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authorH. Peter Anvin <hpa@zytor.com>2002-04-30 20:51:32 +0000
committerH. Peter Anvin <hpa@zytor.com>2002-04-30 20:51:32 +0000
commitea6e34db64c7da7cb885197316c6b5e7d048bdb9 (patch)
tree78e728348f8fe09e394a51c3617e6261de0f4001 /assemble.c
downloadnasm-ea6e34db64c7da7cb885197316c6b5e7d048bdb9.tar.gz
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NASM 0.91nasm-0.91
Diffstat (limited to 'assemble.c')
-rw-r--r--assemble.c945
1 files changed, 945 insertions, 0 deletions
diff --git a/assemble.c b/assemble.c
new file mode 100644
index 00000000..bab6f292
--- /dev/null
+++ b/assemble.c
@@ -0,0 +1,945 @@
+/* assemble.c code generation for the Netwide Assembler
+ *
+ * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
+ * Julian Hall. All rights reserved. The software is
+ * redistributable under the licence given in the file "Licence"
+ * distributed in the NASM archive.
+ *
+ * the actual codes (C syntax, i.e. octal):
+ * \0 - terminates the code. (Unless it's a literal of course.)
+ * \1, \2, \3 - that many literal bytes follow in the code stream
+ * \4, \6 - the POP/PUSH (respectively) codes for CS, DS, ES, SS
+ * (POP is never used for CS) depending on operand 0
+ * \5, \7 - the second byte of POP/PUSH codes for FS, GS, depending
+ * on operand 0
+ * \10, \11, \12 - a literal byte follows in the code stream, to be added
+ * to the register value of operand 0, 1 or 2
+ * \17 - encodes the literal byte 0. (Some compilers don't take
+ * kindly to a zero byte in the _middle_ of a compile time
+ * string constant, so I had to put this hack in.)
+ * \14, \15, \16 - a signed byte immediate operand, from operand 0, 1 or 2
+ * \20, \21, \22 - a byte immediate operand, from operand 0, 1 or 2
+ * \24, \25, \26 - an unsigned byte immediate operand, from operand 0, 1 or 2
+ * \30, \31, \32 - a word immediate operand, from operand 0, 1 or 2
+ * \34, \35, \36 - select between \3[012] and \4[012] depending on 16/32 bit
+ * assembly mode or the address-size override on the operand
+ * \37 - a word constant, from the _segment_ part of operand 0
+ * \40, \41, \42 - a long immediate operand, from operand 0, 1 or 2
+ * \50, \51, \52 - a byte relative operand, from operand 0, 1 or 2
+ * \60, \61, \62 - a word relative operand, from operand 0, 1 or 2
+ * \64, \65, \66 - select between \6[012] and \7[012] depending on 16/32 bit
+ * assembly mode or the address-size override on the operand
+ * \70, \71, \72 - a long relative operand, from operand 0, 1 or 2
+ * \1ab - a ModRM, calculated on EA in operand a, with the spare
+ * field the register value of operand b.
+ * \2ab - a ModRM, calculated on EA in operand a, with the spare
+ * field equal to digit b.
+ * \30x - might be an 0x67 byte, depending on the address size of
+ * the memory reference in operand x.
+ * \310 - indicates fixed 16-bit address size, i.e. optional 0x67.
+ * \311 - indicates fixed 32-bit address size, i.e. optional 0x67.
+ * \320 - indicates fixed 16-bit operand size, i.e. optional 0x66.
+ * \321 - indicates fixed 32-bit operand size, i.e. optional 0x66.
+ * \322 - indicates that this instruction is only valid when the
+ * operand size is the default (instruction to disassembler,
+ * generates no code in the assembler)
+ * \330 - a literal byte follows in the code stream, to be added
+ * to the condition code value of the instruction.
+ * \340 - reserve <operand 0> bytes of uninitialised storage.
+ * Operand 0 had better be a segmentless constant.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "nasm.h"
+#include "assemble.h"
+#include "insns.h"
+
+extern struct itemplate *nasm_instructions[];
+
+typedef struct {
+ int sib_present; /* is a SIB byte necessary? */
+ int bytes; /* # of bytes of offset needed */
+ int size; /* lazy - this is sib+bytes+1 */
+ unsigned char modrm, sib; /* the bytes themselves */
+} ea;
+
+static efunc errfunc;
+static struct ofmt *outfmt;
+
+static long calcsize (long, long, int, insn *, char *);
+static void gencode (long, long, int, insn *, char *, long);
+static int regval (operand *o);
+static int matches (struct itemplate *, insn *);
+static ea *process_ea (operand *, ea *, int, int);
+static int chsize (operand *, int);
+
+long assemble (long segment, long offset, int bits,
+ insn *instruction, struct ofmt *output, efunc error) {
+ int j, itimes, size_prob;
+ long insn_end;
+ long start = offset;
+ struct itemplate *temp;
+
+ errfunc = error; /* to pass to other functions */
+ outfmt = output; /* likewise */
+
+ if (instruction->opcode == -1)
+ return 0;
+
+ if (instruction->opcode == I_DB ||
+ instruction->opcode == I_DW ||
+ instruction->opcode == I_DD ||
+ instruction->opcode == I_DQ ||
+ instruction->opcode == I_DT) {
+ extop *e;
+ long osize, wsize = 0; /* placate gcc */
+ int t = instruction->times;
+
+ switch (instruction->opcode) {
+ case I_DB: wsize = 1; break;
+ case I_DW: wsize = 2; break;
+ case I_DD: wsize = 4; break;
+ case I_DQ: wsize = 8; break;
+ case I_DT: wsize = 10; break;
+ }
+
+ while (t--) {
+ for (e = instruction->eops; e; e = e->next) {
+ osize = 0;
+ if (e->type == EOT_DB_NUMBER) {
+ if (wsize == 1) {
+ if (e->segment != NO_SEG)
+ errfunc (ERR_NONFATAL,
+ "one-byte relocation attempted");
+ else {
+ unsigned char c = e->offset;
+ outfmt->output (segment, &c, OUT_RAWDATA+1,
+ NO_SEG, NO_SEG);
+ }
+ } else if (wsize > 5) {
+ errfunc (ERR_NONFATAL, "integer supplied to a D%c"
+ " instruction", wsize==8 ? 'Q' : 'T');
+ } else
+ outfmt->output (segment, &e->offset,
+ OUT_ADDRESS+wsize, e->segment,
+ e->wrt);
+ offset += wsize;
+ } else if (e->type == EOT_DB_STRING) {
+ int align;
+
+ align = (-e->stringlen) % wsize;
+ if (align < 0)
+ align += wsize;
+ outfmt->output (segment, e->stringval,
+ OUT_RAWDATA+e->stringlen, NO_SEG, NO_SEG);
+ if (align)
+ outfmt->output (segment, "\0\0\0\0",
+ OUT_RAWDATA+align, NO_SEG, NO_SEG);
+ offset += e->stringlen + align;
+ }
+ }
+ }
+ return offset - start;
+ }
+
+ size_prob = FALSE;
+ temp = nasm_instructions[instruction->opcode];
+ while (temp->opcode != -1) {
+ int m = matches (temp, instruction);
+ if (m == 100) { /* matches! */
+ char *codes = temp->code;
+ long insn_size = calcsize(segment, offset, bits,
+ instruction, codes);
+ itimes = instruction->times;
+ if (insn_size < 0) /* shouldn't be, on pass two */
+ error (ERR_PANIC, "errors made it through from pass one");
+ else while (itimes--) {
+ insn_end = offset + insn_size;
+ for (j=0; j<instruction->nprefix; j++) {
+ unsigned char c;
+ switch (instruction->prefixes[j]) {
+ case P_LOCK:
+ c = 0xF0; break;
+ case P_REPNE: case P_REPNZ:
+ c = 0xF2; break;
+ case P_REPE: case P_REPZ: case P_REP:
+ c = 0xF3; break;
+ case R_CS: c = 0x2E; break;
+ case R_DS: c = 0x3E; break;
+ case R_ES: c = 0x26; break;
+ case R_FS: c = 0x64; break;
+ case R_GS: c = 0x65; break;
+ case R_SS: c = 0x36; break;
+ case P_A16:
+ if (bits == 16)
+ c = 0; /* no prefix */
+ else
+ c = 0x67;
+ break;
+ case P_A32:
+ if (bits == 32)
+ c = 0; /* no prefix */
+ else
+ c = 0x67;
+ break;
+ case P_O16:
+ if (bits == 16)
+ c = 0; /* no prefix */
+ else
+ c = 0x66;
+ break;
+ case P_O32:
+ if (bits == 32)
+ c = 0; /* no prefix */
+ else
+ c = 0x66;
+ break;
+ default:
+ error (ERR_PANIC,
+ "invalid instruction prefix");
+ }
+ if (c != 0)
+ outfmt->output (segment, &c, OUT_RAWDATA+1,
+ NO_SEG, NO_SEG);
+ offset++;
+ }
+ gencode (segment, offset, bits, instruction, codes, insn_end);
+ offset += insn_size;
+ }
+ return offset - start;
+ } else if (m > 0) {
+ size_prob = m;
+ }
+ temp++;
+ }
+ if (temp->opcode == -1) { /* didn't match any instruction */
+ if (size_prob == 1) /* would have matched, but for size */
+ error (ERR_NONFATAL, "operation size not specified");
+ else if (size_prob == 2)
+ error (ERR_NONFATAL, "mismatch in operand sizes");
+ else
+ error (ERR_NONFATAL,
+ "invalid combination of opcode and operands");
+ }
+ return 0;
+}
+
+long insn_size (long segment, long offset, int bits,
+ insn *instruction, efunc error) {
+ struct itemplate *temp;
+
+ errfunc = error; /* to pass to other functions */
+
+ if (instruction->opcode == -1)
+ return 0;
+
+ if (instruction->opcode == I_DB ||
+ instruction->opcode == I_DW ||
+ instruction->opcode == I_DD ||
+ instruction->opcode == I_DQ ||
+ instruction->opcode == I_DT) {
+ extop *e;
+ long isize, osize, wsize = 0; /* placate gcc */
+
+ isize = 0;
+ switch (instruction->opcode) {
+ case I_DB: wsize = 1; break;
+ case I_DW: wsize = 2; break;
+ case I_DD: wsize = 4; break;
+ case I_DQ: wsize = 8; break;
+ case I_DT: wsize = 10; break;
+ }
+
+ for (e = instruction->eops; e; e = e->next) {
+ long align;
+
+ osize = 0;
+ if (e->type == EOT_DB_NUMBER)
+ osize = 1;
+ else if (e->type == EOT_DB_STRING)
+ osize = e->stringlen;
+
+ align = (-osize) % wsize;
+ if (align < 0)
+ align += wsize;
+ isize += osize + align;
+ }
+ return isize * instruction->times;
+ }
+
+ temp = nasm_instructions[instruction->opcode];
+ while (temp->opcode != -1) {
+ if (matches(temp, instruction) == 100) {
+ /* we've matched an instruction. */
+ long isize;
+ char *codes = temp->code;
+ int j;
+
+ isize = calcsize(segment, offset, bits, instruction, codes);
+ if (isize < 0)
+ return -1;
+ for (j = 0; j < instruction->nprefix; j++) {
+ if ((instruction->prefixes[j] != P_A16 &&
+ instruction->prefixes[j] != P_O16 && bits==16) ||
+ (instruction->prefixes[j] != P_A32 &&
+ instruction->prefixes[j] != P_O32 && bits==32))
+ isize++;
+ }
+ return isize * instruction->times;
+ }
+ temp++;
+ }
+ return -1; /* didn't match any instruction */
+}
+
+static long calcsize (long segment, long offset, int bits,
+ insn *ins, char *codes) {
+ long length = 0;
+ unsigned char c;
+
+ while (*codes) switch (c = *codes++) {
+ case 01: case 02: case 03:
+ codes += c, length += c; break;
+ case 04: case 05: case 06: case 07:
+ length++; break;
+ case 010: case 011: case 012:
+ codes++, length++; break;
+ case 017:
+ length++; break;
+ case 014: case 015: case 016:
+ length++; break;
+ case 020: case 021: case 022:
+ length++; break;
+ case 024: case 025: case 026:
+ length++; break;
+ case 030: case 031: case 032:
+ length += 2; break;
+ case 034: case 035: case 036:
+ length += ((ins->oprs[c-034].addr_size ?
+ ins->oprs[c-034].addr_size : bits) == 16 ? 2 : 4); break;
+ case 037:
+ length += 2; break;
+ case 040: case 041: case 042:
+ length += 4; break;
+ case 050: case 051: case 052:
+ length++; break;
+ case 060: case 061: case 062:
+ length += 2; break;
+ case 064: case 065: case 066:
+ length += ((ins->oprs[c-064].addr_size ?
+ ins->oprs[c-064].addr_size : bits) == 16 ? 2 : 4); break;
+ case 070: case 071: case 072:
+ length += 4; break;
+ case 0300: case 0301: case 0302:
+ length += chsize (&ins->oprs[c-0300], bits);
+ break;
+ case 0310:
+ length += (bits==32);
+ break;
+ case 0311:
+ length += (bits==16);
+ break;
+ case 0312:
+ break;
+ case 0320:
+ length += (bits==32);
+ break;
+ case 0321:
+ length += (bits==16);
+ break;
+ case 0322:
+ break;
+ case 0330:
+ codes++, length++; break;
+ case 0340: case 0341: case 0342:
+ if (ins->oprs[0].segment != NO_SEG)
+ errfunc (ERR_NONFATAL, "attempt to reserve non-constant"
+ " quantity of BSS space");
+ else
+ length += ins->oprs[0].offset << (c-0340);
+ break;
+ default: /* can't do it by 'case' statements */
+ if (c>=0100 && c<=0277) { /* it's an EA */
+ ea ea_data;
+
+ if (!process_ea (&ins->oprs[(c>>3)&7], &ea_data, bits, 0)) {
+ errfunc (ERR_NONFATAL, "invalid effective address");
+ return -1;
+ } else
+ length += ea_data.size;
+ } else
+ errfunc (ERR_PANIC, "internal instruction table corrupt"
+ ": instruction code 0x%02X given", c);
+ }
+ return length;
+}
+
+static void gencode (long segment, long offset, int bits,
+ insn *ins, char *codes, long insn_end) {
+ static char condval[] = { /* conditional opcodes */
+ 0x7, 0x3, 0x2, 0x6, 0x2, 0x4, 0xF, 0xD, 0xC, 0xE, 0x6, 0x2,
+ 0x3, 0x7, 0x3, 0x5, 0xE, 0xC, 0xD, 0xF, 0x1, 0xB, 0x9, 0x5,
+ 0x0, 0xA, 0xA, 0xB, 0x8, 0x4
+ };
+ unsigned char c, bytes[4];
+ long data, size;
+
+ while (*codes) switch (c = *codes++) {
+ case 01: case 02: case 03:
+ outfmt->output (segment, codes, OUT_RAWDATA+c, NO_SEG, NO_SEG);
+ codes += c;
+ offset += c;
+ break;
+ case 04: case 06:
+ switch (ins->oprs[0].basereg) {
+ case R_CS: bytes[0] = 0x0E + (c == 0x04 ? 1 : 0); break;
+ case R_DS: bytes[0] = 0x1E + (c == 0x04 ? 1 : 0); break;
+ case R_ES: bytes[0] = 0x06 + (c == 0x04 ? 1 : 0); break;
+ case R_SS: bytes[0] = 0x16 + (c == 0x04 ? 1 : 0); break;
+ default:
+ errfunc (ERR_PANIC, "bizarre 8086 segment register received");
+ }
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset++;
+ break;
+ case 05: case 07:
+ switch (ins->oprs[0].basereg) {
+ case R_FS: bytes[0] = 0xA0 + (c == 0x05 ? 1 : 0); break;
+ case R_GS: bytes[0] = 0xA8 + (c == 0x05 ? 1 : 0); break;
+ default:
+ errfunc (ERR_PANIC, "bizarre 386 segment register received");
+ }
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset++;
+ break;
+ case 010: case 011: case 012:
+ bytes[0] = *codes++ + regval(&ins->oprs[c-010]);
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ break;
+ case 017:
+ bytes[0] = 0;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ break;
+ case 014: case 015: case 016:
+ if (ins->oprs[c-014].offset < -128 || ins->oprs[c-014].offset > 127)
+ errfunc (ERR_WARNING, "signed byte value exceeds bounds");
+ bytes[0] = ins->oprs[c-014].offset;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ break;
+ case 020: case 021: case 022:
+ if (ins->oprs[c-020].offset < -128 || ins->oprs[c-020].offset > 255)
+ errfunc (ERR_WARNING, "byte value exceeds bounds");
+ bytes[0] = ins->oprs[c-020].offset;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ break;
+ case 024: case 025: case 026:
+ if (ins->oprs[c-024].offset < 0 || ins->oprs[c-024].offset > 255)
+ errfunc (ERR_WARNING, "unsigned byte value exceeds bounds");
+ bytes[0] = ins->oprs[c-024].offset;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ break;
+ case 030: case 031: case 032:
+ if (ins->oprs[c-030].segment == NO_SEG &&
+ ins->oprs[c-030].wrt == NO_SEG &&
+ (ins->oprs[c-030].offset < -32768 ||
+ ins->oprs[c-030].offset > 65535))
+ errfunc (ERR_WARNING, "word value exceeds bounds");
+ data = ins->oprs[c-030].offset;
+ outfmt->output (segment, &data, OUT_ADDRESS+2,
+ ins->oprs[c-030].segment, ins->oprs[c-030].wrt);
+ offset += 2;
+ break;
+ case 034: case 035: case 036:
+ data = ins->oprs[c-034].offset;
+ size = ((ins->oprs[c-034].addr_size ?
+ ins->oprs[c-034].addr_size : bits) == 16 ? 2 : 4);
+ if (size==16 && (data < -32768 || data > 65535))
+ errfunc (ERR_WARNING, "word value exceeds bounds");
+ outfmt->output (segment, &data, OUT_ADDRESS+size,
+ ins->oprs[c-034].segment, ins->oprs[c-034].wrt);
+ offset += size;
+ break;
+ case 037:
+ if (ins->oprs[0].segment == NO_SEG)
+ errfunc (ERR_NONFATAL, "value referenced by FAR is not"
+ " relocatable");
+ data = 0L;
+ outfmt->output (segment, &data, OUT_ADDRESS+2,
+ outfmt->segbase(1+ins->oprs[0].segment),
+ ins->oprs[0].wrt);
+ offset += 2;
+ break;
+ case 040: case 041: case 042:
+ data = ins->oprs[c-040].offset;
+ outfmt->output (segment, &data, OUT_ADDRESS+4,
+ ins->oprs[c-040].segment, ins->oprs[c-040].wrt);
+ offset += 4;
+ break;
+ case 050: case 051: case 052:
+ if (ins->oprs[c-050].segment != segment)
+ errfunc (ERR_NONFATAL, "short relative jump outside segment");
+ data = ins->oprs[c-050].offset - insn_end;
+ if (data > 127 || data < -128)
+ errfunc (ERR_NONFATAL, "short jump is out of range");
+ bytes[0] = data;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ break;
+ case 060: case 061: case 062:
+ if (ins->oprs[c-060].segment != segment) {
+ data = ins->oprs[c-060].offset;
+ outfmt->output (segment, &data, OUT_REL2ADR+insn_end-offset,
+ ins->oprs[c-060].segment, ins->oprs[c-060].wrt);
+ } else {
+ data = ins->oprs[c-060].offset - insn_end;
+ outfmt->output (segment, &data, OUT_ADDRESS+2, NO_SEG, NO_SEG);
+ }
+ offset += 2;
+ break;
+ case 064: case 065: case 066:
+ size = ((ins->oprs[c-064].addr_size ?
+ ins->oprs[c-064].addr_size : bits) == 16 ? 2 : 4);
+ if (ins->oprs[c-064].segment != segment) {
+ data = ins->oprs[c-064].offset;
+ size = (bits == 16 ? OUT_REL2ADR : OUT_REL4ADR);
+ outfmt->output (segment, &data, size+insn_end-offset,
+ ins->oprs[c-064].segment, ins->oprs[c-064].wrt);
+ size = (bits == 16 ? 2 : 4);
+ } else {
+ data = ins->oprs[c-064].offset - insn_end;
+ outfmt->output (segment, &data, OUT_ADDRESS+size, NO_SEG, NO_SEG);
+ }
+ offset += size;
+ break;
+ case 070: case 071: case 072:
+ if (ins->oprs[c-070].segment != segment) {
+ data = ins->oprs[c-070].offset;
+ outfmt->output (segment, &data, OUT_REL4ADR+insn_end-offset,
+ ins->oprs[c-070].segment, ins->oprs[c-070].wrt);
+ } else {
+ data = ins->oprs[c-070].offset - insn_end;
+ outfmt->output (segment, &data, OUT_ADDRESS+4, NO_SEG, NO_SEG);
+ }
+ offset += 4;
+ break;
+ case 0300: case 0301: case 0302:
+ if (chsize (&ins->oprs[c-0300], bits)) {
+ *bytes = 0x67;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ } else
+ offset += 0;
+ break;
+ case 0310:
+ if (bits==32) {
+ *bytes = 0x67;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ } else
+ offset += 0;
+ break;
+ case 0311:
+ if (bits==16) {
+ *bytes = 0x67;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ } else
+ offset += 0;
+ break;
+ case 0312:
+ break;
+ case 0320:
+ if (bits==32) {
+ *bytes = 0x66;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ } else
+ offset += 0;
+ break;
+ case 0321:
+ if (bits==16) {
+ *bytes = 0x66;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ } else
+ offset += 0;
+ break;
+ case 0322:
+ break;
+ case 0330:
+ *bytes = *codes++ + condval[ins->condition];
+ outfmt->output (segment, bytes, OUT_RAWDATA+1, NO_SEG, NO_SEG);
+ offset += 1;
+ break;
+ case 0340: case 0341: case 0342:
+ if (ins->oprs[0].segment != NO_SEG)
+ errfunc (ERR_PANIC, "non-constant BSS size in pass two");
+ else {
+ long size = ins->oprs[0].offset << (c-0340);
+ outfmt->output (segment, NULL, OUT_RESERVE+size, NO_SEG, NO_SEG);
+ offset += size;
+ }
+ break;
+ default: /* can't do it by 'case' statements */
+ if (c>=0100 && c<=0277) { /* it's an EA */
+ ea ea_data;
+ int rfield;
+ unsigned char *p;
+ long s;
+
+ if (c<=0177) /* pick rfield from operand b */
+ rfield = regval (&ins->oprs[c&7]);
+ else /* rfield is constant */
+ rfield = c & 7;
+ if (!process_ea (&ins->oprs[(c>>3)&7], &ea_data, bits, rfield))
+ errfunc (ERR_NONFATAL, "invalid effective address");
+
+ p = bytes;
+ *p++ = ea_data.modrm;
+ if (ea_data.sib_present)
+ *p++ = ea_data.sib;
+ /*
+ * the cast in the next line is to placate MS C...
+ */
+ outfmt->output (segment, bytes, OUT_RAWDATA+(long)(p-bytes),
+ NO_SEG, NO_SEG);
+ s = p-bytes;
+
+ switch (ea_data.bytes) {
+ case 0:
+ break;
+ case 1:
+ *bytes = ins->oprs[(c>>3)&7].offset;
+ outfmt->output (segment, bytes, OUT_RAWDATA+1,
+ NO_SEG, NO_SEG);
+ s++;
+ break;
+ case 2:
+ case 4:
+ data = ins->oprs[(c>>3)&7].offset;
+ outfmt->output (segment, &data, OUT_ADDRESS+ea_data.bytes,
+ ins->oprs[(c>>3)&7].segment,
+ ins->oprs[(c>>3)&7].wrt);
+ s += ea_data.bytes;
+ break;
+ }
+ offset += s;
+ } else
+ errfunc (ERR_PANIC, "internal instruction table corrupt"
+ ": instruction code 0x%02X given", c);
+ }
+}
+
+static int regval (operand *o) {
+ switch (o->basereg) {
+ case R_EAX: case R_AX: case R_AL: case R_ES: case R_CR0: case R_DR0:
+ case R_ST0: case R_MM0:
+ return 0;
+ case R_ECX: case R_CX: case R_CL: case R_CS: case R_DR1: case R_ST1:
+ case R_MM1:
+ return 1;
+ case R_EDX: case R_DX: case R_DL: case R_SS: case R_CR2: case R_DR2:
+ case R_ST2: case R_MM2:
+ return 2;
+ case R_EBX: case R_BX: case R_BL: case R_DS: case R_CR3: case R_DR3:
+ case R_TR3: case R_ST3: case R_MM3:
+ return 3;
+ case R_ESP: case R_SP: case R_AH: case R_FS: case R_CR4: case R_TR4:
+ case R_ST4: case R_MM4:
+ return 4;
+ case R_EBP: case R_BP: case R_CH: case R_GS: case R_TR5: case R_ST5:
+ case R_MM5:
+ return 5;
+ case R_ESI: case R_SI: case R_DH: case R_DR6: case R_TR6: case R_ST6:
+ case R_MM6:
+ return 6;
+ case R_EDI: case R_DI: case R_BH: case R_DR7: case R_TR7: case R_ST7:
+ case R_MM7:
+ return 7;
+ default: /* panic */
+ errfunc (ERR_PANIC, "invalid register operand given to regval()");
+ return 0;
+ }
+}
+
+static int matches (struct itemplate *itemp, insn *instruction) {
+ int i, size, oprs, ret;
+
+ ret = 100;
+
+ /*
+ * Check the opcode
+ */
+ if (itemp->opcode != instruction->opcode) return 0;
+
+ /*
+ * Count the operands
+ */
+ if (itemp->operands != instruction->operands) return 0;
+
+ /*
+ * Check that no spurious colons or TOs are present
+ */
+ for (i=0; i<itemp->operands; i++)
+ if (instruction->oprs[i].type & ~itemp->opd[i] & (COLON|TO))
+ return 0;
+
+ /*
+ * Check that the operand flags all match up
+ */
+ for (i=0; i<itemp->operands; i++)
+ if (itemp->opd[i] & ~instruction->oprs[i].type ||
+ ((itemp->opd[i] & SIZE_MASK) &&
+ ((itemp->opd[i] ^ instruction->oprs[i].type) & SIZE_MASK))) {
+ if ((itemp->opd[i] & ~instruction->oprs[i].type & NON_SIZE) ||
+ (instruction->oprs[i].type & SIZE_MASK))
+ return 0;
+ else
+ ret = 1;
+ }
+
+ /*
+ * Check operand sizes
+ */
+ if (itemp->flags & IF_SB) {
+ size = BITS8;
+ oprs = itemp->operands;
+ } else if (itemp->flags & IF_SD) {
+ size = BITS32;
+ oprs = itemp->operands;
+ } else if (itemp->flags & (IF_SM | IF_SM2)) {
+ oprs = (itemp->flags & IF_SM2 ? 2 : itemp->operands);
+ size = 0; /* placate gcc */
+ for (i=0; i<oprs; i++)
+ if ( (size = itemp->opd[i] & SIZE_MASK) != 0)
+ break;
+ } else {
+ size = 0;
+ oprs = itemp->operands;
+ }
+
+ for (i=0; i<itemp->operands; i++)
+ if (!(itemp->opd[i] & SIZE_MASK) &&
+ (instruction->oprs[i].type & SIZE_MASK & ~size))
+ ret = 2;
+
+ return ret;
+}
+
+static ea *process_ea (operand *input, ea *output, int addrbits, int rfield) {
+ if (!(REGISTER & ~input->type)) { /* it's a single register */
+ static int regs[] = {
+ R_MM0, R_EAX, R_AX, R_AL, R_MM1, R_ECX, R_CX, R_CL,
+ R_MM2, R_EDX, R_DX, R_DL, R_MM3, R_EBX, R_BX, R_BL,
+ R_MM4, R_ESP, R_SP, R_AH, R_MM5, R_EBP, R_BP, R_CH,
+ R_MM6, R_ESI, R_SI, R_DH, R_MM7, R_EDI, R_DI, R_BH
+ };
+ int i;
+
+ for (i=0; i<elements(regs); i++)
+ if (input->basereg == regs[i]) break;
+ if (i<elements(regs)) {
+ output->sib_present = FALSE;/* no SIB necessary */
+ output->bytes = 0; /* no offset necessary either */
+ output->modrm = 0xC0 | (rfield << 3) | (i/4);
+ } else
+ return NULL;
+ } else { /* it's a memory reference */
+ if (input->basereg==-1 && (input->indexreg==-1 || input->scale==0)) {
+ /* it's a pure offset */
+ if (input->addr_size)
+ addrbits = input->addr_size;
+ output->sib_present = FALSE;
+ output->bytes = (addrbits==32 ? 4 : 2);
+ output->modrm = (addrbits==32 ? 5 : 6) | (rfield << 3);
+ } else { /* it's an indirection */
+ int i=input->indexreg, b=input->basereg, s=input->scale;
+ long o=input->offset, seg=input->segment;
+
+ if (s==0) i = -1; /* make this easy, at least */
+
+ if (i==R_EAX || i==R_EBX || i==R_ECX || i==R_EDX
+ || i==R_EBP || i==R_ESP || i==R_ESI || i==R_EDI
+ || b==R_EAX || b==R_EBX || b==R_ECX || b==R_EDX
+ || b==R_EBP || b==R_ESP || b==R_ESI || b==R_EDI) {
+ /* it must be a 32-bit memory reference. Firstly we have
+ * to check that all registers involved are type Exx. */
+ if (i!=-1 && i!=R_EAX && i!=R_EBX && i!=R_ECX && i!=R_EDX
+ && i!=R_EBP && i!=R_ESP && i!=R_ESI && i!=R_EDI)
+ return NULL;
+ if (b!=-1 && b!=R_EAX && b!=R_EBX && b!=R_ECX && b!=R_EDX
+ && b!=R_EBP && b!=R_ESP && b!=R_ESI && b!=R_EDI)
+ return NULL;
+
+ /* While we're here, ensure the user didn't specify WORD. */
+ if (input->addr_size == 16)
+ return NULL;
+
+ /* now reorganise base/index */
+ if (b==i) /* convert EAX+2*EAX to 3*EAX */
+ b = -1, s++;
+ if (b==-1 && s==1) /* single register should be base */
+ b = i, i = -1;
+ if (((s==2 && i!=R_ESP) || s==3 || s==5 || s==9) && b==-1)
+ b = i, s--; /* convert 3*EAX to EAX+2*EAX */
+ if (i==R_ESP || (s!=1 && s!=2 && s!=4 && s!=8 && i!=-1))
+ return NULL; /* wrong, for various reasons */
+
+ if (i==-1 && b!=R_ESP) {/* no SIB needed */
+ int mod, rm;
+ switch(b) {
+ case R_EAX: rm = 0; break;
+ case R_ECX: rm = 1; break;
+ case R_EDX: rm = 2; break;
+ case R_EBX: rm = 3; break;
+ case R_EBP: rm = 5; break;
+ case R_ESI: rm = 6; break;
+ case R_EDI: rm = 7; break;
+ case -1: rm = 5; break;
+ default: /* should never happen */
+ return NULL;
+ }
+ if (b==-1 || (b!=R_EBP && o==0 && seg==NO_SEG))
+ mod = 0;
+ else if (o>=-128 && o<=127 && seg==NO_SEG)
+ mod = 1;
+ else
+ mod = 2;
+ output->sib_present = FALSE;
+ output->bytes = (b==-1 || mod==2 ? 4 : mod);
+ output->modrm = (mod<<6) | (rfield<<3) | rm;
+ } else { /* we need a SIB */
+ int mod, scale, index, base;
+
+ switch (b) {
+ case R_EAX: base = 0; break;
+ case R_ECX: base = 1; break;
+ case R_EDX: base = 2; break;
+ case R_EBX: base = 3; break;
+ case R_ESP: base = 4; break;
+ case R_EBP: case -1: base = 5; break;
+ case R_ESI: base = 6; break;
+ case R_EDI: base = 7; break;
+ default: /* then what the smeg is it? */
+ return NULL; /* panic */
+ }
+
+ switch (i) {
+ case R_EAX: index = 0; break;
+ case R_ECX: index = 1; break;
+ case R_EDX: index = 2; break;
+ case R_EBX: index = 3; break;
+ case -1: index = 4; break;
+ case R_EBP: index = 5; break;
+ case R_ESI: index = 6; break;
+ case R_EDI: index = 7; break;
+ default: /* then what the smeg is it? */
+ return NULL; /* panic */
+ }
+
+ if (i==-1) s = 1;
+ switch (s) {
+ case 1: scale = 0; break;
+ case 2: scale = 1; break;
+ case 4: scale = 2; break;
+ case 8: scale = 3; break;
+ default: /* then what the smeg is it? */
+ return NULL; /* panic */
+ }
+
+ if (b==-1 || (b!=R_EBP && o==0 && seg==NO_SEG))
+ mod = 0;
+ else if (o>=-128 && o<=127 && seg==NO_SEG)
+ mod = 1;
+ else
+ mod = 2;
+
+ output->sib_present = TRUE;
+ output->bytes = (b==-1 || mod==2 ? 4 : mod);
+ output->modrm = (mod<<6) | (rfield<<3) | 4;
+ output->sib = (scale<<6) | (index<<3) | base;
+ }
+ } else { /* it's 16-bit */
+ int mod, rm;
+
+ /* check all registers are BX, BP, SI or DI */
+ if ((b!=-1 && b!=R_BP && b!=R_BX && b!=R_SI && b!=R_DI) ||
+ (i!=-1 && i!=R_BP && i!=R_BX && i!=R_SI && i!=R_DI))
+ return NULL;
+
+ /* ensure the user didn't specify DWORD */
+ if (input->addr_size == 32)
+ return NULL;
+
+ if (s!=1 && i!=-1) return NULL;/* no can do, in 16-bit EA */
+ if (b==-1 && i!=-1) b ^= i ^= b ^= i; /* swap them round */
+ if ((b==R_SI || b==R_DI) && i!=-1)
+ b ^= i ^= b ^= i; /* have BX/BP as base, SI/DI index */
+ if (b==i) return NULL;/* shouldn't ever happen, in theory */
+ if (i!=-1 && b!=-1 &&
+ (i==R_BP || i==R_BX || b==R_SI || b==R_DI))
+ return NULL; /* invalid combinations */
+ if (b==-1) /* pure offset: handled above */
+ return NULL; /* so if it gets to here, panic! */
+
+ rm = -1;
+ if (i!=-1)
+ switch (i*256 + b) {
+ case R_SI*256+R_BX: rm=0; break;
+ case R_DI*256+R_BX: rm=1; break;
+ case R_SI*256+R_BP: rm=2; break;
+ case R_DI*256+R_BP: rm=3; break;
+ }
+ else
+ switch (b) {
+ case R_SI: rm=4; break;
+ case R_DI: rm=5; break;
+ case R_BP: rm=6; break;
+ case R_BX: rm=7; break;
+ }
+ if (rm==-1) /* can't happen, in theory */
+ return NULL; /* so panic if it does */
+
+ if (o==0 && seg==NO_SEG && rm!=6)
+ mod = 0;
+ else if (o>=-128 && o<=127 && seg==NO_SEG)
+ mod = 1;
+ else
+ mod = 2;
+
+ output->sib_present = FALSE; /* no SIB - it's 16-bit */
+ output->bytes = mod; /* bytes of offset needed */
+ output->modrm = (mod<<6) | (rfield<<3) | rm;
+ }
+ }
+ }
+ output->size = 1 + output->sib_present + output->bytes;
+ return output;
+}
+
+static int chsize (operand *input, int addrbits) {
+ if (!(MEMORY & ~input->type)) {
+ int i=input->indexreg, b=input->basereg;
+
+ if (input->scale==0) i = -1;
+
+ if (i == -1 && b == -1) /* pure offset */
+ return (input->addr_size != 0 && input->addr_size != addrbits);
+
+ if (i==R_EAX || i==R_EBX || i==R_ECX || i==R_EDX
+ || i==R_EBP || i==R_ESP || i==R_ESI || i==R_EDI
+ || b==R_EAX || b==R_EBX || b==R_ECX || b==R_EDX
+ || b==R_EBP || b==R_ESP || b==R_ESI || b==R_EDI)
+ return (addrbits==16);
+ else
+ return (addrbits==32);
+ } else
+ return 0;
+}