Add support for multi-threaded pass timing.
When multi-threading is enabled in the pass manager the meaning of the display
slightly changes. First, a new timing column is added, `User Time`, that
displays the total time spent across all threads. Secondly, the `Wall Time`
column displays the longest individual time spent amongst all of the threads.
This means that the `Wall Time` column will continue to give an indicator on the
perceived time, or clock time, whereas the `User Time` will display the total
cpu time.
Example:
$ mlir-opt foo.mlir -experimental-mt-pm -cse -canonicalize -convert-to-llvmir -pass-timing
===-------------------------------------------------------------------------===
... Pass execution timing report ...
===-------------------------------------------------------------------------===
Total Execution Time: 0.0078 seconds
---User Time--- ---Wall Time--- --- Name ---
0.0175 ( 88.3%) 0.0055 ( 70.4%) Function Pipeline
0.0018 ( 9.3%) 0.0006 ( 8.1%) CSE
0.0013 ( 6.3%) 0.0004 ( 5.8%) (A) DominanceInfo
0.0017 ( 8.7%) 0.0006 ( 7.1%) FunctionVerifier
0.0128 ( 64.6%) 0.0039 ( 50.5%) Canonicalizer
0.0011 ( 5.7%) 0.0004 ( 4.7%) FunctionVerifier
0.0004 ( 2.1%) 0.0004 ( 5.2%) ModuleVerifier
0.0010 ( 5.3%) 0.0010 ( 13.4%) LLVMLowering
0.0009 ( 4.3%) 0.0009 ( 11.0%) ModuleVerifier
0.0198 (100.0%) 0.0078 (100.0%) Total
PiperOrigin-RevId: 240636269
3 files changed
