Daniel Carvalho has uploaded this change for review. (
https://gem5-review.googlesource.com/c/public/gem5/+/19249
Change subject: mem-cache: Use findEntry in Signature Prefetcher V2
......................................................................
mem-cache: Use findEntry in Signature Prefetcher V2
Use the proper table function to find an entry for the global history
register.
As a side effect, getPossibleEntries was removed from the associative
set class.
Change-Id: I226855f7cdc1de8af8ca71e009cb391a883050d9
Signed-off-by: Daniel R. Carvalho <[email protected]>
---
M src/mem/cache/prefetch/associative_set.hh
M src/mem/cache/prefetch/associative_set_impl.hh
M src/mem/cache/prefetch/signature_path_v2.cc
3 files changed, 12 insertions(+), 44 deletions(-)
diff --git a/src/mem/cache/prefetch/associative_set.hh
b/src/mem/cache/prefetch/associative_set.hh
index e4e1b04..548f30c 100644
--- a/src/mem/cache/prefetch/associative_set.hh
+++ b/src/mem/cache/prefetch/associative_set.hh
@@ -181,14 +181,6 @@
Entry* findVictim(Addr addr);
/**
- * Find the set of entries that could be replaced given
- * that we want to add a new entry with the provided key
- * @param addr key to select the set of entries
- * @result vector of candidates matching with the provided key
- */
- std::vector<Entry *> getPossibleEntries(const Addr addr) const;
-
- /**
* Indicate that an entry has just been inserted
* @param addr key of the container
* @param is_secure tag component of the container
diff --git a/src/mem/cache/prefetch/associative_set_impl.hh
b/src/mem/cache/prefetch/associative_set_impl.hh
index 5e6e7c5..8a531cd 100644
--- a/src/mem/cache/prefetch/associative_set_impl.hh
+++ b/src/mem/cache/prefetch/associative_set_impl.hh
@@ -90,22 +90,6 @@
return victim;
}
-
-template<class Entry>
-std::vector<Entry *>
-AssociativeSet<Entry>::getPossibleEntries(const Addr addr) const
-{
- std::vector<ReplaceableEntry *> selected_entries =
- indexingPolicy->getPossibleEntries(addr);
- std::vector<Entry *> entries(selected_entries.size(), nullptr);
-
- unsigned int idx = 0;
- for (auto &entry : selected_entries) {
- entries[idx++] = static_cast<Entry *>(entry);
- }
- return entries;
-}
-
template<class Entry>
void
AssociativeSet<Entry>::insertEntry(Addr addr, bool is_secure, Entry* entry)
diff --git a/src/mem/cache/prefetch/signature_path_v2.cc
b/src/mem/cache/prefetch/signature_path_v2.cc
index 908e8da..8d24bdb 100644
--- a/src/mem/cache/prefetch/signature_path_v2.cc
+++ b/src/mem/cache/prefetch/signature_path_v2.cc
@@ -51,24 +51,15 @@
SignaturePathPrefetcherV2::handleSignatureTableMiss(stride_t current_block,
signature_t &new_signature, double &new_conf, stride_t &new_stride)
{
- bool found = false;
+ GlobalHistoryEntry* gh_entry =
+ globalHistoryRegister.findEntry(current_block, false);
- // This should return all entries of the GHR, since it is a fully
- // associative table
- std::vector<GlobalHistoryEntry *> all_ghr_entries =
- globalHistoryRegister.getPossibleEntries(0 /* any value works
*/);
-
- for (auto gh_entry : all_ghr_entries) {
- if (gh_entry->lastBlock + gh_entry->delta == current_block) {
- new_signature = gh_entry->signature;
- new_conf = gh_entry->confidence;
- new_stride = gh_entry->delta;
- found = true;
- globalHistoryRegister.accessEntry(gh_entry);
- break;
- }
- }
- if (!found) {
+ if (gh_entry) {
+ new_signature = gh_entry->signature;
+ new_conf = gh_entry->confidence;
+ new_stride = gh_entry->delta;
+ globalHistoryRegister.accessEntry(gh_entry);
+ } else {
new_signature = current_block;
new_conf = 1.0;
new_stride = current_block;
@@ -116,12 +107,13 @@
SignaturePathPrefetcherV2::handlePageCrossingLookahead(signature_t
signature,
stride_t last_offset, stride_t delta, double path_confidence)
{
+ const Addr tag = static_cast<Addr>(last_offset + delta);
+
// Always use the replacement policy to assign new entries, as all
// of them are unique, there are never "hits" in the GHR
- GlobalHistoryEntry *gh_entry = globalHistoryRegister.findVictim(0);
+ GlobalHistoryEntry *gh_entry = globalHistoryRegister.findVictim(tag);
assert(gh_entry != nullptr);
- // Any address value works, as it is never used
- globalHistoryRegister.insertEntry(0, false, gh_entry);
+ globalHistoryRegister.insertEntry(tag, false, gh_entry);
gh_entry->signature = signature;
gh_entry->lastBlock = last_offset;
--
To view, visit https://gem5-review.googlesource.com/c/public/gem5/+/19249
To unsubscribe, or for help writing mail filters, visit
https://gem5-review.googlesource.com/settings
Gerrit-Project: public/gem5
Gerrit-Branch: master
Gerrit-Change-Id: I226855f7cdc1de8af8ca71e009cb391a883050d9
Gerrit-Change-Number: 19249
Gerrit-PatchSet: 1
Gerrit-Owner: Daniel Carvalho <[email protected]>
Gerrit-MessageType: newchange
_______________________________________________
gem5-dev mailing list
[email protected]
http://m5sim.org/mailman/listinfo/gem5-dev
