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authorKorey Sewell <ksewell@umich.edu>2011-02-12 10:14:34 -0500
committerKorey Sewell <ksewell@umich.edu>2011-02-12 10:14:34 -0500
commitaf67631790afbfeba01b05f7ae2ca54ae27428f1 (patch)
tree90a68471780569cb0a15bcc0af0c71fc90add7a5 /src/cpu/inorder
parent800e93f3587f769b1caa782c6d5542c372085cd2 (diff)
downloadgem5-af67631790afbfeba01b05f7ae2ca54ae27428f1.tar.xz
inorder: comments for resource sked class
Diffstat (limited to 'src/cpu/inorder')
-rw-r--r--src/cpu/inorder/resource_sked.hh67
1 files changed, 62 insertions, 5 deletions
diff --git a/src/cpu/inorder/resource_sked.hh b/src/cpu/inorder/resource_sked.hh
index 22e29d728..e3c0c6bc1 100644
--- a/src/cpu/inorder/resource_sked.hh
+++ b/src/cpu/inorder/resource_sked.hh
@@ -35,6 +35,17 @@
#include <vector>
#include <list>
+/** ScheduleEntry class represents a single function that an instruction
+ wants to do at any pipeline stage. For example, if an instruction
+ needs to be decoded and do a branch prediction all in one stage
+ then each of those tasks would need it's own ScheduleEntry.
+
+ Each schedule entry corresponds to some resource that the instruction
+ wants to interact with.
+
+ The file pipeline_traits.cc shows how a typical instruction schedule is
+ made up of these schedule entries.
+*/
class ScheduleEntry {
public:
ScheduleEntry(int stage_num, int _priority, int res_num, int _cmd = 0,
@@ -43,43 +54,89 @@ class ScheduleEntry {
idx(_idx), priority(_priority)
{ }
- // Stage number to perform this service.
+ /** Stage number to perform this service. */
int stageNum;
- // Resource ID to access
+ /** Resource ID to access */
int resNum;
- // See specific resource for meaning
+ /** See specific resource for meaning */
unsigned cmd;
- // See specific resource for meaning
+ /** See specific resource for meaning */
unsigned idx;
- // Some Resources May Need Priority
+ /** Some Resources May Need Priority */
int priority;
};
+/** The ResourceSked maintains the complete schedule
+ for an instruction. That schedule includes what
+ resources an instruction wants to acquire at each
+ pipeline stage and is represented by a collection
+ of ScheduleEntry objects (described above) that
+ must be executed in-order.
+
+ In every pipeline stage, the InOrder model will
+ process all entries on the resource schedule for
+ that stage and then send the instruction to the next
+ stage if and only if the instruction successfully
+ completed each ScheduleEntry.
+*/
class ResourceSked {
public:
typedef std::list<ScheduleEntry*>::iterator SkedIt;
ResourceSked();
+ /** Initializee the current entry pointer to
+ pipeline stage 0 and the 1st schedule entry
+ */
void init();
+ /** Goes through the remaining stages on the schedule
+ and sums all the remaining entries left to be
+ processed
+ */
int size();
+
+ /** Is the schedule empty? */
bool empty();
+
+ /** What is the next task for this instruction schedule? */
ScheduleEntry* top();
+
+ /** Top() Task is completed, remove it from schedule */
void pop();
+
+ /** Add To Schedule based on stage num and priority of
+ Schedule Entry
+ */
void push(ScheduleEntry* sked_entry);
+
+ /** Add Schedule Entry to be in front of another Entry */
void pushBefore(ScheduleEntry* sked_entry, int sked_cmd, int sked_cmd_idx);
+
+ /** Print what's left on the instruction schedule */
void print();
private:
+ /** Current Schedule Entry Pointer */
SkedIt curSkedEntry;
+
+ /** The Resource Schedule: Resized to Number of Stages in
+ the constructor
+ */
std::vector<std::list<ScheduleEntry*> > sked;
+ /** Find a place to insert the instruction using the
+ schedule entries priority
+ */
SkedIt findIterByPriority(ScheduleEntry *sked_entry, int stage_num);
+
+ /** Find a place to insert the instruction using a particular command
+ to look for.
+ */
SkedIt findIterByCommand(ScheduleEntry *sked_entry, int stage_num,
int sked_cmd, int sked_cmd_idx = -1);
};