Peter Smith found while trying to support thunk creation for ARM that
LLD sometimes creates broken thunks for MIPS. The cause of the bug is
that we assign file offsets to input sections too early. We need to
create all sections and then assign section offsets because appending
thunks changes file offsets for all following sections.
This patch separates the pass to assign file offsets from thunk
creation pass. This effectively reverts r265673.
Differential Revision: http://reviews.llvm.org/D21598
llvm-svn: 273532
Previously, relocations for MIPS were scanned twice; once in regular
scanRelocs() and the other is in scanRelocsForThunks. In the former
function, we computed types of relocations and skipped R_THUNK relocations.
In the latter function, we computed the same value again and skipped
all but R_THUNK relocations. It was wasteful. This patch fixes that.
Now R_THUNK relocations are handled in the regular manner.
llvm-svn: 273346
There are two motivations for this patch. The first one is a preparation
for support MIPS TLS relocations. It might sound like a joke but for GOT
entries related to TLS relocations MIPS ABI uses almost regular approach
with creation of dynamic relocations for each GOT enty etc. But we need
to separate these 'regular' TLS related entries from MIPS specific local
and global parts of GOT. ABI declare simple solution - all TLS related
entries allocated at the end of GOT after local/global parts. The second
motivation it to support GOT relocations for non-preemptible symbols
with addends. If we have more than one GOT relocations against symbol S
with different addends we need to create GOT entries for each unique
Symbol/Addend pairs.
So we store all MIPS GOT entries in separate containers. For non-preemptible
symbols we have to maintain two data structures. The first one is MipsLocal
vector. Each entry corresponds to the GOT entry from the 'local' part
of the GOT contains the symbol's address plus addend. The second one
is MipsLocalMap. It is a map from Symbol/Addend pair to the GOT index.
Differential Revision: http://reviews.llvm.org/D21297
llvm-svn: 273127
I think it is me who named these variables, but I always find that
they are slightly confusing because align is a verb.
Adding four letters is worth it.
llvm-svn: 272984
In isPreemptible routine we interested in R_MIPS_GPREL16 relocation
only. This relocation fits 0xf. So the new mask 0xff is just to conform
the ABI specification.
llvm-svn: 272388
It was reported in PR28020, that lld does not link code which
gold do. But in fact that is expected behavior as we do not
support DT_TEXTREL.
This patch changes error message as it can report about relocations against
text segments exclusively, other dynamic relocations errors can
be handled separately.
Differential revision: http://reviews.llvm.org/D21133
llvm-svn: 272377
If the symbol is local we don't need to create a R_X86_64_DTPOFF64, we
can just write the correct value in the got.
Should fix pr28018.
llvm-svn: 272205
This is mostly extracted from http://reviews.llvm.org/D18960.
The general idea for tlsdesc is that the two GD got entries are used
for a function pointer and its argument. The dynamic linker sets
both. In the non-dlopen case the dynamic linker sets the function to
the identity and the argument to the offset in the tls block.
All that the static linker has to do in the non-dlopen case is
relocate the code to point to the got entries and create a dynamic
relocation.
The dlopen case is more complicated, but can be implemented in another patch.
llvm-svn: 271569
Patch implements next relaxation from latest ABI:
"Convert memory operand of test and binop into immediate operand, where binop is one of adc, add, and, cmp, or,
sbb, sub, xor instructions, when position-independent code is disabled."
It is described in System V Application Binary Interface AMD64 Architecture Processor
Supplement Draft Version 0.99.8 (https://github.com/hjl-tools/x86-psABI/wiki/x86-64-psABI-r249.pdf,
B.2 "B.2 Optimize GOTPCRELX Relocations").
Differential revision: http://reviews.llvm.org/D20793
llvm-svn: 271405
In case of MIPS, GP-relative relocations always resolve to a definition
in a regular input file, ignoring the one-definition rule. Such
relocations are used to setup GP relative offsets in a function's
prologue. So we, for example, should not attempt to create a dynamic
relocation even if the target symbol is preemptible.
Fixes bug 27880.
Differential Revision: http://reviews.llvm.org/D20664
llvm-svn: 271100
System V Application Binary Interface AMD64 Architecture Processor Supplement Draft Version 0.99.8
(https://github.com/hjl-tools/x86-psABI/wiki/x86-64-psABI-r249.pdf, B.2 "B.2 Optimize GOTPCRELX Relocations")
introduces possible relaxations for R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX.
That patch implements the next relaxation:
mov foo@GOTPCREL(%rip), %reg => lea foo(%rip), %reg
and also opens door for implementing all other ones.
Implementation was suggested by Rafael Ávila de Espíndola with few additions and testcases by myself.
Differential revision: http://reviews.llvm.org/D15779
llvm-svn: 270705
scanReloc and the functions on which scanReloc depends is in total
more than 600 lines of code. Since scanReloc does not depend on Writer,
it is better to move it into a separate file.
Differential Revision: http://reviews.llvm.org/D20554
llvm-svn: 270606
Rui Ueyama