afad5de8693fba6230ff56ba48b
llvm-svn: 199818
This implements the unwind_raw directive for the ARM IAS. The unwind_raw
directive takes the form of a stack offset value followed by one or more bytes
representing the opcodes to be emitted. The opcode emitted will interpreted as
if it were assembled by the opcode assembler via the standard unwinding
directives.
Thanks to Logan Chien for an extra test!
llvm-svn: 199707
The .personalityindex directive is equivalent to the .personality directive with
the ARM EABI personality with the specific index (0, 1, 2). Both of these
directives indicate personality routines, so enhance the personality directive
handling to take into account personalityindex.
Bonus fix: flush the UnwindContext at the beginning of a new function.
Thanks to Logan Chien for additional tests!
llvm-svn: 199706
Ensure that the tag types are reflected on a replacement. This is particularly
important for the compatibility tag which has multiple representations where the
last definition wins.
llvm-svn: 199577
This moves the ARM build attributes definitions and support routines into the
Support library. The support routines simply permit the conversion of the value
to and from a string representation.
The movement is prompted in order to permit access to the constants and string
representations from readobj in order to facilitate decoding of the attributes
section.
llvm-svn: 199575
This will allow it to be called from target independent parts of the main
streamer that don't know if there is a registered target streamer or not. This
in turn will allow targets to perform extra actions at specified points in the
interface: add extra flags for some labels, extra work during finalization, etc.
llvm-svn: 199174
Parse tag names as well as expressions. The former is part of the
specification, the latter is for improved compatibility with the GNU assembler.
Fix attribute value handling to be comformant to the specification.
llvm-svn: 198662
Move the ARM EHABI unwind opcode definitions from the ARM MCTargetDesc into LLVM
Support. This enables sharing of the definitions across the ARM target code as
well as llvm-readobj. This will allow implementation of the unwind decoding in
llvm-readobj.
llvm-svn: 198576
This adds support for the .inst directive. This is an ARM specific directive to
indicate an instruction encoded as a constant expression. The major difference
between .word, .short, or .byte and .inst is that the latter will be
disassembled as an instruction since it does not get flagged as data.
llvm-svn: 197657
According to "Addenda to ABI for ARM architecture", Tag_FP_arch is the
new name for the equivalent Tag_VFP_arch. This commit renames
Tag_VFP_arch to Tag_FP_arch.
llvm-svn: 197587
This commit allows the ARM integrated assembler to parse
and assemble the code with .eabi_attribute, .cpu, and
.fpu directives.
To implement the feature, this commit moves the code from
AttrEmitter to ARMTargetStreamers, and several new test
cases related to cortex-m4, cortex-r5, and cortex-a15 are
added.
Besides, this commit also change the Subtarget->isFPOnlySP()
to Subtarget->hasD16() to match the usage of .fpu directive.
This commit changes the test cases:
* Several .eabi_attribute directives in
2010-09-29-mc-asm-header-test.ll are removed because the .fpu
directive already cover the functionality.
* In the Cortex-A15 test case, the value for
Tag_Advanced_SIMD_arch has be changed from 1 to 2,
which is more precise.
llvm-svn: 193524
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.
llvm-svn: 192181
When MC was first added, targets could use hasRawTextSupport to keep features
working before they were added to the MC interface.
The design goal of MC is to provide an uniform api for printing assembly and
object files. Short of relaxations and other corner cases, a object file is
just another representation of the assembly.
It was never the intention that targets would keep doing things like
if (hasRawTextSupport())
Set flags in one way.
else
Set flags in another way.
When they do that they create two code paths and the object file is no longer
just another representation of the assembly. This also then requires testing
with llc -filetype=obj, which is extremelly brittle.
This patch removes some of these hacks by replacing them with smaller ones.
The ARM flag setting is trivial, so I just moved it to the constructor. For
Mips, the patch adds two temporary hack directives that allow the assembly
to represent the same things as the object file was already able to.
The hope is that the mips developers will replace the hack directives with
the same ones that gas uses and drop the -print-hack-directives flag.
I will also try to implement a target streamer interface, so that we can
move this out of the common code.
In summary, for any new work, two rules of the thumb are
* Don't use "llc -filetype=obj" in tests.
* Don't add calls to hasRawTextSupport.
llvm-svn: 192035
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).
llvm-svn: 185436
According to ARM EHABI section 9.2, if the
__aeabi_unwind_cpp_pr1() or __aeabi_unwind_cpp_pr2() is
used, then the handler data must be emitted after the unwind
opcodes. The handler data consists of several words, and
should be terminated by zero.
In case that the .handlerdata directive is not specified by
the programmer, we should emit zero to terminate the handler
data.
llvm-svn: 185422
Changes to ARM unwind opcode assembler:
* Fix multiple .save or .vsave directives. Besides, the
order is preserved now.
* For the directives which will generate multiple opcodes,
such as ".save {r0-r11}", the order of the unwind opcode
is fixed now, i.e. the registers with less encoding value
are popped first.
* Fix the $sp offset calculation. Now, we can use the
.setfp, .pad, .save, and .vsave directives at any order.
Changes to test cases:
* Add test cases to check the order of multiple opcodes
for the .save directive.
* Fix the incorrect $sp offset in the test case. The
stack pointer offset specified in the test case was
incorrect. (Changed test cases: ehabi-mc-section.ll and
ehabi-mc.ll)
* The opcode to restore $sp are slightly reordered. The
behavior are not changed, and the new output is same
as the output of GNU as. (Changed test cases:
eh-directive-pad.s and eh-directive-setfp.s)
llvm-svn: 183627
This commit implements the AsmParser for fnstart, fnend,
cantunwind, personality, handlerdata, pad, setfp, save, and
vsave directives.
This commit fixes some minor issue in the ARMELFStreamer:
* The switch back to corresponding section after the .fnend
directive.
* Emit the unwind opcode while processing .fnend directive
if there is no .handlerdata directive.
* Emit the unwind opcode to .ARM.extab while processing
.handlerdata even if .personality directive does not exist.
llvm-svn: 181603
