/*-----------------------------------------------------------------*/ static void discardDeadParamReceives (eBBlock ** ebbs, int count) { int i; iCode *ic; iCode dummyIcode; for (i = 0; i < count; i++) { for (ic = ebbs[i]->sch; ic; ic = ic->next) { if (ic->op == RECEIVE) { if (IC_RESULT (ic) && OP_SYMBOL (IC_RESULT (ic)) && !OP_SYMBOL (IC_RESULT (ic))->used) { #if 0 fprintf (stderr, "discarding dead receive for %s\n", OP_SYMBOL (IC_RESULT (ic))->name); #endif dummyIcode.next = ic->next; remiCodeFromeBBlock (ebbs[i], ic); ic = &dummyIcode; } } } } }
/*--------------------------------------------------------------------*/ void ptrPseudoSymConvert (symbol *sym, iCode *dic, char *name) { symbol *psym = newSymbol (name, 1); psym->psbase = ptrBaseRematSym (OP_SYMBOL (IC_LEFT (dic))); psym->type = sym->type; psym->etype = psym->psbase->etype; strcpy (psym->rname, psym->name); sym->isspilt = 1; sym->usl.spillLoc = psym; #if 0 // an alternative fix for bug #480076 /* now this is a useless assignment to itself */ remiCodeFromeBBlock (ebbs, dic); #else /* now this really is an assignment to itself, make it so; it will be optimized out later */ dic->op='='; ReplaceOpWithCheaperOp(&IC_RIGHT(dic), IC_RESULT(dic)); IC_LEFT(dic)=NULL; #endif }
/*-----------------------------------------------------------------*/ int killDeadCode (eBBlock ** ebbs, int count) { int change = 1; int gchange = 0; int i = 0; /* basic algorithm :- */ /* first the exclusion rules :- */ /* 1. if result is a global or volatile then skip */ /* 2. if assignment and result is a temp & isaddr then skip */ /* since this means array & pointer access, will be taken */ /* care of by alias analysis. */ /* 3. if the result is used in the remainder of the block skip */ /* 4. if this definition does not reach the end of the block */ /* i.e. the result is not present in the outExprs then KILL */ /* 5. if it reaches the end of block & is used by some success */ /* or then skip */ /* else KILL */ /* this whole process is carried on iteratively till no change */ while (1) { change = 0; /* for all blocks do */ for (i = 0; i < count; i++) { iCode *ic; /* for all instructions in the block do */ for (ic = ebbs[i]->sch; ic; ic = ic->next) { int kill, j; kill = 0; if (SKIP_IC (ic) || ic->op == IFX || ic->op == RETURN) continue; /* if the result is volatile then continue */ if (IC_RESULT (ic) && isOperandVolatile (IC_RESULT (ic), FALSE)) continue; /* if the result is a temp & isaddr then skip */ if (IC_RESULT (ic) && POINTER_SET (ic)) continue; /* if the result is used in the remainder of the */ /* block then skip */ if (usedInRemaining (IC_RESULT (ic), ic->next)) continue; /* does this definition reach the end of the block or the usage is zero then we can kill */ if (!bitVectBitValue (ebbs[i]->outDefs, ic->key)) kill = 1; /* if not we can kill it */ else { /* if this is a global variable or function parameter */ /* we cannot kill anyway */ if (isOperandGlobal (IC_RESULT (ic)) || (OP_SYMBOL (IC_RESULT (ic))->_isparm && !OP_SYMBOL (IC_RESULT (ic))->ismyparm)) continue; /* if we are sure there are no usages */ if (bitVectIsZero (OP_USES (IC_RESULT (ic)))) { kill = 1; goto kill; } /* reset visited flag */ for (j = 0; j < count; ebbs[j++]->visited = 0); /* find out if this definition is alive */ if (applyToSet (ebbs[i]->succList, isDefAlive, ic)) continue; kill = 1; } kill: /* kill this one if required */ if (kill) { change = 1; gchange++; /* eliminate this */ remiCodeFromeBBlock (ebbs[i], ic); /* now delete from defUseSet */ deleteItemIf (&ebbs[i]->outExprs, ifDiCodeIsX, ic); bitVectUnSetBit (ebbs[i]->outDefs, ic->key); /* and defset of the block */ bitVectUnSetBit (ebbs[i]->defSet, ic->key); /* for the left & right remove the usage */ if (IS_SYMOP (IC_LEFT (ic))) bitVectUnSetBit (OP_USES (IC_LEFT (ic)), ic->key); if (IS_SYMOP (IC_RIGHT (ic))) bitVectUnSetBit (OP_USES (IC_RIGHT (ic)), ic->key); } } /* end of all instructions */ if (!ebbs[i]->sch && !ebbs[i]->noPath) disconBBlock (ebbs[i], ebbs, count); } /* end of for all blocks */ if (!change) break; } /* end of while(1) */ return gchange; }
/*-----------------------------------------------------------------*/ static void cnvToFcall (iCode * ic, eBBlock * ebp) { iCode *ip; iCode *newic; operand *left; operand *right; symbol *func = NULL; int lineno = ic->lineno; int bytesPushed=0; ip = ic->next; /* insertion point */ /* remove it from the iCode */ remiCodeFromeBBlock (ebp, ic); left = IC_LEFT (ic); right = IC_RIGHT (ic); switch (ic->op) { case '+': func = __fsadd; break; case '-': func = __fssub; break; case '/': func = __fsdiv; break; case '*': func = __fsmul; break; case EQ_OP: func = __fseq; break; case NE_OP: func = __fsneq; break; case '<': func = __fslt; break; case '>': func = __fsgt; break; case LE_OP: func = __fslteq; break; case GE_OP: func = __fsgteq; break; } /* if float support routines NOT compiled as reentrant */ if (!options.float_rent) { /* first one */ if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) { newic = newiCode (SEND, IC_LEFT (ic), NULL); } else { newic = newiCode ('=', NULL, IC_LEFT (ic)); IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type)); } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; /* second one */ if (IS_REGPARM (FUNC_ARGS(func->type)->next->etype)) { newic = newiCode (SEND, IC_LEFT (ic), NULL); } else { newic = newiCode ('=', NULL, IC_RIGHT (ic)); IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type)->next); } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; } else { /* push right */ if (IS_REGPARM (FUNC_ARGS(func->type)->next->etype)) { newic = newiCode (SEND, right, NULL); } else { newic = newiCode (IPUSH, right, NULL); newic->parmPush = 1; bytesPushed+=4; } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; /* insert push left */ if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) { newic = newiCode (SEND, left, NULL); } else { newic = newiCode (IPUSH, left, NULL); newic->parmPush = 1; bytesPushed+=4; } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; } /* insert the call */ newic = newiCode (CALL, operandFromSymbol (func), NULL); IC_RESULT (newic) = IC_RESULT (ic); newic->lineno = lineno; newic->parmBytes+=bytesPushed; addiCodeToeBBlock (ebp, newic, ip); }
/*-----------------------------------------------------------------*/ static void convilong (iCode * ic, eBBlock * ebp, sym_link * type, int op) { symbol *func = NULL; iCode *ip = ic->next; iCode *newic; int lineno = ic->lineno; int bwd; int su; int bytesPushed=0; remiCodeFromeBBlock (ebp, ic); /* depending on the type */ for (bwd = 0; bwd < 3; bwd++) { for (su = 0; su < 2; su++) { if (compareType (type, __multypes[bwd][su]) == 1) { if (op == '*') func = __muldiv[0][bwd][su]; else if (op == '/') func = __muldiv[1][bwd][su]; else if (op == '%') func = __muldiv[2][bwd][su]; else if (op == RRC) func = __rlrr[1][bwd][su]; else if (op == RLC) func = __rlrr[0][bwd][su]; else if (op == RIGHT_OP) func = __rlrr[1][bwd][su]; else if (op == LEFT_OP) func = __rlrr[0][bwd][su]; else assert (0); goto found; } } } assert (0); found: /* if int & long support routines NOT compiled as reentrant */ if (!options.intlong_rent) { /* first one */ if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) newic = newiCode (SEND, IC_LEFT (ic), NULL); else { newic = newiCode ('=', NULL, IC_LEFT (ic)); IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type)); } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; /* second one */ if (IS_REGPARM (FUNC_ARGS(func->type)->next->etype)) newic = newiCode (SEND, IC_RIGHT (ic), NULL); else { newic = newiCode ('=', NULL, IC_RIGHT (ic)); IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type)->next); } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; } else { /* compiled as reentrant then push */ /* push right */ if (IS_REGPARM (FUNC_ARGS(func->type)->next->etype)) { newic = newiCode (SEND, IC_RIGHT (ic), NULL); } else { newic = newiCode (IPUSH, IC_RIGHT (ic), NULL); newic->parmPush = 1; bytesPushed += getSize(operandType(IC_RIGHT(ic))); } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; /* insert push left */ if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) { newic = newiCode (SEND, IC_LEFT (ic), NULL); } else { newic = newiCode (IPUSH, IC_LEFT (ic), NULL); newic->parmPush = 1; bytesPushed += getSize(operandType(IC_LEFT(ic))); } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; } /* for the result */ newic = newiCode (CALL, operandFromSymbol (func), NULL); IC_RESULT (newic) = IC_RESULT (ic); newic->lineno = lineno; newic->parmBytes+=bytesPushed; // to clear the stack after the call addiCodeToeBBlock (ebp, newic, ip); }
/*-----------------------------------------------------------------*/ static void cnvFromFloatCast (iCode * ic, eBBlock * ebp) { iCode *ip, *newic; symbol *func; sym_link *type = operandType (IC_LEFT (ic)); int lineno = ic->lineno; int bwd, su; ip = ic->next; /* remove it from the iCode */ remiCodeFromeBBlock (ebp, ic); /* depending on the type */ for (bwd = 0; bwd < 3; bwd++) { for (su = 0; su < 2; su++) { if (compareType (type, __multypes[bwd][su]) == 1) { func = __conv[1][bwd][su]; goto found; } } } assert (0); found: /* if float support routines NOT compiled as reentrant */ if (!options.float_rent) { /* first one */ if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) newic = newiCode (SEND, IC_RIGHT (ic), NULL); else { newic = newiCode ('=', NULL, IC_RIGHT (ic)); IC_RESULT (newic) = operandFromValue (FUNC_ARGS(func->type)); } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; } else { /* push the left */ if (IS_REGPARM (FUNC_ARGS(func->type)->etype)) newic = newiCode (SEND, IC_RIGHT (ic), NULL); else { newic = newiCode (IPUSH, IC_RIGHT (ic), NULL); newic->parmPush = 1; } addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; } /* make the call */ newic = newiCode (CALL, operandFromSymbol (func), NULL); IC_RESULT (newic) = IC_RESULT (ic); addiCodeToeBBlock (ebp, newic, ip); newic->lineno = lineno; }
/** Register reduction for assignment. */ static int packRegsForAssign (iCode *ic, eBBlock *ebp) { iCode *dic, *sic; if (!IS_ITEMP (IC_RIGHT (ic)) || OP_SYMBOL (IC_RIGHT (ic))->isind || OP_LIVETO (IC_RIGHT (ic)) > ic->seq) return 0; /* Avoid having multiple named address spaces in one iCode. */ if (IS_SYMOP (IC_RESULT (ic)) && SPEC_ADDRSPACE (OP_SYMBOL (IC_RESULT (ic))->etype)) return 0; /* find the definition of iTempNN scanning backwards if we find a a use of the true symbol in before we find the definition then we cannot */ for (dic = ic->prev; dic; dic = dic->prev) { /* PENDING: Don't pack across function calls. */ if (dic->op == CALL || dic->op == PCALL) { dic = NULL; break; } if (SKIP_IC2 (dic)) continue; if (dic->op == IFX) { if (IS_SYMOP (IC_COND (dic)) && (IC_COND (dic)->key == IC_RESULT (ic)->key || IC_COND (dic)->key == IC_RIGHT (ic)->key)) { dic = NULL; break; } } else { if (IS_TRUE_SYMOP (IC_RESULT (dic)) && IS_OP_VOLATILE (IC_RESULT (dic))) { dic = NULL; break; } if (IS_SYMOP (IC_RESULT (dic)) && IC_RESULT (dic)->key == IC_RIGHT (ic)->key) { if (POINTER_SET (dic)) dic = NULL; break; } if (IS_SYMOP (IC_RIGHT (dic)) && (IC_RIGHT (dic)->key == IC_RESULT (ic)->key || IC_RIGHT (dic)->key == IC_RIGHT (ic)->key)) { dic = NULL; break; } if (IS_SYMOP (IC_LEFT (dic)) && (IC_LEFT (dic)->key == IC_RESULT (ic)->key || IC_LEFT (dic)->key == IC_RIGHT (ic)->key)) { dic = NULL; break; } if (IS_SYMOP (IC_RESULT (dic)) && IC_RESULT (dic)->key == IC_RESULT (ic)->key) { dic = NULL; break; } } } if (!dic) return 0; /* did not find */ /* if assignment then check that right is not a bit */ if (ASSIGNMENT (ic) && !POINTER_SET (ic)) { sym_link *etype = operandType (IC_RESULT (dic)); if (IS_BITFIELD (etype)) { /* if result is a bit too then it's ok */ etype = operandType (IC_RESULT (ic)); if (!IS_BITFIELD (etype)) { return 0; } } } /* if the result is on stack or iaccess then it must be the same atleast one of the operands */ if (OP_SYMBOL (IC_RESULT (ic))->onStack || OP_SYMBOL (IC_RESULT (ic))->iaccess) { /* the operation has only one symbol operator then we can pack */ if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) || (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic)))) goto pack; if (!((IC_LEFT (dic) && IC_RESULT (ic)->key == IC_LEFT (dic)->key) || (IC_RIGHT (dic) && IC_RESULT (ic)->key == IC_RIGHT (dic)->key))) return 0; } pack: /* found the definition */ /* replace the result with the result of */ /* this assignment and remove this assignment */ bitVectUnSetBit (OP_SYMBOL (IC_RESULT (dic))->defs, dic->key); IC_RESULT (dic) = IC_RESULT (ic); if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq) { OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq; } /* delete from liverange table also delete from all the points inbetween and the new one */ for (sic = dic; sic != ic; sic = sic->next) { bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key); if (IS_ITEMP (IC_RESULT (dic))) bitVectSetBit (sic->rlive, IC_RESULT (dic)->key); } remiCodeFromeBBlock (ebp, ic); // PENDING: Check vs mcs51 bitVectUnSetBit (OP_SYMBOL (IC_RESULT (ic))->defs, ic->key); hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL); OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key); return 1; }