On Thu, Feb 13, 2014 at 3:50 PM, Andrew Pinski <pins...@gmail.com> wrote: > On Thu, Feb 13, 2014 at 3:46 PM, Roland McGrath <mcgra...@google.com> wrote: >> Non-ancient assemblers support the "ud2" mnemonic, so there is no need >> to emit the literal opcode as data. >> >> OK for trunk and 4.8? > > I changed this to use .word due to openbsd3.1: > http://gcc.gnu.org/ml/gcc-patches/2005-07/msg01347.html . I no longer > have access to this older openbsd box so I don't object to this > change. In fact I doubt we support any binutils that are pre 2.0 any > more; so maybe move over unconditionally to ud.
Oh looking into this further, it looks like Sun's assembler does not support it either: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23359 Thanks, Andrew > > Thanks, > Andrew Pinski > >> >> >> Thanks, >> Roland >> >> >> gcc/ >> 2014-02-13 Roland McGrath <mcgra...@google.com> >> >> * configure.ac (HAVE_AS_IX86_UD2): New test for 'ud2' mnemonic. >> * configure: Regenerated. >> * config.in: Regenerated. >> * config/i386/i386.md (trap) [HAVE_AS_IX86_UD2]: Use the mnemonic >> instead of ASM_SHORT. >> >> --- a/gcc/config.in >> +++ b/gcc/config.in >> @@ -375,6 +375,12 @@ >> #endif >> >> >> +/* Define if your assembler supports the 'ud2' mnemonic. */ >> +#ifndef USED_FOR_TARGET >> +#undef HAVE_AS_IX86_UD2 >> +#endif >> + >> + >> /* Define if your assembler supports the lituse_jsrdirect relocation. */ >> #ifndef USED_FOR_TARGET >> #undef HAVE_AS_JSRDIRECT_RELOCS >> --- a/gcc/config/i386/i386.md >> +++ b/gcc/config/i386/i386.md >> @@ -17843,7 +17843,13 @@ >> (define_insn "trap" >> [(trap_if (const_int 1) (const_int 6))] >> "" >> - { return ASM_SHORT "0x0b0f"; } >> +{ >> +#ifdef HAVE_AS_IX86_UD2 >> + return "ud2"; >> +#else >> + return ASM_SHORT "0x0b0f"; >> +#endif >> +} >> [(set_attr "length" "2")]) >> >> (define_expand "prefetch" >> --- a/gcc/configure >> +++ b/gcc/configure >> @@ -25109,6 +25109,37 @@ $as_echo "#define >> HAVE_AS_IX86_REP_LOCK_PREFIX 1" >>confdefs.h >> >> fi >> >> + { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for >> ud2 mnemonic" >&5 >> +$as_echo_n "checking assembler for ud2 mnemonic... " >&6; } >> +if test "${gcc_cv_as_ix86_ud2+set}" = set; then : >> + $as_echo_n "(cached) " >&6 >> +else >> + gcc_cv_as_ix86_ud2=no >> + if test x$gcc_cv_as != x; then >> + $as_echo 'ud2' > conftest.s >> + if { ac_try='$gcc_cv_as $gcc_cv_as_flags -o conftest.o conftest.s >&5' >> + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 >> + (eval $ac_try) 2>&5 >> + ac_status=$? >> + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 >> + test $ac_status = 0; }; } >> + then >> + gcc_cv_as_ix86_ud2=yes >> + else >> + echo "configure: failed program was" >&5 >> + cat conftest.s >&5 >> + fi >> + rm -f conftest.o conftest.s >> + fi >> +fi >> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_ix86_ud2" >&5 >> +$as_echo "$gcc_cv_as_ix86_ud2" >&6; } >> +if test $gcc_cv_as_ix86_ud2 = yes; then >> + >> +$as_echo "#define HAVE_AS_IX86_UD2 1" >>confdefs.h >> + >> +fi >> + >> { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for >> R_386_TLS_GD_PLT reloc" >&5 >> $as_echo_n "checking assembler for R_386_TLS_GD_PLT reloc... " >&6; } >> if test "${gcc_cv_as_ix86_tlsgdplt+set}" = set; then : >> --- a/gcc/configure.ac >> +++ b/gcc/configure.ac >> @@ -3895,6 +3895,12 @@ foo: nop >> [AC_DEFINE(HAVE_AS_IX86_REP_LOCK_PREFIX, 1, >> [Define if the assembler supports 'rep <insn>, lock <insn>'.])]) >> >> + gcc_GAS_CHECK_FEATURE([ud2 mnemonic], >> + gcc_cv_as_ix86_ud2,,, >> + [ud2],, >> + [AC_DEFINE(HAVE_AS_IX86_UD2, 1, >> + [Define if your assembler supports the 'ud2' mnemonic.])]) >> + >> gcc_GAS_CHECK_FEATURE([R_386_TLS_GD_PLT reloc], >> gcc_cv_as_ix86_tlsgdplt,,, >> [call tls_gd@tlsgdplt],