IRExpr* findPutI ( IRBB* bb, Int startHere,
IRArray* descrG, IRTemp tmpG, Int biasG )
{
- Int j, iters;
- UInt minoffP, maxoffP, minoffG, maxoffG;
- IRArray* descrP;
- IRStmt* st;
- IRTemp tmpP;
- Int biasP;
-
- if (0) {
- vex_printf("\nfindPutI ");
- ppIRArray(descrG);
- vex_printf(" ");
- ppIRTemp(tmpG);
- vex_printf(" %d\n", biasG);
- }
-
- /* Scan backwards in bb from startHere to find a suitable
- PutI binding for (descr, tmp, bias), if any. */
+ Int j, iters, biasP;
+ UInt minoffP, maxoffP, minoffG, maxoffG;
+ IRArray* descrP;
+ IRStmt* st;
+ IRTemp tmpP;
+
+ if (0) {
+ vex_printf("\nfindPutI ");
+ ppIRArray(descrG);
+ vex_printf(" ");
+ ppIRTemp(tmpG);
+ vex_printf(" %d\n", biasG);
+ }
+
+ /* Scan backwards in bb from startHere to find a suitable PutI
+ binding for (descr, tmp, bias), if any. */
minoffG = descrG->base;
maxoffG = minoffG + descrG->nElems*sizeofIRType(descrG->elemTy) - 1;
vassert((minoffG & 0xFFFF0000) == 0);
vassert((maxoffG & 0xFFFF0000) == 0);
vassert(minoffG < maxoffG);
- for (j = startHere; j >= 0; j--) {
- st = bb->stmts[j];
- if (!st) continue;
-
- if (st->tag == Ist_Put) {
- /* Non-indexed Put. This can't give a binding, but we do need
- to check it doesn't invalidate the search by overlapping any
- part of the indexed guest state. */
- minoffP = st->Ist.Put.offset;
- maxoffP = minoffP + sizeofIRType(typeOfIRExpr(bb->tyenv,st->Ist.Put.data)) - 1;
- vassert((minoffP & 0xFFFF0000) == 0);
- vassert((maxoffP & 0xFFFF0000) == 0);
- vassert(minoffP < maxoffP);
- if (maxoffP < minoffG || maxoffG < minoffP) {
- /* we're OK; keep going */
- continue;
- } else {
- /* This Put potentially writes guest state that the GetI reads;
- we must fail. */
- return NULL;
- }
- }
-
- if (st->tag == Ist_PutI) {
-
- /* Indexed Put. First off, do an invalidation check. */
- descrP = st->Ist.PutI.descr;
- minoffP = descrP->base;
- maxoffP = minoffP + descrP->nElems*sizeofIRType(descrP->elemTy) - 1;
- vassert((minoffP & 0xFFFF0000) == 0);
- vassert((maxoffP & 0xFFFF0000) == 0);
- vassert(minoffP < maxoffP);
- if (maxoffP < minoffG || maxoffG < minoffP) {
- /* This PutI definitely doesn't overlap. Ignore it and keep going. */
- continue;
- }
- /* This PutI potentially writes the same array that the GetI reads.
-It's safe to keep going provided we can show the PutI writes some
-*other* element in the same array -- not this one. */
- if (!eqIRArray(descrG, descrP))
- /* The written array has different base, type or size from
- the read array. Better give up. */
- return NULL;
-
- if (st->Ist.PutI.off->tag != Iex_Tmp) {
- ppIRStmt(st);
- vpanic("vex iropt: findPutI: .off is not Tmp");
- }
- tmpP = st->Ist.PutI.off->Iex.Tmp.tmp;
- if (tmpP != tmpG)
- /* We can't show that the base offsets are different. Prior CSE and
- Add/Sub-chain collapsing passes should have made them the same wherever possible. Give up. */
- return NULL;
-
- biasP = st->Ist.PutI.bias;
- /* So now we know that the GetI and PutI index the same array with the same base. Are the offsets the same, modulo the array size? Do this paranoidly. */
- vassert(descrP->nElems == descrG->nElems);
- iters = 0;
- while (biasP < 0 || biasG < 0) {
- biasP += descrP->nElems;
- biasG += descrP->nElems;
- iters++;
- if (iters > 10)
- vpanic("findPutI: iters");
- }
- vassert(biasP >= 0 && biasG >= 0);
- biasP %= descrP->nElems;
- biasG %= descrP->nElems;
-
- /* Finally, biasP and biasG are normalised into the range
- 0 .. descrP/G->nElems - 1. And so we can establish equality/non-equality. */
+ for (j = startHere; j >= 0; j--) {
+ st = bb->stmts[j];
+ if (!st) continue;
- /* Now we know the PutI doesn't invalidate the search. But does it
- supply a binding for the GetI ? */
- if (0) {
- vex_printf("considering P ");
- ppIRStmt(st);
- vex_printf("\n");
- }
- if (biasP == biasG) {
- /* Yup, found a replacement. */
- return st->Ist.PutI.data;
- }
+ if (st->tag == Ist_Put) {
+ /* Non-indexed Put. This can't give a binding, but we do
+ need to check it doesn't invalidate the search by
+ overlapping any part of the indexed guest state. */
+ minoffP = st->Ist.Put.offset;
+ maxoffP = minoffP + sizeofIRType(
+ typeOfIRExpr(bb->tyenv,st->Ist.Put.data))
+ - 1;
+ vassert((minoffP & 0xFFFF0000) == 0);
+ vassert((maxoffP & 0xFFFF0000) == 0);
+ vassert(minoffP < maxoffP);
+ if (maxoffP < minoffG || maxoffG < minoffP) {
+ /* we're OK; keep going */
+ continue;
+ } else {
+ /* This Put potentially writes guest state that the GetI
+ reads; we must fail. */
+ return NULL;
+ }
+ }
- /* else ... no, they don't match. Keep going. */
+ if (st->tag == Ist_PutI) {
+ /* Indexed Put. First off, do an invalidation check. */
+ descrP = st->Ist.PutI.descr;
+ minoffP = descrP->base;
+ maxoffP = minoffP + descrP->nElems*sizeofIRType(descrP->elemTy) - 1;
+ vassert((minoffP & 0xFFFF0000) == 0);
+ vassert((maxoffP & 0xFFFF0000) == 0);
+ vassert(minoffP < maxoffP);
+ if (maxoffP < minoffG || maxoffG < minoffP) {
+ /* This PutI definitely doesn't overlap. Ignore it and
+ keep going. */
+ continue;
+ }
+ /* This PutI potentially writes the same array that the GetI
+ reads. It's safe to keep going provided we can show the
+ PutI writes some *other* element in the same array -- not
+ this one. */
+
+ if (!eqIRArray(descrG, descrP))
+ /* The written array has different base, type or size from
+ the read array. Better give up. */
+ return NULL;
+ if (st->Ist.PutI.off->tag != Iex_Tmp) {
+ ppIRStmt(st);
+ vpanic("vex iropt: findPutI: .off is not Tmp");
+ }
+ tmpP = st->Ist.PutI.off->Iex.Tmp.tmp;
+ if (tmpP != tmpG)
+ /* We can't show that the base offsets are different.
+ Prior CSE and Add/Sub-chain collapsing passes should
+ have made them the same wherever possible. Give up. */
+ return NULL;
- }
+ biasP = st->Ist.PutI.bias;
+ /* So now we know that the GetI and PutI index the same array
+ with the same base. Are the offsets the same, modulo the
+ array size? Do this paranoidly. */
+ vassert(descrP->nElems == descrG->nElems);
+ iters = 0;
+ while (biasP < 0 || biasG < 0) {
+ biasP += descrP->nElems;
+ biasG += descrP->nElems;
+ iters++;
+ if (iters > 10)
+ vpanic("findPutI: iters");
+ }
+ vassert(biasP >= 0 && biasG >= 0);
+ biasP %= descrP->nElems;
+ biasG %= descrP->nElems;
+
+ /* Finally, biasP and biasG are normalised into the range
+ 0 .. descrP/G->nElems - 1. And so we can establish
+ equality/non-equality. */
+
+ /* Now we know the PutI doesn't invalidate the search. But
+ does it supply a binding for the GetI ? */
+ if (0) {
+ vex_printf("considering P ");
+ ppIRStmt(st);
+ vex_printf("\n");
+ }
+ if (biasP == biasG) {
+ /* Yup, found a replacement. */
+ return st->Ist.PutI.data;
+ }
+ /* else ... no, they don't match. Keep going. */
+ } /* if (st->tag == Ist_PutI) */
- } /* for */
+ } /* for */
- return NULL;
+ return NULL;
}
if (st->tag == Ist_Tmp
&& st->Ist.Tmp.data->tag == Iex_GetI
&& st->Ist.Tmp.data->Iex.GetI.off->tag == Iex_Tmp) {
- IRArray* descr = st->Ist.Tmp.data->Iex.GetI.descr;
- IRTemp tmp = st->Ist.Tmp.data->Iex.GetI.off->Iex.Tmp.tmp;
- Int bias = st->Ist.Tmp.data->Iex.GetI.bias;
- IRExpr* replacement
- = findPutI(bb, i-1, descr, tmp, bias);
- if (replacement && isAtom(replacement)) {
- if (DEBUG_IROPT) {
- vex_printf("PiGi: ");
- ppIRExpr(st->Ist.Tmp.data);
- vex_printf(" -> ");
- ppIRExpr(replacement);
- vex_printf("\n");
- }
- bb->stmts[i] = IRStmt_Tmp(st->Ist.Tmp.tmp,
- replacement);
- }
+ IRArray* descr = st->Ist.Tmp.data->Iex.GetI.descr;
+ IRTemp tmp = st->Ist.Tmp.data->Iex.GetI.off->Iex.Tmp.tmp;
+ Int bias = st->Ist.Tmp.data->Iex.GetI.bias;
+ IRExpr* replacement = findPutI(bb, i-1, descr, tmp, bias);
+ if (replacement && isAtom(replacement)) {
+ if (DEBUG_IROPT) {
+ vex_printf("PiGi: ");
+ ppIRExpr(st->Ist.Tmp.data);
+ vex_printf(" -> ");
+ ppIRExpr(replacement);
+ vex_printf("\n");
+ }
+ bb->stmts[i] = IRStmt_Tmp(st->Ist.Tmp.tmp, replacement);
+ }
}
}
projects / thirdparty / valgrind.git / commitdiff
