{
werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
"createRegMask cannot find live range");
+ fprintf(stderr, "\tmissing live range: key=%d\n", j);
exit (0);
}
}
-/*-----------------------------------------------------------------*/
+/*------------------------------------------------------------------*/
/* findAssignToSym : scanning backwards looks for first assig found */
-/*-----------------------------------------------------------------*/
+/*------------------------------------------------------------------*/
static iCode *
findAssignToSym (operand * op, iCode * ic)
{
iCode *dic;
+ /* This routine is used to find sequences like
+ iTempAA = FOO;
+ ...; (intervening ops don't use iTempAA or modify FOO)
+ blah = blah + iTempAA;
+
+ and eliminate the use of iTempAA, freeing up its register for
+ other uses.
+ */
+
+
for (dic = ic->prev; dic; dic = dic->prev)
{
IC_RESULT (dic)->key == op->key
/* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
)
- {
-
- /* we are interested only if defined in far space */
- /* or in stack space in case of + & - */
-
- /* if assigned to a non-symbol then return
- FALSE */
- if (!IS_SYMOP (IC_RIGHT (dic)))
- return NULL;
-
- /* if the symbol is in far space then
- we should not */
- if (isOperandInFarSpace (IC_RIGHT (dic)))
- return NULL;
-
- /* for + & - operations make sure that
- if it is on the stack it is the same
- as one of the three operands */
- if ((ic->op == '+' || ic->op == '-') &&
- OP_SYMBOL (IC_RIGHT (dic))->onStack)
- {
-
- if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
- IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
- IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
- return NULL;
- }
-
- break;
-
- }
+ break; /* found where this temp was defined */
/* if we find an usage then we cannot delete it */
if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
return NULL;
}
+ if (!dic)
+ return NULL; /* didn't find any assignment to op */
+
+ /* we are interested only if defined in far space */
+ /* or in stack space in case of + & - */
+
+ /* if assigned to a non-symbol then don't repack regs */
+ if (!IS_SYMOP (IC_RIGHT (dic)))
+ return NULL;
+
+ /* if the symbol is volatile then we should not */
+ if (isOperandVolatile (IC_RIGHT (dic), TRUE))
+ return NULL;
+ /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
+ What does it mean for an iTemp to be volatile, anyway? Passing
+ TRUE is more cautious but may prevent possible optimizations */
+
+ /* if the symbol is in far space then we should not */
+ if (isOperandInFarSpace (IC_RIGHT (dic)))
+ return NULL;
+
+ /* for + & - operations make sure that
+ if it is on the stack it is the same
+ as one of the three operands */
+ if ((ic->op == '+' || ic->op == '-') &&
+ OP_SYMBOL (IC_RIGHT (dic))->onStack)
+ {
+
+ if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
+ IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
+ IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
+ return NULL;
+ }
+
/* now make sure that the right side of dic
is not defined between ic & dic */
if (dic)
}
return dic;
+}
+
+/*-----------------------------------------------------------------*/
+/* reassignAliasedSym - used by packRegsForSupport to replace */
+/* redundant iTemp with equivalent symbol */
+/*-----------------------------------------------------------------*/
+static void
+reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
+{
+ iCode *ic;
+ unsigned oldSymKey, newSymKey;
+ oldSymKey = op->key;
+ newSymKey = IC_RIGHT(assignment)->key;
+ /* only track live ranges of compiler-generated temporaries */
+ if (!IS_ITEMP(IC_RIGHT(assignment)))
+ newSymKey = 0;
+
+ /* update the live-value bitmaps */
+ for (ic = assignment; ic != use; ic = ic->next) {
+ bitVectUnSetBit (ic->rlive, oldSymKey);
+ if (newSymKey != 0)
+ ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
+ }
+
+ /* update the sym of the used operand */
+ OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
+ op->key = OP_SYMBOL(op)->key;
+
+ /* update the sym's liverange */
+ if ( OP_LIVETO(op) < ic->seq )
+ setToRange(op, ic->seq, FALSE);
+
+ /* remove the assignment iCode now that its result is unused */
+ remiCodeFromeBBlock (ebp, assignment);
+ bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
+ hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
}
+
/*-----------------------------------------------------------------*/
/* packRegsForSupport :- reduce some registers for support calls */
static int
packRegsForSupport (iCode * ic, eBBlock * ebp)
{
- int change = 0;
- iCode *dic, *sic;
-
+ iCode *dic;
+
/* for the left & right operand :- look to see if the
left was assigned a true symbol in far space in that
case replace them */
{
dic = findAssignToSym (IC_LEFT (ic), ic);
- if (!dic)
- goto right;
-
- /* found it we need to remove it from the
- block */
- for (sic = dic; sic != ic; sic = sic->next) {
- bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
- sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
- }
-
- OP_SYMBOL(IC_LEFT (ic))=OP_SYMBOL(IC_RIGHT (dic));
- OP_SYMBOL(IC_LEFT(ic))->liveTo = ic->seq;
- IC_LEFT (ic)->key = OP_SYMBOL(IC_RIGHT (dic))->key;
- remiCodeFromeBBlock (ebp, dic);
- bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
- hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
- change++;
+ if (dic)
+ {
+ /* found it we need to remove it from the block */
+ reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
+ return 1;
+ }
}
/* do the same for the right operand */
- right:
- if (!change &&
- IS_ITEMP (IC_RIGHT (ic)) &&
+ if (IS_ITEMP (IC_RIGHT (ic)) &&
OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
{
iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
- iCode *sic;
-
- if (!dic)
- return change;
- /* if this is a subtraction & the result
- is a true symbol in far space then don't pack */
- if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
+ if (dic)
{
- sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
- if (IN_FARSPACE (SPEC_OCLS (etype)))
- return change;
+ /* if this is a subtraction & the result
+ is a true symbol in far space then don't pack */
+ if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
+ {
+ sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
+ if (IN_FARSPACE (SPEC_OCLS (etype)))
+ return 0;
+ }
+ /* found it we need to remove it from the
+ block */
+ reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
+
+ return 1;
}
- /* found it we need to remove it from the
- block */
- for (sic = dic; sic != ic; sic = sic->next) {
- bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
- sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
- }
-
- IC_RIGHT (ic)->operand.symOperand =
- IC_RIGHT (dic)->operand.symOperand;
- OP_SYMBOL(IC_RIGHT(ic))->liveTo = ic->seq;
- IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
-
- remiCodeFromeBBlock (ebp, dic);
- bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
- hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
- change++;
}
- return change;
+ return 0;
}
#define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
return FALSE;
}
+/*-----------------------------------------------------------------*/
+/* isCommutativeOp - tests whether this op cares what order its */
+/* operands are in */
+/*-----------------------------------------------------------------*/
+bool isCommutativeOp(char op)
+{
+ if (op == '+' || op == '*' || op == EQ_OP ||
+ op == '^' || op == '|' || op == BITWISEAND)
+ return TRUE;
+ else
+ return FALSE;
+}
+
+/*-----------------------------------------------------------------*/
+/* operandUsesAcc - determines whether the code generated for this */
+/* operand will have to use the accumulator */
+/*-----------------------------------------------------------------*/
+bool operandUsesAcc(operand *op)
+{
+ if (!op)
+ return FALSE;
+
+ if (IS_SYMOP(op)) {
+ symbol *sym = OP_SYMBOL(op);
+ memmap *symspace;
+
+ if (sym->accuse)
+ return TRUE; /* duh! */
+
+ if (IN_STACK(sym->etype) || sym->onStack ||
+ (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
+ return TRUE; /* acc is used to calc stack offset */
+
+ if (IS_ITEMP(op))
+ {
+ if (SPIL_LOC(op)) {
+ sym = SPIL_LOC(op); /* if spilled, look at spill location */
+ } else {
+ return FALSE; /* more checks? */
+ }
+ }
+
+ symspace = SPEC_OCLS(sym->etype);
+
+ if (sym->iaccess && symspace->paged)
+ return TRUE; /* must fetch paged indirect sym via accumulator */
+
+ if (IN_BITSPACE(symspace))
+ return TRUE; /* fetching bit vars uses the accumulator */
+
+ if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
+ return TRUE; /* fetched via accumulator and dptr */
+ }
+
+ return FALSE;
+}
+
/*-----------------------------------------------------------------*/
/* packRegsForAccUse - pack registers for acc use */
/*-----------------------------------------------------------------*/
if (uic->op == JUMPTABLE)
return;
- /* if the usage is not is an assignment
- or an arithmetic / bitwise / shift operation then not */
if (POINTER_SET (uic) &&
getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
return;
+ /* if the usage is not is an assignment
+ or an arithmetic / bitwise / shift operation then not */
if (uic->op != '=' &&
!IS_ARITHMETIC_OP (uic) &&
!IS_BITWISE_OP (uic) &&
return;
/* if used in ^ operation then make sure right is not a
- literl */
+ literal (WIML: Why is this?) */
if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
return;
/* if shift operation make sure right side is not a literal */
+ /* WIML: Why is this? */
if (uic->op == RIGHT_OP &&
(isOperandLiteral (IC_RIGHT (uic)) ||
getSize (operandType (IC_RESULT (uic))) > 1))
return;
-
if (uic->op == LEFT_OP &&
(isOperandLiteral (IC_RIGHT (uic)) ||
getSize (operandType (IC_RESULT (uic))) > 1))
return;
#endif
- /* if either one of them in far space then we cannot */
- if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
- isOperandInFarSpace (IC_LEFT (uic))) ||
- (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
- isOperandInFarSpace (IC_RIGHT (uic))))
+ /* if the other operand uses the accumulator then we cannot */
+ if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
+ operandUsesAcc(IC_RIGHT(uic))) ||
+ (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
+ operandUsesAcc(IC_LEFT(uic))) )
return;
/* if the usage has only one operand then we can */
IC_RIGHT (uic) == NULL)
goto accuse;
- /* make sure this is on the left side if not
- a '+' since '+' is commutative */
- if (ic->op != '+' &&
- IC_LEFT (uic)->key != IC_RESULT (ic)->key)
+ /* make sure this is on the left side if not commutative */
+ /* except for '-', which has been written to be able to
+ handle reversed operands */
+ if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
+ IC_LEFT (uic)->key != IC_RESULT (ic)->key)
return;
#if 0
}
#endif
- /* if the other one is not on stack then we can */
- if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
- (IS_ITEMP (IC_RIGHT (uic)) ||
- (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
- !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
- goto accuse;
-
- if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
- (IS_ITEMP (IC_LEFT (uic)) ||
- (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
- !OP_SYMBOL (IC_LEFT (uic))->onStack)))
- goto accuse;
-
- return;
-
accuse:
OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
-
}
/*-----------------------------------------------------------------*/
projects / fw / sdcc / blobdiff