| /* tc-tahoe.c |
| Not part of GAS yet. */ |
| |
| #include "as.h" |
| #include "obstack.h" |
| |
| /* this bit glommed from tahoe-inst.h */ |
| |
| typedef unsigned char byte; |
| typedef byte tahoe_opcodeT; |
| |
| /* |
| * This is part of tahoe-ins-parse.c & friends. |
| * We want to parse a tahoe instruction text into a tree defined here. |
| */ |
| |
| #define TIT_MAX_OPERANDS (4) /* maximum number of operands in one |
| single tahoe instruction */ |
| |
| struct top /* tahoe instruction operand */ |
| { |
| int top_ndx; /* -1, or index register. eg 7=[R7] */ |
| int top_reg; /* -1, or register number. eg 7 = R7 or (R7) */ |
| byte top_mode; /* Addressing mode byte. This byte, defines |
| which of the 11 modes opcode is. */ |
| |
| char top_access; /* Access type wanted for this opperand |
| 'b'branch ' 'no-instruction 'amrvw' */ |
| char top_width; /* Operand width expected, one of "bwlq?-:!" */ |
| |
| char *top_error; /* Say if operand is inappropriate */ |
| |
| segT seg_of_operand; /* segment as returned by expression()*/ |
| |
| expressionS exp_of_operand; /* The expression as parsed by expression()*/ |
| |
| byte top_dispsize; /* Number of bytes in the displacement if we |
| can figure it out */ |
| }; |
| |
| /* The addressing modes for an operand. These numbers are the acutal values |
| for certain modes, so be carefull if you screw with them. */ |
| #define TAHOE_DIRECT_REG (0x50) |
| #define TAHOE_REG_DEFERRED (0x60) |
| |
| #define TAHOE_REG_DISP (0xE0) |
| #define TAHOE_REG_DISP_DEFERRED (0xF0) |
| |
| #define TAHOE_IMMEDIATE (0x8F) |
| #define TAHOE_IMMEDIATE_BYTE (0x88) |
| #define TAHOE_IMMEDIATE_WORD (0x89) |
| #define TAHOE_IMMEDIATE_LONGWORD (0x8F) |
| #define TAHOE_ABSOLUTE_ADDR (0x9F) |
| |
| #define TAHOE_DISPLACED_RELATIVE (0xEF) |
| #define TAHOE_DISP_REL_DEFERRED (0xFF) |
| |
| #define TAHOE_AUTO_DEC (0x7E) |
| #define TAHOE_AUTO_INC (0x8E) |
| #define TAHOE_AUTO_INC_DEFERRED (0x9E) |
| /* INDEXED_REG is decided by the existance or lack of a [reg] */ |
| |
| /* These are encoded into top_width when top_access=='b' |
| and it's a psuedo op.*/ |
| #define TAHOE_WIDTH_ALWAYS_JUMP '-' |
| #define TAHOE_WIDTH_CONDITIONAL_JUMP '?' |
| #define TAHOE_WIDTH_BIG_REV_JUMP '!' |
| #define TAHOE_WIDTH_BIG_NON_REV_JUMP ':' |
| |
| /* The hex code for certain tahoe commands and modes. |
| This is just for readability. */ |
| #define TAHOE_JMP (0x71) |
| #define TAHOE_PC_REL_LONG (0xEF) |
| #define TAHOE_BRB (0x11) |
| #define TAHOE_BRW (0x13) |
| /* These, when 'ored' with, or added to, a register number, |
| set up the number for the displacement mode. */ |
| #define TAHOE_PC_OR_BYTE (0xA0) |
| #define TAHOE_PC_OR_WORD (0xC0) |
| #define TAHOE_PC_OR_LONG (0xE0) |
| |
| struct tit /* get it out of the sewer, it stands for |
| tahoe instruction tree (Geeze!) */ |
| { |
| tahoe_opcodeT tit_opcode; /* The opcode. */ |
| byte tit_operands; /* How many operands are here. */ |
| struct top tit_operand[TIT_MAX_OPERANDS]; /* Operands */ |
| char *tit_error; /* "" or fatal error text */ |
| }; |
| |
| /* end: tahoe-inst.h */ |
| |
| /* tahoe.c - tahoe-specific - |
| Not part of gas yet. |
| */ |
| |
| #include "opcode/tahoe.h" |
| |
| /* This is the number to put at the beginning of the a.out file */ |
| long omagic = OMAGIC; |
| |
| /* These chars start a comment anywhere in a source file (except inside |
| another comment or a quoted string. */ |
| const char comment_chars[] = "#;"; |
| |
| /* These chars only start a comment at the beginning of a line. */ |
| const char line_comment_chars[] = "#"; |
| |
| /* Chars that can be used to separate mant from exp in floating point nums */ |
| const char EXP_CHARS[] = "eE"; |
| |
| /* Chars that mean this number is a floating point constant |
| as in 0f123.456 |
| or 0d1.234E-12 (see exp chars above) |
| Note: The Tahoe port doesn't support floating point constants. This is |
| consistant with 'as' If it's needed, I can always add it later. */ |
| const char FLT_CHARS[] = "df"; |
| |
| /* Also be aware that MAXIMUM_NUMBER_OF_CHARS_FOR_FLOAT may have to be |
| changed in read.c . Ideally it shouldn't have to know about it at all, |
| but nothing is ideal around here. |
| (The tahoe has plenty of room, so the change currently isn't needed.) |
| */ |
| |
| static struct tit t; /* A tahoe instruction after decoding. */ |
| |
| void float_cons (); |
| /* A table of pseudo ops (sans .), the function called, and an integer op |
| that the function is called with. */ |
| |
| const pseudo_typeS md_pseudo_table[] = |
| { |
| {"dfloat", float_cons, 'd'}, |
| {"ffloat", float_cons, 'f'}, |
| {0} |
| }; |
| |
| /* |
| * For Tahoe, relative addresses of "just the right length" are pretty easy. |
| * The branch displacement is always the last operand, even in |
| * synthetic instructions. |
| * For Tahoe, we encode the relax_substateTs (in e.g. fr_substate) as: |
| * |
| * 4 3 2 1 0 bit number |
| * ---/ /--+-------+-------+-------+-------+-------+ |
| * | what state ? | how long ? | |
| * ---/ /--+-------+-------+-------+-------+-------+ |
| * |
| * The "how long" bits are 00=byte, 01=word, 10=long. |
| * This is a Un*x convention. |
| * Not all lengths are legit for a given value of (what state). |
| * The four states are listed below. |
| * The "how long" refers merely to the displacement length. |
| * The address usually has some constant bytes in it as well. |
| * |
| |
| States for Tahoe address relaxing. |
| 1. TAHOE_WIDTH_ALWAYS_JUMP (-) |
| Format: "b-" |
| Tahoe opcodes are: (Hex) |
| jr 11 |
| jbr 11 |
| Simple branch. |
| Always, 1 byte opcode, then displacement/absolute. |
| If word or longword, change opcode to brw or jmp. |
| |
| |
| 2. TAHOE_WIDTH_CONDITIONAL_JUMP (?) |
| J<cond> where <cond> is a simple flag test. |
| Format: "b?" |
| Tahoe opcodes are: (Hex) |
| jneq/jnequ 21 |
| jeql/jeqlu 31 |
| jgtr 41 |
| jleq 51 |
| jgeq 81 |
| jlss 91 |
| jgtru a1 |
| jlequ b1 |
| jvc c1 |
| jvs d1 |
| jlssu/jcs e1 |
| jgequ/jcc f1 |
| Always, you complement 4th bit to reverse the condition. |
| Always, 1-byte opcode, then 1-byte displacement. |
| |
| 3. TAHOE_WIDTH_BIG_REV_JUMP (!) |
| Jbc/Jbs where cond tests a memory bit. |
| Format: "rlvlb!" |
| Tahoe opcodes are: (Hex) |
| jbs 0e |
| jbc 1e |
| Always, you complement 4th bit to reverse the condition. |
| Always, 1-byte opcde, longword, longword-address, 1-word-displacement |
| |
| 4. TAHOE_WIDTH_BIG_NON_REV_JUMP (:) |
| JaoblXX/Jbssi |
| Format: "rlmlb:" |
| Tahoe opcodes are: (Hex) |
| aojlss 2f |
| jaoblss 2f |
| aojleq 3f |
| jaobleq 3f |
| jbssi 5f |
| Always, we cannot reverse the sense of the branch; we have a word |
| displacement. |
| |
| We need to modify the opcode is for class 1, 2 and 3 instructions. |
| After relax() we may complement the 4th bit of 2 or 3 to reverse sense of |
| branch. |
| |
| We sometimes store context in the operand literal. This way we can figure out |
| after relax() what the original addressing mode was. (Was is pc_rel, or |
| pc_rel_disp? That sort of thing.) */ |
| |
| /* These displacements are relative to the START address of the |
| displacement which is at the start of the displacement, not the end of |
| the instruction. The hardware pc_rel is at the end of the instructions. |
| That's why all the displacements have the length of the displacement added |
| to them. (WF + length(word)) |
| |
| The first letter is Byte, Word. |
| 2nd letter is Forward, Backward. */ |
| #define BF (1+ 127) |
| #define BB (1+-128) |
| #define WF (2+ 32767) |
| #define WB (2+-32768) |
| /* Dont need LF, LB because they always reach. [They are coded as 0.] */ |
| |
| #define C(a,b) ENCODE_RELAX(a,b) |
| /* This macro has no side-effects. */ |
| #define ENCODE_RELAX(what,length) (((what) << 2) + (length)) |
| #define RELAX_STATE(what) ((what) >> 2) |
| #define RELAX_LENGTH(length) ((length) && 3) |
| |
| #define STATE_ALWAYS_BRANCH (1) |
| #define STATE_CONDITIONAL_BRANCH (2) |
| #define STATE_BIG_REV_BRANCH (3) |
| #define STATE_BIG_NON_REV_BRANCH (4) |
| #define STATE_PC_RELATIVE (5) |
| |
| #define STATE_BYTE (0) |
| #define STATE_WORD (1) |
| #define STATE_LONG (2) |
| #define STATE_UNDF (3) /* Symbol undefined in pass1 */ |
| |
| /* This is the table used by gas to figure out relaxing modes. The fields are |
| forward_branch reach, backward_branch reach, number of bytes it would take, |
| where the next biggest branch is. */ |
| const relax_typeS md_relax_table[] = |
| { |
| { |
| 1, 1, 0, 0 |
| }, /* error sentinel 0,0 */ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 0,1 */ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 0,2 */ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 0,3 */ |
| /* Unconditional branch cases "jrb" |
| The relax part is the actual displacement */ |
| { |
| BF, BB, 1, C (1, 1) |
| }, /* brb B`foo 1,0 */ |
| { |
| WF, WB, 2, C (1, 2) |
| }, /* brw W`foo 1,1 */ |
| { |
| 0, 0, 5, 0 |
| }, /* Jmp L`foo 1,2 */ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 1,3 */ |
| /* Reversible Conditional Branch. If the branch won't reach, reverse |
| it, and jump over a brw or a jmp that will reach. The relax part is the |
| actual address. */ |
| { |
| BF, BB, 1, C (2, 1) |
| }, /* b<cond> B`foo 2,0 */ |
| { |
| WF + 2, WB + 2, 4, C (2, 2) |
| }, /* brev over, brw W`foo, over: 2,1 */ |
| { |
| 0, 0, 7, 0 |
| }, /* brev over, jmp L`foo, over: 2,2 */ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 2,3 */ |
| /* Another type of reversable branch. But this only has a word |
| displacement. */ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 3,0 */ |
| { |
| WF, WB, 2, C (3, 2) |
| }, /* jbX W`foo 3,1 */ |
| { |
| 0, 0, 8, 0 |
| }, /* jrevX over, jmp L`foo, over: 3,2 */ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 3,3 */ |
| /* These are the non reversable branches, all of which have a word |
| displacement. If I can't reach, branch over a byte branch, to a |
| jump that will reach. The jumped branch jumps over the reaching |
| branch, to continue with the flow of the program. It's like playing |
| leap frog. */ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 4,0 */ |
| { |
| WF, WB, 2, C (4, 2) |
| }, /* aobl_ W`foo 4,1 */ |
| { |
| 0, 0, 10, 0 |
| }, /*aobl_ W`hop,br over,hop: jmp L^foo,over 4,2*/ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 4,3 */ |
| /* Normal displacement mode, no jumping or anything like that. |
| The relax points to one byte before the address, thats why all |
| the numbers are up by one. */ |
| { |
| BF + 1, BB + 1, 2, C (5, 1) |
| }, /* B^"foo" 5,0 */ |
| { |
| WF + 1, WB + 1, 3, C (5, 2) |
| }, /* W^"foo" 5,1 */ |
| { |
| 0, 0, 5, 0 |
| }, /* L^"foo" 5,2 */ |
| { |
| 1, 1, 0, 0 |
| }, /* unused 5,3 */ |
| }; |
| |
| #undef C |
| #undef BF |
| #undef BB |
| #undef WF |
| #undef WB |
| /* End relax stuff */ |
| |
| /* Handle of the OPCODE hash table. NULL means any use before |
| md_begin() will crash. */ |
| static struct hash_control *op_hash; |
| |
| /* Init function. Build the hash table. */ |
| void |
| md_begin () |
| { |
| struct tot *tP; |
| char *errorval = 0; |
| int synthetic_too = 1; /* If 0, just use real opcodes. */ |
| |
| op_hash = hash_new (); |
| |
| for (tP = totstrs; *tP->name && !errorval; tP++) |
| errorval = hash_insert (op_hash, tP->name, &tP->detail); |
| |
| if (synthetic_too) |
| for (tP = synthetic_totstrs; *tP->name && !errorval; tP++) |
| errorval = hash_insert (op_hash, tP->name, &tP->detail); |
| |
| if (errorval) |
| as_fatal (errorval); |
| } |
| |
| CONST char *md_shortopts = "ad:STt:V"; |
| struct option md_longopts[] = { |
| {NULL, no_argument, NULL, 0} |
| }; |
| size_t md_longopts_size = sizeof(md_longopts); |
| |
| int |
| md_parse_option (c, arg) |
| int c; |
| char *arg; |
| { |
| switch (c) |
| { |
| case 'a': |
| as_warn (_("The -a option doesn't exist. (Despite what the man page says!")); |
| break; |
| |
| case 'd': |
| as_warn (_("Displacement length %s ignored!"), arg); |
| break; |
| |
| case 'S': |
| as_warn (_("SYMBOL TABLE not implemented")); |
| break; |
| |
| case 'T': |
| as_warn (_("TOKEN TRACE not implemented")); |
| break; |
| |
| case 't': |
| as_warn (_("I don't need or use temp. file \"%s\"."), arg); |
| break; |
| |
| case 'V': |
| as_warn (_("I don't use an interpass file! -V ignored")); |
| break; |
| |
| default: |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| void |
| md_show_usage (stream) |
| FILE *stream; |
| { |
| fprintf(stream, _("\ |
| Tahoe options:\n\ |
| -a ignored\n\ |
| -d LENGTH ignored\n\ |
| -J ignored\n\ |
| -S ignored\n\ |
| -t FILE ignored\n\ |
| -T ignored\n\ |
| -V ignored\n")); |
| } |
| |
| /* The functions in this section take numbers in the machine format, and |
| munges them into Tahoe byte order. |
| They exist primarily for cross assembly purpose. */ |
| void /* Knows about order of bytes in address. */ |
| md_number_to_chars (con, value, nbytes) |
| char con[]; /* Return 'nbytes' of chars here. */ |
| valueT value; /* The value of the bits. */ |
| int nbytes; /* Number of bytes in the output. */ |
| { |
| number_to_chars_bigendian (con, value, nbytes); |
| } |
| |
| #ifdef comment |
| void /* Knows about order of bytes in address. */ |
| md_number_to_imm (con, value, nbytes) |
| char con[]; /* Return 'nbytes' of chars here. */ |
| long int value; /* The value of the bits. */ |
| int nbytes; /* Number of bytes in the output. */ |
| { |
| md_number_to_chars (con, value, nbytes); |
| } |
| |
| #endif /* comment */ |
| |
| void |
| tc_apply_fix (fixP, val) |
| fixS *fixP; |
| long val; |
| { |
| /* should never be called */ |
| know (0); |
| } |
| |
| void /* Knows about order of bytes in address. */ |
| md_number_to_disp (con, value, nbytes) |
| char con[]; /* Return 'nbytes' of chars here. */ |
| long int value; /* The value of the bits. */ |
| int nbytes; /* Number of bytes in the output. */ |
| { |
| md_number_to_chars (con, value, nbytes); |
| } |
| |
| void /* Knows about order of bytes in address. */ |
| md_number_to_field (con, value, nbytes) |
| char con[]; /* Return 'nbytes' of chars here. */ |
| long int value; /* The value of the bits. */ |
| int nbytes; /* Number of bytes in the output. */ |
| { |
| md_number_to_chars (con, value, nbytes); |
| } |
| |
| /* Put the bits in an order that a tahoe will understand, despite the ordering |
| of the native machine. |
| On Tahoe: first 4 bytes are normal unsigned big endian long, |
| next three bytes are symbolnum, in kind of 3 byte big endian (least sig. byte last). |
| The last byte is broken up with bit 7 as pcrel, |
| bits 6 & 5 as length, |
| bit 4 as extern and the last nibble as 'undefined'. */ |
| |
| #if comment |
| void |
| md_ri_to_chars (ri_p, ri) |
| struct relocation_info *ri_p, ri; |
| { |
| byte the_bytes[sizeof (struct relocation_info)]; |
| /* The reason I can't just encode these directly into ri_p is that |
| ri_p may point to ri. */ |
| |
| /* This is easy */ |
| md_number_to_chars (the_bytes, ri.r_address, sizeof (ri.r_address)); |
| |
| /* now the fun stuff */ |
| the_bytes[4] = (ri.r_symbolnum >> 16) & 0x0ff; |
| the_bytes[5] = (ri.r_symbolnum >> 8) & 0x0ff; |
| the_bytes[6] = ri.r_symbolnum & 0x0ff; |
| the_bytes[7] = (((ri.r_extern << 4) & 0x10) | ((ri.r_length << 5) & 0x60) | |
| ((ri.r_pcrel << 7) & 0x80)) & 0xf0; |
| |
| bcopy (the_bytes, (char *) ri_p, sizeof (struct relocation_info)); |
| } |
| |
| #endif /* comment */ |
| |
| /* Put the bits in an order that a tahoe will understand, despite the ordering |
| of the native machine. |
| On Tahoe: first 4 bytes are normal unsigned big endian long, |
| next three bytes are symbolnum, in kind of 3 byte big endian (least sig. byte last). |
| The last byte is broken up with bit 7 as pcrel, |
| bits 6 & 5 as length, |
| bit 4 as extern and the last nibble as 'undefined'. */ |
| |
| void |
| tc_aout_fix_to_chars (where, fixP, segment_address_in_file) |
| char *where; |
| fixS *fixP; |
| relax_addressT segment_address_in_file; |
| { |
| long r_symbolnum; |
| |
| know (fixP->fx_addsy != NULL); |
| |
| md_number_to_chars (where, |
| fixP->fx_frag->fr_address + fixP->fx_where - segment_address_in_file, |
| 4); |
| |
| r_symbolnum = (S_IS_DEFINED (fixP->fx_addsy) |
| ? S_GET_TYPE (fixP->fx_addsy) |
| : fixP->fx_addsy->sy_number); |
| |
| where[4] = (r_symbolnum >> 16) & 0x0ff; |
| where[5] = (r_symbolnum >> 8) & 0x0ff; |
| where[6] = r_symbolnum & 0x0ff; |
| where[7] = (((is_pcrel (fixP) << 7) & 0x80) |
| | ((((fixP->fx_type == FX_8 || fixP->fx_type == FX_PCREL8 |
| ? 0 |
| : (fixP->fx_type == FX_16 || fixP->fx_type == FX_PCREL16 |
| ? 1 |
| : (fixP->fx_type == FX_32 || fixP->fx_type == FX_PCREL32 |
| ? 2 |
| : 42)))) << 5) & 0x60) |
| | ((!S_IS_DEFINED (fixP->fx_addsy) << 4) & 0x10)); |
| } |
| |
| /* Relocate byte stuff */ |
| |
| /* This is for broken word. */ |
| const int md_short_jump_size = 3; |
| |
| void |
| md_create_short_jump (ptr, from_addr, to_addr, frag, to_symbol) |
| char *ptr; |
| addressT from_addr, to_addr; |
| fragS *frag; |
| symbolS *to_symbol; |
| { |
| valueT offset; |
| |
| offset = to_addr - (from_addr + 1); |
| *ptr++ = TAHOE_BRW; |
| md_number_to_chars (ptr, offset, 2); |
| } |
| |
| const int md_long_jump_size = 6; |
| const int md_reloc_size = 8; /* Size of relocation record */ |
| |
| void |
| md_create_long_jump (ptr, from_addr, to_addr, frag, to_symbol) |
| char *ptr; |
| addressT from_addr, to_addr; |
| fragS *frag; |
| symbolS *to_symbol; |
| { |
| valueT offset; |
| |
| offset = to_addr - (from_addr + 4); |
| *ptr++ = TAHOE_JMP; |
| *ptr++ = TAHOE_PC_REL_LONG; |
| md_number_to_chars (ptr, offset, 4); |
| } |
| |
| /* |
| * md_estimate_size_before_relax() |
| * |
| * Called just before relax(). |
| * Any symbol that is now undefined will not become defined, so we assumed |
| * that it will be resolved by the linker. |
| * Return the correct fr_subtype in the frag, for relax() |
| * Return the initial "guess for fr_var" to caller. (How big I think this |
| * will be.) |
| * The guess for fr_var is ACTUALLY the growth beyond fr_fix. |
| * Whatever we do to grow fr_fix or fr_var contributes to our returned value. |
| * Although it may not be explicit in the frag, pretend fr_var starts with a |
| * 0 value. |
| */ |
| int |
| md_estimate_size_before_relax (fragP, segment_type) |
| register fragS *fragP; |
| segT segment_type; /* N_DATA or N_TEXT. */ |
| { |
| register char *p; |
| register int old_fr_fix; |
| /* int pc_rel; FIXME: remove this */ |
| |
| old_fr_fix = fragP->fr_fix; |
| switch (fragP->fr_subtype) |
| { |
| case ENCODE_RELAX (STATE_PC_RELATIVE, STATE_UNDF): |
| if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type) |
| { |
| /* The symbol was in the same segment as the opcode, and it's |
| a real pc_rel case so it's a relaxable case. */ |
| fragP->fr_subtype = ENCODE_RELAX (STATE_PC_RELATIVE, STATE_BYTE); |
| } |
| else |
| { |
| /* This case is still undefined, so asume it's a long word for the |
| linker to fix. */ |
| p = fragP->fr_literal + old_fr_fix; |
| *p |= TAHOE_PC_OR_LONG; |
| /* We now know how big it will be, one long word. */ |
| fragP->fr_fix += 1 + 4; |
| fix_new (fragP, old_fr_fix + 1, fragP->fr_symbol, |
| fragP->fr_offset, FX_PCREL32, NULL); |
| frag_wane (fragP); |
| } |
| break; |
| |
| case ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_UNDF): |
| if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type) |
| { |
| fragP->fr_subtype = ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_BYTE); |
| } |
| else |
| { |
| p = fragP->fr_literal + old_fr_fix; |
| *fragP->fr_opcode ^= 0x10; /* Reverse sense of branch. */ |
| *p++ = 6; |
| *p++ = TAHOE_JMP; |
| *p++ = TAHOE_PC_REL_LONG; |
| fragP->fr_fix += 1 + 1 + 1 + 4; |
| fix_new (fragP, old_fr_fix + 3, fragP->fr_symbol, |
| fragP->fr_offset, FX_PCREL32, NULL); |
| frag_wane (fragP); |
| } |
| break; |
| |
| case ENCODE_RELAX (STATE_BIG_REV_BRANCH, STATE_UNDF): |
| if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type) |
| { |
| fragP->fr_subtype = |
| ENCODE_RELAX (STATE_BIG_REV_BRANCH, STATE_WORD); |
| } |
| else |
| { |
| p = fragP->fr_literal + old_fr_fix; |
| *fragP->fr_opcode ^= 0x10; /* Reverse sense of branch. */ |
| *p++ = 0; |
| *p++ = 6; |
| *p++ = TAHOE_JMP; |
| *p++ = TAHOE_PC_REL_LONG; |
| fragP->fr_fix += 2 + 2 + 4; |
| fix_new (fragP, old_fr_fix + 4, fragP->fr_symbol, |
| fragP->fr_offset, FX_PCREL32, NULL); |
| frag_wane (fragP); |
| } |
| break; |
| |
| case ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH, STATE_UNDF): |
| if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type) |
| { |
| fragP->fr_subtype = ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH, STATE_WORD); |
| } |
| else |
| { |
| p = fragP->fr_literal + old_fr_fix; |
| *p++ = 2; |
| *p++ = 0; |
| *p++ = TAHOE_BRB; |
| *p++ = 6; |
| *p++ = TAHOE_JMP; |
| *p++ = TAHOE_PC_REL_LONG; |
| fragP->fr_fix += 2 + 2 + 2 + 4; |
| fix_new (fragP, old_fr_fix + 6, fragP->fr_symbol, |
| fragP->fr_offset, FX_PCREL32, NULL); |
| frag_wane (fragP); |
| } |
| break; |
| |
| case ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_UNDF): |
| if (S_GET_SEGMENT (fragP->fr_symbol) == segment_type) |
| { |
| fragP->fr_subtype = ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_BYTE); |
| } |
| else |
| { |
| p = fragP->fr_literal + old_fr_fix; |
| *fragP->fr_opcode = TAHOE_JMP; |
| *p++ = TAHOE_PC_REL_LONG; |
| fragP->fr_fix += 1 + 4; |
| fix_new (fragP, old_fr_fix + 1, fragP->fr_symbol, |
| fragP->fr_offset, FX_PCREL32, NULL); |
| frag_wane (fragP); |
| } |
| break; |
| |
| default: |
| break; |
| } |
| return (fragP->fr_var + fragP->fr_fix - old_fr_fix); |
| } /* md_estimate_size_before_relax() */ |
| |
| /* |
| * md_convert_frag(); |
| * |
| * Called after relax() is finished. |
| * In: Address of frag. |
| * fr_type == rs_machine_dependent. |
| * fr_subtype is what the address relaxed to. |
| * |
| * Out: Any fixSs and constants are set up. |
| * Caller will turn frag into a ".space 0". |
| */ |
| void |
| md_convert_frag (headers, seg, fragP) |
| object_headers *headers; |
| segT seg; |
| register fragS *fragP; |
| { |
| register char *addressP; /* -> _var to change. */ |
| register char *opcodeP; /* -> opcode char(s) to change. */ |
| register short int length_code; /* 2=long 1=word 0=byte */ |
| register short int extension = 0; /* Size of relaxed address. |
| Added to fr_fix: incl. ALL var chars. */ |
| register symbolS *symbolP; |
| register long int where; |
| register long int address_of_var; |
| /* Where, in file space, is _var of *fragP? */ |
| register long int target_address; |
| /* Where, in file space, does addr point? */ |
| |
| know (fragP->fr_type == rs_machine_dependent); |
| length_code = RELAX_LENGTH (fragP->fr_subtype); |
| know (length_code >= 0 && length_code < 3); |
| where = fragP->fr_fix; |
| addressP = fragP->fr_literal + where; |
| opcodeP = fragP->fr_opcode; |
| symbolP = fragP->fr_symbol; |
| know (symbolP); |
| target_address = S_GET_VALUE (symbolP) + fragP->fr_offset; |
| address_of_var = fragP->fr_address + where; |
| switch (fragP->fr_subtype) |
| { |
| case ENCODE_RELAX (STATE_PC_RELATIVE, STATE_BYTE): |
| /* *addressP holds the registers number, plus 0x10, if it's deferred |
| mode. To set up the right mode, just OR the size of this displacement */ |
| /* Byte displacement. */ |
| *addressP++ |= TAHOE_PC_OR_BYTE; |
| *addressP = target_address - (address_of_var + 2); |
| extension = 2; |
| break; |
| |
| case ENCODE_RELAX (STATE_PC_RELATIVE, STATE_WORD): |
| /* Word displacement. */ |
| *addressP++ |= TAHOE_PC_OR_WORD; |
| md_number_to_chars (addressP, target_address - (address_of_var + 3), 2); |
| extension = 3; |
| break; |
| |
| case ENCODE_RELAX (STATE_PC_RELATIVE, STATE_LONG): |
| /* Long word displacement. */ |
| *addressP++ |= TAHOE_PC_OR_LONG; |
| md_number_to_chars (addressP, target_address - (address_of_var + 5), 4); |
| extension = 5; |
| break; |
| |
| case ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_BYTE): |
| *addressP = target_address - (address_of_var + 1); |
| extension = 1; |
| break; |
| |
| case ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_WORD): |
| *opcodeP ^= 0x10; /* Reverse sense of test. */ |
| *addressP++ = 3; /* Jump over word branch */ |
| *addressP++ = TAHOE_BRW; |
| md_number_to_chars (addressP, target_address - (address_of_var + 4), 2); |
| extension = 4; |
| break; |
| |
| case ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, STATE_LONG): |
| *opcodeP ^= 0x10; /* Reverse sense of test. */ |
| *addressP++ = 6; |
| *addressP++ = TAHOE_JMP; |
| *addressP++ = TAHOE_PC_REL_LONG; |
| md_number_to_chars (addressP, target_address, 4); |
| extension = 7; |
| break; |
| |
| case ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_BYTE): |
| *addressP = target_address - (address_of_var + 1); |
| extension = 1; |
| break; |
| |
| case ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_WORD): |
| *opcodeP = TAHOE_BRW; |
| md_number_to_chars (addressP, target_address - (address_of_var + 2), 2); |
| extension = 2; |
| break; |
| |
| case ENCODE_RELAX (STATE_ALWAYS_BRANCH, STATE_LONG): |
| *opcodeP = TAHOE_JMP; |
| *addressP++ = TAHOE_PC_REL_LONG; |
| md_number_to_chars (addressP, target_address - (address_of_var + 5), 4); |
| extension = 5; |
| break; |
| |
| case ENCODE_RELAX (STATE_BIG_REV_BRANCH, STATE_WORD): |
| md_number_to_chars (addressP, target_address - (address_of_var + 2), 2); |
| extension = 2; |
| break; |
| |
| case ENCODE_RELAX (STATE_BIG_REV_BRANCH, STATE_LONG): |
| *opcodeP ^= 0x10; |
| *addressP++ = 0; |
| *addressP++ = 6; |
| *addressP++ = TAHOE_JMP; |
| *addressP++ = TAHOE_PC_REL_LONG; |
| md_number_to_chars (addressP, target_address, 4); |
| extension = 8; |
| break; |
| |
| case ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH, STATE_WORD): |
| md_number_to_chars (addressP, target_address - (address_of_var + 2), 2); |
| extension = 2; |
| break; |
| |
| case ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH, STATE_LONG): |
| *addressP++ = 0; |
| *addressP++ = 2; |
| *addressP++ = TAHOE_BRB; |
| *addressP++ = 6; |
| *addressP++ = TAHOE_JMP; |
| *addressP++ = TAHOE_PC_REL_LONG; |
| md_number_to_chars (addressP, target_address, 4); |
| extension = 10; |
| break; |
| |
| default: |
| BAD_CASE (fragP->fr_subtype); |
| break; |
| } |
| fragP->fr_fix += extension; |
| } /* md_convert_frag */ |
| |
| |
| /* This is the stuff for md_assemble. */ |
| #define FP_REG 13 |
| #define SP_REG 14 |
| #define PC_REG 15 |
| #define BIGGESTREG PC_REG |
| |
| /* |
| * Parse the string pointed to by START |
| * If it represents a valid register, point START to the character after |
| * the last valid register char, and return the register number (0-15). |
| * If invalid, leave START alone, return -1. |
| * The format has to be exact. I don't do things like eat leading zeros |
| * or the like. |
| * Note: This doesn't check for the next character in the string making |
| * this invalid. Ex: R123 would return 12, it's the callers job to check |
| * what start is point to apon return. |
| * |
| * Valid registers are R1-R15, %1-%15, FP (13), SP (14), PC (15) |
| * Case doesn't matter. |
| */ |
| int |
| tahoe_reg_parse (start) |
| char **start; /* A pointer to the string to parse. */ |
| { |
| register char *regpoint = *start; |
| register int regnum = -1; |
| |
| switch (*regpoint++) |
| { |
| case '%': /* Registers can start with a %, |
| R or r, and then a number. */ |
| case 'R': |
| case 'r': |
| if (isdigit (*regpoint)) |
| { |
| /* Got the first digit. */ |
| regnum = *regpoint++ - '0'; |
| if ((regnum == 1) && isdigit (*regpoint)) |
| { |
| /* Its a two digit number. */ |
| regnum = 10 + (*regpoint++ - '0'); |
| if (regnum > BIGGESTREG) |
| { /* Number too big? */ |
| regnum = -1; |
| } |
| } |
| } |
| break; |
| case 'F': /* Is it the FP */ |
| case 'f': |
| switch (*regpoint++) |
| { |
| case 'p': |
| case 'P': |
| regnum = FP_REG; |
| } |
| break; |
| case 's': /* How about the SP */ |
| case 'S': |
| switch (*regpoint++) |
| { |
| case 'p': |
| case 'P': |
| regnum = SP_REG; |
| } |
| break; |
| case 'p': /* OR the PC even */ |
| case 'P': |
| switch (*regpoint++) |
| { |
| case 'c': |
| case 'C': |
| regnum = PC_REG; |
| } |
| break; |
| } |
| |
| if (regnum != -1) |
| { /* No error, so move string pointer */ |
| *start = regpoint; |
| } |
| return regnum; /* Return results */ |
| } /* tahoe_reg_parse */ |
| |
| /* |
| * This chops up an operand and figures out its modes and stuff. |
| * It's a little touchy about extra characters. |
| * Optex to start with one extra character so it can be overwritten for |
| * the backward part of the parsing. |
| * You can't put a bunch of extra characters in side to |
| * make the command look cute. ie: * foo ( r1 ) [ r0 ] |
| * If you like doing a lot of typing, try COBOL! |
| * Actually, this parser is a little weak all around. It's designed to be |
| * used with compliers, so I emphisise correct decoding of valid code quickly |
| * rather that catching every possable error. |
| * Note: This uses the expression function, so save input_line_pointer before |
| * calling. |
| * |
| * Sperry defines the semantics of address modes (and values) |
| * by a two-letter code, explained here. |
| * |
| * letter 1: access type |
| * |
| * a address calculation - no data access, registers forbidden |
| * b branch displacement |
| * m read - let go of bus - write back "modify" |
| * r read |
| * w write |
| * v bit field address: like 'a' but registers are OK |
| * |
| * letter 2: data type (i.e. width, alignment) |
| * |
| * b byte |
| * w word |
| * l longword |
| * q quadword (Even regs < 14 allowed) (if 12, you get a warning) |
| * - unconditional synthetic jbr operand |
| * ? simple synthetic reversable branch operand |
| * ! complex synthetic reversable branch operand |
| * : complex synthetic non-reversable branch operand |
| * |
| * The '-?!:' letter 2's are not for external consumption. They are used |
| * by GAS for psuedo ops relaxing code. |
| * |
| * After parsing topP has: |
| * |
| * top_ndx: -1, or the index register. eg 7=[R7] |
| * top_reg: -1, or register number. eg 7 = R7 or (R7) |
| * top_mode: The addressing mode byte. This byte, defines which of |
| * the 11 modes opcode is. |
| * top_access: Access type wanted for this opperand 'b'branch ' ' |
| * no-instruction 'amrvw' |
| * top_width: Operand width expected, one of "bwlq?-:!" |
| * exp_of_operand: The expression as parsed by expression() |
| * top_dispsize: Number of bytes in the displacement if we can figure it |
| * out and it's relavent. |
| * |
| * Need syntax checks built. |
| */ |
| |
| void |
| tip_op (optex, topP) |
| char *optex; /* The users text input, with one leading character */ |
| struct top *topP; /* The tahoe instruction with some fields already set: |
| in: access, width |
| out: ndx, reg, mode, error, dispsize */ |
| |
| { |
| int mode = 0; /* This operand's mode. */ |
| char segfault = *optex; /* To keep the back parsing from freaking. */ |
| char *point = optex + 1; /* Parsing from front to back. */ |
| char *end; /* Parsing from back to front. */ |
| int reg = -1; /* major register, -1 means absent */ |
| int imreg = -1; /* Major register in immediate mode */ |
| int ndx = -1; /* index register number, -1 means absent */ |
| char dec_inc = ' '; /* Is the SP auto-incremented '+' or |
| auto-decremented '-' or neither ' '. */ |
| int immediate = 0; /* 1 if '$' immediate mode */ |
| int call_width = 0; /* If the caller casts the displacement */ |
| int abs_width = 0; /* The width of the absolute displacment */ |
| int com_width = 0; /* Displacement width required by branch */ |
| int deferred = 0; /* 1 if '*' deferral is used */ |
| byte disp_size = 0; /* How big is this operand. 0 == don't know */ |
| char *op_bad = ""; /* Bad operand error */ |
| |
| char *tp, *temp, c; /* Temporary holders */ |
| |
| char access = topP->top_access; /* Save on a deref. */ |
| char width = topP->top_width; |
| |
| int really_none = 0; /* Empty expressions evaluate to 0 |
| but I need to know if it's there or not */ |
| expressionS *expP; /* -> expression values for this operand */ |
| |
| /* Does this command restrict the displacement size. */ |
| if (access == 'b') |
| com_width = (width == 'b' ? 1 : |
| (width == 'w' ? 2 : |
| (width == 'l' ? 4 : 0))); |
| |
| *optex = '\0'; /* This is kind of a back stop for all |
| the searches to fail on if needed.*/ |
| if (*point == '*') |
| { /* A dereference? */ |
| deferred = 1; |
| point++; |
| } |
| |
| /* Force words into a certain mode */ |
| /* Bitch, Bitch, Bitch! */ |
| /* |
| * Using the ^ operator is ambigous. If I have an absolute label |
| * called 'w' set to, say 2, and I have the expression 'w^1', do I get |
| * 1, forced to be in word displacement mode, or do I get the value of |
| * 'w' or'ed with 1 (3 in this case). |
| * The default is 'w' as an offset, so that's what I use. |
| * Stick with `, it does the same, and isn't ambig. |
| */ |
| |
| if (*point != '\0' && ((point[1] == '^') || (point[1] == '`'))) |
| switch (*point) |
| { |
| case 'b': |
| case 'B': |
| case 'w': |
| case 'W': |
| case 'l': |
| case 'L': |
| if (com_width) |
| as_warn (_("Casting a branch displacement is bad form, and is ignored.")); |
| else |
| { |
| c = (isupper (*point) ? tolower (*point) : *point); |
| call_width = ((c == 'b') ? 1 : |
| ((c == 'w') ? 2 : 4)); |
| } |
| point += 2; |
| break; |
| } |
| |
| /* Setting immediate mode */ |
| if (*point == '$') |
| { |
| immediate = 1; |
| point++; |
| } |
| |
| /* |
| * I've pulled off all the easy stuff off the front, move to the end and |
| * yank. |
| */ |
| |
| for (end = point; *end != '\0'; end++) /* Move to the end. */ |
| ; |
| |
| if (end != point) /* Null string? */ |
| end--; |
| |
| if (end > point && *end == ' ' && end[-1] != '\'') |
| end--; /* Hop white space */ |
| |
| /* Is this an index reg. */ |
| if ((*end == ']') && (end[-1] != '\'')) |
| { |
| temp = end; |
| |
| /* Find opening brace. */ |
| for (--end; (*end != '[' && end != point); end--) |
| ; |
| |
| /* If I found the opening brace, get the index register number. */ |
| if (*end == '[') |
| { |
| tp = end + 1; /* tp should point to the start of a reg. */ |
| ndx = tahoe_reg_parse (&tp); |
| if (tp != temp) |
| { /* Reg. parse error. */ |
| ndx = -1; |
| } |
| else |
| { |
| end--; /* Found it, move past brace. */ |
| } |
| if (ndx == -1) |
| { |
| op_bad = _("Couldn't parse the [index] in this operand."); |
| end = point; /* Force all the rest of the tests to fail. */ |
| } |
| } |
| else |
| { |
| op_bad = _("Couldn't find the opening '[' for the index of this operand."); |
| end = point; /* Force all the rest of the tests to fail. */ |
| } |
| } |
| |
| /* Post increment? */ |
| if (*end == '+') |
| { |
| dec_inc = '+'; |
| /* was: *end--; */ |
| end--; |
| } |
| |
| /* register in parens? */ |
| if ((*end == ')') && (end[-1] != '\'')) |
| { |
| temp = end; |
| |
| /* Find opening paren. */ |
| for (--end; (*end != '(' && end != point); end--) |
| ; |
| |
| /* If I found the opening paren, get the register number. */ |
| if (*end == '(') |
| { |
| tp = end + 1; |
| reg = tahoe_reg_parse (&tp); |
| if (tp != temp) |
| { |
| /* Not a register, but could be part of the expression. */ |
| reg = -1; |
| end = temp; /* Rest the pointer back */ |
| } |
| else |
| { |
| end--; /* Found the reg. move before opening paren. */ |
| } |
| } |
| else |
| { |
| op_bad = _("Couldn't find the opening '(' for the deref of this operand."); |
| end = point; /* Force all the rest of the tests to fail. */ |
| } |
| } |
| |
| /* Pre decrement? */ |
| if (*end == '-') |
| { |
| if (dec_inc != ' ') |
| { |
| op_bad = _("Operand can't be both pre-inc and post-dec."); |
| end = point; |
| } |
| else |
| { |
| dec_inc = '-'; |
| /* was: *end--; */ |
| end--; |
| } |
| } |
| |
| /* |
| * Everything between point and end is the 'expression', unless it's |
| * a register name. |
| */ |
| |
| c = end[1]; |
| end[1] = '\0'; |
| |
| tp = point; |
| imreg = tahoe_reg_parse (&point); /* Get the immediate register |
| if it is there.*/ |
| if (*point != '\0') |
| { |
| /* If there is junk after point, then the it's not immediate reg. */ |
| point = tp; |
| imreg = -1; |
| } |
| |
| if (imreg != -1 && reg != -1) |
| op_bad = _("I parsed 2 registers in this operand."); |
| |
| /* |
| * Evaluate whats left of the expression to see if it's valid. |
| * Note again: This assumes that the calling expression has saved |
| * input_line_pointer. (Nag, nag, nag!) |
| */ |
| |
| if (*op_bad == '\0') |
| { |
| /* statement has no syntax goofs yet: lets sniff the expression */ |
| input_line_pointer = point; |
| expP = &(topP->exp_of_operand); |
| topP->seg_of_operand = expression (expP); |
| switch (expP->X_op) |
| { |
| case O_absent: |
| /* No expression. For BSD4.2 compatibility, missing expression is |
| absolute 0 */ |
| expP->X_op = O_constant; |
| expP->X_add_number = 0; |
| really_none = 1; |
| case O_constant: |
| /* for SEG_ABSOLUTE, we shouldnt need to set X_op_symbol, |
| X_add_symbol to any particular value. */ |
| /* But, we will program defensively. Since this situation occurs |
| rarely so it costs us little to do so. */ |
| expP->X_add_symbol = NULL; |
| expP->X_op_symbol = NULL; |
| /* How many bytes are needed to express this abs value? */ |
| abs_width = |
| ((((expP->X_add_number & 0xFFFFFF80) == 0) || |
| ((expP->X_add_number & 0xFFFFFF80) == 0xFFFFFF80)) ? 1 : |
| (((expP->X_add_number & 0xFFFF8000) == 0) || |
| ((expP->X_add_number & 0xFFFF8000) == 0xFFFF8000)) ? 2 : 4); |
| |
| case O_symbol: |
| break; |
| |
| default: |
| /* |
| * Major bug. We can't handle the case of a operator |
| * expression in a synthetic opcode variable-length |
| * instruction. We don't have a frag type that is smart |
| * enough to relax a operator, and so we just force all |
| * operators to behave like SEG_PASS1s. Clearly, if there is |
| * a demand we can invent a new or modified frag type and |
| * then coding up a frag for this case will be easy. |
| */ |
| need_pass_2 = 1; |
| op_bad = _("Can't relocate expression error."); |
| break; |
| |
| case O_big: |
| /* This is an error. Tahoe doesn't allow any expressions |
| bigger that a 32 bit long word. Any bigger has to be referenced |
| by address. */ |
| op_bad = _("Expression is too large for a 32 bits."); |
| break; |
| } |
| if (*input_line_pointer != '\0') |
| { |
| op_bad = _("Junk at end of expression."); |
| } |
| } |
| |
| end[1] = c; |
| |
| /* I'm done, so restore optex */ |
| *optex = segfault; |
| |
| |
| /* |
| * At this point in the game, we (in theory) have all the components of |
| * the operand at least parsed. Now it's time to check for syntax/semantic |
| * errors, and build the mode. |
| * This is what I have: |
| * deferred = 1 if '*' |
| * call_width = 0,1,2,4 |
| * abs_width = 0,1,2,4 |
| * com_width = 0,1,2,4 |
| * immediate = 1 if '$' |
| * ndx = -1 or reg num |
| * dec_inc = '-' or '+' or ' ' |
| * reg = -1 or reg num |
| * imreg = -1 or reg num |
| * topP->exp_of_operand |
| * really_none |
| */ |
| /* Is there a displacement size? */ |
| disp_size = (call_width ? call_width : |
| (com_width ? com_width : |
| abs_width ? abs_width : 0)); |
| |
| if (*op_bad == '\0') |
| { |
| if (imreg != -1) |
| { |
| /* Rn */ |
| mode = TAHOE_DIRECT_REG; |
| if (deferred || immediate || (dec_inc != ' ') || |
| (reg != -1) || !really_none) |
| op_bad = _("Syntax error in direct register mode."); |
| else if (ndx != -1) |
| op_bad = _("You can't index a register in direct register mode."); |
| else if (imreg == SP_REG && access == 'r') |
| op_bad = |
| _("SP can't be the source operand with direct register addressing."); |
| else if (access == 'a') |
| op_bad = _("Can't take the address of a register."); |
| else if (access == 'b') |
| op_bad = _("Direct Register can't be used in a branch."); |
| else if (width == 'q' && ((imreg % 2) || (imreg > 13))) |
| op_bad = _("For quad access, the register must be even and < 14."); |
| else if (call_width) |
| op_bad = _("You can't cast a direct register."); |
| |
| if (*op_bad == '\0') |
| { |
| /* No errors, check for warnings */ |
| if (width == 'q' && imreg == 12) |
| as_warn (_("Using reg 14 for quadwords can tromp the FP register.")); |
| |
| reg = imreg; |
| } |
| |
| /* We know: imm = -1 */ |
| } |
| else if (dec_inc == '-') |
| { |
| /* -(SP) */ |
| mode = TAHOE_AUTO_DEC; |
| if (deferred || immediate || !really_none) |
| op_bad = _("Syntax error in auto-dec mode."); |
| else if (ndx != -1) |
| op_bad = _("You can't have an index auto dec mode."); |
| else if (access == 'r') |
| op_bad = _("Auto dec mode cant be used for reading."); |
| else if (reg != SP_REG) |
| op_bad = _("Auto dec only works of the SP register."); |
| else if (access == 'b') |
| op_bad = _("Auto dec can't be used in a branch."); |
| else if (width == 'q') |
| op_bad = _("Auto dec won't work with quadwords."); |
| |
| /* We know: imm = -1, dec_inc != '-' */ |
| } |
| else if (dec_inc == '+') |
| { |
| if (immediate || !really_none) |
| op_bad = _("Syntax error in one of the auto-inc modes."); |
| else if (deferred) |
| { |
| /* *(SP)+ */ |
| mode = TAHOE_AUTO_INC_DEFERRED; |
| if (reg != SP_REG) |
| op_bad = _("Auto inc deferred only works of the SP register."); |
| else if (ndx != -1) |
| op_bad = _("You can't have an index auto inc deferred mode."); |
| else if (access == 'b') |
| op_bad = _("Auto inc can't be used in a branch."); |
| } |
| else |
| { |
| /* (SP)+ */ |
| mode = TAHOE_AUTO_INC; |
| if (access == 'm' || access == 'w') |
| op_bad = _("You can't write to an auto inc register."); |
| else if (reg != SP_REG) |
| op_bad = _("Auto inc only works of the SP register."); |
| else if (access == 'b') |
| op_bad = _("Auto inc can't be used in a branch."); |
| else if (width == 'q') |
| op_bad = _("Auto inc won't work with quadwords."); |
| else if (ndx != -1) |
| op_bad = _("You can't have an index in auto inc mode."); |
| } |
| |
| /* We know: imm = -1, dec_inc == ' ' */ |
| } |
| else if (reg != -1) |
| { |
| if ((ndx != -1) && (reg == SP_REG)) |
| op_bad = _("You can't index the sp register."); |
| if (deferred) |
| { |
| /* *<disp>(Rn) */ |
| mode = TAHOE_REG_DISP_DEFERRED; |
| if (immediate) |
| op_bad = _("Syntax error in register displaced mode."); |
| } |
| else if (really_none) |
| { |
| /* (Rn) */ |
| mode = TAHOE_REG_DEFERRED; |
| /* if reg = SP then cant be indexed */ |
| } |
| else |
| { |
| /* <disp>(Rn) */ |
| mode = TAHOE_REG_DISP; |
| } |
| |
| /* We know: imm = -1, dec_inc == ' ', Reg = -1 */ |
| } |
| else |
| { |
| if (really_none) |
| op_bad = _("An offest is needed for this operand."); |
| if (deferred && immediate) |
| { |
| /* *$<ADDR> */ |
| mode = TAHOE_ABSOLUTE_ADDR; |
| disp_size = 4; |
| } |
| else if (immediate) |
| { |
| /* $<disp> */ |
| mode = TAHOE_IMMEDIATE; |
| if (ndx != -1) |
| op_bad = _("You can't index a register in immediate mode."); |
| if (access == 'a') |
| op_bad = _("Immediate access can't be used as an address."); |
| /* ponder the wisdom of a cast because it doesn't do any good. */ |
| } |
| else if (deferred) |
| { |
| /* *<disp> */ |
| mode = TAHOE_DISP_REL_DEFERRED; |
| } |
| else |
| { |
| /* <disp> */ |
| mode = TAHOE_DISPLACED_RELATIVE; |
| } |
| } |
| } |
| |
| /* |
| * At this point, all the errors we can do have be checked for. |
| * We can build the 'top'. */ |
| |
| topP->top_ndx = ndx; |
| topP->top_reg = reg; |
| topP->top_mode = mode; |
| topP->top_error = op_bad; |
| topP->top_dispsize = disp_size; |
| } /* tip_op */ |
| |
| /* |
| * t i p ( ) |
| * |
| * This converts a string into a tahoe instruction. |
| * The string must be a bare single instruction in tahoe (with BSD4 frobs) |
| * format. |
| * It provides at most one fatal error message (which stops the scan) |
| * some warning messages as it finds them. |
| * The tahoe instruction is returned in exploded form. |
| * |
| * The exploded instruction is returned to a struct tit of your choice. |
| * #include "tahoe-inst.h" to know what a struct tit is. |
| * |
| */ |
| |
| static void |
| tip (titP, instring) |
| struct tit *titP; /* We build an exploded instruction here. */ |
| char *instring; /* Text of a vax instruction: we modify. */ |
| { |
| register struct tot_wot *twP = NULL; /* How to bit-encode this opcode. */ |
| register char *p; /* 1/skip whitespace.2/scan vot_how */ |
| register char *q; /* */ |
| register unsigned char count; /* counts number of operands seen */ |
| register struct top *operandp;/* scan operands in struct tit */ |
| register char *alloperr = ""; /* error over all operands */ |
| register char c; /* Remember char, (we clobber it |
| with '\0' temporarily). */ |
| char *save_input_line_pointer; |
| |
| if (*instring == ' ') |
| ++instring; /* Skip leading whitespace. */ |
| for (p = instring; *p && *p != ' '; p++) |
| ; /* MUST end in end-of-string or |
| exactly 1 space. */ |
| /* Scanned up to end of operation-code. */ |
| /* Operation-code is ended with whitespace. */ |
| if (p == instring) |
| { |
| titP->tit_error = _("No operator"); |
| count = 0; |
| titP->tit_opcode = 0; |
| } |
| else |
| { |
| c = *p; |
| *p = '\0'; |
| /* |
| * Here with instring pointing to what better be an op-name, and p |
| * pointing to character just past that. |
| * We trust instring points to an op-name, with no whitespace. |
| */ |
| twP = (struct tot_wot *) hash_find (op_hash, instring); |
| *p = c; /* Restore char after op-code. */ |
| if (twP == 0) |
| { |
| titP->tit_error = _("Unknown operator"); |
| count = 0; |
| titP->tit_opcode = 0; |
| } |
| else |
| { |
| /* |
| * We found a match! So lets pick up as many operands as the |
| * instruction wants, and even gripe if there are too many. |
| * We expect comma to seperate each operand. |
| * We let instring track the text, while p tracks a part of the |
| * struct tot. |
| */ |
| |
| count = 0; /* no operands seen yet */ |
| instring = p + (*p != '\0'); /* point past the operation code */ |
| /* tip_op() screws with the input_line_pointer, so save it before |
| I jump in */ |
| save_input_line_pointer = input_line_pointer; |
| for (p = twP->args, operandp = titP->tit_operand; |
| !*alloperr && *p; |
| operandp++, p += 2) |
| { |
| /* |
| * Here to parse one operand. Leave instring pointing just |
| * past any one ',' that marks the end of this operand. |
| */ |
| if (!p[1]) |
| as_fatal (_("Compiler bug: ODD number of bytes in arg structure %s."), |
| twP->args); |
| else if (*instring) |
| { |
| for (q = instring; (*q != ',' && *q != '\0'); q++) |
| { |
| if (*q == '\'' && q[1] != '\0') /* Jump quoted characters */ |
| q++; |
| } |
| c = *q; |
| /* |
| * Q points to ',' or '\0' that ends argument. C is that |
| * character. |
| */ |
| *q = '\0'; |
| operandp->top_access = p[0]; |
| operandp->top_width = p[1]; |
| tip_op (instring - 1, operandp); |
| *q = c; /* Restore input text. */ |
| if (*(operandp->top_error)) |
| { |
| alloperr = operandp->top_error; |
| } |
| instring = q + (c ? 1 : 0); /* next operand (if any) */ |
| count++; /* won another argument, may have an operr */ |
| } |
| else |
| alloperr = _("Not enough operands"); |
| } |
| /* Restore the pointer. */ |
| input_line_pointer = save_input_line_pointer; |
| |
| if (!*alloperr) |
| { |
| if (*instring == ' ') |
| instring++; /* Skip whitespace. */ |
| if (*instring) |
| alloperr = _("Too many operands"); |
| } |
| titP->tit_error = alloperr; |
| } |
| } |
| |
| titP->tit_opcode = twP->code; /* The op-code. */ |
| titP->tit_operands = count; |
| } /* tip */ |
| |
| /* md_assemble() emit frags for 1 instruction */ |
| void |
| md_assemble (instruction_string) |
| char *instruction_string; /* A string: assemble 1 instruction. */ |
| { |
| char *p; |
| register struct top *operandP;/* An operand. Scans all operands. */ |
| /* char c_save; fixme: remove this line *//* What used to live after an expression. */ |
| /* struct frag *fragP; fixme: remove this line *//* Fragment of code we just made. */ |
| /* register struct top *end_operandP; fixme: remove this line *//* -> slot just after last operand |
| Limit of the for (each operand). */ |
| register expressionS *expP; /* -> expression values for this operand */ |
| |
| /* These refer to an instruction operand expression. */ |
| segT to_seg; /* Target segment of the address. */ |
| |
| register valueT this_add_number; |
| register symbolS *this_add_symbol; /* +ve (minuend) symbol. */ |
| |
| /* tahoe_opcodeT opcode_as_number; fixme: remove this line *//* The opcode as a number. */ |
| char *opcodeP; /* Where it is in a frag. */ |
| /* char *opmodeP; fixme: remove this line *//* Where opcode type is, in a frag. */ |
| |
| int dispsize; /* From top_dispsize: tahoe_operand_width |
| (in bytes) */ |
| int is_undefined; /* 1 if operand expression's |
| segment not known yet. */ |
| int pc_rel; /* Is this operand pc relative? */ |
| |
| /* Decode the operand. */ |
| tip (&t, instruction_string); |
| |
| /* |
| * Check to see if this operand decode properly. |
| * Notice that we haven't made any frags yet. |
| * If it goofed, then this instruction will wedge in any pass, |
| * and we can safely flush it, without causing interpass symbol phase |
| * errors. That is, without changing label values in different passes. |
| */ |
| if (*t.tit_error) |
| { |
| as_warn (_("Ignoring statement due to \"%s\""), t.tit_error); |
| } |
| else |
| { |
| /* We saw no errors in any operands - try to make frag(s) */ |
| /* Emit op-code. */ |
| /* Remember where it is, in case we want to modify the op-code later. */ |
| opcodeP = frag_more (1); |
| *opcodeP = t.tit_opcode; |
| /* Now do each operand. */ |
| for (operandP = t.tit_operand; |
| operandP < t.tit_operand + t.tit_operands; |
| operandP++) |
| { /* for each operand */ |
| expP = &(operandP->exp_of_operand); |
| if (operandP->top_ndx >= 0) |
| { |
| /* Indexed addressing byte |
| Legality of indexed mode already checked: it is OK */ |
| FRAG_APPEND_1_CHAR (0x40 + operandP->top_ndx); |
| } /* if(top_ndx>=0) */ |
| |
| /* Here to make main operand frag(s). */ |
| this_add_number = expP->X_add_number; |
| this_add_symbol = expP->X_add_symbol; |
| to_seg = operandP->seg_of_operand; |
| know (to_seg == SEG_UNKNOWN || \ |
| to_seg == SEG_ABSOLUTE || \ |
| to_seg == SEG_DATA || \ |
| to_seg == SEG_TEXT || \ |
| to_seg == SEG_BSS); |
| is_undefined = (to_seg == SEG_UNKNOWN); |
| /* Do we know how big this opperand is? */ |
| dispsize = operandP->top_dispsize; |
| pc_rel = 0; |
| /* Deal with the branch possabilities. (Note, this doesn't include |
| jumps.)*/ |
| if (operandP->top_access == 'b') |
| { |
| /* Branches must be expressions. A psuedo branch can also jump to |
| an absolute address. */ |
| if (to_seg == now_seg || is_undefined) |
| { |
| /* If is_undefined, then it might BECOME now_seg by relax time. */ |
| if (dispsize) |
| { |
| /* I know how big the branch is supposed to be (it's a normal |
| branch), so I set up the frag, and let GAS do the rest. */ |
| p = frag_more (dispsize); |
| fix_new (frag_now, p - frag_now->fr_literal, |
| this_add_symbol, this_add_number, |
| size_to_fx (dispsize, 1), |
| NULL); |
| } |
| else |
| { |
| /* (to_seg==now_seg || to_seg == SEG_UNKNOWN) && dispsize==0 */ |
| /* If we don't know how big it is, then its a synthetic branch, |
| so we set up a simple relax state. */ |
| switch (operandP->top_width) |
| { |
| case TAHOE_WIDTH_CONDITIONAL_JUMP: |
| /* Simple (conditional) jump. I may have to reverse the |
| condition of opcodeP, and then jump to my destination. |
| I set 1 byte aside for the branch off set, and could need 6 |
| more bytes for the pc_rel jump */ |
| frag_var (rs_machine_dependent, 7, 1, |
| ENCODE_RELAX (STATE_CONDITIONAL_BRANCH, |
| is_undefined ? STATE_UNDF : STATE_BYTE), |
| this_add_symbol, this_add_number, opcodeP); |
| break; |
| case TAHOE_WIDTH_ALWAYS_JUMP: |
| /* Simple (unconditional) jump. I may have to convert this to |
| a word branch, or an absolute jump. */ |
| frag_var (rs_machine_dependent, 5, 1, |
| ENCODE_RELAX (STATE_ALWAYS_BRANCH, |
| is_undefined ? STATE_UNDF : STATE_BYTE), |
| this_add_symbol, this_add_number, opcodeP); |
| break; |
| /* The smallest size for the next 2 cases is word. */ |
| case TAHOE_WIDTH_BIG_REV_JUMP: |
| frag_var (rs_machine_dependent, 8, 2, |
| ENCODE_RELAX (STATE_BIG_REV_BRANCH, |
| is_undefined ? STATE_UNDF : STATE_WORD), |
| this_add_symbol, this_add_number, |
| opcodeP); |
| break; |
| case TAHOE_WIDTH_BIG_NON_REV_JUMP: |
| frag_var (rs_machine_dependent, 10, 2, |
| ENCODE_RELAX (STATE_BIG_NON_REV_BRANCH, |
| is_undefined ? STATE_UNDF : STATE_WORD), |
| this_add_symbol, this_add_number, |
| opcodeP); |
| break; |
| default: |
| as_fatal (_("Compliler bug: Got a case (%d) I wasn't expecting."), |
| operandP->top_width); |
| } |
| } |
| } |
| else |
| { |
| /* to_seg != now_seg && to_seg != seg_unknown (still in branch) |
| In other words, I'm jumping out of my segment so extend the |
| branches to jumps, and let GAS fix them. */ |
| |
| /* These are "branches" what will always be branches around a jump |
| to the correct addresss in real life. |
| If to_seg is SEG_ABSOLUTE, just encode the branch in, |
| else let GAS fix the address. */ |
| |
| switch (operandP->top_width) |
| { |
| /* The theory: |
| For SEG_ABSOLUTE, then mode is ABSOLUTE_ADDR, jump |
| to that addresss (not pc_rel). |
| For other segs, address is a long word PC rel jump. */ |
| case TAHOE_WIDTH_CONDITIONAL_JUMP: |
| /* b<cond> */ |
| /* To reverse the condition in a TAHOE branch, |
| complement bit 4 */ |
| *opcodeP ^= 0x10; |
| p = frag_more (7); |
| *p++ = 6; |
| *p++ = TAHOE_JMP; |
| *p++ = (operandP->top_mode == |
| TAHOE_ABSOLUTE_ADDR ? TAHOE_ABSOLUTE_ADDR : |
| TAHOE_PC_REL_LONG); |
| fix_new (frag_now, p - frag_now->fr_literal, |
| this_add_symbol, this_add_number, |
| (to_seg != SEG_ABSOLUTE) ? FX_PCREL32 : FX_32, NULL); |
| /* |
| * Now (eg) BLEQ 1f |
| * JMP foo |
| * 1: |
| */ |
| break; |
| case TAHOE_WIDTH_ALWAYS_JUMP: |
| /* br, just turn it into a jump */ |
| *opcodeP = TAHOE_JMP; |
| p = frag_more (5); |
| *p++ = (operandP->top_mode == |
| TAHOE_ABSOLUTE_ADDR ? TAHOE_ABSOLUTE_ADDR : |
| TAHOE_PC_REL_LONG); |
| fix_new (frag_now, p - frag_now->fr_literal, |
| this_add_symbol, this_add_number, |
| (to_seg != SEG_ABSOLUTE) ? FX_PCREL32 : FX_32, NULL); |
| /* Now (eg) JMP foo */ |
| break; |
| case TAHOE_WIDTH_BIG_REV_JUMP: |
| p = frag_more (8); |
| *opcodeP ^= 0x10; |
| *p++ = 0; |
| *p++ = 6; |
| *p++ = TAHOE_JMP; |
| *p++ = (operandP->top_mode == |
| TAHOE_ABSOLUTE_ADDR ? TAHOE_ABSOLUTE_ADDR : |
| TAHOE_PC_REL_LONG); |
| fix_new (frag_now, p - frag_now->fr_literal, |
| this_add_symbol, this_add_number, |
| (to_seg != SEG_ABSOLUTE) ? FX_PCREL32 : FX_32, NULL); |
| /* |
| * Now (eg) ACBx 1f |
| * JMP foo |
| * 1: |
| */ |
| break; |
| case TAHOE_WIDTH_BIG_NON_REV_JUMP: |
| p = frag_more (10); |
| *p++ = 0; |
| *p++ = 2; |
| *p++ = TAHOE_BRB; |
| *p++ = 6; |
| *p++ = TAHOE_JMP; |
| *p++ = (operandP->top_mode == |
| TAHOE_ABSOLUTE_ADDR ? TAHOE_ABSOLUTE_ADDR : |
| TAHOE_PC_REL_LONG); |
| fix_new (frag_now, p - frag_now->fr_literal, |
| this_add_symbol, this_add_number, |
| (to_seg != SEG_ABSOLUTE) ? FX_PCREL32 : FX_32, NULL); |
| /* |
| * Now (eg) xOBxxx 1f |
| * BRB 2f |
| * 1: JMP @#foo |
| * 2: |
| */ |
| break; |
| case 'b': |
| case 'w': |
| as_warn (_("Real branch displacements must be expressions.")); |
| break; |
| default: |
| as_fatal (_("Complier error: I got an unknown synthetic branch :%c"), |
| operandP->top_width); |
| break; |
| } |
| } |
| } |
| else |
| { |
| /* It ain't a branch operand. */ |
| switch (operandP->top_mode) |
| { |
| /* Auto-foo access, only works for one reg (SP) |
| so the only thing needed is the mode. */ |
| case TAHOE_AUTO_DEC: |
| case TAHOE_AUTO_INC: |
| case TAHOE_AUTO_INC_DEFERRED: |
| FRAG_APPEND_1_CHAR (operandP->top_mode); |
| break; |
| |
| /* Numbered Register only access. Only thing needed is the |
| mode + Register number */ |
| case TAHOE_DIRECT_REG: |
| case TAHOE_REG_DEFERRED: |
| FRAG_APPEND_1_CHAR (operandP->top_mode + operandP->top_reg); |
| break; |
| |
| /* An absolute address. It's size is always 5 bytes. |
| (mode_type + 4 byte address). */ |
| case TAHOE_ABSOLUTE_ADDR: |
| know ((this_add_symbol == NULL)); |
| p = frag_more (5); |
| *p = TAHOE_ABSOLUTE_ADDR; |
| md_number_to_chars (p + 1, this_add_number, 4); |
| break; |
| |
| /* Immediate data. If the size isn't known, then it's an address |
| + and offset, which is 4 bytes big. */ |
| case TAHOE_IMMEDIATE: |
| if (this_add_symbol != NULL) |
| { |
| p = frag_more (5); |
| *p++ = TAHOE_IMMEDIATE_LONGWORD; |
| fix_new (frag_now, p - frag_now->fr_literal, |
| this_add_symbol, this_add_number, |
| FX_32, NULL); |
| } |
| else |
| { |
| /* It's a integer, and I know it's size. */ |
| if ((unsigned) this_add_number < 0x40) |
| { |
| /* Will it fit in a literal? */ |
| FRAG_APPEND_1_CHAR ((byte) this_add_number); |
| } |
| else |
| { |
| p = frag_more (dispsize + 1); |
| switch (dispsize) |
| { |
| case 1: |
| *p++ = TAHOE_IMMEDIATE_BYTE; |
| *p = (byte) this_add_number; |
| break; |
| case 2: |
| *p++ = TAHOE_IMMEDIATE_WORD; |
| md_number_to_chars (p, this_add_number, 2); |
| break; |
| case 4: |
| *p++ = TAHOE_IMMEDIATE_LONGWORD; |
| md_number_to_chars (p, this_add_number, 4); |
| break; |
| } |
| } |
| } |
| break; |
| |
| /* Distance from the PC. If the size isn't known, we have to relax |
| into it. The difference between this and disp(sp) is that |
| this offset is pc_rel, and disp(sp) isn't. |
| Note the drop through code. */ |
| |
| case TAHOE_DISPLACED_RELATIVE: |
| case TAHOE_DISP_REL_DEFERRED: |
| operandP->top_reg = PC_REG; |
| pc_rel = 1; |
| |
| /* Register, plus a displacement mode. Save the register number, |
| and weather its deffered or not, and relax the size if it isn't |
| known. */ |
| case TAHOE_REG_DISP: |
| case TAHOE_REG_DISP_DEFERRED: |
| if (operandP->top_mode == TAHOE_DISP_REL_DEFERRED || |
| operandP->top_mode == TAHOE_REG_DISP_DEFERRED) |
| operandP->top_reg += 0x10; /* deffered mode is always 0x10 higher |
| than it's non-deffered sibling. */ |
| |
| /* Is this a value out of this segment? |
| The first part of this conditional is a cludge to make gas |
| produce the same output as 'as' when there is a lable, in |
| the current segment, displaceing a register. It's strange, |
| and no one in their right mind would do it, but it's easy |
| to cludge. */ |
| if ((dispsize == 0 && !pc_rel) || |
| (to_seg != now_seg && !is_undefined && to_seg != SEG_ABSOLUTE)) |
| dispsize = 4; |
| |
| if (dispsize == 0) |
| { |
| /* |
| * We have a SEG_UNKNOWN symbol, or the size isn't cast. |
| * It might turn out to be in the same segment as |
| * the instruction, permitting relaxation. |
| */ |
| p = frag_var (rs_machine_dependent, 5, 2, |
| ENCODE_RELAX (STATE_PC_RELATIVE, |
| is_undefined ? STATE_UNDF : STATE_BYTE), |
| this_add_symbol, this_add_number, 0); |
| *p = operandP->top_reg; |
| } |
| else |
| { |
| /* Either this is an abs, or a cast. */ |
| p = frag_more (dispsize + 1); |
| switch (dispsize) |
| { |
| case 1: |
| *p = TAHOE_PC_OR_BYTE + operandP->top_reg; |
| break; |
| case 2: |
| *p = TAHOE_PC_OR_WORD + operandP->top_reg; |
| break; |
| case 4: |
| *p = TAHOE_PC_OR_LONG + operandP->top_reg; |
| break; |
| }; |
| fix_new (frag_now, p + 1 - frag_now->fr_literal, |
| this_add_symbol, this_add_number, |
| size_to_fx (dispsize, pc_rel), NULL); |
| } |
| break; |
| default: |
| as_fatal (_("Barf, bad mode %x\n"), operandP->top_mode); |
| } |
| } |
| } /* for(operandP) */ |
| } /* if(!need_pass_2 && !goofed) */ |
| } /* tahoe_assemble() */ |
| |
| |
| /* We have no need to default values of symbols. */ |
| |
| /* ARGSUSED */ |
| symbolS * |
| md_undefined_symbol (name) |
| char *name; |
| { |
| return 0; |
| } /* md_undefined_symbol() */ |
| |
| /* Round up a section size to the appropriate boundary. */ |
| valueT |
| md_section_align (segment, size) |
| segT segment; |
| valueT size; |
| { |
| return ((size + 7) & ~7); /* Round all sects to multiple of 8 */ |
| } /* md_section_align() */ |
| |
| /* Exactly what point is a PC-relative offset relative TO? |
| On the sparc, they're relative to the address of the offset, plus |
| its size. This gets us to the following instruction. |
| (??? Is this right? FIXME-SOON) */ |
| long |
| md_pcrel_from (fixP) |
| fixS *fixP; |
| { |
| return (((fixP->fx_type == FX_8 |
| || fixP->fx_type == FX_PCREL8) |
| ? 1 |
| : ((fixP->fx_type == FX_16 |
| || fixP->fx_type == FX_PCREL16) |
| ? 2 |
| : ((fixP->fx_type == FX_32 |
| || fixP->fx_type == FX_PCREL32) |
| ? 4 |
| : 0))) + fixP->fx_where + fixP->fx_frag->fr_address); |
| } /* md_pcrel_from() */ |
| |
| int |
| tc_is_pcrel (fixP) |
| fixS *fixP; |
| { |
| /* should never be called */ |
| know (0); |
| return (0); |
| } /* tc_is_pcrel() */ |
| |
| /* end of tc-tahoe.c */ |