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8507b6e797
Implement the relaxation of MIPS16 PC-relative synthetic LA, DLA, LW and LD instructions to an equivalent sequence of instructions produced where the address operand requested is out of range, absolute or requires linker relocation, for ABIs that use 32-bit addressing and non-PIC code. The sequence generated uses the register specified for the destination operand as a temporary and begins with LI to load the high 16-bit part of the address, then continues with SLL by 16 bits to move that part into place and finally completes with a suitable operation corresponding to the synthetic instruction used, one of: 2-argument ADDIU, 2-argument DADDIU, absolute LW, and absolute LD respectively, providing the low 16-bit part of the address. All instructions use the extended encoding. As a special exception accept absolute addresses for relaxation even in PIC code. For example: la $2, 0x12345678 produces code as: li $2, 0x1234 sll $2, $2, 16 addiu $2, 0x5678 would. Where linker relocation is required emit an R_MIPS16_HI16 relocation on the initial LI instruction and an R_MIPS16_LO16 relocation on the final operation. For example (where `foo' is not local): lw $3, foo produces code as: li $3, %hi(foo) sll $3, $3, 16 lw $3, %lo(foo)($3) would. Emit assembly warnings as appropriate where this new relaxation triggers in the `nomacro' mode or for an instruction manually placed in a branch delay slot in the `noreorder' mode. Refrain from relaxation where an explicit instruction size suffix has been used and in the `noautoextend' mode. gas/ * config/tc-mips.c (RELAX_MIPS16_ENCODE): Add `pic', `sym32' and `nomacro' flags. (RELAX_MIPS16_PIC, RELAX_MIPS16_SYM32, RELAX_MIPS16_NOMACRO): New macros. (RELAX_MIPS16_USER_SMALL, RELAX_MIPS16_USER_EXT) (RELAX_MIPS16_DSLOT, RELAX_MIPS16_JAL_DSLOT) (RELAX_MIPS16_EXTENDED, RELAX_MIPS16_MARK_EXTENDED) (RELAX_MIPS16_CLEAR_EXTENDED, RELAX_MIPS16_ALWAYS_EXTENDED) (RELAX_MIPS16_MARK_ALWAYS_EXTENDED) (RELAX_MIPS16_CLEAR_ALWAYS_EXTENDED): Shift bits. (RELAX_MIPS16_MACRO, RELAX_MIPS16_MARK_MACRO) (RELAX_MIPS16_CLEAR_MACRO): New macros. (append_insn): Pass `mips_pic', HAVE_32BIT_SYMBOLS and `mips_opts.warn_about_macros' settings to RELAX_MIPS16_ENCODE. (mips16_macro_frag): New function. (md_estimate_size_before_relax): Handle HI16/LO16 relaxation. (mips_relax_frag): Likewise. (md_convert_frag): Likewise. * testsuite/gas/mips/mips16@relax-swap3.d: Remove error output, add dump patterns. * testsuite/gas/mips/mips16e@relax-swap3.d: New test subarchitecture. * testsuite/gas/mips/micromips@relax-swap3.d: Remove trailing NOP padding. * testsuite/gas/mips/mips16-pcrel-reloc-2.d: Remove error output, add dump patterns. * testsuite/gas/mips/mips16-pcrel-reloc-3.d: Remove error output, add dump patterns. * testsuite/gas/mips/mips16-pcrel-reloc-6.d: Remove error output, add dump patterns. * testsuite/gas/mips/mips16-pcrel-reloc-7.d: Remove error output, add dump patterns. * testsuite/gas/mips/mips16-pcrel-addend-2.d: Remove error output, add dump patterns. * testsuite/gas/mips/mips16-pcrel-addend-3.d: Remove error output, add dump patterns. * testsuite/gas/mips/mips16-pcrel-absolute.d: Remove error output, add dump patterns. * testsuite/gas/mips/mips16-pcrel-absolute-1.d: Remove error output, add dump patterns. * testsuite/gas/mips/mips16@relax-swap3.l: Remove file. * testsuite/gas/mips/mips16-pcrel-reloc-2.l: Remove file. * testsuite/gas/mips/mips16-pcrel-reloc-3.l: Remove file. * testsuite/gas/mips/mips16-pcrel-reloc-6.l: Remove file. * testsuite/gas/mips/mips16-pcrel-reloc-7.l: Remove file. * testsuite/gas/mips/mips16-pcrel-addend-2.l: Remove file. * testsuite/gas/mips/mips16-pcrel-addend-3.l: Remove file. * testsuite/gas/mips/mips16-pcrel-absolute.l: Remove file. * testsuite/gas/mips/mips16-pcrel-absolute-1.l: Remove file. * testsuite/gas/mips/relax-swap3.s: Adjust trailing padding. * testsuite/gas/mips/mips16-pcrel-0.d: New test. * testsuite/gas/mips/mips16-pcrel-1.d: New test. * testsuite/gas/mips/mips16-pcrel-2.d: New test. * testsuite/gas/mips/mips16-pcrel-3.d: New test. * testsuite/gas/mips/mips16-pcrel-4.d: New test. * testsuite/gas/mips/mips16-pcrel-5.d: New test. * testsuite/gas/mips/mips16-pcrel-pic-0.d: New test. * testsuite/gas/mips/mips16-pcrel-pic-1.d: New test. * testsuite/gas/mips/mips16-pcrel-n32-0.d: New test. * testsuite/gas/mips/mips16-pcrel-n32-1.d: New test. * testsuite/gas/mips/mips16-pcrel-n64-sym32-0.d: New test. * testsuite/gas/mips/mips16-pcrel-n64-sym32-1.d: New test. * testsuite/gas/mips/mips16-pcrel-n64-0.d: New test. * testsuite/gas/mips/mips16-pcrel-n64-1.d: New test. * testsuite/gas/mips/mips16-pcrel-delay-0.d: New test. * testsuite/gas/mips/mips16-pcrel-delay-1.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-4.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-5.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-6.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-7.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-8.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-9.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-pic-8.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-pic-9.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-n32-8.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-n32-9.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-n64-sym32-8.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-n64-sym32-9.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-n64-8.d: New test. * testsuite/gas/mips/mips16-pcrel-addend-n64-9.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-2.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-3.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-4.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-5.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-6.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-7.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-pic-4.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-pic-6.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-n32-4.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-n32-6.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-n64-4.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-n64-6.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-n64-sym32-4.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-n64-sym32-6.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-pic-n32-4.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-pic-n32-6.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-pic-n64-4.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-pic-n64-6.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-pic-n64-sym32-4.d: New test. * testsuite/gas/mips/mips16-pcrel-absolute-pic-n64-sym32-6.d: New test. * testsuite/gas/mips/mips16-pcrel-0.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-1.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-2.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-3.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-4.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-5.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-delay-0.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-delay-1.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-addend-8.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-addend-9.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-absolute-4.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-absolute-6.l: New stderr output. * testsuite/gas/mips/mips16-pcrel-0.s: New test source. * testsuite/gas/mips/mips16-pcrel-1.s: New test source. * testsuite/gas/mips/mips16-pcrel-2.s: New test source. * testsuite/gas/mips/mips16-pcrel-3.s: New test source. * testsuite/gas/mips/mips16-pcrel-4.s: New test source. * testsuite/gas/mips/mips16-pcrel-5.s: New test source. * testsuite/gas/mips/mips16-pcrel-delay-0.s: New test source. * testsuite/gas/mips/mips16-pcrel-delay-1.s: New test source. * testsuite/gas/mips/mips16-pcrel-addend-4.s: New test source. * testsuite/gas/mips/mips16-pcrel-addend-5.s: New test source. * testsuite/gas/mips/mips16-pcrel-addend-6.s: New test source. * testsuite/gas/mips/mips16-pcrel-addend-7.s: New test source. * testsuite/gas/mips/mips16-pcrel-addend-8.s: New test source. * testsuite/gas/mips/mips16-pcrel-addend-9.s: New test source. * testsuite/gas/mips/mips16-pcrel-absolute-2.s: New test. * testsuite/gas/mips/mips16-pcrel-absolute-3.s: New test. * testsuite/gas/mips/mips16-pcrel-absolute-4.s: New test. * testsuite/gas/mips/mips16-pcrel-absolute-5.s: New test. * testsuite/gas/mips/mips16-pcrel-absolute-6.s: New test. * testsuite/gas/mips/mips16-pcrel-absolute-7.s: New test. * testsuite/gas/mips/mips.exp: Run the new tests. ld/ * testsuite/ld-mips-elf/mips16-pcrel-0.d: New test. * testsuite/ld-mips-elf/mips16-pcrel-1.d: New test. * testsuite/ld-mips-elf/mips16-pcrel-addend-2.d: New test. * testsuite/ld-mips-elf/mips16-pcrel-addend-6.d: New test. * testsuite/ld-mips-elf/mips16-pcrel-n32-0.d: New test. * testsuite/ld-mips-elf/mips16-pcrel-n32-1.d: New test. * testsuite/ld-mips-elf/mips16-pcrel-n64-sym32-0.d: New test. * testsuite/ld-mips-elf/mips16-pcrel-n64-sym32-1.d: New test. * testsuite/ld-mips-elf/mips-elf.exp: Run the new tests. |
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.. | ||
emulparams | ||
emultempl | ||
po | ||
scripttempl | ||
testsuite | ||
.gitignore | ||
aclocal.m4 | ||
ChangeLog | ||
ChangeLog-0001 | ||
ChangeLog-0203 | ||
ChangeLog-2004 | ||
ChangeLog-2005 | ||
ChangeLog-2006 | ||
ChangeLog-2007 | ||
ChangeLog-2008 | ||
ChangeLog-2009 | ||
ChangeLog-2010 | ||
ChangeLog-2011 | ||
ChangeLog-2012 | ||
ChangeLog-2013 | ||
ChangeLog-2014 | ||
ChangeLog-2015 | ||
ChangeLog-2016 | ||
ChangeLog-9197 | ||
ChangeLog-9899 | ||
config.in | ||
configure | ||
configure.ac | ||
configure.host | ||
configure.tgt | ||
deffile.h | ||
deffilep.y | ||
dep-in.sed | ||
elf-hints-local.h | ||
fdl.texi | ||
gen-doc.texi | ||
genscrba.sh | ||
genscripts.sh | ||
h8-doc.texi | ||
ld.h | ||
ld.texinfo | ||
ldbuildid.c | ||
ldbuildid.h | ||
ldcref.c | ||
ldctor.c | ||
ldctor.h | ||
ldemul.c | ||
ldemul.h | ||
ldexp.c | ||
ldexp.h | ||
ldfile.c | ||
ldfile.h | ||
ldgram.y | ||
ldint.texinfo | ||
ldlang.c | ||
ldlang.h | ||
ldlex-wrapper.c | ||
ldlex.h | ||
ldlex.l | ||
ldmain.c | ||
ldmain.h | ||
ldmisc.c | ||
ldmisc.h | ||
ldver.c | ||
ldver.h | ||
ldwrite.c | ||
ldwrite.h | ||
lexsup.c | ||
MAINTAINERS | ||
Makefile.am | ||
Makefile.in | ||
mri.c | ||
mri.h | ||
NEWS | ||
pe-dll.c | ||
pe-dll.h | ||
pep-dll.c | ||
pep-dll.h | ||
plugin.c | ||
plugin.h | ||
README | ||
stamp-h.in | ||
sysdep.h | ||
testplug2.c | ||
testplug3.c | ||
testplug4.c | ||
testplug.c | ||
TODO |
README for LD
This is the GNU linker. It is distributed with other "binary
utilities" which should be in ../binutils. See ../binutils/README for
more general notes, including where to send bug reports.
There are many features of the linker:
* The linker uses a Binary File Descriptor library (../bfd)
that it uses to read and write object files. This helps
insulate the linker itself from the format of object files.
* The linker supports a number of different object file
formats. It can even handle multiple formats at once:
Read two input formats and write a third.
* The linker can be configured for cross-linking.
* The linker supports a control language.
* There is a user manual (ld.texinfo), as well as the
beginnings of an internals manual (ldint.texinfo).
Installation
============
See ../binutils/README.
If you want to make a cross-linker, you may want to specify
a different search path of -lfoo libraries than the default.
You can do this by setting the LIB_PATH variable in ./Makefile
or using the --with-lib-path configure switch.
To build just the linker, make the target all-ld from the top level
directory (one directory above this one).
Porting to a new target
=======================
See the ldint.texinfo manual.
Reporting bugs etc
===========================
See ../binutils/README.
Known problems
==============
The Solaris linker normally exports all dynamic symbols from an
executable. The GNU linker does not do this by default. This is
because the GNU linker tries to present the same interface for all
similar targets (in this case, all native ELF targets). This does not
matter for normal programs, but it can make a difference for programs
which try to dlopen an executable, such as PERL or Tcl. You can make
the GNU linker export all dynamic symbols with the -E or
--export-dynamic command line option.
HP/UX 9.01 has a shell bug that causes the linker scripts to be
generated incorrectly. The symptom of this appears to be "fatal error
- scanner input buffer overflow" error messages. There are various
workarounds to this:
* Build and install bash, and build with "make SHELL=bash".
* Update to a version of HP/UX with a working shell (e.g., 9.05).
* Replace "(. ${srcdir}/scripttempl/${SCRIPT_NAME}.sc)" in
genscripts.sh with "sh ${srcdir}..." (no parens) and make sure the
emulparams script used exports any shell variables it sets.
Copyright (C) 2012-2017 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.