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Fix: illegal optimizations of muls

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This commit is contained in:
ceriel 1990-01-30 13:41:36 +00:00
parent 3ad14daa2e
commit ca659ea85a
1 changed files with 36 additions and 0 deletions
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36
mach/m68020/top/table
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@ -145,6 +145,9 @@ move.l A, B : bra LAB : labdef L1 : move.l A, B : labdef LAB
labdef LAB ;
/* some strength reduction */
mulu.l #NUM,DREG -> muls.l #NUM,DREG ;
muls.l #NUM,DREG
{isshift_once(NUM,X,Y)} -> asl.l #X,DREG :
asl.l #Y,DREG ;
muls.l #NUM,DREG
{is_shift_twice(NUM,X,Y)} -> asl.l #X,DREG :
move.l DREG,-(sp) :
@ -179,6 +182,38 @@ int no_side_effects(s)
/* NOTREACHED */
}
int isshift_once(s, c1, c2)
char *s, *c1, *c2;
{
long atol();
register int i = 0;
long val = atol(s), pow = 1;
while (i <= 8) {
if (pow & val) {
val -= pow;
sprintf(c1, "%d", i);
strcpy(c2, "0");
if (val == 0) return 1;
return 0;
}
pow <<= 1;
i++;
}
i = 0;
strcpy(c1, "8");
while (i <= 8) {
if (pow & val) {
val -= pow;
sprintf(c2, "%d", i);
if (val == 0) return 1;
return 0;
}
pow <<= 1;
i++;
}
return 0;
}
int is_shift_twice(s, c1, c2)
char *s, *c1, *c2;
@ -196,6 +231,7 @@ int is_shift_twice(s, c1, c2)
pow <<= 1;
i++;
}
if (i > 8) return 0;
if (pow > 0 && val) {
i = 0;
while (i <= 8) {