mips.md

c语言编译器

        usedmask[IREG] &= 0xc0ff0000;
        usedmask[FREG] &= 0xfff00000;
        if (pic && ncalls)
                usedmask[IREG] |= 1<<25;
        maxargoffset = roundup(maxargoffset, usedmask[FREG] ? 8 : 4);
        if (ncalls && maxargoffset < 16)
                maxargoffset = 16;
        sizefsave = 4*bitcount(usedmask[FREG]);
        sizeisave = 4*bitcount(usedmask[IREG]);
        framesize = roundup(maxargoffset + sizefsave
                + sizeisave + maxoffset, 16);
        segment(CODE);
        print(".align 2\n");
        print(".ent %s\n", f->x.name);
        print("%s:\n", f->x.name);
        i = maxargoffset + sizefsave - framesize;
        print(".frame $sp,%d,$31\n", framesize);
        if (pic)
                print(".set noreorder\n.cpload $25\n.set reorder\n");
        if (framesize > 0)
                print("addu $sp,$sp,%d\n", -framesize);
        if (usedmask[FREG])
                print(".fmask 0x%x,%d\n", usedmask[FREG], i - 8);
        if (usedmask[IREG])
                print(".mask 0x%x,%d\n",  usedmask[IREG],
                        i + sizeisave - 4);
        saved = maxargoffset;
        for (i = 20; i <= 30; i += 2)
                if (usedmask[FREG]&(3<<i)) {
                        print("s.d $f%d,%d($sp)\n", i, saved);
                        saved += 8;
                }

        for (i = 16; i <= 31; i++)
                if (usedmask[IREG]&(1<<i)) {
                        if (i == 25)
                                print(".cprestore %d\n", saved);
                        else
                                print("sw $%d,%d($sp)\n", i, saved);
                        saved += 4;
                }
        for (i = 0; i < 4 && callee[i]; i++) {
                r = argregs[i];
                if (r && r->x.regnode != callee[i]->x.regnode) {
                        Symbol out = callee[i];
                        Symbol in  = caller[i];
                        int rn = r->x.regnode->number;
                        int rs = r->x.regnode->set;
                        int tyin = ttob(in->type);

                        assert(out && in && r && r->x.regnode);
                        assert(out->sclass != REGISTER || out->x.regnode);
                        if (out->sclass == REGISTER
                        && (isint(out->type) || out->type == in->type)) {
                                int outn = out->x.regnode->number;
                                if (rs == FREG && tyin == F+sizeop(8))
                                        print("mov.d $f%d,$f%d\n", outn, rn);
                                else if (rs == FREG && tyin == F+sizeop(4))
                                        print("mov.s $f%d,$f%d\n", outn, rn);
                                else if (rs == IREG && tyin == F+sizeop(8))
                                        print("mtc1.d $%d,$f%d\n", rn,   outn);
                                else if (rs == IREG && tyin == F+sizeop(4))
                                        print("mtc1 $%d,$f%d\n",   rn,   outn);
                                else
                                        print("move $%d,$%d\n",    outn, rn);
                        } else {
                                int off = in->x.offset + framesize;
                                if (rs == FREG && tyin == F+sizeop(8))
                                        print("s.d $f%d,%d($sp)\n", rn, off);
                                else if (rs == FREG && tyin == F+sizeop(4))
                                        print("s.s $f%d,%d($sp)\n", rn, off);
                                else {
                                        int i, n = (in->type->size + 3)/4;
                                        for (i = rn; i < rn+n && i <= 7; i++)
                                                print("sw $%d,%d($sp)\n", i, off + (i-rn)*4);
                                }
                        }
                }
        }
        if (varargs && callee[i-1]) {
                i = callee[i-1]->x.offset + callee[i-1]->type->size;
                for (i = roundup(i, 4)/4; i <= 3; i++)
                        print("sw $%d,%d($sp)\n", i + 4, framesize + 4*i);
                }
        emitcode();
        saved = maxargoffset;
        for (i = 20; i <= 30; i += 2)
                if (usedmask[FREG]&(3<<i)) {
                        print("l.d $f%d,%d($sp)\n", i, saved);
                        saved += 8;
                }
        for (i = 16; i <= 31; i++)
                if (usedmask[IREG]&(1<<i)) {
                        print("lw $%d,%d($sp)\n", i, saved);
                        saved += 4;
                }
        if (framesize > 0)
                print("addu $sp,$sp,%d\n", framesize);
        print("j $31\n");
        print(".end %s\n", f->x.name);
}
static void defconst(int suffix, int size, Value v) {
        if (suffix == F && size == 4) {
                float f = v.d;
                print(".word 0x%x\n", *(unsigned *)&f);
        }
        else if (suffix == F && size == 8) {
                double d = v.d;
                unsigned *p = (unsigned *)&d;
                print(".word 0x%x\n.word 0x%x\n", p[swap], p[!swap]);
        }
        else if (suffix == P)
                print(".word 0x%x\n", (unsigned)v.p);
        else if (size == 1)
                print(".byte 0x%x\n", (unsigned)((unsigned char)(suffix == I ? v.i : v.u)));
        else if (size == 2)
                print(".half 0x%x\n", (unsigned)((unsigned short)(suffix == I ? v.i : v.u)));
        else if (size == 4)
                print(".word 0x%x\n", (unsigned)(suffix == I ? v.i : v.u));
}
static void defaddress(Symbol p) {
        if (pic && p->scope == LABELS)
                print(".gpword %s\n", p->x.name);
        else
                print(".word %s\n", p->x.name);
}
static void defstring(int n, char *str) {
        char *s;

        for (s = str; s < str + n; s++)
                print(".byte %d\n", (*s)&0377);
}
static void export(Symbol p) {
        print(".globl %s\n", p->x.name);
}
static void import(Symbol p) {
        if (!isfunc(p->type))
                print(".extern %s %d\n", p->name, p->type->size);
}
static void defsymbol(Symbol p) {
        if (p->scope >= LOCAL && p->sclass == STATIC)
                p->x.name = stringf("L.%d", genlabel(1));
        else if (p->generated)
                p->x.name = stringf("L.%s", p->name);
        else
                assert(p->scope != CONSTANTS || isint(p->type) || isptr(p->type)),
                p->x.name = p->name;
}
static void address(Symbol q, Symbol p, long n) {
        if (p->scope == GLOBAL
        || p->sclass == STATIC || p->sclass == EXTERN)
                q->x.name = stringf("%s%s%D", p->x.name,
                        n >= 0 ? "+" : "", n);
        else {
                assert(n <= INT_MAX && n >= INT_MIN);
                q->x.offset = p->x.offset + n;
                q->x.name = stringd(q->x.offset);
        }
}
static void global(Symbol p) {
        if (p->u.seg == BSS) {
                if (p->sclass == STATIC || Aflag >= 2)
                        print(".lcomm %s,%d\n", p->x.name, p->type->size);
                else
                        print( ".comm %s,%d\n", p->x.name, p->type->size);
        } else {
                if (p->u.seg == DATA
                && (p->type->size == 0 || p->type->size > gnum))
                        print(".data\n");
                else if (p->u.seg == DATA)
                        print(".sdata\n");
                print(".align %c\n", ".01.2...3"[p->type->align]);
                print("%s:\n", p->x.name);
        }
}
static void segment(int n) {
        cseg = n;
        switch (n) {
        case CODE: print(".text\n");  break;
        case LIT:  print(".rdata\n"); break;
        }
}
static void space(int n) {
        if (cseg != BSS)
                print(".space %d\n", n);
}
static void blkloop(int dreg, int doff, int sreg, int soff, int size, int tmps[]) {
        int lab = genlabel(1);

        print("addu $%d,$%d,%d\n", sreg, sreg, size&~7);
        print("addu $%d,$%d,%d\n", tmps[2], dreg, size&~7);
        blkcopy(tmps[2], doff, sreg, soff, size&7, tmps);
        print("L.%d:\n", lab);
        print("addu $%d,$%d,%d\n", sreg, sreg, -8);
        print("addu $%d,$%d,%d\n", tmps[2], tmps[2], -8);
        blkcopy(tmps[2], doff, sreg, soff, 8, tmps);
        print("bltu $%d,$%d,L.%d\n", dreg, tmps[2], lab);
}
static void blkfetch(int size, int off, int reg, int tmp) {
        assert(size == 1 || size == 2 || size == 4);
        if (size == 1)
                print("lbu $%d,%d($%d)\n",  tmp, off, reg);
        else if (salign >= size && size == 2)
                print("lhu $%d,%d($%d)\n",  tmp, off, reg);
        else if (salign >= size)
                print("lw $%d,%d($%d)\n",   tmp, off, reg);
        else if (size == 2)
                print("ulhu $%d,%d($%d)\n", tmp, off, reg);
        else
                print("ulw $%d,%d($%d)\n",  tmp, off, reg);
}
static void blkstore(int size, int off, int reg, int tmp) {
        if (size == 1)
                print("sb $%d,%d($%d)\n",  tmp, off, reg);
        else if (dalign >= size && size == 2)
                print("sh $%d,%d($%d)\n",  tmp, off, reg);
        else if (dalign >= size)
                print("sw $%d,%d($%d)\n",  tmp, off, reg);
        else if (size == 2)
                print("ush $%d,%d($%d)\n", tmp, off, reg);
        else
                print("usw $%d,%d($%d)\n", tmp, off, reg);
}
static void stabinit(char *, int, char *[]);
static void stabline(Coordinate *);
static void stabsym(Symbol);

static char *currentfile;

static int bitcount(unsigned mask) {
        unsigned i, n = 0;

        for (i = 1; i; i <<= 1)
                if (mask&i)
                        n++;
        return n;
}

/* stabinit - initialize stab output */
static void stabinit(char *file, int argc, char *argv[]) {
        if (file) {
                print(".file 2,\"%s\"\n", file);
                currentfile = file;
        }
}

/* stabline - emit stab entry for source coordinate *cp */
static void stabline(Coordinate *cp) {
        if (cp->file && cp->file != currentfile) {
                print(".file 2,\"%s\"\n", cp->file);
                currentfile = cp->file;
        }
        print(".loc 2,%d\n", cp->y);
}

/* stabsym - output a stab entry for symbol p */
static void stabsym(Symbol p) {
        if (p == cfunc && IR->stabline)
                (*IR->stabline)(&p->src);
}
Interface mipsebIR = {
        1, 1, 0,  /* char */
        2, 2, 0,  /* short */
        4, 4, 0,  /* int */
        4, 4, 0,  /* long */
        4, 4, 0,  /* long long */
        4, 4, 1,  /* float */
        8, 8, 1,  /* double */
        8, 8, 1,  /* long double */
        4, 4, 0,  /* T * */
        0, 1, 0,  /* struct */
        0,      /* little_endian */
        0,  /* mulops_calls */
        0,  /* wants_callb */
        1,  /* wants_argb */
        1,  /* left_to_right */
        0,  /* wants_dag */
        0,  /* unsigned_char */
        address,
        blockbeg,
        blockend,
        defaddress,
        defconst,
        defstring,
        defsymbol,
        emit,
        export,
        function,
        gen,
        global,
        import,
        local,
        progbeg,
        progend,
        segment,
        space,
        0, 0, 0, stabinit, stabline, stabsym, 0,
        {
                4,      /* max_unaligned_load */
                rmap,
                blkfetch, blkstore, blkloop,
                _label,
                _rule,
                _nts,
                _kids,
                _string,
                _templates,
                _isinstruction,
                _ntname,
                emit2,
                doarg,
                target,
                clobber,

        }
}, mipselIR = {
        1, 1, 0,  /* char */
        2, 2, 0,  /* short */
        4, 4, 0,  /* int */
        4, 4, 0,  /* long */
        4, 4, 0,  /* long long */
        4, 4, 1,  /* float */
        8, 8, 1,  /* double */
        8, 8, 1,  /* long double */
        4, 4, 0,  /* T * */
        0, 1, 0,  /* struct */
        1,      /* little_endian */
        0,  /* mulops_calls */
        0,  /* wants_callb */
        1,  /* wants_argb */
        1,  /* left_to_right */
        0,  /* wants_dag */
        0,  /* unsigned_char */
        address,
        blockbeg,
        blockend,
        defaddress,
        defconst,
        defstring,
        defsymbol,
        emit,
        export,
        function,
        gen,
        global,
        import,
        local,
        progbeg,
        progend,
        segment,
        space,
        0, 0, 0, stabinit, stabline, stabsym, 0,
        {
                4,      /* max_unaligned_load */
                rmap,
                blkfetch, blkstore, blkloop,
                _label,
                _rule,
                _nts,
                _kids,
                _string,
                _templates,
                _isinstruction,
                _ntname,
                emit2,
                doarg,
                target,
                clobber,

        }
};
static char rcsid[] = "$Id: mips.md,v 1.1 2002/08/28 23:12:44 drh Exp $";