/* if it has a spillocation & is used less than
all other live ranges then spill this */
- if (willCS && sym->usl.spillLoc)
- {
-
- symbol *leastUsed =
- leastUsedLR (liveRangesWith (spillable,
- allLRs,
- ebbs[i],
- ic));
- if (leastUsed &&
- leastUsed->used > sym->used)
- {
- spillThis (sym);
- continue;
+ if (willCS) {
+ if (sym->usl.spillLoc) {
+ symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
+ allLRs, ebbs[i], ic));
+ if (leastUsed && leastUsed->used > sym->used) {
+ spillThis (sym);
+ continue;
+ }
+ } else {
+ /* if none of the liveRanges have a spillLocation then better
+ to spill this one than anything else already assigned to registers */
+ if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
+ spillThis (sym);
+ continue;
+ }
}
}
isBitwiseOptimizable (iCode * ic)
{
sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
- // jwk sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
+ sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
/* bitwise operations are considered optimizable
under the following conditions (Jean-Louis VERN)
- x & lit <== jwk: should be x && lit
+ x & lit
bit & bit
bit & x
bit ^ bit
bit ^ x
- x ^ lit <== jwk: should be x ^^ lit
- x | lit <== jwk: should be x || lit
+ x ^ lit
+ x | lit
bit | bit
bit | x
*/
- if ( /* jwk IS_LITERAL (rtype) || */
+ if ( IS_LITERAL (rtype) ||
(IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
return TRUE;
else
for (lic = ic; lic != dic ; lic = lic->prev) {
if (bitVectBitValue(dbv,lic->key)) return ;
}
-
+ /* extend the live range of replaced operand if needed */
+ if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
+ OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
+ }
/* we now we know that it has one & only one def & use
and the that the definition is an assignment */
IC_LEFT (ic) = IC_RIGHT (dic);
}
}
+#if 0
/* if the condition of an if instruction
is defined in the previous instruction then
mark the itemp as a conditional */
OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
continue;
}
+#else
+ /* if the condition of an if instruction
+ is defined in the previous instruction and
+ this is the only usage then
+ mark the itemp as a conditional */
+ if ((IS_CONDITIONAL (ic) ||
+ (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
+ ic->next && ic->next->op == IFX &&
+ bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
+ isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
+ OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
+ {
+ OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
+ continue;
+ }
+#endif
/* reduce for support function calls */
if (ic->supportRtn || ic->op == '+' || ic->op == '-')