STATIC void touchlvalue(elem *e)
{ register int i;
if (e->Eoper == OPind) /* if indirect store */
{
/* NOTE: Some types of array assignments do not need
* to touch all variables. (Like a[5], where a is an
* array instead of a pointer.)
*/
touchfunc(0);
return;
}
for (i = hcstop; --i >= 0;)
{ if (hcstab[i].Helem &&
hcstab[i].Helem->EV.sp.Vsym == e->EV.sp.Vsym)
hcstab[i].Helem = NULL;
}
assert(e->Eoper == OPvar || e->Eoper == OPrelconst);
switch (e->EV.sp.Vsym->Sclass)
{
case SCregpar:
case SCregister:
case SCtmp:
case SCpseudo:
break;
case SCauto:
case SCparameter:
case SCfastpar:
case SCshadowreg:
case SCbprel:
if (e->EV.sp.Vsym->Sflags & SFLunambig)
break;
/* FALL-THROUGH */
case SCstatic:
case SCextern:
case SCglobal:
case SClocstat:
case SCcomdat:
case SCinline:
case SCsinline:
case SCeinline:
case SCcomdef:
touchstar();
break;
default:
#ifdef DEBUG
elem_print(e);
symbol_print(e->EV.sp.Vsym);
#endif
assert(0);
}
}
STATIC void ecom(elem **pe)
{ int i,op,hcstopsave;
unsigned hash;
elem *e,*ehash;
tym_t tym;
e = *pe;
assert(e);
elem_debug(e);
#ifdef DEBUG
assert(e->Ecount == 0);
//assert(e->Ecomsub == 0);
#endif
tym = tybasic(e->Ety);
op = e->Eoper;
switch (op)
{
case OPconst:
case OPvar:
case OPrelconst:
break;
case OPstreq:
case OPpostinc:
case OPpostdec:
case OPeq:
case OPaddass:
case OPminass:
case OPmulass:
case OPdivass:
case OPmodass:
case OPshrass:
case OPashrass:
case OPshlass:
case OPandass:
case OPxorass:
case OPorass:
#if TX86
/* Reverse order of evaluation for double op=. This is so that */
/* the pushing of the address of the second operand is easier. */
/* However, with the 8087 we don't need the kludge. */
if (op != OPeq && tym == TYdouble && !config.inline8087)
{ if (EOP(e->E1))
ecom(&e->E1->E1);
ecom(&e->E2);
}
else
#endif
{
/* Don't mark the increment of an i++ or i-- as a CSE, if it */
/* can be done with an INC or DEC instruction. */
if (!(OTpost(op) && elemisone(e->E2)))
ecom(&e->E2); /* evaluate 2nd operand first */
case OPnegass:
if (EOP(e->E1)) /* if lvalue is an operator */
{
#ifdef DEBUG
if (e->E1->Eoper != OPind)
elem_print(e);
#endif
assert(e->E1->Eoper == OPind);
ecom(&(e->E1->E1));
}
}
touchlvalue(e->E1);
if (!OTpost(op)) /* lvalue of i++ or i-- is not a cse*/
{
hash = cs_comphash(e->E1);
vec_setbit(hash % CSVECDIM,csvec);
addhcstab(e->E1,hash); // add lvalue to hcstab[]
}
return;
case OPbtc:
case OPbts:
case OPbtr:
ecom(&e->E1);
ecom(&e->E2);
touchfunc(0); // indirect assignment
return;
case OPandand:
case OPoror:
ecom(&e->E1);
hcstopsave = hcstop;
ecom(&e->E2);
hcstop = hcstopsave; /* no common subs by E2 */
return; /* if comsub then logexp() will */
/* break */
case OPcond:
ecom(&e->E1);
hcstopsave = hcstop;
ecom(&e->E2->E1); /* left condition */
hcstop = hcstopsave; /* no common subs by E2 */
ecom(&e->E2->E2); /* right condition */
hcstop = hcstopsave; /* no common subs by E2 */
return; /* can't be a common sub */
case OPcall:
case OPcallns:
ecom(&e->E2); /* eval right first */
/* FALL-THROUGH */
case OPucall:
case OPucallns:
ecom(&e->E1);
touchfunc(1);
return;
case OPstrpar: /* so we don't break logexp() */
#if TX86
case OPinp: /* never CSE the I/O instruction itself */
#endif
case OPdctor:
ecom(&e->E1);
/* FALL-THROUGH */
case OPasm:
case OPstrthis: // don't CSE these
case OPframeptr:
case OPgot:
case OPctor:
case OPdtor:
case OPmark:
return;
case OPddtor:
return;
case OPparam:
#if TX86
case OPoutp:
#endif
ecom(&e->E1);
case OPinfo:
ecom(&e->E2);
return;
case OPcomma:
case OPremquo:
ecom(&e->E1);
ecom(&e->E2);
break;
#if TARGET_SEGMENTED
case OPvp_fp:
case OPcvp_fp:
ecom(&e->E1);
touchaccess(e);
break;
#endif
case OPind:
ecom(&e->E1);
/* Generally, CSEing a *(double *) results in worse code */
if (tyfloating(tym))
return;
break;
#if TX86
case OPstrcpy:
case OPstrcat:
case OPmemcpy:
case OPmemset:
ecom(&e->E2);
case OPsetjmp:
ecom(&e->E1);
touchfunc(0);
return;
#endif
default: /* other operators */
#if TX86
#ifdef DEBUG
if (!EBIN(e)) WROP(e->Eoper);
#endif
assert(EBIN(e));
case OPadd:
case OPmin:
case OPmul:
case OPdiv:
case OPor:
case OPxor:
case OPand:
case OPeqeq:
case OPne:
case OPscale:
case OPyl2x:
case OPyl2xp1:
ecom(&e->E1);
ecom(&e->E2);
break;
#else
#ifdef DEBUG
if (!EOP(e)) WROP(e->Eoper);
#endif
assert(EOP(e));
ecom(&e->E1);
if (EBIN(e))
ecom(&e->E2); /* eval left first */
break;
#endif
case OPstring:
case OPaddr:
case OPbit:
#ifdef DEBUG
WROP(e->Eoper);
elem_print(e);
#endif
assert(0); /* optelem() should have removed these */
/* NOTREACHED */
// Explicitly list all the unary ops for speed
case OPnot: case OPcom: case OPneg: case OPuadd:
case OPabs: case OPsqrt: case OPrndtol: case OPsin: case OPcos: case OPrint:
case OPpreinc: case OPpredec:
case OPbool: case OPstrlen: case OPs16_32: case OPu16_32:
case OPd_s32: case OPd_u32:
case OPs32_d: case OPu32_d: case OPd_s16: case OPs16_d: case OP32_16:
case OPd_f: case OPf_d:
case OPd_ld: case OPld_d:
case OPc_r: case OPc_i:
case OPu8_16: case OPs8_16: case OP16_8:
case OPu32_64: case OPs32_64: case OP64_32: case OPmsw:
case OPu64_128: case OPs64_128: case OP128_64:
case OPd_s64: case OPs64_d: case OPd_u64: case OPu64_d:
case OPstrctor: case OPu16_d: case OPd_u16:
case OParrow:
case OPvoid: case OPnullcheck:
case OPbsf: case OPbsr: case OPbswap:
case OPld_u64:
#if TARGET_SEGMENTED
case OPoffset: case OPnp_fp: case OPnp_f16p: case OPf16p_np:
#endif
ecom(&e->E1);
break;
case OPhalt:
return;
}
/* don't CSE structures or unions or volatile stuff */
if (tym == TYstruct ||
tym == TYvoid ||
e->Ety & mTYvolatile
#if TX86
// don't CSE doubles if inline 8087 code (code generator can't handle it)
|| (tyfloating(tym) && config.inline8087)
#endif
)
return;
hash = cs_comphash(e); /* must be AFTER leaves are done */
/* Search for a match in hcstab[].
* Search backwards, as most likely matches will be towards the end
* of the list.
*/
#ifdef DEBUG
if (debugx) dbg_printf("elem: %p hash: %6d\n",e,hash);
#endif
int csveci = hash % CSVECDIM;
if (vec_testbit(csveci,csvec))
{
for (i = hcstop; i--;)
{
#ifdef DEBUG
if (debugx)
dbg_printf("i: %2d Hhash: %6d Helem: %p\n",
i,hcstab[i].Hhash,hcstab[i].Helem);
#endif
if (hash == hcstab[i].Hhash && (ehash = hcstab[i].Helem) != NULL)
{
/* if elems are the same and we still have room for more */
if (el_match(e,ehash) && ehash->Ecount < 0xFF)
{
/* Make sure leaves are also common subexpressions
* to avoid false matches.
*/
if (!OTleaf(op))
{
if (!e->E1->Ecount)
continue;
if (OTbinary(op) && !e->E2->Ecount)
continue;
}
ehash->Ecount++;
*pe = ehash;
#ifdef DEBUG
if (debugx)
dbg_printf("**MATCH** %p with %p\n",e,*pe);
#endif
el_free(e);
return;
}
}
}
}
else
vec_setbit(csveci,csvec);
addhcstab(e,hash); // add this elem to hcstab[]
}