From ee57d586166f36f4a6bddaa2305fd66a7752f967 Mon Sep 17 00:00:00 2001 From: Ilya Tocar Date: Fri, 1 Aug 2014 17:58:32 +0400 Subject: [PATCH] Add -momit_lock_prefix=[no|yes] option This option serves as a workaround for processors, which fail on lock prefix. gas/ * config/tc-i386.c (omit_lock_prefix): New. (output_insn): Omit lock prefix if omit_lock_prefix is true. (OPTION_omit_lock_prefix): New. (md_longopts): Add momit-lock-prefix. (md_parse_option): Handle momit-lock-prefix. (md_show_usage): Add momit-lock-prefix=[no|yes]. * doc/c-i386.texi (momit-lock-prefix): Document. gas/testsuite/ * gas/i386/i386.exp: Run new tests. * gas/i386/omit-lock-no.d: New. * gas/i386/omit-lock-yes.d: Ditto. * gas/i386/omit-lock.s: Ditto. Cherry-pick from git://sourceware.org/git/binutils-gdb.git rev d022bddd4fd93428a7fa3cc7ad404c912ed20dbf into binutils v2.24 Upstream-Status: [Accepted] Signed-off-by: Ong Boon Leong Signed-off-by: Saul Wold --- gas/ChangeLog | 10 ++++++++++ gas/config/tc-i386.c | 27 +++++++++++++++++++++++++++ gas/doc/c-i386.texi | 12 ++++++++++++ gas/testsuite/ChangeLog | 7 +++++++ gas/testsuite/gas/i386/i386.exp | 2 ++ gas/testsuite/gas/i386/omit-lock-no.d | 12 ++++++++++++ gas/testsuite/gas/i386/omit-lock-yes.d | 12 ++++++++++++ gas/testsuite/gas/i386/omit-lock.s | 6 ++++++ 8 files changed, 88 insertions(+) create mode 100644 gas/testsuite/gas/i386/omit-lock-no.d create mode 100644 gas/testsuite/gas/i386/omit-lock-yes.d create mode 100644 gas/testsuite/gas/i386/omit-lock.s Index: binutils-2.24/gas/ChangeLog =================================================================== --- binutils-2.24.orig/gas/ChangeLog +++ binutils-2.24/gas/ChangeLog @@ -4,6 +4,17 @@ single-bit bitfields. (build_modrm_byte): Don't compare single-bit bitfields to "1". +2014-08-06 Ilya Tocar + + * config/tc-i386.c (omit_lock_prefix): New. + (output_insn): Omit lock prefix if omit_lock_prefix is true. + (OPTION_omit_lock_prefix): New. + (md_longopts): Add momit-lock-prefix. + (md_parse_option): Handle momit-lock-prefix. + (md_show_usage): Add momit-lock-prefix=[no|yes]. + * doc/c-i386.texi (momit-lock-prefix): Document. + + 2013-11-18 H.J. Lu * config/tc-i386.c (lex_got): Add a dummy "int bnd_prefix" Index: binutils-2.24/gas/config/tc-i386.c =================================================================== --- binutils-2.24.orig/gas/config/tc-i386.c +++ binutils-2.24/gas/config/tc-i386.c @@ -541,6 +541,10 @@ static int add_bnd_prefix = 0; /* 1 if pseudo index register, eiz/riz, is allowed . */ static int allow_index_reg = 0; +/* 1 if the assembler should ignore LOCK prefix, even if it was + specified explicitly. */ +static int omit_lock_prefix = 0; + static enum check_kind { check_none = 0, @@ -6910,6 +6914,15 @@ output_insn (void) unsigned int j; unsigned int prefix; + /* Some processors fail on LOCK prefix. This options makes + assembler ignore LOCK prefix and serves as a workaround. */ + if (omit_lock_prefix) + { + if (i.tm.base_opcode == LOCK_PREFIX_OPCODE) + return; + i.prefix[LOCK_PREFIX] = 0; + } + /* Since the VEX/EVEX prefix contains the implicit prefix, we don't need the explicit prefix. */ if (!i.tm.opcode_modifier.vex && !i.tm.opcode_modifier.evex) @@ -9483,6 +9496,7 @@ const char *md_shortopts = "qn"; #define OPTION_MADD_BND_PREFIX (OPTION_MD_BASE + 15) #define OPTION_MEVEXLIG (OPTION_MD_BASE + 16) #define OPTION_MEVEXWIG (OPTION_MD_BASE + 17) +#define OPTION_omit_lock_prefix (OPTION_MD_BASE + 18) struct option md_longopts[] = { @@ -9509,6 +9523,7 @@ struct option md_longopts[] = {"madd-bnd-prefix", no_argument, NULL, OPTION_MADD_BND_PREFIX}, {"mevexlig", required_argument, NULL, OPTION_MEVEXLIG}, {"mevexwig", required_argument, NULL, OPTION_MEVEXWIG}, + {"momit-lock-prefix", required_argument, NULL, OPTION_omit_lock_prefix}, {NULL, no_argument, NULL, 0} }; size_t md_longopts_size = sizeof (md_longopts); @@ -9790,6 +9805,15 @@ md_parse_option (int c, char *arg) as_fatal (_("invalid -mevexwig= option: `%s'"), arg); break; + case OPTION_omit_lock_prefix: + if (strcasecmp (arg, "yes") == 0) + omit_lock_prefix = 1; + else if (strcasecmp (arg, "no") == 0) + omit_lock_prefix = 0; + else + as_fatal (_("invalid -momit-lock-prefix= option: `%s'"), arg); + break; + default: return 0; } @@ -9942,6 +9966,9 @@ md_show_usage (FILE *stream) -mold-gcc support old (<= 2.8.1) versions of gcc\n")); fprintf (stream, _("\ -madd-bnd-prefix add BND prefix for all valid branches\n")); + fprintf (stream, _("\ + -momit-lock-prefix=[no|yes]\n\ + strip all lock prefixes\n")); } #if ((defined (OBJ_MAYBE_COFF) && defined (OBJ_MAYBE_AOUT)) \ Index: binutils-2.24/gas/doc/c-i386.texi =================================================================== --- binutils-2.24.orig/gas/doc/c-i386.texi +++ binutils-2.24/gas/doc/c-i386.texi @@ -282,6 +282,18 @@ The @code{.att_syntax} and @code{.intel_ This option forces the assembler to add BND prefix to all branches, even if such prefix was not explicitly specified in the source code. +@cindex @samp{-momit-lock-prefix=} option, i386 +@cindex @samp{-momit-lock-prefix=} option, x86-64 +@item -momit-lock-prefix=@var{no} +@itemx -momit-lock-prefix=@var{yes} +These options control how the assembler should encode lock prefix. +This option is intended as a workaround for processors, that fail on +lock prefix. This option can only be safely used with single-core, +single-thread computers +@option{-momit-lock-prefix=@var{yes}} will omit all lock prefixes. +@option{-momit-lock-prefix=@var{no}} will encode lock prefix as usual, +which is the default. + @end table @c man end Index: binutils-2.24/gas/testsuite/ChangeLog =================================================================== --- binutils-2.24.orig/gas/testsuite/ChangeLog +++ binutils-2.24/gas/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2014-08-06 Ilya Tocar + + * gas/i386/i386.exp: Run new tests. + * gas/i386/omit-lock-no.d: New. + * gas/i386/omit-lock-yes.d: Ditto. + * gas/i386/omit-lock.s: Ditto.+ + 2013-11-20 Yufeng Zhang * gas/aarch64/msr.s: Add tests. Index: binutils-2.24/gas/testsuite/gas/i386/i386.exp =================================================================== --- binutils-2.24.orig/gas/testsuite/gas/i386/i386.exp +++ binutils-2.24/gas/testsuite/gas/i386/i386.exp @@ -267,6 +267,8 @@ if [expr ([istarget "i*86-*-*"] || [ist run_list_test "mpx-inval-1" "-al" run_dump_test "mpx-add-bnd-prefix" run_dump_test "sha" + run_dump_test "omit-lock-yes" + run_dump_test "omit-lock-no" # These tests require support for 8 and 16 bit relocs, # so we only run them for ELF and COFF targets. Index: binutils-2.24/gas/testsuite/gas/i386/omit-lock-no.d =================================================================== --- /dev/null +++ binutils-2.24/gas/testsuite/gas/i386/omit-lock-no.d @@ -0,0 +1,12 @@ +#source: omit-lock.s +#as: -momit-lock-prefix=yes -momit-lock-prefix=no +#objdump: -dw +#name: i386 omit lock = no + +.*: +file format .*i386.* + +Disassembly of section .text: + +0+
: + 0: f0 f0 83 00 01 lock lock addl \$0x1,\(%eax\) +#pass Index: binutils-2.24/gas/testsuite/gas/i386/omit-lock-yes.d =================================================================== --- /dev/null +++ binutils-2.24/gas/testsuite/gas/i386/omit-lock-yes.d @@ -0,0 +1,12 @@ +#source: omit-lock.s +#as: -momit-lock-prefix=yes +#objdump: -dw +#name: i386 omit lock = yes + +.*: +file format .*i386.* + +Disassembly of section .text: + +0+
: + 0: 83 00 01 addl \$0x1,\(%eax\) +#pass Index: binutils-2.24/gas/testsuite/gas/i386/omit-lock.s =================================================================== --- /dev/null +++ binutils-2.24/gas/testsuite/gas/i386/omit-lock.s @@ -0,0 +1,6 @@ + .code32 +.globl main + .type main, @function +main: + lock + lock addl $0x1,(%eax)