This should allow the list of relocations for a particular
architecture to be kept in a single header rather than duplicated
whenever we need to enumerate all the relocations.
Patch by Will Newton.
llvm-svn: 222565
Summary:
Large-model was added first. With the addition of support for multiple PIC
models in LLVM, now add small-model PIC for 32-bit PowerPC, SysV4 ABI. This
generates more optimal code, for shared libraries with less than about 16380
data objects.
Test Plan: Test cases added or updated
Reviewers: joerg, hfinkel
Reviewed By: hfinkel
Subscribers: jholewinski, mcrosier, emaste, llvm-commits
Differential Revision: http://reviews.llvm.org/D5399
llvm-svn: 221791
A second binutils feature needed to support ELFv2 is the .localentry
directive. In the ELFv2 ABI, functions may have two entry points:
one for calling the routine locally via "bl", and one for calling the
function via function pointer (either at the source level, or implicitly
via a PLT stub for global calls). The two entry points share a single
ELF symbol, where the ELF symbol address identifies the global entry
point address, while the local entry point is found by adding a delta
offset to the symbol address. That offset is encoded into three
platform-specific bits of the ELF symbol st_other field.
The .localentry directive instructs the assembler to set those fields
to encode a particular offset. This is typically used by a function
prologue sequence like this:
func:
addis r2, r12, (.TOC.-func)@ha
addi r2, r2, (.TOC.-func)@l
.localentry func, .-func
Note that according to the ABI, when calling the global entry point,
r12 must be set to point the global entry point address itself; while
when calling the local entry point, r2 must be set to point to the TOC
base. The two instructions between the global and local entry point in
the above example translate the first requirement into the second.
This patch implements support in the PowerPC MC streamers to emit the
.localentry directive (both into assembler and ELF object output), as
well as support in the assembler parser to parse that directive.
In addition, there is another change required in MC fixup/relocation
handling to properly deal with relocations targeting function symbols
with two entry points: When the target function is known local, the MC
layer would immediately handle the fixup by inserting the target
address -- this is wrong, since the call may need to go to the local
entry point instead. The GNU assembler handles this case by *not*
directly resolving fixups targeting functions with two entry points,
but always emits the relocation and relies on the linker to handle
this case correctly. This patch changes LLVM MC to do the same (this
is done via the processFixupValue routine).
Similarly, there are cases where the assembler would normally emit a
relocation, but "simplify" it to a relocation targeting a *section*
instead of the actual symbol. For the same reason as above, this
may be wrong when the target symbol has two entry points. The GNU
assembler again handles this case by not performing this simplification
in that case, but leaving the relocation targeting the full symbol,
which is then resolved by the linker. This patch changes LLVM MC
to do the same (via the needsRelocateWithSymbol routine).
NOTE: The method used in this patch is overly pessimistic, since the
needsRelocateWithSymbol routine currently does not have access to the
actual target symbol, and thus must always assume that it might have
two entry points. This will be improved upon by a follow-on patch
that modifies common code to pass the target symbol when calling
needsRelocateWithSymbol.
Reviewed by Hal Finkel.
llvm-svn: 213485
ELFv2 binaries are marked by a bit in the ELF header e_flags field.
A new assembler directive .abiversion can be used to set that flag.
This patch implements support in the PowerPC MC streamers to emit the
.abiversion directive (both into assembler and ELF binary output),
as well as support in the assembler parser to parse the .abiversion
directive.
Reviewed by Hal Finkel.
llvm-svn: 213484
This adds initial support for PPC32 ELF PIC (Position Independent Code; the
-fPIC variety), thus rectifying a long-standing deficiency in the PowerPC
backend.
Patch by Justin Hibbits!
llvm-svn: 213427
This is so that EF_MIPS_NAN2008 is set if we are using IEEE 754-2008
NaN encoding (-mnan=2008). This patch also adds support for parsing
'.nan legacy' and '.nan 2008' assembly directives. The handling of
these directives should match GAS' behaviour i.e., the last directive
in use sets the ELF header bit (EF_MIPS_NAN2008).
Differential Revision: http://reviews.llvm.org/D3346
llvm-svn: 206396
Unlike my previous commit, don't try to remove the corresponding VK_Mips_GOT yet
even though it shares the same assembly text since that is used.
llvm-svn: 205196
These were:
* noreorder handling on the target object streamer and asm parser.
* setting the initial flag bits based on the enabled features.
* setting the elf header flag for micromips
It is *really* depressing I am the one doing this instead of someone at
mips actually taking the time to understand the infrastructure.
llvm-svn: 200138
The underlying type of all plain enums in MSVC is 'int', even if the
enumerator contains large 32-bit unsigned values or values greater than
UINT_MAX. The only way to get a large or unsigned enum type is to
request it explicitly with the C++11 strong enum types feature.
However, since LLVM isn't C++11 yet, I had to add a conditional
LLVM_ENUM_INT_TYPE to Compiler.h to control its usage.
The motivating true positive for this change is compiling PointerIntPair
with MSVC for win64. The PointerIntMask value is supposed to be pointer
sized value of all ones with some low zeros. Instead, it's truncated to
32-bits! We are only saved later because it is sign extended back in
the AND with int64_t, and we happen to want all ones.
This silences lots of -Wmicrosoft warnings during a clang self-host
targeting Windows.
llvm-svn: 191241
Similar to ARM change r182800, dynamic linker will read bits/addends from
the original object rather than from the object that might have been patched
previously. For the purpose of relocations for MCJIT stubs on MIPS, we
internally use otherwise unused MIPS relocations.
The change also enables MCJIT unit tests for MIPS (EL/BE), and the following
two tests now pass:
- MCJITTest.return_global and
- MCJITTest.multiple_functions.
These issues have been tracked as Bug 16250.
Patch by Petar Jovanovic.
llvm-svn: 187019
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.
llvm-svn: 185394
The GNU assembler supports (as extension to the ABI) use of PC-relative
relocations in half16 fields, which allows writing code like:
li 1, base-.
This patch adds support for those relocation types in the assembler.
llvm-svn: 184552
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.
llvm-svn: 184551
All R_PPC_... relocs should also be present (using the same number)
under the corresponding R_PPC64_... name. The latter were missing
for a couple of cases, which this patch adds.
This is not a big problem when emitting the reloc, because we can
just use the R_PPC_... define instead. But it is a problem when
*dumping* relocations e.g. using llvm-readobj, because this will
expect only R_PPC64_... values when inspecting a ppc64 ELF file.
llvm-svn: 181451
