X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=src%2FSDCCloop.c;h=476554a6d6d200ca469cfed57c2e38e715d695b7;hb=9182d601aa287fff2b037d607180a06bcf0b281b;hp=7ab87a7ff8277d62140a6b17be62365b2b250715;hpb=9a33d11ed4da527058a0407d9ae493865430f316;p=fw%2Fsdcc diff --git a/src/SDCCloop.c b/src/SDCCloop.c index 7ab87a7f..476554a6 100644 --- a/src/SDCCloop.c +++ b/src/SDCCloop.c @@ -46,7 +46,7 @@ newInduction (operand * sym, unsigned int op, ip->op = op; ip->cval = constVal; ip->ic = ic; - updateSpillLocation(ic,1); +//updateSpillLocation(ic,1); return ip; } @@ -148,7 +148,7 @@ intersectLoopSucc (set * lexits, eBBlock ** ebbs) /*-----------------------------------------------------------------*/ /* loopInsert will insert a block into the loop set */ /*-----------------------------------------------------------------*/ -static void +static void loopInsert (set ** regionSet, eBBlock * block) { if (!isinSet (*regionSet, block)) @@ -188,7 +188,7 @@ DEFSETFUNC (isNotInBlocks) /* hasIncomingDefs - has definitions coming into the loop. i.e. */ /* check to see if the preheaders outDefs has any definitions */ /*-----------------------------------------------------------------*/ -int +int hasIncomingDefs (region * lreg, operand * op) { eBBlock *preHdr = lreg->entry->preHeader; @@ -202,7 +202,7 @@ hasIncomingDefs (region * lreg, operand * op) /* findLoopEndSeq - will return the sequence number of the last */ /* iCode with the maximum dfNumber in the region */ /*-----------------------------------------------------------------*/ -int +int findLoopEndSeq (region * lreg) { eBBlock *block; @@ -235,7 +235,6 @@ DEFSETFUNC (addToExitsMarkDepth) if (ebp->depthdepth = depth; - /* put the loop region info in the block */ /* NOTE: here we will update only the inner most loop that it is a part of */ if (!ebp->partOfLoop) @@ -307,14 +306,14 @@ DEFSETFUNC (addDefInExprs) V_ARG (int, count); addSetHead (&ebp->inExprs, cdp); - cseBBlock (ebp, 0, ebbs, count); + cseBBlock (ebp, optimize.global_cse, ebbs, count); return 0; } /*-----------------------------------------------------------------*/ /* assignmentsToSym - for a set of blocks determine # time assigned */ /*-----------------------------------------------------------------*/ -int +int assignmentsToSym (set * sset, operand * sym) { eBBlock *ebp; @@ -329,7 +328,7 @@ assignmentsToSym (set * sset, operand * sym) in this block */ bitVect *defs = bitVectIntersect (ebp->ldefs, OP_DEFS (sym)); assigns += bitVectnBitsOn (defs); - setToNull ((void **) &defs); + setToNull ((void *) &defs); } @@ -340,7 +339,7 @@ assignmentsToSym (set * sset, operand * sym) /*-----------------------------------------------------------------*/ /* isOperandInvariant - determines if an operand is an invariant */ /*-----------------------------------------------------------------*/ -int +int isOperandInvariant (operand * op, region * theLoop, set * lInvars) { int opin = 0; @@ -380,7 +379,22 @@ DEFSETFUNC (pointerAssigned) eBBlock *ebp = item; V_ARG (operand *, op); - return ebp->hasFcall || bitVectBitValue (ebp->ptrsSet, op->key); + if (ebp->hasFcall) + return 1; + + if (bitVectBitValue (ebp->ptrsSet, op->key)) + return 1; + + /* Unfortunately, one of the other pointer set operations */ + /* may be using an alias of this operand, and the above */ + /* test would miss it. To be thorough, some aliasing */ + /* analysis should be done here. In the meantime, be */ + /* conservative and assume any other pointer set operation */ + /* is dangerous */ + if (!bitVectIsZero (ebp->ptrsSet)) + return 1; + + return 0; } /*-----------------------------------------------------------------*/ @@ -402,7 +416,7 @@ DEFSETFUNC (hasNonPtrUse) /*-----------------------------------------------------------------*/ /* loopInvariants - takes loop invariants out of region */ /*-----------------------------------------------------------------*/ -int +int loopInvariants (region * theLoop, eBBlock ** ebbs, int count) { eBBlock *lBlock; @@ -417,8 +431,8 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count) theLoop->exits == NULL) return 0; - /* we will do the elimination for those blocks */ - /* in the loop that dominates all exits from the loop */ + /* we will do the elimination for those blocks */ + /* in the loop that dominate all exits from the loop */ for (lBlock = setFirstItem (theLoop->regBlocks); lBlock; lBlock = setNextItem (theLoop->regBlocks)) { @@ -446,16 +460,33 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count) int lin, rin; cseDef *ivar; - /* if there are function calls in this block and this - is a pointer get, the function could have changed it - so skip, ISO-C99 according to David A. Long */ - if (fCallsInBlock && POINTER_GET(ic)) { - continue; + /* TODO this is only needed if the call is between + here and the definition, but I am too lazy to do that now */ + + /* if there are function calls in this block */ + if (fCallsInBlock) { + + /* if this is a pointer get */ + if (POINTER_GET(ic)) { + continue; + } + + /* if this is an assignment from a global */ + if (ic->op=='=' && isOperandGlobal(IC_RIGHT(ic))) { + continue; + } } if (SKIP_IC (ic) || POINTER_SET (ic) || ic->op == IFX) continue; + /* iTemp assignment from a literal may be invariant, but it + will needlessly increase register pressure if the + iCode(s) that use this iTemp are not also invariant */ + if (ic->op=='=' && IS_ITEMP (IC_RESULT (ic)) + && IS_OP_LITERAL (IC_RIGHT (ic))) + continue; + /* if result is volatile then skip */ if (IC_RESULT (ic) && (isOperandVolatile (IC_RESULT (ic), TRUE) || @@ -468,7 +499,7 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count) continue; lin = rin = 0; - + /* special case */ /* if address of then it is an invariant */ if (ic->op == ADDRESS_OF && @@ -482,14 +513,14 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count) that the pointer set does not exist in any of the blocks */ if (POINTER_GET (ic) && - (applyToSet (theLoop->regBlocks, + (applyToSet (theLoop->regBlocks, pointerAssigned, IC_LEFT (ic)))) lin = 0; } - + /* do the same for right */ rin = isOperandInvariant (IC_RIGHT (ic), theLoop, lInvars); - + /* if this is a POINTER_GET then special case, make sure all usages within the loop are POINTER_GET any other usage would mean that this is not an invariant , since the pointer @@ -498,18 +529,19 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count) applyToSet (theLoop->regBlocks, hasNonPtrUse, IC_LEFT (ic))) continue; - /* if both the left & right are invariants : then check that */ - /* this definition exists in the out definition of all the */ - /* blocks, this will ensure that this is not assigned any */ - /* other value in the loop , and not used in this block */ + + /* if both the left & right are invariants : then check that */ + /* this definition exists in the out definition of all the */ + /* blocks, this will ensure that this is not assigned any */ + /* other value in the loop, and not used in this block */ /* prior to this definition which means only this definition */ - /* is used in this loop */ + /* is used in this loop */ if (lin && rin && IC_RESULT (ic)) { eBBlock *sBlock; set *lSet = setFromSet (theLoop->regBlocks); - /* if this block does not dominate all exists */ + /* if this block does not dominate all exits */ /* make sure this defintion is not used anywhere else */ if (!domsAllExits) { @@ -545,6 +577,20 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count) } else if (bitVectBitsInCommon (sBlock->defSet, OP_DEFS (IC_RESULT (ic)))) break; + + if (IC_RESULT(ic)) + { + iCode *ic2; + /* check that this definition is not assigned */ + /* any other value in this block */ + for (ic2 = sBlock->sch; ic2; ic2 = ic2->next) + { + if ((ic != ic2) && (isOperandEqual(IC_RESULT(ic), IC_RESULT(ic2)))) + break; + } + if (ic2) /* found another definition */ + break; + } } if (sBlock) @@ -558,7 +604,9 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count) /* now we know it is a true invariant */ /* remove it from the insts chain & put */ /* in the invariant set */ - OP_SYMBOL (IC_RESULT (ic))->isinvariant = 1; + + OP_SYMBOL (IC_RESULT (ic))->isinvariant = 1; + SPIL_LOC (IC_RESULT (ic)) = NULL; remiCodeFromeBBlock (lBlock, ic); /* maintain the data flow */ @@ -621,7 +669,7 @@ loopInvariants (region * theLoop, eBBlock ** ebbs, int count) /*-----------------------------------------------------------------*/ /* addressTaken - returns true if the symbol is found in the addrof */ /*-----------------------------------------------------------------*/ -int +int addressTaken (set * sset, operand * sym) { set *loop; @@ -716,13 +764,27 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count) { operand *aSym; - unsigned long litValue; + long litValue; induction *ip; iCode *indIc; eBBlock *owner = NULL; int nexits; - - /* look for assignments of the form */ + sym_link *optype; + + /* To find an induction variable, we need to */ + /* find within the loop three iCodes in this */ + /* general form: */ + /* */ + /* ddic: iTempB := symbolVar */ + /* dic: iTempA := iTempB + lit */ + /* or iTempA := iTempB - lit */ + /* or iTempA := lit + iTempB */ + /* ic: symbolVar := iTempA */ + /* */ + /* (symbolVar may also be an iTemp if it is */ + /* register equivalent) */ + + /* look for assignments of the form */ /* symbolVar := iTempNN */ if (ic->op != '=') continue; @@ -745,6 +807,15 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count) if (addressTaken (loopReg->regBlocks, IC_RESULT (ic))) continue; + /* Only consider variables with integral type. */ + /* (2004/12/06 - EEP - ds390 fails regression tests unless */ + /* pointers are also considered for induction (due to some */ + /* register alloctaion bugs). Remove !IS_PTR clause when */ + /* that gets fixed) */ + optype = operandType (IC_RIGHT (ic)); + if (!IS_INTEGRAL (optype) && !IS_PTR (optype)) + continue; + /* find the definition for the result in the block */ if (!(dic = findDefInRegion (setFromSet (loopReg->regBlocks), IC_RIGHT (ic), &owner))) @@ -753,14 +824,30 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count) /* if not +/- continue */ if (dic->op != '+' && dic->op != '-') continue; - + /* make sure definition is of the form a +/- c */ if (!IS_OP_LITERAL (IC_LEFT (dic)) && !IS_OP_LITERAL (IC_RIGHT (dic))) continue; + + /* make sure the definition found is the only one */ + if (assignmentsToSym (loopReg->regBlocks, IC_RIGHT (ic)) > 1) + continue; - aSym = (IS_OP_LITERAL (IC_RIGHT (dic)) ? - (litValue = (unsigned long) operandLitValue (IC_RIGHT (dic)), IC_LEFT (dic)) : - (litValue = (unsigned long) operandLitValue (IC_LEFT (dic)), IC_RIGHT (dic))); + if (IS_OP_LITERAL (IC_RIGHT (dic))) + { + aSym = IC_LEFT (dic); + litValue = (long) operandLitValue (IC_RIGHT (dic)); + } + else + { + /* For minus, the literal must not be on the left side. */ + /* (Actually, this case could be handled, but it's probably */ + /* not worth the extra code) */ + if (dic->op == '-') + continue; + aSym = IC_RIGHT (dic); + litValue = (long) operandLitValue (IC_LEFT (dic)); + } if (!isOperandEqual (IC_RESULT (ic), aSym) && !isOperandEqual (IC_RIGHT (ic), aSym)) @@ -808,7 +895,6 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count) if (nexits == 1) { eBBlock *exit = setFirstItem (loopReg->exits); - /* if it is the same block then there is no need to move it about */ if (exit != lBlock) @@ -846,7 +932,18 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count) if (bitVectBitValue (loopSuccs, i)) { - eBBlock *eblock = ebbs[i]; + eBBlock *eblock = NULL; + int j; + + /* Need to search for bbnum == i since ebbs is */ + /* sorted by dfnum; a direct index won't do. */ + for (j=0; jbbnum == i) + { + eblock = ebbs[j]; + break; + } + assert(eblock); /* if the successor does not belong to the loop and will be executed after the loop : then @@ -858,9 +955,9 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count) iCode *newic = newiCode ('=', NULL, operandFromOperand (IC_RIGHT (ic))); IC_RESULT (newic) = operandFromOperand (IC_RESULT (ic)); - OP_DEFS (IC_RESULT (newic)) = + OP_DEFS(IC_RESULT (newic))= bitVectSetBit (OP_DEFS (IC_RESULT (newic)), newic->key); - OP_USES (IC_RIGHT (newic)) = + OP_USES(IC_RIGHT (newic))= bitVectSetBit (OP_USES (IC_RIGHT (newic)), newic->key); /* and add it */ if (eblock->sch && eblock->sch->op == LABEL) @@ -886,11 +983,11 @@ basicInduction (region * loopReg, eBBlock ** ebbs, int count) /*-----------------------------------------------------------------*/ /* loopInduction - remove induction variables from a loop */ /*-----------------------------------------------------------------*/ -int +int loopInduction (region * loopReg, eBBlock ** ebbs, int count) { int change = 0; - eBBlock *lBlock, *lastBlock = NULL; + eBBlock *lBlock, *owner, *lastBlock = NULL; set *indVars = NULL; set *basicInd = NULL; @@ -909,7 +1006,7 @@ loopInduction (region * loopReg, eBBlock ** ebbs, int count) lBlock = setNextItem (loopReg->regBlocks)) { - iCode *ic, *indIc; + iCode *ic, *indIc, *dic; induction *ip; /* last block is the one with the highest block @@ -920,14 +1017,17 @@ loopInduction (region * loopReg, eBBlock ** ebbs, int count) for (ic = lBlock->sch; ic; ic = ic->next) { operand *aSym; - unsigned long litVal; - int lr = 0; + long litVal; /* consider only * & / */ if (ic->op != '*' && ic->op != '/') continue; - /* if the result has more definitions then */ + /* only consider variables with integral type */ + if (!IS_INTEGRAL (operandType (IC_RESULT (ic)))) + continue; + + /* if the result has more definitions then */ if (assignmentsToSym (loopReg->regBlocks, IC_RESULT (ic)) > 1) continue; @@ -937,9 +1037,19 @@ loopInduction (region * loopReg, eBBlock ** ebbs, int count) (IS_OP_LITERAL (IC_LEFT (ic)) && IS_SYMOP (IC_RIGHT (ic))))) continue; - aSym = (IS_SYMOP (IC_LEFT (ic)) ? - (lr = 1, litVal = (unsigned long) operandLitValue (IC_RIGHT (ic)), IC_LEFT (ic)) : - (litVal = (unsigned long) operandLitValue (IC_LEFT (ic)), IC_RIGHT (ic))); + if (IS_SYMOP (IC_LEFT (ic))) + { + aSym = IC_LEFT (ic); + litVal = (long) operandLitValue (IC_RIGHT (ic)); + } + else + { + /* For division, the literal must not be on the left side */ + if (ic->op == '/') + continue; + aSym = IC_RIGHT (ic); + litVal = (long) operandLitValue (IC_LEFT (ic)); + } ip = NULL; /* check if this is an induction variable */ @@ -976,32 +1086,23 @@ loopInduction (region * loopReg, eBBlock ** ebbs, int count) addSet (&indVars, newInduction (IC_RESULT (ic), ip->op, litVal, indIc, NULL)); - /* now change this instruction */ - ic->op = ip->op; - if (lr) - { - IC_LEFT (ic) = operandFromOperand (IC_RESULT (ic)); - IC_RIGHT (ic) = operandFromLit (litVal); - } - else - { - IC_RIGHT (ic) = operandFromOperand (IC_RESULT (ic)); - IC_LEFT (ic) = operandFromLit (litVal); - } - - /* we need somemore initialisation code */ - /* we subtract the litVal from itself if increment */ - if (ic->op == '+') - { - indIc = newiCode ('-', - operandFromOperand (IC_RESULT (ic)), - operandFromLit (litVal)); - indIc->lineno = ic->lineno; - IC_RESULT (indIc) = operandFromOperand (IC_RESULT (ic)); - - addSet (&indVars, - newInduction (IC_RESULT (ic), ip->op, litVal, indIc, NULL)); - } + /* Replace mul/div with assignment to self; killDeadCode() will */ + /* clean this up since we can't use remiCodeFromeBBlock() here. */ + ic->op = '='; + IC_LEFT (ic) = NULL; + IC_RIGHT (ic) = IC_RESULT (ic); + + /* Insert an update of the induction variable just before */ + /* the update of the basic induction variable. */ + indIc = newiCode (ip->op, + operandFromOperand (IC_RESULT (ic)), + operandFromLit (litVal)); + IC_RESULT (indIc) = operandFromOperand (IC_RESULT (ic)); + owner = NULL; + dic = findDefInRegion (setFromSet (loopReg->regBlocks), aSym, &owner); + assert (dic); + addiCodeToeBBlock (owner, indIc, dic); + } } @@ -1044,10 +1145,10 @@ loopInduction (region * loopReg, eBBlock ** ebbs, int count) /* add the induction variable vector to the last block in the loop */ lastBlock->isLastInLoop = 1; - lastBlock->linds = indVect; + lastBlock->linds = bitVectUnion(lastBlock->linds,indVect); } - setToNull ((void **) &indVars); + setToNull ((void *) &indVars); return change; } @@ -1075,7 +1176,7 @@ DEFSETFUNC (mergeRegions) if (lp->entry == theLoop->entry) { theLoop->regBlocks = unionSets (theLoop->regBlocks, - lp->regBlocks, THROW_BOTH); + lp->regBlocks, THROW_DEST); lp->merged = 1; } } @@ -1158,6 +1259,7 @@ createLoopRegions (eBBlock ** ebbs, int count) applyToSet (allRegion, mergeInnerLoops, allRegion, &maxDepth); maxDepth++; + /* now create all the exits .. also */ /* create an ordered set of loops */ /* i.e. we process loops in the inner to outer order */ @@ -1176,7 +1278,7 @@ createLoopRegions (eBBlock ** ebbs, int count) /*-----------------------------------------------------------------*/ /* loopOptimizations - identify region & remove invariants & ind */ /*-----------------------------------------------------------------*/ -int +int loopOptimizations (hTab * orderedLoops, eBBlock ** ebbs, int count) { region *lp;