4.4BSD/usr/src/old/pcc/c2.vax/c21.c
#ifndef lint
static char sccsid[] = "@(#)c21.c 4.25 7/15/92";
#endif
/* char C21[] = {"@(#)c21.c 1.83 80/10/16 21:18:22 JFR"}; /* sccs ident */
/*
* C object code improver-- second part
*/
#include "c2.h"
#include <stdio.h>
#include <ctype.h>
#define NUSE 6
int ioflag;
int biti[NUSE] = {1,2,4,8,16,32};
int bitsize[] = { /* index by type codes */
0, /* 0 not allocated */
8, /* 1 BYTE */
16, /* 2 WORD */
32, /* 3 LONG */
32, /* 4 FFLOAT */
64, /* 5 DFLOAT */
64, /* 6 QUAD */
0, /* 7 OP2 */
0, /* 8 OP3 */
0, /* 9 OPB */
0, /* 10 OPX */
64, /* 11 GFLOAT */
128, /* 12 HFLOAT */
128 /* 13 OCTA */
};
int pos,siz; long f; /* for bit field communication */
struct node *uses[NUSE]; /* for backwards flow analysis */
char *lastrand; /* last operand of instruction */
struct node *bflow();
struct node *bicopt();
char *findcon();
char *strcpy();
redun3(p,split) register struct node *p; int split; {
/* check for 3 addr instr which should be 2 addr */
if (OP3==((p->subop>>4)&0xF)) {
if (split) splitrand(p);
if (equstr(regs[RT1],regs[RT3])
&& (p->op==ADD || p->op==MUL || p->op==BIS || p->op==XOR)) {
register char *t=regs[RT1]; regs[RT1]=regs[RT2]; regs[RT2]=t;
}
if (equstr(regs[RT2],regs[RT3])) {
p->subop=(p->subop&0xF)|(OP2<<4); p->pop=0;
lastrand=regs[RT2]; *regs[RT3]=0; return(1);
}
} return(0);
}
bmove() {
register struct node *p, *lastp; register char *cp1,*cp2; register int r;
refcount();
for (p=lastp= &first; 0!=(p=p->forw); lastp=p);
clearreg(); clearuse();
for (p=lastp; p!= &first; p=p->back) {
if (debug) {
printf("Uses:\n");
for (r=NUSE;--r>=0;) if (uses[r])
printf("%d: %s\n",r,uses[r]->code? uses[r]->code:"");
printf("-\n");
}
r=(p->subop>>4)&0xF;
if (OP2==r && (cp1=p->code, *cp1++)=='$' && *cp1++=='0' && *cp1++==',' &&
!source(cp1)) {/* a no-op unless MUL or DIV */
if (p->op==MUL) {p->op=MOV; p->subop&=0xF; p->pop=0;}
else if (p->op==DIV) fprintf(stderr,"c2: zero divide\n");
else {delnode(p); redunm++; continue;}
}
if (OP3==r && 0!=redun3(p,1)) {newcode(p); redunm++;}
switch (p->op) {
case LABEL: case DLABEL:
for (r=NUSE; --r>=0;)
if (uses[r]) p->ref=(struct node *) (((int)p->ref)|biti[r]);
break;
case CALLS:
clearuse(); goto std;
case 0:
/*
* Be conservative -- if we don't know what it is, then we
* assume that it can set anything.
*/
for ( r = 0; r < NUSE; ++r )
uses[r] = p;
break;
case SUB:
if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
if (*cp1++!='$') goto std; splitrand(p);
if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
char buf[C2_ASIZE]; cp2=buf; *cp2++='-';
cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
cp1="(fp),"; while (*cp2++= *cp1++); --cp2;
cp1=regs[RT3]; while (*cp2++= *cp1++);
p->code=copy(buf); p->combop=T(MOVA,LONG); p->pop=0;
} else if (*cp1++=='-' && 0<=(r=getnum(cp1))) {
p->op=ADD; p->pop=0; *--cp1='$'; p->code=cp1;
} goto std;
case ADD:
if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
if (*cp1++!='$') goto std; splitrand(p);
if (isstatic(cp1) && (r=isreg(regs[RT2]))>=0 && r<NUSE && uses[r]==p->forw)
{
/* address comp:
** addl2 $_foo,r0 \ movab _foo[r0],bar
** movl r0,bar /
*/
register struct node *pnext = p->forw;
char buf[C2_ASIZE];
if (pnext->op == MOV && pnext->subop == LONG)
{
cp1 = ®s[RT1][1]; cp2 = &buf[0];
while (*cp2++ = *cp1++) ; cp2--;
splitrand(pnext);
if (r == isreg(regs[RT1]))
{
delnode(p); p = pnext;
p->op = MOVA; p->subop = BYTE;
p->pop = 0;
cp1 = regs[RT1]; *cp2++ = '[';
while (*cp2++ = *cp1++) ; cp2--;
*cp2++ = ']'; *cp2++ = ',';
cp1 = regs[RT2];
while (*cp2++ = *cp1++) ;
p->code = copy(buf);
}
}
}
else
if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
cp2=cp1-1; cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
cp1="(fp)"; while (*cp2++= *cp1++); *--cp2=',';
p->combop=T(MOVA,LONG); p->pop=0;
} else if (*cp1++=='-' && 0<=(r=getnum(cp1))) {
p->op=SUB; p->pop=0; *--cp1='$'; p->code=cp1;
}
/* fall thru ... */
case CASE:
default: std:
p=bflow(p); break;
case MUL:
{
/*
** Change multiplication by constant powers of 2 to
** shifts.
*/
splitrand(p);
if (regs[RT1][0] != '$' || regs[RT1][1] == '-') goto std;
if ((r = ispow2(getnum(®s[RT1][1]))) < 0) goto std;
switch (r)
{
case 0: /* mull3 $1,x,y */
if (p->subop == U(LONG,OP3))
{
if (equstr(regs[RT2], regs[RT3]))
{
delnode(p); p = p->forw;
}
else
{
p->op = MOV; p->subop = LONG;
p->pop = 0; newcode(p); nchange++;
}
}
else
if (p->subop == U(LONG,OP2))
{
delnode(p); p = p->forw;
}
goto std;
case 1: /* mull2 $2,x */
if (p->subop == U(LONG, OP2) && !source(regs[RT2]))
{
strcpy(regs[RT1], regs[RT2]);
p->op = ADD; p->pop = 0; newcode(p); nchange++;
}
goto std;
}
if(p->subop==U(LONG,OP3)||(p->subop==U(LONG,OP2)&&!source(regs[RT2])))
{
if (p->subop == U(LONG,OP2))
strcpy(regs[RT3], regs[RT2]);
sprintf(regs[RT1], "$%d", r);
p->op = ASH; p->subop = LONG;
p->pop = 0; newcode(p); nchange++;
}
goto std;
}
case ASH:
{
/* address comp:
** ashl $1,bar,r0 \ movl bar,r0
** movab _foo[r0] / movaw _foo[r0]
**
** ashl $2,r0,r0 \ moval _foo[r0]
** movab _foo[r0] /
*/
register struct node *pf;
register int shfrom, shto;
long shcnt;
char *regfrom;
splitrand(p);
if (regs[RT1][0] != '$') goto std;
if ((shcnt = getnum(®s[RT1][1])) < 1 || shcnt > 3) goto std;
if ((shfrom = isreg(regs[RT2])) >= 0)
regfrom = copy(regs[RT2]);
if ((shto = isreg(regs[RT3])) >= 0 && shto<NUSE)
{
int regnum;
if (uses[shto] != (pf = p->forw)) goto ashadd;
if (pf->op != MOVA && pf->op != PUSHA) goto ashadd;
if (pf->subop != BYTE) goto ashadd;
splitrand(pf);
if (!indexa(regs[RT1])) goto std;
cp2 = regs[RT1];
if(!isstatic(cp2)) goto std;
while (*cp2++ != '[') ;
if (*cp2++ != 'r' || !isdigit(*cp2)) goto std;
regnum = *cp2++ - '0';
if (isdigit(*cp2))
{
if (cp2[1] != ']') goto std;
regnum *= 10; regnum += *cp2 - '0';
}
if (regnum != shto) goto std;
if (shfrom >= 0) /* ashl $N,r*,r0 */
{
delnode(p);
p = pf;
if (shfrom != shto)
{
uses[shto] = NULL; splitrand(p);
cp2=regs[RT1]; while (*cp2++!='[');
cp1=regfrom; while (*cp2++= *cp1++);
*--cp2 = ']';
*++cp2 = '\0';
newcode(p);
}
if (p->op == MOVA)
{
int movato;
splitrand(p);
if ((movato = isreg(regs[RT2])) >= 0
&& movato < NUSE)
/*
* this register is dead;
* resurrect it temporarily
*/
uses[movato] = p;
}
}
else
{
p->op = MOV; splitrand(p);
strcpy(regs[RT1], regs[RT2]);
strcpy(regs[RT2], regs[RT3]);
regs[RT3][0] = '\0';
p->pop = 0; newcode(p);
}
switch (shcnt)
{
case 1: pf->subop = WORD; break;
case 2: pf->subop = LONG; break;
case 3: pf->subop = QUAD; break;
}
pf->pop = 0;
redunm++; nsaddr++; nchange++;
goto std;
}
ashadd:
/* at this point, RT2 and RT3 are guaranteed to be simple regs*/
if (shcnt == 1 && equstr(regs[RT2], regs[RT3]))
{
/*
** quickie:
** ashl $1,A,A > addl2 A,A
*/
p->op = ADD; p->subop = U(LONG,OP2); p->pop = 0;
strcpy(regs[RT1], regs[RT2]); regs[RT3][0] = '\0';
newcode(p); nchange++;
}
goto std;
}
case EXTV:
case EXTZV:
{
/* bit tests:
** extv A,$1,B,rC \
** tstl rC > jbc A,B,D
** jeql D /
**
** also byte- and word-size fields:
** extv $n*8,$8,A,B > cvtbl n+A,B
** extv $n*16,$16,A,B > cvtwl 2n+A,B
** extzv $n*8,$8,A,B > movzbl n+A,B
** extzv $n*16,$16,A,B > movzwl 2n+A,B
*/
register struct node *pf; /* forward node */
register struct node *pn; /* next node (after pf) */
int flen; /* field length */
splitrand(p);
if (regs[RT2][0] != '$') goto std;
if ((flen = getnum(®s[RT2][1])) < 0) goto std;
if (flen == 1)
{
register int extreg; /* reg extracted to */
extreg = isreg(regs[RT4]);
if (extreg < 0 || extreg >= NUSE) goto std;
if ((pf = p->forw)->op != TST) goto std;
if (uses[extreg] && uses[extreg] != pf) goto std;
splitrand(pf);
if (extreg != isreg(regs[RT1])) goto std;
if ((pn = pf->forw)->op != CBR) goto std;
if (pn->subop != JEQ && pn->subop != JNE) goto std;
delnode(p); delnode(pf);
pn->subop = (pn->subop == JEQ) ? JBC : JBS;
for(cp2=p->code; *cp2++!=',';);
for(cp1=cp2; *cp1++!=',';);
while (*cp1!=',') *cp2++= *cp1++; *cp2='\0';
pn->code = p->code; pn->pop = NULL;
uses[extreg] = NULL;
p = pn;
break;
}
else
if (flen == 8 || flen == 16)
{
register int boff; /* bit offset */
register int coff; /* chunk (byte or word) offset*/
if (regs[RT1][0] != '$') goto std;
if ((boff = getnum(®s[RT1][1])) < 0) goto std;
coff = boff / flen;
if (coff && (isreg(regs[RT3]) >= 0)) goto std;
if (boff < 0 || (boff % flen) != 0) goto std;
p->op = (p->op == EXTV) ? CVT : MOVZ;
p->subop = U((flen == 8 ? BYTE : WORD), LONG);
if (coff == 0)
strcpy(regs[RT1], regs[RT3]);
else
sprintf(regs[RT1], "%d%s%s",
(flen == 8 ? coff : 2*coff),
(regs[RT3][0] == '(' ? "" : "+"),
regs[RT3]);
strcpy(regs[RT2], regs[RT4]);
regs[RT3][0] = '\0'; regs[RT4][0] = '\0';
p->pop = 0; newcode(p);
}
nchange++;
goto std;
}
case CMP:
{
/* comparison to -63 to -1:
** cmpl r0,$-1 > incl r0
** jeql ...
**
** cmpl r0,$-63 > addl2 $63,r0
** jeql ...
*/
register int num;
register int reg;
register struct node *regp = p->back;
if (p->forw->op != CBR) goto std;
if (p->forw->subop != JEQ && p->forw->subop != JNE) goto std;
splitrand(p);
if (strncmp(regs[RT2], "$-", 2) != 0) goto std;
reg = r = isreg(regs[RT1]);
if (r < 0) goto std;
if (r < NUSE && uses[r] != 0) goto std;
if (r >= NUSE && regp->op == MOV && p->subop == regp->subop)
{
if (*regp->code != 'r') goto std;
reg = regp->code[1] - '0';
if (isdigit(regp->code[2]) || reg >= NUSE || uses[reg])
goto std;
}
if (r >= NUSE) goto std;
if (reg != r)
sprintf(regs[RT1], "r%d", reg);
if ((num = getnum(®s[RT2][2])) <= 0 || num > 63) goto std;
if (num == 1)
{
p->op = INC; regs[RT2][0] = '\0';
}
else
{
register char *t;
t=regs[RT1];regs[RT1]=regs[RT2];regs[RT2]=t;
p->op = ADD; p->subop = U(p->subop, OP2);
for (t = ®s[RT1][2]; t[-1] = *t; t++) ;
}
p->pop = 0; newcode(p);
nchange++;
goto std;
}
case JSB:
if (equstr(p->code,"mcount")) {uses[0]=p; regs[0][0]= -1;}
goto std;
case JBR: case JMP:
clearuse();
if (p->subop==RET || p->subop==RSB) {uses[0]=p; regs[0][0]= -1; break;}
if (p->ref==0) goto std; /* jmp (r0) */
/* fall through */
case CBR:
if (p->ref->ref!=0) for (r=NUSE;--r>=0;)
if (biti[r] & (int)p->ref->ref) {uses[r]=p; regs[r][0]= -1;}
case EROU: case JSW:
case TEXT: case DATA: case BSS: case ALIGN: case WGEN: case END: ;
}
}
for (p= &first; p!=0; p=p->forw)
if (p->op==LABEL || p->op==DLABEL) p->ref=0; /* erase our tracks */
}
rmove()
{
register struct node *p;
register int r;
int r1;
clearreg();
for (p=first.forw; p!=0; p = p->forw) {
if (debug) {
if (*conloc) {
r1=conval[0];
printf("Con %s = %d%d %s\n", conloc, r1&0xF, r1>>4, conval+1);
}
printf("Regs:\n");
for (r=0; r<NREG; r++)
if (regs[r][0]) {
r1=regs[r][0];
printf("%d: %d%d %s\n", r, r1&0xF, r1>>4, regs[r]+1);
}
printf("-\n");
}
switch (p->op) {
case CVT:
splitrand(p); goto mov;
case MOV:
splitrand(p);
if ((r = findrand(regs[RT1],p->subop)) >= 0) {
if (r == isreg(regs[RT2]) && p->forw->op!=CBR) {
delnode(p); redunm++; break;
}
}
mov:
repladdr(p);
r = isreg(regs[RT1]);
r1 = isreg(regs[RT2]);
dest(regs[RT2],p->subop);
if (r>=0) {
if (r1>=0) savereg(r1, regs[r]+1, p->subop);
else if (p->op!=CVT) savereg(r, regs[RT2], p->subop);
} else if (r1>=0) savereg(r1, regs[RT1], p->subop);
else if (p->op!=CVT) setcon(regs[RT1], regs[RT2], p->subop);
break;
/* .rx,.wx */
case MFPR:
case COM:
case NEG:
/* .rx,.wx or .rx,.rx,.wx */
case ADD:
case SUB:
case BIC:
case BIS:
case XOR:
case MUL:
case DIV:
case ASH:
case MOVZ:
/* .rx,.rx,.rx,.wx */
case EXTV:
case EXTZV:
case INSV:
splitrand(p);
repladdr(p);
dest(lastrand,p->subop);
if (p->op==INSV) ccloc[0]=0;
break;
/* .mx or .wx */
case CLR:
case INC:
case DEC:
splitrand(p);
dest(lastrand,p->subop);
if (p->op==CLR)
if ((r = isreg(regs[RT1])) >= 0)
savereg(r, "$0", p->subop);
else
setcon("$0", regs[RT1], p->subop);
break;
/* .rx */
case TST:
case PUSH:
splitrand(p);
lastrand=regs[RT1+1]; /* fool repladdr into doing 1 operand */
repladdr(p);
if (p->op==TST && equstr(lastrand=regs[RT1], ccloc+1)
&& ((0xf&(ccloc[0]>>4))==p->subop || equtype(ccloc[0],p->subop))
&&!source(lastrand)) {
delnode(p); p = p->back; nrtst++; nchange++;
}
setcc(lastrand,p->subop);
break;
/* .rx,.rx,.rx */
case PROBER:
case PROBEW:
case CASE:
case MOVC3:
/* .rx,.rx */
case MTPR:
case CALLS:
case CMP:
case BIT:
splitrand(p);
/* fool repladdr into doing right number of operands */
if (p->op==CASE || p->op==PROBER || p->op==PROBEW) lastrand=regs[RT4];
/* else if (p->op==CMPV || p->op==CMPZV) lastrand=regs[RT4+1]; */
else if (p->op==MOVC3) lastrand=regs[RT1];
else lastrand=regs[RT3];
repladdr(p);
if (p->op==CALLS || p->op==MOVC3) clearreg();
/*if (p->op==BIT) bitopt(p);*/
ccloc[0]=0; break;
case CBR:
if (p->subop>=JBC) {
splitrand(p);
if (p->subop<JBCC) lastrand=regs[RT3]; /* 2 operands can be optimized */
else lastrand=regs[RT2]; /* .mb destinations lose */
repladdr(p);
}
ccloc[0] = 0;
break;
case JBR:
redunbr(p);
/* .wx,.bb */
case SOB:
default:
clearreg();
}
}
}
char *
byondrd(p) register struct node *p; {
/* return pointer to register which is "beyond last read/modify operand" */
if (OP2==(p->subop>>4)) return(regs[RT3]);
switch (p->op) {
case MFPR:
case JSB:
case PUSHA:
case TST: case INC: case DEC: case PUSH: return(regs[RT2]);
case MTPR:
case BIT: case CMP: case CALLS: return(regs[RT3]);
case PROBER: case PROBEW:
case CASE: case MOVC3: return(regs[RT4]);
}
return(lastrand);
}
struct node *
bflow(p)
register struct node *p;
{
register char *cp1,*cp2,**preg; register int r;
int flow= -1;
struct node *olduse=0;
splitrand(p);
if (p->op!=PUSH && p->subop && 0<=(r=isreg(lastrand)) && r<NUSE && uses[r]==p->forw) {
if ((p->op==CVT || p->op==MOVZ)
&& (p->forw->op==CVT || p->forw->op==MOVZ)
&& p->forw->subop&0xf
&& equtype(p->subop,p->forw->subop)
&& !source(cp1=regs[RT1])
&& !indexa(cp1)) goto movit;
if (equtype(p->subop,regs[r][0])
|| ((p->op==CVT || p->op==MOVZ)
&& 0xf®s[r][0] && compat(0xf&(p->subop>>4),regs[r][0]))) {
register int r2;
if (regs[r][1]!=0) {/* send directly to destination */
if (p->op==INC || p->op==DEC) {
if (p->op==DEC) p->op=SUB; else p->op=ADD;
p->subop=(OP2<<4)+(p->subop&0xF); /* use 2 now, convert to 3 later */
p->pop=0;
cp1=lastrand; cp2=regs[RT2]; while (*cp2++= *cp1++); /* copy reg */
cp1=lastrand; *cp1++='$'; *cp1++='1'; *cp1=0;
}
cp1=regs[r]+1; cp2=lastrand;
if (OP2==(p->subop>>4)) {/* use 3 operand form of instruction */
p->pop=0;
p->subop += (OP3-OP2)<<4; lastrand=cp2=regs[RT3];
}
while (*cp2++= *cp1++);
if (p->op==MOVA && p->forw->op==PUSH) {
p->op=PUSHA; *regs[RT2]=0; p->pop=0;
} else if (p->op==MOV && p->forw->op==PUSH) {
p->op=PUSH ; *regs[RT2]=0; p->pop=0;
}
delnode(p->forw);
if (0<=(r2=isreg(lastrand)) && r2<NUSE) {
uses[r2]=uses[r]; uses[r]=0;
}
(void) redun3(p,0);
newcode(p); redunm++; flow=r;
} else if (p->op==MOV && p->forw->op!=EXTV && p->forw->op!=EXTZV) {
/* superfluous fetch */
int nmatch;
char src[C2_ASIZE];
movit:
cp2=src; cp1=regs[RT1]; while (*cp2++= *cp1++);
splitrand(p->forw);
if (p->forw->op != INC && p->forw->op != DEC)
lastrand=byondrd(p->forw);
nmatch=0;
for (preg=regs+RT1;*preg!=lastrand;preg++)
if (r==isreg(*preg)) {
cp2= *preg; cp1=src; while (*cp2++= *cp1++); ++nmatch;
}
if (nmatch==1) {
if (OP2==(p->forw->subop>>4) && equstr(src,regs[RT2])) {
p->forw->pop=0;
p->forw->subop += (OP3-OP2)<<4; cp1=regs[RT3];
*cp1++='r'; *cp1++=r+'0'; *cp1=0;
}
delnode(p); p=p->forw;
if (0<=(r2=isreg(src)) && r2<NUSE) {
uses[r2]=uses[r]; uses[r]=0;
}
(void) redun3(p,0);
newcode(p); redunm++;
return(p); /* avoid stale uses[] data */
} else splitrand(p);
}
} else if (p->op==MOV && (p->forw->op==CVT || p->forw->op==MOVZ)
&& p->forw->subop&0xf /* if base or index, then forget it */
&& compat(p->subop,p->forw->subop) && !source(cp1=regs[RT1])
&& !indexa(cp1)) goto movit;
}
/* adjust 'lastrand' past any 'read' or 'modify' operands. */
lastrand=byondrd(p);
/* a 'write' clobbers the register. */
if (0<=(r=isreg(lastrand)) && r<NUSE
|| OP2==(p->subop>>4) && 0<=(r=isreg(regs[RT2])) && r<NUSE && uses[r]==0) {
/* writing a dead register is useless, but watch side effects */
switch (p->op) {
case ACB:
case AOBLEQ: case AOBLSS: case SOBGTR: case SOBGEQ: break;
default:
if (uses[r]==0) {/* no direct uses, check for use of condition codes */
register struct node *q=p;
while ((q=nonlab(q->forw))->combop==JBR) q=q->ref; /* cc unused, unchanged */
if (q->op!=CBR) {/* ... and destroyed */
preg=regs+RT1;
while (cp1= *preg++) {
if (cp1==lastrand) {redunm++; delnode(p); return(p->forw);}
if (source(cp1) || equstr(cp1,lastrand)) break;
}
}
}
flow=r;
}
}
if (0<=(r=flow)) {
olduse=uses[r];
uses[r]=0;
regs[r][0]=regs[r][1]=0;
}
/* these two are here, rather than in bmove(),
/* because I decided that it was better to go for 3-address code
/* (save time) rather than fancy jbxx (save 1 byte)
/* on sequences like bisl2 $64,r0; movl r0,foo
*/
if (p->op==BIC) {p=bicopt(p); splitrand(p); lastrand=byondrd(p);}
if (p->op==BIS) {(void) bixprep(p,JBSS); lastrand=byondrd(p);}
/* now look for 'read' or 'modify' (read & write) uses */
preg=regs+RT1;
while (*(cp1= *preg++)) {
/* check for r */
if (lastrand!=cp1 && 0<=(r=isreg(cp1)) && r<NUSE && uses[r]==0) {
uses[r]=p; cp2=regs[r]; *cp2++=p->subop;
if (p->op==ASH && preg==(regs+RT1+1)) cp2[-1]=BYTE; /* stupid DEC */
if (p->op==MOV || p->op==PUSH || p->op==CVT || p->op==MOVZ || p->op==COM || p->op==NEG) {
if (p->op==PUSH) cp1="-(sp)";
else {
cp1=regs[RT2];
if (0<=(r=isreg(cp1)) && r<NUSE && uses[r]==0)
uses[r]=olduse; /* reincarnation!! */
/* as in addl2 r0,r1; movl r1,r0; ret */
if (p->op!=MOV) cp1=0;
}
if (cp1) while (*cp2++= *cp1++);
else *cp2=0;
} else *cp2=0;
continue;
}
/* check for (r),(r)+,-(r),[r] */
do if (*cp1=='(' || *cp1=='[') {/* get register number */
char t;
cp2= ++cp1; while (*++cp1!=')' && *cp1!=']'); t= *cp1; *cp1=0;
if (0<=(r=isreg(cp2)) && r<NUSE && (uses[r]==0 || uses[r]==p)) {
uses[r]=p; regs[r][0]=(*--cp2=='[' ? OPX<<4 : OPB<<4);
}
*cp1=t;
} while (*++cp1);
}
/* pushax or movax possibility? */
cp1=regs[RT1];
if (*cp1++=='$' && isstatic(cp1) && natural(regs[RT1])) {
if (p->combop==T(MOV,LONG)) {
if (regs[RT1][1]=='L' && 0!=(p->labno=getnum(regs[RT1]+2))) {
cp1=p->code; while (*cp1++!=','); p->code= --cp1;
}
p->combop=T(MOVA,LONG); ++p->code; p->pop=0;
} else if (p->combop==T(PUSH,LONG)) {
p->combop=T(PUSHA,LONG); ++p->code; p->pop=0;
} else if ((p->combop&0xFFFF)==T(ADD,U(LONG,OP3))
&& 0<=(r=isreg(regs[RT2]))) {
cp1=cp2=p->code; ++cp1;
do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]='[';
do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]=']';
if (!equstr(regs[RT3],"-(sp)")) p->combop=T(MOVA,BYTE);
else {p->combop=T(PUSHA,BYTE); *cp2=0;}
if (r < NUSE && uses[r] == 0) {
uses[r]=p;
regs[r][0]=OPX<<4;
}
p->pop=0;
}
}
return(p);
}
ispow2(n) register long n; {/* -1 -> no; else -> log to base 2 */
register int log;
if (n==0 || n&(n-1)) return(-1); log=0;
for (;;) {n >>= 1; if (n==0) return(log); ++log; if (n== -1) return(log);}
}
#ifdef notdef
bitopt(p) register struct node *p; {
/* change "bitx $<power_of_2>,a" followed by JEQ or JNE
/* into JBC or JBS. watch out for I/O registers. (?)
/* assumes that 'splitrand' has already been called.
*/
register char *cp1,*cp2; int b;
cp1=regs[RT1]; cp2=regs[RT2];
if (*cp1++!='$' || !okio(cp2) || p->forw->op!=CBR || p->forw->subop&-2 ||
0>(b=ispow2(getnum(cp1)))) return;
if (p->subop!=BYTE && !(b==0 && p->subop==LONG) &&
(source(cp2) || indexa(cp2))) return;
if (b>=bitsize[p->subop]) {/* you dummy! */
if (source(cp2)) {/* side effect: auto increment or decrement */
p->pop=0;
p->op=TST; --cp1; while (*cp1++= *cp2++);
regs[RT2][0]=0; newcode(p);
} else delnode(p);
p = p->forw;
if (p->subop==JEQ) {p->combop=JBR; p->pop=0;}
else delnode(p);
nchange++; nbj++; return;
}
if (cp1=p->forw->code) {/* destination is not an internal label */
cp2=regs[RT3]; while (*cp2++= *cp1++);
}
if (b==0 && (p->subop==LONG || !(source(regs[RT2]) || indexa(regs[RT2])))) {
/* JLB optimization, ala BLISS */
cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++);
cp2=regs[RT2]; cp1=regs[RT3]; while (*cp2++= *cp1++);
*(regs[RT3])=0; p->forw->subop += JLBC-JBC;
p->forw->pop=0;
} else {
cp1=regs[RT1]+1;
if (b>9) *cp1++= b/10 +'0'; *cp1++= b%10 +'0'; *cp1=0; /* $<bit_number> */
}
nbj++; newcode(p); p->combop = p->forw->combop+((JBC-JEQ)<<8);
p->labno = p->forw->labno; delnode(p->forw);
p->pop=0;
}
#endif
isfield(n) register long n; {/* -1 -> no; else -> position of low bit */
register int p; register long t;
t= ((n-1)|n) +1;
if (n!=0 && (0==t || 0<=ispow2(t))) {
p=0; while(!(n&1)) {n >>= 1; ++p;} return(p);
} else return(-1);
}
bixprep(p,bix) register struct node *p; {
/* initial setup, single-bit checking for bisopt, bicopt.
/* return: 0->don't bother any more; 1->worthwhile trying
*/
register char *cp1,*cp2;
splitrand(p); cp1=regs[RT1]; cp2=regs[RT2];
if (*cp1++!='$' || 0>(pos=isfield(f=getnum(cp1)))
|| !okio(cp2) || indexa(cp2) || source(cp2) || !okio(lastrand)) return(0);
f |= f-1; if (++f==0) siz=32-pos; else siz=ispow2(f)-pos;
if (siz==1 && pos>5 && (p->subop>>4)==OP2 && (p->subop&0xF)!=BYTE
&& pos<bitsize[p->subop&0xF]) {
p->ref = insertl(p->forw); p->combop = CBR | (bix<<8);
p->pop=0;
p->labno = p->ref->labno;
if (pos>9) {*cp1++= pos/10 +'0'; pos %= 10;}
*cp1++=pos+'0'; *cp1=0; newcode(p); nbj++; return(0);
}
return(1);
}
struct node *
bicopt(p) register struct node *p; {
/* use field operations or MOVZ if possible. done as part of 'bflow'.
*/
register char *cp1,*cp2; int r;
char src[C2_ASIZE];
char lhssiz, sop;
if (!bixprep(p,JBCC)) return(p);
if (f==0) {/* the BIC isolates low order bits */
siz=pos; pos=0;
if ((p->subop&0xF)==LONG && *(regs[RT2])!='$') {/* result of EXTZV is long */
/* save source of BICL in 'src' */
cp1=regs[RT2]; cp2=src; while (*cp2++= *cp1++);
if (p->back->op==ASH) {/* try for more */
splitrand(p->back); cp1=regs[RT1]; cp2=regs[RT3];
if (*cp1++=='$' && *(regs[RT2])!='$' && !indexa(regs[RT2])
&& 0>(f=getnum(cp1)) && equstr(src,cp2)
&& 0<=(r=isreg(cp2)) && r<NUSE
&& siz-f <= 32) { /* a good ASH */
pos -= f; cp1=regs[RT2]; cp2=src; while (*cp2++= *cp1++);
delnode(p->back);
}
}
/*
* 'pos', 'siz' known; find out the size of the
* left-hand operand of what the bicl will turn into.
*/
if (pos==0 && siz==16)
lhssiz = WORD; /* movzwl */
else
lhssiz = BYTE; /* movzbl or extzvl */
if (p->back->op==CVT || p->back->op==MOVZ) {/* greedy, aren't we? */
splitrand(p->back); cp1=regs[RT1]; cp2=regs[RT2];
/*
* If indexa(cp1) || autoid(cp1), the fold may
* still be OK if the CVT/MOVZ has the same
* size operand on its left size as what we
* will turn the bicl into.
* However, if the CVT is from a float or
* double, forget it!
*/
sop = p->back->subop&0xF; /* type of LHS of CVT/MOVZ */
if (equstr(src,cp2) && okio(cp1)
&& sop != FFLOAT && sop != DFLOAT
&& sop != GFLOAT && sop != HFLOAT
&& ((!indexa(cp1) && !autoid(cp1)) || lhssiz == sop)
&& 0<=(r=isreg(cp2)) && r<NUSE
&& bitsize[sop]>=(pos+siz)
&& bitsize[p->back->subop>>4]>=(pos+siz)) {/* good CVT */
cp1=regs[RT1]; cp2=src; while (*cp2++= *cp1++);
delnode(p->back);
}
}
/* 'pos', 'siz' known; source of field is in 'src' */
splitrand(p); /* retrieve destination of BICL */
if ((siz==8 || siz==16) && pos==0) {
p->combop = T(MOVZ,U(lhssiz,LONG));
sprintf(line,"%s,%s",src,lastrand);
} else {
p->combop = T(EXTZV,LONG);
sprintf(line,"$%d,$%d,%s,%s",pos,siz,src,lastrand);
}
p->pop=0;
p->code = copy(line); nfield++; return(p);
}/* end EXTZV possibility */
}/* end low order bits */
/* unfortunately, INSV clears the condition codes, thus cannot be used */
/* else {/* see if BICL2 of positive field should be INSV $0 */
/* if (p->subop==(LONG | (OP2<<4)) && 6<=(pos+siz)) {
/* p->combop = INSV;
/* sprintf(line,"$0,$%d,$%d,%s",pos,siz,lastrand);
/* p->code = copy(line); nfield++; return(p);
/* }
/* }
*/
return(p);
}
jumpsw()
{
register struct node *p, *p1;
register struct node *tp;
long tl;
char *tcp;
int ti;
int nj;
ti = 0;
nj = 0;
for (p=first.forw; p!=0; p = p->forw)
p->seq = ++ti;
for (p=first.forw; p!=0; p = p1) {
p1 = p->forw;
if (p->op == CBR && p1->op==JBR && p->ref && p1->ref
&& abs(p->seq - p->ref->seq) > abs(p1->seq - p1->ref->seq)) {
if (p->ref==p1->ref)
continue;
p->subop = revbr[p->subop];
p->pop=0;
tp = p1->ref;
p1->ref = p->ref;
p->ref = tp;
tl = p1->labno;
p1->labno = p->labno;
p->labno = tl;
#ifdef COPYCODE
if (p->labno == 0) {
tcp = p1->code;
p1->code = p->code;
p->code = tcp;
}
#endif
nrevbr++;
nj++;
}
}
return(nj);
}
addsob()
{
register struct node *p, *p1, *p2, *p3;
for (p = &first; (p1 = p->forw)!=0; p = p1) {
if (p->combop==T(DEC,LONG) && p1->op==CBR) {
if (abs(p->seq - p1->ref->seq) > 8) continue;
if (p1->subop==JGE || p1->subop==JGT) {
if (p1->subop==JGE) p->combop=SOBGEQ; else p->combop=SOBGTR;
p->pop=0;
p->labno = p1->labno; delnode(p1); nsob++;
}
} else if (p->combop==T(INC,LONG)) {
if (p1->op==LABEL && p1->refc==1 && p1->forw->combop==T(CMP,LONG)
&& (p2=p1->forw->forw)->combop==T(CBR,JLE)
&& (p3=p2->ref->back)->combop==JBR && p3->ref==p1
&& p3->forw->op==LABEL && p3->forw==p2->ref) {
/* change INC LAB: CMP to LAB: INC CMP */
p->back->forw=p1; p1->back=p->back;
p->forw=p1->forw; p1->forw->back=p;
p->back=p1; p1->forw=p;
p1=p->forw;
/* adjust beginning value by 1 */
p2=alloc(sizeof first); p2->combop=T(DEC,LONG);
p2->pop=0;
p2->forw=p3; p2->back=p3->back; p3->back->forw=p2;
p3->back=p2; p2->code=p->code; p2->labno=0;
}
if (p1->combop==T(CMP,LONG) && (p2=p1->forw)->op==CBR) {
register char *cp1,*cp2;
splitrand(p1); if (!equstr(p->code,regs[RT1])) continue;
if (abs(p->seq - p2->ref->seq)>8) {/* outside byte displ range */
if (p2->subop!=JLE) continue;
p->combop=T(ACB,LONG);
cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++); /* limit */
cp2=regs[RT2]; cp1="$1"; while (*cp2++= *cp1++); /* increment */
cp2=regs[RT3]; cp1=p->code; while (*cp2++= *cp1++); /* index */
p->pop=0; newcode(p);
p->labno = p2->labno; delnode(p2); delnode(p1); nsob++;
} else if (p2->subop==JLE || p2->subop==JLT) {
if (p2->subop==JLE) p->combop=AOBLEQ; else p->combop=AOBLSS;
cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++); /* limit */
cp2=regs[RT2]; cp1=p->code; while (*cp2++= *cp1++); /* index */
p->pop=0; newcode(p);
p->labno = p2->labno; delnode(p2); delnode(p1); nsob++;
}
}
}
}
}
equop(p1, p2)
register struct node *p1;
struct node *p2;
{
register char *cp1, *cp2;
if (p1->combop != p2->combop)
return(0);
if (p1->combop == 0 && p1->pop != p2->pop)
return(0);
if (p1->op>0 && p1->op<MOV)
return(0);
switch (p1->combop) {
case EROU: case JSW: case TEXT: case DATA:
case BSS: case ALIGN: case WGEN: case END:
/*
* Consider all pseudo-ops to be unique.
*/
return(0);
}
if (p1->op==MOVA && p1->labno!=p2->labno) return(0);
cp1 = p1->code;
cp2 = p2->code;
if (cp1==0 && cp2==0)
return(1);
if (cp1==0 || cp2==0)
return(0);
while (*cp1 == *cp2++)
if (*cp1++ == 0)
return(1);
return(0);
}
#ifndef delnode
delnode(p) register struct node *p; {
p->back->forw = p->forw;
p->forw->back = p->back;
}
#endif
#ifndef decref
decref(p)
register struct node *p;
{
if (p && --p->refc <= 0) {
nrlab++;
delnode(p);
}
}
#endif
struct node *
nonlab(ap)
struct node *ap;
{
register struct node *p;
p = ap;
while (p && p->op==LABEL)
p = p->forw;
return(p);
}
clearuse() {
register struct node **i;
for (i=uses+NUSE; i>uses;) *--i=0;
}
clearreg() {
register char **i;
for (i=regs; i<regs+NREG; ++i) {
**i = 0;
*(*i+1) = 0;
}
conloc[0] = 0;
ccloc[0] = 0;
}
savereg(ai, s, type)
register char *s;
{
register char *p, *sp;
sp = p = regs[ai];
if (source(s)) /* side effects in addressing */
return;
/* if any indexing, must be parameter or local */
/* indirection (as in "*-4(fp)") is ok, however */
*p++ = type;
while (*p++ = *s)
if (*s=='[' || *s++=='(' && *s!='a' && *s!='f') {*sp = 0; return;}
}
dest(s,type)
register char *s;
{
register int i;
(void) source(s); /* handle addressing side effects */
if (!natural(s)) {
/* wild store, everything except constants vanishes */
for (i=NREG; --i>=0;)
if (regs[i][1] != '$')
regs[i][0] = regs[i][1] = 0;
conloc[0] = 0; ccloc[0] = 0;
return;
}
if ((i = isreg(s)) >= 0) {
/* if register destination, that reg is a goner */
regs[i][0] = regs[i][1] = 0;
switch(type & 0xF){
case DFLOAT: /* clobber two at once */
/*FALLTHROUGH*/
case GFLOAT:
regs[i+1][0] = regs[i+1][1] = 0;
break;
case HFLOAT: /* clobber four at once */
regs[i+1][0] = regs[i+1][1] = 0;
regs[i+2][0] = regs[i+2][1] = 0;
regs[i+3][0] = regs[i+3][1] = 0;
break;
}
switch((type>>4)&0xF){
case DFLOAT: /* clobber two at once */
/*FALLTHROUGH*/
case GFLOAT:
regs[i+1][0] = regs[i+1][1] = 0;
break;
case HFLOAT: /* clobber four at once */
regs[i+1][0] = regs[i+1][1] = 0;
regs[i+2][0] = regs[i+2][1] = 0;
regs[i+3][0] = regs[i+3][1] = 0;
break;
}
}
for (i=NREG; --i>=0;)
if (regs[i][1]=='*' && equstr(s, regs[i]+2))
regs[i][0] = regs[i][1] = 0; /* previous indirection through destination is invalid */
while ((i = findrand(s,0)) >= 0) /* previous values of destination are invalid */
regs[i][0] = regs[i][1] = 0;
if (*conloc && equstr(conloc, s))
conloc[0] = 0;
setcc(s, type); /* natural destinations set condition codes */
}
/* separate operands at commas, set up 'regs' and 'lastrand' */
splitrand(p) struct node *p; {
register char *p1, *p2;
register char **preg;
preg = regs+RT1;
if (p1 = p->code)
while (*p1) {
lastrand = p2 = *preg++;
while (*p1)
if (',' == (*p2++ = *p1++)) {
--p2;
break;
}
*p2 = 0;
}
while (preg < (regs+RT1+5))
*(*preg++) = 0;
}
compat(have, want) {
register int hsrc, hdst;
if (0==(want &= 0xF)) return(1); /* anything satisfies a wildcard want */
hsrc=have&0xF;
if (0==(hdst=((have>>4)&0xF)) || (hdst>=OP2 && hdst<=OPX)) hdst=hsrc;
if (want>=FFLOAT) return(hdst==want && hsrc==want);
/* FLOAT, DFLOAT not compat: rounding */
return(hsrc>=want && hdst>=want && hdst<FFLOAT);
}
equtype(t1,t2) {return(compat(t1,t2) && compat(t2,t1));}
findrand(as, type)
char *as;
{
register char **i;
for (i = regs+NREG; --i>=regs;) {
if (**i && equstr(*i+1, as) && compat(**i,type))
return(i-regs);
}
return(-1);
}
isreg(s)
register char *s;
{
if (*s++!='r' || !isdigit(*s++)) return(-1);
if (*s==0) return(*--s-'0');
if (*(s-1)=='1' && isdigit(*s++) && *s==0) return(10+*--s-'0');
return(-1);
}
check()
{
register struct node *p, *lp;
lp = &first;
for (p=first.forw; p!=0; p = p->forw) {
if (p->back != lp) {
fprintf(stderr, "c2: failed internal consistency check -- help!\n");
exit(-1);
}
lp = p;
}
}
source(ap)
char *ap;
{
register char *p1, *p2;
p1 = ap;
p2 = p1;
if (*p1==0)
return(0);
while (*p2++ && *(p2-1)!='[');
if (*p1=='-' && *(p1+1)=='('
|| *p1=='*' && *(p1+1)=='-' && *(p1+2)=='('
|| *(p2-2)=='+') {
while (*p1 && *p1++!='r');
if (isdigit(*p1++))
if (isdigit(*p1))
regs[10+*p1-'0'][0] = regs[10+*p1-'0'][1] = 0;
else {
--p1;
regs[*p1-'0'][0] = regs[*p1-'0'][1] = 0;
}
return(1);
}
return(0);
}
newcode(p) struct node *p; {
register char *p1,*p2,**preg;
preg=regs+RT1; p2=line;
while (*(p1= *preg++)) {while (*p2++= *p1++); *(p2-1)=',';}
*--p2=0;
p->code=copy(line);
}
repladdr(p)
struct node *p;
{
register r;
register char *p1;
char **preg; int nrepl;
preg=regs+RT1; nrepl=0;
while (lastrand!=(p1= *preg++))
if (!source(p1) && 0<=(r=findrand(p1,p->subop))) {
*p1++='r'; if (r>9) {*p1++='1'; r -= 10;} *p1++=r+'0'; *p1=0;
nrepl++; nsaddr++;
}
if (nrepl) newcode(p);
}
/* movedat()
/* {
/* register struct node *p1, *p2;
/* struct node *p3;
/* register seg;
/* struct node data;
/* struct node *datp;
/*
/* if (first.forw == 0)
/* return;
/* datp = &data;
/* for (p1 = first.forw; p1!=0; p1 = p1->forw) {
/* if (p1->op == DATA) {
/* p2 = p1->forw;
/* while (p2 && p2->op!=TEXT)
/* p2 = p2->forw;
/* if (p2==0)
/* break;
/* p3 = p1->back;
/* p1->back->forw = p2->forw;
/* p2->forw->back = p3;
/* p2->forw = 0;
/* datp->forw = p1;
/* p1->back = datp;
/* p1 = p3;
/* datp = p2;
/* }
/* }
/* if (data.forw) {
/* datp->forw = first.forw;
/* first.forw->back = datp;
/* data.forw->back = &first;
/* first.forw = data.forw;
/* }
/* seg = -1;
/* for (p1 = first.forw; p1!=0; p1 = p1->forw) {
/* if (p1->op==TEXT||p1->op==DATA||p1->op==BSS) {
/* if (p1->op == seg || p1->forw&&p1->forw->op==seg) {
/* p1->back->forw = p1->forw;
/* p1->forw->back = p1->back;
/* p1 = p1->back;
/* continue;
/* }
/* seg = p1->op;
/* }
/* }
/* }
*/
redunbr(p)
register struct node *p;
{
register struct node *p1;
register char *ap1;
char *ap2;
if ((p1 = p->ref) == 0)
return;
p1 = nonlab(p1);
if (p1->op==TST) {
splitrand(p1);
savereg(RT2, "$0", p1->subop);
} else if (p1->op==CMP)
splitrand(p1);
else
return;
if (p1->forw->op==CBR) {
ap1 = findcon(RT1, p1->subop);
ap2 = findcon(RT2, p1->subop);
p1 = p1->forw;
if (compare(p1->subop, ap1, ap2)) {
nredunj++;
nchange++;
decref(p->ref);
p->ref = p1->ref;
p->labno = p1->labno;
#ifdef COPYCODE
if (p->labno == 0)
p->code = p1->code;
#endif
if (p->ref)
p->ref->refc++;
}
} else if (p1->op==TST && equstr(regs[RT1],ccloc+1) &&
equtype(ccloc[0],p1->subop)) {
p1=insertl(p1->forw);
decref(p->ref);
p->ref=p1;
p->labno=p1->labno;
nrtst++; nchange++;
}
}
char *
findcon(i, type)
{
register char *p;
register r;
p = regs[i];
if (*p=='$')
return(p);
if ((r = isreg(p)) >= 0 && compat(regs[r][0],type))
return(regs[r]+1);
if (equstr(p, conloc))
return(conval+1);
return(p);
}
compare(opc, acp1, acp2)
char *acp1, *acp2;
{
register char *cp1, *cp2;
register n1;
int n2; int sign;
cp1 = acp1;
cp2 = acp2;
if (*cp1++ != '$' || *cp2++ != '$')
return(0);
n1 = 0; sign=1; if (*cp2=='-') {++cp2; sign= -1;}
while (isdigit(*cp2)) {n1 *= 10; n1 += (*cp2++ - '0')*sign;}
n2 = n1;
n1 = 0; sign=1; if (*cp1=='-') {++cp1; sign= -1;}
while (isdigit(*cp1)) {n1 *= 10; n1 += (*cp1++ - '0')*sign;}
if (*cp1=='+')
cp1++;
if (*cp2=='+')
cp2++;
do {
if (*cp1++ != *cp2)
return(0);
} while (*cp2++);
switch(opc) {
case JEQ:
return(n1 == n2);
case JNE:
return(n1 != n2);
case JLE:
return(n1 <= n2);
case JGE:
return(n1 >= n2);
case JLT:
return(n1 < n2);
case JGT:
return(n1 > n2);
case JLO:
return((unsigned) n1 < (unsigned) n2);
case JHI:
return((unsigned) n1 > (unsigned) n2);
case JLOS:
return((unsigned) n1 <= (unsigned) n2);
case JHIS:
return((unsigned) n1 >= (unsigned) n2);
}
return(0);
}
setcon(cv, cl, type)
register char *cv, *cl;
{
register char *p;
if (*cv != '$')
return;
if (!natural(cl))
return;
p = conloc;
while (*p++ = *cl++);
p = conval;
*p++ = type;
while (*p++ = *cv++);
}
equstr(p1, p2)
register char *p1, *p2;
{
do {
if (*p1++ != *p2)
return(0);
} while (*p2++);
return(1);
}
setcc(ap,type)
char *ap;
{
register char *p, *p1;
p = ap;
if (!natural(p)) {
ccloc[0] = 0;
return;
}
p1 = ccloc;
*p1++ = type;
while (*p1++ = *p++);
}
okio(p) register char *p; {/* 0->probable I/O space address; 1->not */
if (ioflag && (!natural(p) || 0>getnum(p))) return(0);
return(1);
}
indexa(p) register char *p; {/* 1-> uses [r] addressing mode; 0->doesn't */
while (*p) if (*p++=='[') return(1);
return(0);
}
natural(p)
register char *p;
{/* 1->simple local, parameter, global, or register; 0->otherwise */
if (*p=='*' || *p=='(' || *p=='-'&&p[1]=='(' || *p=='$'&&getnum(p+1))
return(0);
while (*p++);
p--;
if (*--p=='+' || *p==']' || *p==')' && p[-2]!='a' && p[-2]!='f')
return(0);
return(1);
}
/*
** Tell if an argument is most likely static.
*/
isstatic(cp)
register char *cp;
{
if (*cp == '_' || *cp == 'L' || (*cp++ == 'v' && *cp == '.'))
return (1);
return (0);
}
autoid(p) register char *p; {/* 1-> uses autoincrement/autodecrement; 0->doesn't */
if (*p == '-' && *(p+1) == '(') return(1);
while (*p) p++;
if (*--p == '+' && *--p == ')') return(1);
return(0);
}