Commit Graph

183 Commits

Author SHA1 Message Date
Ross Thompson
857f59ab5c Now have global history working correctly. 2021-06-01 10:57:43 -05:00
Ross Thompson
f6c88666cf may have fixed the global branch history predictor.
The solution required a completed rewrite and understanding of how the GHR needs to be speculatively updated and repaired.
2021-05-31 16:11:12 -05:00
bbracker
39ae743543 turns out I should not have tried renaming FStallD to FPUStallD because that name was already used! All the same it does feel weird to have two such signals floating around \(ah pun!\) 2021-05-28 23:11:37 -04:00
Ross Thompson
8a035104ac It's a bit sloppy, but the global history predictor is working correctly now.
There were two major bugs with the predictor.
First the update mechanism was completely wrong.  The PHT is updated with the GHR that was used to lookup the prediction.  PHT[GHR] = Sat2(PHT[GHR], branch outcome).
Second the GHR needs to be updated speculatively as the branch is predicted.  This is important so that back to back branches' GHRs are not the same.  The must be different to avoid aliasing.  Speculation of the GHR update allows them to be different.  On mis prediction the GHR must be reverted.
This implementation is a bit sloppy with names and now the GHR recovery is performed.  Updates to follow.
2021-05-27 23:06:28 -05:00
Ross Thompson
fec40a1b75 fixed bug with icache miss spill fsm branch. 2021-05-25 14:26:22 -05:00
Ross Thompson
16e037b8e9 Fixed bug in the two bit sat counter branch predictor. The SRAM needs to be read enabled by StallF. 2021-05-24 23:24:54 -05:00
Ross Thompson
65632cb7c9 Fixed minor bug in instruction class decoding. 2021-05-24 13:41:14 -05:00
Ross Thompson
72f77656a3 Fixed bug with instruction classification. The class decoder was incorretly labeling jalr acting as both jalr and jr (no link). 2021-05-24 12:37:16 -05:00
Ross Thompson
21acc45121 Fixed synthesis bug with icache valid bit. 2021-05-04 13:03:08 -05:00
Ross Thompson
52e4c49bbb Fixed icache pcmux control for handling miss spill miss. 2021-05-04 11:05:01 -05:00
Ross Thompson
7f38056879 fixed subtle typo in icache fsm. Was messing up hit spill hit.
I believe the mibench qsort benchmark runs after this icache fix.
2021-05-03 16:55:36 -05:00
Ross Thompson
cdb602c9ce Removed combinational loops between icache and PMA checker. 2021-05-03 14:51:25 -05:00
Ross Thompson
19a93345b5 Reduced icache to 1 port memory. 2021-05-03 14:47:49 -05:00
Ross Thompson
a54c231489 Eliminated extra register and fixed ports to icache.
Still need to support physical tag check and write in icache memory.
Still need to reduce to 1 port SRAM in icache.
I would like to refactor the icache code.
2021-05-03 12:04:54 -05:00
Ross Thompson
c0a4b7cb17 Fixed typo in ifu for bypassing branch predictor.
Fixed missing signal name in local history predictor.
2021-05-03 08:56:45 -05:00
Jarred Allen
8fd9cc679b Fix compile error in branch predictor 2021-04-29 14:36:56 -04:00
Shreya Sanghai
1e57c6bb92 fixed bug in gshare, global and local history BP 2021-04-29 06:14:32 -04:00
Ross Thompson
72363f5c66 Added the ability to exclude branch predictor. 2021-04-26 14:27:42 -05:00
Ross Thompson
afbb100860 Fixed issue with not saving the first cache block read on a miss spill. 2021-04-26 12:57:34 -05:00
bbracker
31a0387136 merge cleanup; mem init is broken 2021-04-26 08:00:17 -04:00
bbracker
ba94fa3436 it says I need to merge in order to pull 2021-04-26 07:46:24 -04:00
bbracker
1cc0dcc83f progress on bus and lrsc 2021-04-26 07:43:16 -04:00
Ross Thompson
6e803b724e Merge branch 'tests' into icache-almost-working 2021-04-25 21:25:36 -05:00
Ross Thompson
020fb65adf Fixed icache for 32 bit.
Merge branch 'cache' into main
2021-04-22 16:45:29 -05:00
Ross Thompson
d8ab7a5de2 Partially working icache.
The current issue is a StallF is required to halt the icache from getting an updated PCF. However
if the dmemory is the reason for a stall it is possible for the icache stall to hold the d memory request continuously causing d memory to repeatedly read from memory.  This keeps StallF high and
the icache FSM is never allowed to complete.
2021-04-22 10:20:36 -05:00
Thomas Fleming
e336fbd108 Merge branch 'main' of github.com:davidharrishmc/riscv-wally into main
Conflicts:
	wally-pipelined/src/ifu/ifu.sv
2021-04-21 20:01:08 -04:00
Thomas Fleming
4bae666fa1 Implement virtual memory protection 2021-04-21 19:58:36 -04:00
Ross Thompson
7b3735fc25 Fixed for the instruction spills. 2021-04-21 16:47:05 -05:00
Teo Ene
ddc98e7d08 Fixed most relevant remaining synthesis compilation warnings with Ben 2021-04-21 16:06:27 -05:00
Ross Thompson
532c8771ba major progress.
It's running the icache is imperas tests now.
Compressed does not work yet.
2021-04-21 08:39:54 -05:00
Ross Thompson
f3093ac612 Why was the linter messed up?
There are a number of combo loops which need fixing outside the icache.  They may be fixed in main.
We get to instruction address 50 now!
2021-04-20 22:06:12 -05:00
Ross Thompson
99424fb983 Progress on icache. Fixed some issues aligning the PC with instruction. Still broken. 2021-04-20 21:19:53 -05:00
Ross Thompson
251ece20fe Broken icache. Design is done. Time to debug. 2021-04-20 19:55:49 -05:00
Jarred Allen
850f728cc7 Merge branch 'main' into cache 2021-04-19 00:05:23 -04:00
Thomas Fleming
ff9f1e5e72 Connect tlb and icache properly 2021-04-15 14:48:39 -04:00
Jarred Allen
81c02bda55 Merge branch 'main' into cache 2021-04-15 13:47:19 -04:00
Shreya Sanghai
0369fc5d1e Cherry Pick merge of Shreya's localhistory predictor changes into main.
fixed minor bugs in localHistory
2021-04-15 09:04:36 -05:00
ShreyaSanghai
6d4042e479 added localHistoryPredictor 2021-04-15 08:58:22 -05:00
Shreya Sanghai
7e9a0602ea fixed bugs in global history to read latest GHRE
Cherry pick Shreya's commits into main branch.
2021-04-15 08:55:22 -05:00
Jarred Allen
3717699ad9 Add a comment to explain a detail 2021-04-14 23:14:59 -04:00
Jarred Allen
892dfd5a9b More icache bugfixes 2021-04-14 19:03:33 -04:00
Teo Ene
1018a10625 Various code syntax changes to bring HDL to a synthesizable level 2021-04-13 11:27:12 -05:00
Jarred Allen
fc8b8ad7aa A few more cache fixes 2021-04-13 01:07:40 -04:00
Jarred Allen
d99b8f772e Merge from branch 'main' 2021-04-08 17:19:34 -04:00
Thomas Fleming
303c2c4839 Implement support for superpages 2021-04-08 02:44:59 -04:00
Ross Thompson
c91436d3b7 Merge branch 'icache_bp_bug' into tests
Not sure this merge is right.
2021-04-06 21:46:40 -05:00
Ross Thompson
98a04abe6c Merge remote-tracking branch 'refs/remotes/origin/tests' into tests 2021-04-06 21:20:55 -05:00
Jarred Allen
bd8f1eea3c Fix another bug in icache 2021-04-06 17:47:00 -04:00
Jarred Allen
3afc358974 Fix another bug in icache 2021-04-06 12:48:42 -04:00
Jarred Allen
c95da7d11e Fix bug in icache 2021-04-03 18:10:54 -04:00
Thomas Fleming
fdb20ee1cf Implement sfence.vma and fix tlb writing 2021-04-01 15:55:05 -04:00
Shreya Sanghai
df149d1be7 fixed minor bugs in localHistory 2021-04-01 13:40:08 -04:00
ShreyaSanghai
28a9c6ba56 added localHistoryPredictor 2021-04-01 22:22:40 +05:30
Shreya Sanghai
b544526766 fixed bugs in global history to read latest GHRE 2021-03-31 21:56:14 -04:00
Ross Thompson
9172e52286 Corrected a number of bugs in the branch predictor.
Added performance counters to individually track
branches; jumps, jump register, jal, and jalr; return.
jump and jump register are special cases of jal and jalr.
Similarlly return is a special case of jalr.
Also added counters to track if the branch direction was wrong,
btb target wrong, or the ras target was wrong.
Finally added one more counter to track if the BP incorrectly predicts
a non-cfi instruction.
2021-03-31 11:54:02 -05:00
Ross Thompson
a64a37d702 Merge of main with the new icache and the branch predictor. I believe there is a bug in the icache with unaligned memory access. The second part of the access is incorrectly relying on the PCF being the address of the next two bytes of the instruction. However this is not always the case as the branch predictor can get the wrong target address. The icache needs to generate the +2 address internally. 2021-03-30 23:18:20 -05:00
Thomas Fleming
eca2427f94 Merge remote-tracking branch 'origin/main' into main
Bring icache and MMU code together

Conflicts:
	wally-pipelined/src/ifu/ifu.sv
	wally-pipelined/testbench/testbench-imperas.sv
2021-03-30 22:24:47 -04:00
Thomas Fleming
7126ab7864 Complete basic page table walker 2021-03-30 22:19:27 -04:00
ushakya22
6b9ae41302 Merge branch 'main' of https://github.com/davidharrishmc/riscv-wally into main 2021-03-30 15:25:07 -04:00
Ross Thompson
2a308309e4 fixed some bugs with the RAS. 2021-03-30 13:57:40 -05:00
Jarred Allen
631454ccf9 Merge branch 'cache2' into cache
Conflicts:
	wally-pipelined/testbench/testbench-imperas.sv
2021-03-30 13:32:33 -04:00
Jarred Allen
7ca57cc4fc Merge branch 'main' into cache
Conflicts:
	wally-pipelined/regression/wave-dos/ahb-waves.do
	wally-pipelined/src/ifu/ifu.sv
	wally-pipelined/testbench/testbench-busybear.sv
	wally-pipelined/testbench/testbench-imperas.sv
2021-03-30 12:55:01 -04:00
Jarred Allen
39bf2347bc Fix error when reading an instruction that crosses a line boundary 2021-03-25 18:47:23 -04:00
ShreyaSanghai
139c2076a1 Removed PCW and InstrW from ifu 2021-03-26 01:53:19 +05:30
Jarred Allen
32829bf7a1 Remove old icache 2021-03-25 15:46:35 -04:00
Jarred Allen
5f4feb0ff1 Works for misaligned instructions not on line boundaries 2021-03-25 15:42:17 -04:00
Jarred Allen
3b4f0141f4 Begin work on compressed instructions 2021-03-25 14:43:10 -04:00
Jarred Allen
0290568a52 Make cache output NOP after a reset 2021-03-25 13:18:30 -04:00
Jarred Allen
602271ff7b rv64i linear control flow now working 2021-03-25 13:02:26 -04:00
Jarred Allen
ba95557c44 More progress on icache controller 2021-03-25 13:01:11 -04:00
Jarred Allen
ad0d77e9e1 Begin rewrite of icache module to use a direct-mapped scheme 2021-03-25 13:01:10 -04:00
Jarred Allen
b774d35c34 Output NOP instead of BAD when reset 2021-03-25 12:42:48 -04:00
bbracker
02e924e55a instrfaults not respecting stalls bugfix 2021-03-25 00:16:26 -04:00
Ross Thompson
1c6e37120e Fixed RAS errors. Still some room for improvement with the BTB and RAS. 2021-03-23 23:00:44 -05:00
Jarred Allen
4410944049 Merge branch 'main' into cache 2021-03-23 23:35:36 -04:00
Ross Thompson
84ad1353e4 Fixed a bunch of bugs with the RAS. 2021-03-23 21:49:16 -05:00
Ross Thompson
4fb7a1e0a6 Fixed the valid bit issue. Now the branch predictor is actually predicting instructions. 2021-03-23 20:20:23 -05:00
Ross Thompson
49348d734b fixed issue with BTB's valid bit not updating. There is still a problem is valid not ocurring in the correct clock cycle. 2021-03-23 20:06:45 -05:00
Ross Thompson
95dbc5f1fa fixed a whole bunch of bugs with the branch predictor. Still an issue with how PCNextF is not updated because the CPU is stalled. 2021-03-23 16:53:48 -05:00
Shreya Sanghai
1d6a2989ed PC counts branch instructions 2021-03-23 14:25:51 -04:00
Jarred Allen
0f8fe8fb3b Document some internal signals 2021-03-23 00:10:35 -04:00
Jarred Allen
6ffa01cc4d Add comments explaining icache inputs 2021-03-23 00:07:39 -04:00
Jarred Allen
827993598d Small commit to see if new hook tests non-main branch 2021-03-22 23:57:01 -04:00
Jarred Allen
6ce52f9b80 Remove DelaySideD since it isn't needed 2021-03-22 15:13:23 -04:00
Jarred Allen
b871bfe714 Update icache interface 2021-03-22 15:04:46 -04:00
Jarred Allen
f9cf05a7d4 Fix bug with PC incrementing 2021-03-20 18:06:03 -04:00
Jarred Allen
a2bf5ac202 Fix another bug in the icache (why so many of them?) 2021-03-20 17:54:40 -04:00
Jarred Allen
c5f99c4a34 Revert "Change flop to listen to StallF"
This reverts commit c8028710a5.
2021-03-20 17:34:19 -04:00
Jarred Allen
c8028710a5 Change flop to listen to StallF 2021-03-20 17:04:13 -04:00
Jarred Allen
279c09b27c Merge changes from main 2021-03-18 18:58:10 -04:00
Shreya Sanghai
bbe0957df5 Merge branch 'gshare' into main
Conflicts:
	wally-pipelined/regression/wave.do
2021-03-18 17:25:48 -04:00
Ross Thompson
1091dd10c1 Switched to gshare from global history.
Fixed a few minor bugs.
2021-03-18 16:05:59 -05:00
Ross Thompson
8f4051543c Fixed minor bug with the size of gshare. 2021-03-18 16:00:09 -05:00
Shreya Sanghai
eb86bfc084 removed unnecesary PC registers in ifu 2021-03-18 16:31:21 -04:00
Thomas Fleming
7f7597e667 Connect tlb, pagetablewalker, and memory 2021-03-18 14:35:46 -04:00
Shreya Sanghai
36f0631203 added gshare and global history predictor 2021-03-16 17:03:01 -04:00
Jarred Allen
a82aa23399 Fix icache for jumping into misaligned instructions 2021-03-16 16:57:51 -04:00
Shreya Sanghai
9eed875886 added global history branch predictor 2021-03-16 16:06:40 -04:00
Jarred Allen
ac9fd5a323 Fix BEQZ tests 2021-03-14 15:42:27 -04:00
Jarred Allen
926235b180 Merge upstream changes 2021-03-14 14:57:53 -04:00