Andrew Waterman
35a983275e
Guarantee one-hotness of BTB entries
2016-07-06 15:58:01 -07:00
Andrew Waterman
c0e6ecebfc
Fix BTB perf bug
...
In rare cases, it would replace into a different row than it recorded.
2016-07-06 03:16:05 -07:00
Andrew Waterman
25fdabdd59
Don't implicitly create Vecs, since they're heavyweight
2016-07-06 01:41:31 -07:00
Andrew Waterman
ebefe57036
simplify BTB fetchWidth=1 special case
2016-07-04 23:43:47 -07:00
Andrew Waterman
5aa8ef1855
Remove invalidation support from BTB
...
Validating the target PC in the pipeline is cheaper than maintaining
the valid bits and control logic to guarantee the BTB won't ever
mispredict branch targets.
2016-07-02 14:27:29 -07:00
Andrew Waterman
8acec8eb36
Remove dead code from BTB
2016-04-27 00:28:12 -07:00
Andrew Waterman
d406dc1231
Remove vestigial BTB enable option
2016-04-01 15:14:34 -07:00
Christopher Celio
f526d380fd
separate btb response mask from the frontend mask
...
It is now the job of the pipeline to monitor the frontend's valid mask (of
instructions) and the BTB's suggested valid mask (based on the prediction it
makes). Some processors may want to ignore or override the BTB's prediction and
thus can supply their own instruction mask.
2016-03-26 05:37:26 -07:00
Christopher Celio
b96343a4e5
[btb] fix mix type error for fetch-width > 1
...
closes #24
2016-02-08 17:41:38 -08:00
Howard Mao
120361226d
fix more Chisel3 deprecations
2016-01-14 14:46:31 -08:00
Henry Cook
4f8468b60f
depend on external cde library
2015-10-21 18:19:23 -07:00
Henry Cook
1441590c3b
add enabled field to BTBParameters
2015-10-16 19:12:39 -07:00
Henry Cook
8173695800
added HasAddrMapParameters
2015-10-06 18:22:40 -07:00
Henry Cook
84576650b5
Removed all traces of params
2015-10-05 21:48:05 -07:00
Andrew Waterman
833909a2b5
Chisel3 compatibility fixes
2015-09-30 14:36:26 -07:00
Andrew Waterman
a7c908cb83
Don't declare Reg inside of when
...
We haven't yet decided what the Chisel3 semantics for this will be.
2015-09-30 12:43:36 -07:00
Andrew Waterman
78b2e947de
Chisel3 compatibility fixes
2015-09-11 15:43:07 -07:00
Andrew Waterman
6d7cc37e87
Specify some uninferrable widths
...
It's really scary that Chisel2 passed this stuff.
2015-07-31 14:23:52 -07:00
Andrew Waterman
45cf64dbd7
Use UInt instead of Vec[Bool]
2015-07-31 04:59:45 -07:00
Henry Cook
d2a594fb57
new junctions repo has mem size constants
2015-07-29 18:05:54 -07:00
Andrew Waterman
ce161b83e3
Chisel3 compatibility: avoid subword assignment
2015-07-29 15:03:13 -07:00
Andrew Waterman
c8c312e860
minor btb cleanup
2015-07-29 15:03:01 -07:00
Andrew Waterman
f2dcc40e67
Chisel3 compatibility changes
2015-07-27 12:42:20 -07:00
Andrew Waterman
ac6e73e317
Add Wire() wrap
2015-07-15 20:24:18 -07:00
Andrew Waterman
be2ff6dec7
Vec(Reg) -> Reg(Vec)
2015-07-15 12:33:46 -07:00
Henry Cook
741e6b77ad
Rename some params, use refactored TileLink
2015-02-01 20:37:31 -08:00
Scott Beamer
00e074cdd9
fixes slight bug for non-power of 2 number of ras entries
2015-01-29 15:29:25 -08:00
Christopher Celio
6749f67b7f
Fixed BHT update error.
...
- separated out BTB/BHT update
- BHT updates counters on every branch
- BTB update only on mispredicted and taken branches
2014-11-16 22:02:27 -08:00
Christopher Celio
fea31d2167
Significant changes and fixes to BTB for superscalar fetch.
...
- BTBUpdate only occurs on mispredicts now.
- RASUpdate broken out from BTBUpdate (allows RASUpdate to be performed in
Decode).
- Added optional 2nd CAM port to BTB for updates (for when updates to the
BTB may occur out-of-order).
- Fixed resp.mask bit logic.
2014-11-11 03:34:05 -08:00
Christopher Celio
3be3cd7731
Fixed error with icache/btb resp mask.
2014-11-03 01:13:22 -08:00
Christopher Celio
08d2c13330
Fixed btb/icache bugs regarding resp mask, fw==1
2014-10-20 18:45:23 -07:00
Christopher Celio
91efdc379b
Merge remote-tracking branch 'origin/master' into ss-frontend
...
Also fixed bridx logic and zero-width wire logic.
Conflicts:
src/main/scala/btb.scala
2014-10-14 18:10:29 -07:00
Andrew Waterman
7bb7299018
Don't pollute BTB with PC+4 target predictions
2014-10-14 17:28:37 -07:00
Christopher Celio
59eb7d194d
Finalize superscalar btb.
2014-10-03 16:08:08 -07:00
Christopher Celio
99614e37aa
Merge remote-tracking branch 'origin/master' into ss-frontend
...
Conflicts:
src/main/scala/btb.scala
src/main/scala/core.scala
2014-10-03 04:22:58 -07:00
Christopher Celio
9cc35dee9a
Returned history update to fetch.
...
- Global history only contains branches.
- Only update BHT and history on BTB hits.
- Gate off speculative update on stall or icmiss.
- Fixed bug where BHT updates were delayed a cycle.
2014-09-29 21:41:07 -07:00
Christopher Celio
8ccd07cfeb
Moved updating global history from fetch to decode.
...
- No longer update global history in fetch stage.
- Only update global history when instruction is a branch.
- Does allow for the possibility of back-to-back branches to see
slightly different histories on subsequent executions.
2014-09-28 05:16:36 -07:00
Christopher Celio
681b43f398
Bug fixes with global history register.
...
- Updated in fetch speculatively.
* Updates gated off by cpu.resp.fire().
* BTB direction factored into history update.
- All branches update the BHT.
- Each instruction carries history; index into BHT is recomputed by
passing in mem_reg_pc.
2014-09-26 10:39:57 -07:00
Christopher Celio
a71bdbbc54
Update history register in fetch speculatively
2014-09-26 05:42:08 -07:00
Christopher Celio
180d3d365d
Expanded front-end to support superscalar fetch.
2014-09-17 14:24:03 -07:00
Yunsup Lee
8abf62fae3
add LICENSE
2014-09-12 18:06:41 -07:00
Henry Cook
b42a2ab40a
Final parameter refactor
2014-09-01 13:28:58 -07:00
Henry Cook
2de268b3b1
Cache utility traits. Completely compiles, asm tests hang.
2014-08-19 11:38:20 -07:00
Henry Cook
0dac9a7467
Full conversion to params. Compiles but does not elaborate.
2014-08-19 11:38:02 -07:00
Andrew Waterman
88899eafe0
Reduce node count a bit
2014-06-14 13:58:07 -07:00
Andrew Waterman
8bc1c33540
Fix BTB error (requires Chisel update)
2014-05-19 18:56:30 -07:00
Andrew Waterman
cbb37ccc3e
Use Mem instead of Vec[Reg]
2014-05-18 19:25:43 -07:00
Andrew Waterman
4ca152b012
Use BundleWithConf to avoid clone method boilerplate
2014-05-09 19:37:16 -07:00
Andrew Waterman
0c13c00d08
Reduce node count by avoiding elsewhen :-(
2014-05-09 19:30:57 -07:00
Henry Cook
910b3b203a
removed AddressSpaceConstants, CacheConstants, and TileLinkSizeConstants
2014-04-10 12:32:44 -07:00