From d022bddd4fd93428a7fa3cc7ad404c912ed20dbf 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. --- 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 diff --git a/gas/ChangeLog b/gas/ChangeLog index b7926f45aa0..2a584fd2d00 100644 --- a/gas/ChangeLog +++ b/gas/ChangeLog @@ -1,3 +1,13 @@ +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. + 2014-08-01 Takashi Yoshii PR 10378 diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c index c61d22b03a3..ab5a319d04e 100644 --- a/gas/config/tc-i386.c +++ b/gas/config/tc-i386.c @@ -543,6 +543,10 @@ 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, @@ -6938,6 +6942,15 @@ 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) @@ -9532,6 +9545,7 @@ const char *md_shortopts = "qn"; #define OPTION_MEVEXLIG (OPTION_MD_BASE + 16) #define OPTION_MEVEXWIG (OPTION_MD_BASE + 17) #define OPTION_MBIG_OBJ (OPTION_MD_BASE + 18) +#define OPTION_omit_lock_prefix (OPTION_MD_BASE + 19) struct option md_longopts[] = { @@ -9561,6 +9575,7 @@ struct option md_longopts[] = # if defined (TE_PE) || defined (TE_PEP) {"mbig-obj", no_argument, NULL, OPTION_MBIG_OBJ}, #endif + {"momit-lock-prefix", required_argument, NULL, OPTION_omit_lock_prefix}, {NULL, no_argument, NULL, 0} }; size_t md_longopts_size = sizeof (md_longopts); @@ -9848,6 +9863,15 @@ md_parse_option (int c, char *arg) break; #endif + 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; } @@ -10004,6 +10028,9 @@ md_show_usage (FILE *stream) fprintf (stream, _("\ -mbig-obj generate big object files\n")); #endif + fprintf (stream, _("\ + -momit-lock-prefix=[no|yes]\n\ + strip all lock prefixes\n")); } #if ((defined (OBJ_MAYBE_COFF) && defined (OBJ_MAYBE_AOUT)) \ diff --git a/gas/doc/c-i386.texi b/gas/doc/c-i386.texi index c1631c2ecf2..0c2e134ddfb 100644 --- a/gas/doc/c-i386.texi +++ b/gas/doc/c-i386.texi @@ -291,6 +291,18 @@ if such prefix was not explicitly specified in the source code. On x86-64 PE/COFF target this option forces the use of big object file format, which allows more than 32768 sections. +@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 diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog index acb0ac2b98a..44e3c3435f2 100644 --- a/gas/testsuite/ChangeLog +++ b/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. + 2014-07-29 Matthew Fortune * gas/mips/attr-gnu-4-0.d: New. diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp index 01de5d9d034..680d28cf4f6 100644 --- a/gas/testsuite/gas/i386/i386.exp +++ b/gas/testsuite/gas/i386/i386.exp @@ -301,6 +301,8 @@ if [expr ([istarget "i*86-*-*"] || [istarget "x86_64-*-*"]) && [gas_32_check]] run_dump_test "avx512dq" run_dump_test "avx512dq_vl-intel" run_dump_test "avx512dq_vl" + run_dump_test "omit-lock-yes" + run_dump_test "omit-lock-no" run_dump_test "disassem" # These tests require support for 8 and 16 bit relocs, diff --git a/gas/testsuite/gas/i386/omit-lock-no.d b/gas/testsuite/gas/i386/omit-lock-no.d new file mode 100644 index 00000000000..87f796f3a89 --- /dev/null +++ b/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 diff --git a/gas/testsuite/gas/i386/omit-lock-yes.d b/gas/testsuite/gas/i386/omit-lock-yes.d new file mode 100644 index 00000000000..67f0ef196ed --- /dev/null +++ b/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 diff --git a/gas/testsuite/gas/i386/omit-lock.s b/gas/testsuite/gas/i386/omit-lock.s new file mode 100644 index 00000000000..b267ebe264a --- /dev/null +++ b/gas/testsuite/gas/i386/omit-lock.s @@ -0,0 +1,6 @@ + .code32 +.globl main + .type main, @function +main: + lock + lock addl $0x1,(%eax) -- 2.30.2