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cpu: Change literal integer constants to meaningful labels

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fu_pool and inst_queue were using -1 for "no such FU" and -2 for "all those
FUs are busy at the moment" when requesting for a FU and replying. This
patch introduces new constants NoCapableFU and NoFreeFU respectively.

In addition, the condition (idx == -2 || idx != -1) is equivalent to
(idx != -1), so this patch also simplifies that.

--HG--
extra : rebase_source : 4833717b9d1e09d7594d1f34f882e13fc4b86846
This commit is contained in:
Rekai Gonzalez Alberquilla 2015-05-05 16:47:24 +01:00
parent 8faeec44a6
commit 21f8242430
2 changed files with 12 additions and 7 deletions
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13
src/cpu/o3/fu_pool.hh
View file

@ -134,12 +134,17 @@ class FUPool : public SimObject
FUPool(const Params *p);
~FUPool();
static constexpr auto NoCapableFU = -2;
static constexpr auto NoFreeFU = -1;
/**
* Gets a FU providing the requested capability. Will mark the unit as busy,
* but leaves the freeing of the unit up to the IEW stage.
* Gets a FU providing the requested capability. Will mark the
* unit as busy, but leaves the freeing of the unit up to the IEW
* stage.
*
* @param capability The capability requested.
* @return Returns -2 if the FU pool does not have the capability, -1 if
* there is no free FU, and the FU's index otherwise.
* @return Returns NoCapableFU if the FU pool does not have the
* capability, NoFreeFU if there is no free FU, and the FU's index
* otherwise.
*/
int getUnit(OpClass capability);

6
src/cpu/o3/inst_queue_impl.hh
View file

@ -801,21 +801,21 @@ InstructionQueue<Impl>::scheduleReadyInsts()
continue;
}
int idx = -2;
int idx = FUPool::NoCapableFU;
Cycles op_latency = Cycles(1);
ThreadID tid = issuing_inst->threadNumber;
if (op_class != No_OpClass) {
idx = fuPool->getUnit(op_class);
issuing_inst->isFloating() ? fpAluAccesses++ : intAluAccesses++;
if (idx > -1) {
if (idx > FUPool::NoFreeFU) {
op_latency = fuPool->getOpLatency(op_class);
}
}
// If we have an instruction that doesn't require a FU, or a
// valid FU, then schedule for execution.
if (idx == -2 || idx != -1) {
if (idx != FUPool::NoFreeFU) {
if (op_latency == Cycles(1)) {
i2e_info->size++;
instsToExecute.push_back(issuing_inst);