diff options
Diffstat (limited to 'gas/config')
| -rw-r--r-- | gas/config/tc-i386.c | 280 | ||||
| -rw-r--r-- | gas/config/tc-i386.h | 21 |
2 files changed, 147 insertions, 154 deletions
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c index 4174d19..a10a36c 100644 --- a/gas/config/tc-i386.c +++ b/gas/config/tc-i386.c @@ -1179,63 +1179,27 @@ static const unsigned char f32_3[] = {0x8d,0x76,0x00}; /* leal 0(%esi),%esi */ static const unsigned char f32_4[] = {0x8d,0x74,0x26,0x00}; /* leal 0(%esi,1),%esi */ -static const unsigned char f32_5[] = - {0x90, /* nop */ - 0x8d,0x74,0x26,0x00}; /* leal 0(%esi,1),%esi */ static const unsigned char f32_6[] = {0x8d,0xb6,0x00,0x00,0x00,0x00}; /* leal 0L(%esi),%esi */ static const unsigned char f32_7[] = {0x8d,0xb4,0x26,0x00,0x00,0x00,0x00}; /* leal 0L(%esi,1),%esi */ -static const unsigned char f32_8[] = - {0x90, /* nop */ - 0x8d,0xb4,0x26,0x00,0x00,0x00,0x00}; /* leal 0L(%esi,1),%esi */ -static const unsigned char f32_9[] = - {0x89,0xf6, /* movl %esi,%esi */ - 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ -static const unsigned char f32_10[] = - {0x8d,0x76,0x00, /* leal 0(%esi),%esi */ - 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ -static const unsigned char f32_11[] = - {0x8d,0x74,0x26,0x00, /* leal 0(%esi,1),%esi */ - 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ -static const unsigned char f32_12[] = - {0x8d,0xb6,0x00,0x00,0x00,0x00, /* leal 0L(%esi),%esi */ - 0x8d,0xbf,0x00,0x00,0x00,0x00}; /* leal 0L(%edi),%edi */ -static const unsigned char f32_13[] = - {0x8d,0xb6,0x00,0x00,0x00,0x00, /* leal 0L(%esi),%esi */ - 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ -static const unsigned char f32_14[] = - {0x8d,0xb4,0x26,0x00,0x00,0x00,0x00, /* leal 0L(%esi,1),%esi */ - 0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */ static const unsigned char f16_3[] = - {0x8d,0x74,0x00}; /* lea 0(%esi),%esi */ + {0x8d,0x74,0x00}; /* lea 0(%si),%si */ static const unsigned char f16_4[] = - {0x8d,0xb4,0x00,0x00}; /* lea 0w(%si),%si */ -static const unsigned char f16_5[] = - {0x90, /* nop */ - 0x8d,0xb4,0x00,0x00}; /* lea 0w(%si),%si */ -static const unsigned char f16_6[] = - {0x89,0xf6, /* mov %si,%si */ - 0x8d,0xbd,0x00,0x00}; /* lea 0w(%di),%di */ -static const unsigned char f16_7[] = - {0x8d,0x74,0x00, /* lea 0(%si),%si */ - 0x8d,0xbd,0x00,0x00}; /* lea 0w(%di),%di */ -static const unsigned char f16_8[] = - {0x8d,0xb4,0x00,0x00, /* lea 0w(%si),%si */ - 0x8d,0xbd,0x00,0x00}; /* lea 0w(%di),%di */ -static const unsigned char jump_31[] = - {0xeb,0x1d,0x90,0x90,0x90,0x90,0x90, /* jmp .+31; lotsa nops */ - 0x90,0x90,0x90,0x90,0x90,0x90,0x90,0x90, - 0x90,0x90,0x90,0x90,0x90,0x90,0x90,0x90, - 0x90,0x90,0x90,0x90,0x90,0x90,0x90,0x90}; + {0x8d,0xb4,0x00,0x00}; /* lea 0W(%si),%si */ +static const unsigned char jump_disp8[] = + {0xeb}; /* jmp disp8 */ +static const unsigned char jump32_disp32[] = + {0xe9}; /* jmp disp32 */ +static const unsigned char jump16_disp32[] = + {0x66,0xe9}; /* jmp disp32 */ /* 32-bit NOPs patterns. */ static const unsigned char *const f32_patt[] = { - f32_1, f32_2, f32_3, f32_4, f32_5, f32_6, f32_7, f32_8, - f32_9, f32_10, f32_11, f32_12, f32_13, f32_14 + f32_1, f32_2, f32_3, f32_4, NULL, f32_6, f32_7 }; /* 16-bit NOPs patterns. */ static const unsigned char *const f16_patt[] = { - f32_1, f32_2, f16_3, f16_4, f16_5, f16_6, f16_7, f16_8 + f32_1, f32_2, f16_3, f16_4 }; /* nopl (%[re]ax) */ static const unsigned char alt_3[] = @@ -1261,18 +1225,13 @@ static const unsigned char alt_9[] = /* nopw %cs:0L(%[re]ax,%[re]ax,1) */ static const unsigned char alt_10[] = {0x66,0x2e,0x0f,0x1f,0x84,0x00,0x00,0x00,0x00,0x00}; +/* data16 nopw %cs:0L(%eax,%eax,1) */ +static const unsigned char alt_11[] = + {0x66,0x66,0x2e,0x0f,0x1f,0x84,0x00,0x00,0x00,0x00,0x00}; /* 32-bit and 64-bit NOPs patterns. */ static const unsigned char *const alt_patt[] = { f32_1, f32_2, alt_3, alt_4, alt_5, alt_6, alt_7, alt_8, - alt_9, alt_10 -}; -/* 64-bit only: nopw %cs:0L(%eax,%eax,1) */ -static const unsigned char alt64_11[] = - {0x67,0x66,0x2e,0x0f,0x1f,0x84,0x00,0x00,0x00,0x00,0x00}; -/* 64-bit NOPs patterns. */ -static const unsigned char *const alt64_patt[] = { - f32_1, f32_2, alt_3, alt_4, alt_5, alt_6, alt_7, alt_8, - alt_9, alt_10, alt64_11 + alt_9, alt_10, alt_11 }; /* Genenerate COUNT bytes of NOPs to WHERE from PATT with the maximum @@ -1283,63 +1242,73 @@ i386_output_nops (char *where, const unsigned char *const *patt, int count, int max_single_nop_size) { - while (count > max_single_nop_size) + /* Place the longer NOP first. */ + int last; + int offset; + const unsigned char *nops = patt[max_single_nop_size - 1]; + + /* Use the smaller one if the requsted one isn't available. */ + if (nops == NULL) + { + max_single_nop_size--; + nops = patt[max_single_nop_size - 1]; + } + + last = count % max_single_nop_size; + + count -= last; + for (offset = 0; offset < count; offset += max_single_nop_size) + memcpy (where + offset, nops, max_single_nop_size); + + if (last) { - count -= max_single_nop_size; - memcpy (where + count, patt[max_single_nop_size - 1], - max_single_nop_size); + nops = patt[last - 1]; + if (nops == NULL) + { + /* Use the smaller one plus one-byte NOP if the needed one + isn't available. */ + last--; + nops = patt[last - 1]; + memcpy (where + offset, nops, last); + where[offset + last] = *patt[0]; + } + else + memcpy (where + offset, nops, last); } +} - if (count) - memcpy (where, patt[count - 1], count); +static INLINE int +fits_in_imm7 (offsetT num) +{ + return (num & 0x7f) == num; } +static INLINE int +fits_in_imm31 (offsetT num) +{ + return (num & 0x7fffffff) == num; +} /* Genenerate COUNT bytes of NOPs to WHERE with the maximum size of a single NOP instruction LIMIT. */ void -i386_generate_nops (fragS *f, char *where, offsetT count, int limit) +i386_generate_nops (fragS *fragP, char *where, offsetT count, int limit) { - /* Output NOPs for .nop directive. */ + const unsigned char *const *patt = NULL; int max_single_nop_size; - const unsigned char *const *patt; + /* Maximum number of NOPs before switching to jump over NOPs. */ + int max_number_of_nops; - if (flag_code == CODE_16BIT) - { - patt = f16_patt; - max_single_nop_size = sizeof (f16_patt) / sizeof (f16_patt[0]); - } - else if (flag_code == CODE_64BIT) - { - patt = alt64_patt; - max_single_nop_size = sizeof (alt64_patt) / sizeof (alt64_patt[0]); - } - else - { - patt = alt_patt; - max_single_nop_size = sizeof (alt_patt) / sizeof (alt_patt[0]); - } - if (limit == 0) - limit = max_single_nop_size; - else if (limit > max_single_nop_size) + switch (fragP->fr_type) { - as_bad_where (f->fr_file, f->fr_line, - _("invalide single nop size: %d (expect within [0, %d])"), - limit, max_single_nop_size); + case rs_fill_nop: + case rs_align_code: + break; + default: return; } - i386_output_nops (where, patt, count, limit); -} - -void -i386_align_code (fragS *fragP, int count) -{ - /* Only align for at least a positive non-zero boundary. */ - if (count <= 0 || count > MAX_MEM_FOR_RS_ALIGN_CODE) - return; - /* We need to decide which NOP sequence to use for 32bit and 64bit. When -mtune= is used: @@ -1356,21 +1325,13 @@ i386_align_code (fragS *fragP, int count) if (flag_code == CODE_16BIT) { - if (count > 8) - { - memcpy (fragP->fr_literal + fragP->fr_fix, - jump_31, count); - /* Adjust jump offset. */ - fragP->fr_literal[fragP->fr_fix + 1] = count - 2; - } - else - memcpy (fragP->fr_literal + fragP->fr_fix, - f16_patt[count - 1], count); + patt = f16_patt; + max_single_nop_size = sizeof (f16_patt) / sizeof (f16_patt[0]); + /* Limit number of NOPs to 2 in 16-bit mode. */ + max_number_of_nops = 2; } else { - const unsigned char *const *patt = NULL; - if (fragP->tc_frag_data.isa == PROCESSOR_UNKNOWN) { /* PROCESSOR_UNKNOWN means that all ISAs may be used. */ @@ -1461,38 +1422,79 @@ i386_align_code (fragS *fragP, int count) if (patt == f32_patt) { - /* If the padding is less than 15 bytes, we use the normal - ones. Otherwise, we use a jump instruction and adjust - its offset. */ - int limit; + max_single_nop_size = sizeof (f32_patt) / sizeof (f32_patt[0]); + /* Limit number of NOPs to 2 for older processors. */ + max_number_of_nops = 2; + } + else + { + max_single_nop_size = sizeof (alt_patt) / sizeof (alt_patt[0]); + /* Limit number of NOPs to 7 for newer processors. */ + max_number_of_nops = 7; + } + } - /* For 64bit, the limit is 3 bytes. */ - if (flag_code == CODE_64BIT - && fragP->tc_frag_data.isa_flags.bitfield.cpulm) - limit = 3; - else - limit = 15; - if (count < limit) - memcpy (fragP->fr_literal + fragP->fr_fix, - patt[count - 1], count); - else - { - memcpy (fragP->fr_literal + fragP->fr_fix, - jump_31, count); - /* Adjust jump offset. */ - fragP->fr_literal[fragP->fr_fix + 1] = count - 2; - } + if (limit == 0) + limit = max_single_nop_size; + + if (fragP->fr_type == rs_fill_nop) + { + /* Output NOPs for .nop directive. */ + if (limit > max_single_nop_size) + { + as_bad_where (fragP->fr_file, fragP->fr_line, + _("invalid single nop size: %d " + "(expect within [0, %d])"), + limit, max_single_nop_size); + return; + } + } + else + fragP->fr_var = count; + + if ((count / max_single_nop_size) > max_number_of_nops) + { + /* Generate jump over NOPs. */ + offsetT disp = count - 2; + if (fits_in_imm7 (disp)) + { + /* Use "jmp disp8" if possible. */ + count = disp; + where[0] = jump_disp8[0]; + where[1] = count; + where += 2; } else { - /* Maximum length of an instruction is 10 byte. If the - padding is greater than 10 bytes and we don't use jump, - we have to break it into smaller pieces. */ - i386_output_nops (fragP->fr_literal + fragP->fr_fix, - patt, count, 10); + unsigned int size_of_jump; + + if (flag_code == CODE_16BIT) + { + where[0] = jump16_disp32[0]; + where[1] = jump16_disp32[1]; + size_of_jump = 2; + } + else + { + where[0] = jump32_disp32[0]; + size_of_jump = 1; + } + + count -= size_of_jump + 4; + if (!fits_in_imm31 (count)) + { + as_bad_where (fragP->fr_file, fragP->fr_line, + _("jump over nop padding out of range")); + return; + } + + md_number_to_chars (where + size_of_jump, count, 4); + where += size_of_jump + 4; } } - fragP->fr_var = count; + + /* Generate multiple NOPs. */ + i386_output_nops (where, patt, count, limit); } static INLINE int @@ -2204,18 +2206,6 @@ fits_in_imm4 (offsetT num) return (num & 0xf) == num; } -static INLINE int -fits_in_imm7 (offsetT num) -{ - return (num & 0x7f) == num; -} - -static INLINE int -fits_in_imm31 (offsetT num) -{ - return (num & 0x7fffffff) == num; -} - static i386_operand_type smallest_imm_type (offsetT num) { diff --git a/gas/config/tc-i386.h b/gas/config/tc-i386.h index 1250bc2..c7c53be 100644 --- a/gas/config/tc-i386.h +++ b/gas/config/tc-i386.h @@ -205,15 +205,7 @@ if ((n) \ goto around; \ } -#define MAX_MEM_FOR_RS_ALIGN_CODE 31 - -extern void i386_align_code (fragS *, int); - -#define HANDLE_ALIGN(fragP) \ -if (fragP->fr_type == rs_align_code) \ - i386_align_code (fragP, (fragP->fr_next->fr_address \ - - fragP->fr_address \ - - fragP->fr_fix)); +#define MAX_MEM_FOR_RS_ALIGN_CODE 4095 void i386_print_statistics (FILE *); #define tc_print_statistics i386_print_statistics @@ -286,6 +278,17 @@ extern void i386_generate_nops (fragS *, char *, offsetT, int); #define md_generate_nops(frag, where, amount, control) \ i386_generate_nops ((frag), (where), (amount), (control)) +#define HANDLE_ALIGN(fragP) \ +if (fragP->fr_type == rs_align_code) \ + { \ + offsetT __count = (fragP->fr_next->fr_address \ + - fragP->fr_address \ + - fragP->fr_fix); \ + if (__count > 0 && __count <= MAX_MEM_FOR_RS_ALIGN_CODE) \ + md_generate_nops (fragP, fragP->fr_literal + fragP->fr_fix, \ + __count, 0); \ + } + /* We want .cfi_* pseudo-ops for generating unwind info. */ #define TARGET_USE_CFIPOP 1 |