AMD64 spec and Intel64 spec differ in direct unconditional branches in
64-bit mode. AMD64 supports direct unconditional branches with 16-bit
offset via the data size prefix, which truncates RIP to 16 bits, while
the data size prefix is ignored by Intel64.
This patch adds -mamd64/-mintel64 option to x86-64 assembler and
-Mamd64/-Mintel64 option to x86-64 disassembler. The most permissive
ISA, which is AMD64, is the default.
GDB can add an option, similar to
(gdb) help set disassembly-flavor
Set the disassembly flavor.
The valid values are "att" and "intel", and the default value is "att".
to select which ISA to disassemble.
binutils/
PR binutis/18386
* doc/binutils.texi: Document -Mamd64 and -Mintel64.
gas/
PR binutis/18386
* config/tc-i386.c (OPTION_MAMD64): New.
(OPTION_MINTEL64): Likewise.
(md_longopts): Add -mamd64 and -mintel64.
(md_parse_option): Handle OPTION_MAMD64 and OPTION_MINTEL64.
(md_show_usage): Add -mamd64 and -mintel64.
* doc/c-i386.texi: Document -mamd64 and -mintel64.
gas/testsuite/
PR binutis/18386
* gas/i386/i386.exp: Run x86-64-branch-2 and x86-64-branch-3.
* gas/i386/x86-64-branch.d: Also pass -Mintel64 to objdump.
* gas/i386/ilp32/x86-64-branch.d: Likewise.
* gas/i386/x86-64-branch-2.d: New file.
* gas/i386/x86-64-branch-2.s: Likewise.
* gas/i386/x86-64-branch-3.l: Likewise.
* gas/i386/x86-64-branch-3.s: Likewise.
ld/testsuite/
PR binutis/18386
* ld-x86-64/tlsgdesc.dd: Also pass -Mintel64 to objdump.
* ld-x86-64/tlspic.dd: Likewise.
* ld-x86-64/x86-64.exp (x86_64tests): Also pass -Mintel64 to
objdump for tlspic.dd and tlsgdesc.dd.
opcodes/
PR binutis/18386
* i386-dis.c: Add comments for '@'.
(x86_64_table): Use '@' on call/jmp for X86_64_E8/X86_64_E9.
(enum x86_64_isa): New.
(isa64): Likewise.
(print_i386_disassembler_options): Add amd64 and intel64.
(print_insn): Handle amd64 and intel64.
(putop): Handle '@'.
(OP_J): Don't ignore the operand size prefix for AMD64 in 64-bit.
* i386-gen.c (cpu_flags): Add CpuAMD64 and CpuIntel64.
* i386-opc.h (AMD64): New.
(CpuIntel64): Likewise.
(i386_cpu_flags): Add cpuamd64 and cpuintel64.
* i386-opc.tbl: Add direct call/jmp with Disp16|Disp32 for AMD64.
Mark direct call/jmp without Disp16|Disp32 as Intel64.
* i386-init.h: Regenerated.
* i386-tbl.h: Likewise.
This patch adds -mshared option to x86 ELF assembler. By default,
assembler will optimize out non-PLT relocations against defined non-weak
global branch targets with default visibility. The -mshared option tells
the assembler to generate code which may go into a shared library
where all non-weak global branch targets with default visibility can
be preempted. The resulting code is slightly bigger. This option
only affects the handling of branch instructions.
This Linux kernel patch is needed to create a working x86 Linux kernel if
it hasn't been applied:
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index ae6588b..b91a00c 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -339,8 +339,8 @@ early_idt_handlers:
i = i + 1
.endr
-/* This is global to keep gas from relaxing the jumps */
-ENTRY(early_idt_handler)
+/* This is weak to keep gas from relaxing the jumps */
+WEAK(early_idt_handler)
cld
cmpl $2,(%rsp) # X86_TRAP_NMI
--
gas/
* config/tc-i386.c (shared): New.
(OPTION_MSHARED): Likewise.
(elf_symbol_resolved_in_segment_p): Add relocation argument.
Check PLT relocations and shared.
(md_estimate_size_before_relax): Pass fragP->fr_var to
elf_symbol_resolved_in_segment_p.
(md_longopts): Add -mshared.
(md_show_usage): Likewise.
(md_parse_option): Handle OPTION_MSHARED.
* doc/c-i386.texi: Document -mshared.
gas/testsuite/
* gas/i386/i386.exp: Don't run pcrel for ELF targets. Run
pcrel-elf, relax-4 and x86-64-relax-3 for ELF targets.
* gas/i386/pcrel-elf.d: New file.
* gas/i386/relax-4.d: Likewise.
* gas/i386/x86-64-relax-3.d: Likewise.
* gas/i386/relax-3.d: Pass -mshared to assembler. Updated.
* gas/i386/x86-64-relax-2.d: Likewise.
* gas/i386/relax-3.s: Add test for PLT relocation.
On ELF target, the assembler normally generates code which can go into a
shared library where non-weak symbols can be preempted. The -mno-shared
option tells the assembler to generate code not for a shared library,
where non-weak symbols won't be preempted. The resulting code is slightly
smaller. This option mainly affects the handling of branch instructions.
gas/
* config/tc-i386.c (no_shared): New.
(OPTION_MNO_SHARED): Likewise.
(elf_symbol_resolved_in_segment_p): Check no_shared.
(md_longopts): Add mno-shared.
(md_parse_option): Handle OPTION_MNO_SHARED.
(md_show_usage): Add -mno-shared.
* doc/c-i386.texi: Document -mno-shared.
gas/testsuite/
* gas/i386/i386.exp: Run relax-4 and x86-64-relax-3.
* gas/i386/relax-4.d: New file.
* gas/i386/x86-64-relax-3.d: Likewise.
This patch silences texinfo 5.1 warnings by using @subsection and
sorting entries in Machine Dependencies menu.
* doc/as.texinfo (Bundle directives): Shorten menu entry and
use @subsection.
(CFI directives): Use @subsection.
(SH-Dependent, SH64-Dependent): Moved after SCORE-Dependent.
* doc/c-i386.texi (i386-Mnemonics): Use @subsection.
bfd/
* peicode.h (pe_ILF_object_p): Adjust, as the version number
has been read.
(pe_bfd_object_p): Also read version number to detect ILF.
* pe-x86_64.c (COFF_WITH_PE_BIGOBJ): Define.
(x86_64pe_bigobj_vec): Define
* coffcode.h (bfd_coff_backend_data): Add _bfd_coff_max_nscns field.
(bfd_coff_max_nscns): New macro.
(coff_compute_section_file_positions): Use unsigned int for
target_index. Compare with bfd_coff_max_nscns.
(bfd_coff_std_swap_table, ticoff0_swap_table, ticoff1_swap_table):
Set a value for _bfd_coff_max_nscns.
(header_bigobj_classid): New constant.
(coff_bigobj_swap_filehdr_in, coff_bigobj_swap_filehdr_out)
(coff_bigobj_swap_sym_in, coff_bigobj_swap_sym_out)
(coff_bigobj_swap_aux_in, coff_bigobj_swap_aux_out): New
functions.
(bigobj_swap_table): New table.
* libcoff.h: Regenerate.
* coff-sh.c (bfd_coff_small_swap_table): Likewise.
* coff-alpha.c (alpha_ecoff_backend_data): Add value for
_bfd_coff_max_nscns.
* coff-mips.c (mips_ecoff_backend_data): Likewise.
* coff-rs6000.c (bfd_xcoff_backend_data)
(bfd_pmac_xcoff_backend_data): Likewise.
* coff64-rs6000.c (bfd_xcoff_backend_data)
(bfd_xcoff_aix5_backend_data): Likewise.
* targets.c (x86_64pe_bigobj_vec): Declare.
* configure.in (x86_64pe_bigobj_vec): New vector.
* configure: Regenerate.
* config.bfd: Add bigobj object format for Windows targets.
gas/
* config/tc-i386.c (use_big_obj): Declare.
(OPTION_MBIG_OBJ): Define.
(md_longopts): Add -mbig-obj option.
(md_parse_option): Handle it.
(md_show_usage): Display help for this option.
(i386_target_format): Use bigobj for x86-64 if -mbig-obj.
* doc/c-i386.texi: Document the option.
gas/testsuite/
* gas/pe/big-obj.d, gas/pe/big-obj.s: Add test.
* gas/pe/pe.exp: Add test.
include/coff/
* pe.h (struct external_ANON_OBJECT_HEADER_BIGOBJ): Declare.
(FILHSZ_BIGOBJ): Define.
(struct external_SYMBOL_EX): Declare.
(SYMENT_BIGOBJ, SYMESZ_BIGOBJ): Define.
(union external_AUX_SYMBOL_EX): Declare.
(AUXENT_BIGOBJ, AUXESZ_BIGOBJ): Define.
* internal.h (struct internal_filehdr): Change type
of f_nscns.
2010-11-23 H.J. Lu <hongjiu.lu@intel.com>
* doc/as.texinfo: Refer to and include c-i386.texi for i386
options.
* doc/c-i386.texi: Add markup for use in manpage generation.
gas/
2010-10-14 H.J. Lu <hongjiu.lu@intel.com>
* config/tc-i386.c (_i386_insn): Add disp32_encoding.
(md_assemble): Don't call optimize_disp if disp32_encoding is
set.
(parse_insn): Support .d32 to force 32bit displacement.
(output_branch): Use BIG if disp32_encoding is set.
* doc/c-i386.texi: Document .d32 encoding suffix.
gas/testsuite/
2010-10-14 H.J. Lu <hongjiu.lu@intel.com>
* gas/i386/disp32.d: New.
* gas/i386/disp32.s: Likewise.
* gas/i386/x86-64-disp32.d: Likewise.
* gas/i386/x86-64-disp32.s: Likewise.
* gas/i386/i386.exp: Run disp32 and x86-64-disp32.