summaryrefslogtreecommitdiffstats
path: root/llvm/test/tools/llvm-mca/X86/BtVer2/add-sequence.s
Commit message (Collapse)AuthorAgeFilesLines
* [MCA] Show aggregate over Average Wait times for the whole snippet (PR43219)Roman Lebedev2019-10-101-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: As disscused in https://bugs.llvm.org/show_bug.cgi?id=43219, i believe it may be somewhat useful to show //some// aggregates over all the sea of statistics provided. Example: ``` Average Wait times (based on the timeline view): [0]: Executions [1]: Average time spent waiting in a scheduler's queue [2]: Average time spent waiting in a scheduler's queue while ready [3]: Average time elapsed from WB until retire stage [0] [1] [2] [3] 0. 3 1.0 1.0 4.7 vmulps %xmm0, %xmm1, %xmm2 1. 3 2.7 0.0 2.3 vhaddps %xmm2, %xmm2, %xmm3 2. 3 6.0 0.0 0.0 vhaddps %xmm3, %xmm3, %xmm4 3 3.2 0.3 2.3 <total> ``` I.e. we average the averages. Reviewers: andreadb, mattd, RKSimon Reviewed By: andreadb Subscribers: gbedwell, arphaman, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68714 llvm-svn: 374361
* [llvm-mca] Add fields "Total uOps" and "uOps Per Cycle" to the report ↵Andrea Di Biagio2018-08-291-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | generated by the SummaryView. This patch adds two new fields to the perf report generated by the SummaryView. Fields are now logically organized into two small groups; only the second group contains throughput indicators. Example: ``` Iterations: 100 Instructions: 300 Total Cycles: 414 Total uOps: 700 Dispatch Width: 4 uOps Per Cycle: 1.69 IPC: 0.72 Block RThroughput: 4.0 ``` This patch also updates the docs for llvm-mca. Due to the nature of this change, several tests in the tools/llvm-mca directory were affected, and had to be updated using script `update_mca_test_checks.py`. llvm-svn: 340946
* [llvm-mca] Use a different character to flag instructions with side-effects ↵Andrea Di Biagio2018-07-111-1/+1
| | | | | | | | | | | | | | | | | | | | | in the Instruction Info View. NFC This makes easier to identify changes in the instruction info flags. It also helps spotting potential regressions similar to the one recently introduced at r336728. Using the same character to mark MayLoad/MayStore/HasSideEffects is problematic for llvm-lit. When pattern matching substrings, llvm-lit consumes tabs and spaces. A change in position of the flag marker may not trigger a test failure. This patch only changes the character used for flag `hasSideEffects`. The reason why I didn't touch other flags is because I want to avoid spamming the mailing because of the massive diff due to the numerous tests affected by this change. In future, each instruction flag should be associated with a different character in the Instruction Info View. llvm-svn: 336797
* [llvm-mca] improve the instruction issue logic implemented by the Scheduler.Andrea Di Biagio2018-07-061-0/+98
This patch modifies the Scheduler heuristic used to select the next instruction to issue to the pipelines. The motivating example is test X86/BtVer2/add-sequence.s, for which llvm-mca wrongly reported an estimated IPC of 1.50. According to perf, the actual IPC for that test should have been ~2.00. It turns out that an IPC of 2.00 for test add-sequence.s cannot possibly be predicted by a Scheduler that only prioritizes instructions based on their "age". A similar issue also affected test X86/BtVer2/dependent-pmuld-paddd.s, for which llvm-mca wrongly estimated an IPC of 0.84 instead of an IPC of 1.00. Instructions in the ReadyQueue are now ranked based on two factors: - The "age" of an instruction. - The number of unique users of writes associated with an instruction. The new logic still prioritizes older instructions over younger instructions to minimize the pressure on the reorder buffer. However, the number of users of an instruction now also affects the overall rank. This potentially increases the ability of the Scheduler to extract instruction level parallelism. This patch fixes the problem with the wrong IPC reported for test add-sequence.s and test dependent-pmuld-paddd.s. llvm-svn: 336420
OpenPOWER on IntegriCloud