From 0440fb92abc0ac72d03787aa24238deb22abbb7b Mon Sep 17 00:00:00 2001
From: David Li
Date: Fri, 1 Jan 2016 10:47:01 -0700
Subject: Finish read_word for cache
---
src/memory.rs | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/src/memory.rs b/src/memory.rs
index 7dc017c..5a30e17 100644
--- a/src/memory.rs
+++ b/src/memory.rs
@@ -244,6 +244,7 @@ impl MemoryInterface for DirectMappedCache {
let stall = self.latency();
let (tag, index, offset) = self.parse_address(address);
let ref mut set = self.cache[index as usize];
+
if set.valid && set.tag == tag {
return Ok(set.contents[(offset / 4) as usize]);
}
@@ -256,19 +257,29 @@ impl MemoryInterface for DirectMappedCache {
data: vec![0, self.block_words],
error: None,
waiting_on: 0,
- })
+ });
}
- else if let Some(ref fetch_request) = set.fetch_request {
+ else if let Some(ref mut fetch_request) = set.fetch_request {
if let Some(ref err) = fetch_request.error {
- // TODO: check to make sure the fetch request is for
- // this address, else just clear the request
- // TODO: clear the fetch request
- return Err(err.clone());
+ if fetch_request.address == normalized {
+ return Err(err.clone());
+ }
+ else {
+ fetch_request.address = normalized;
+ fetch_request.prefetch = false;
+ fetch_request.cycles_left = stall;
+ fetch_request.tag = new_tag;
+ fetch_request.waiting_on = 0;
+ }
}
+ // Do the assignment outside the borrow of the error
+ fetch_request.error = None;
+
return Err(MemoryError::CacheMiss {
stall_cycles: fetch_request.cycles_left
});
}
+
Err(MemoryError::CacheMiss {
stall_cycles: stall,
})
--
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