ack/lang/basic/src.old/split.c

87 lines
1.4 KiB
C

#include "bem.h"
/* Split the intermediate code into procedures.
This is necessary to make the EM code fit on
smaller machines. (for the Peephole optimizer!)
*/
/* Heuristic is to collect all basic blocks of more then THRESHOLD
em instructions into a procedure
*/
int procnum;
int threshold; /* can be set by the user */
fix(lnr)
int lnr;
{
/* this block may not be moved to a procedure */
Linerecord *lr;
if(debug) printf("fixate %d\n",lnr);
for(lr= firstline;lr; lr=lr->nextline)
if( lr->linenr == lnr)
lr->fixed=1;
}
fixblock(l)
List *l;
{
while(l)
{
fix(l->linenr);
l=l->nextlist;
}
}
phase1()
{
/* copy all offloaded blocks */
Linerecord *lr, *lf,*lr2;
int blksize;
lf= lr= firstline;
blksize= lr->codelines;
while( lr)
{
if( lr->fixed){
if( !lf->fixed && blksize>threshold)
{
/*move block */
if(debug) printf("%d %d->%d moved\n",
blksize,lf->linenr, lr->linenr);
}
lf= lr;
blksize= lr->codelines;
}
lr= lr->nextline;
}
}
phase2()
{
/* copy main procedure */
prolog2();
epilogcode();
}
split()
{
/* selectively copy the intermediate code to procedures */
Linerecord *lr;
if( debug) printf("split EM code using %d\n",threshold);
/* First consolidate the goto's and caller's */
lr= firstline;
while(lr)
{
fixblock(lr->callers);
fixblock(lr->gotos);
lr= lr->nextline;
}
/* Copy the temporary file piecewise */
prologcode();
phase1();
phase2();
}