Summary:
There's still a little bit of constant factor that could be trimmed (e.g.
more overloads to avoid round-tripping primitives through json::Value).
But this solves the memory scaling problem, and greatly improves the performance
constant factor, and the API should leave room for optimization if needed.
Adapt TimeProfiler to use it, eliminating almost all the performance regression
from r358476.
Performance test on my machine:
perf stat -r 5 ~/llvmbuild-opt/bin/clang++ -w -S -ftime-trace -mllvm -time-trace-granularity=0 spirit.cpp
Handcrafted JSON (HEAD=r358532 with r358476 reverted): 2480ms
json::Value (HEAD): 2757ms (+11%)
After this patch: 2520 ms (+1.6%)
Reviewers: anton-afanasyev, lebedev.ri
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60804
llvm-svn: 359186
Summary:
Use llvm::json::Array.reserve() to optimize json output time. Here is motivation:
https://reviews.llvm.org/D60609#1468941. In short: for the json array
with ~32K entries, pushing back each entry takes ~4% of whole time compared
to the method of preliminary memory reservation: (3995-3845)/3995 = 3.75%.
Reviewers: lebedev.ri
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60792
llvm-svn: 358522
Summary:
Use optimized hashing while writing time trace by join two hashes to one.
Used for -ftime-trace option.
Reviewers: rnk, takuto.ikuta
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60404
llvm-svn: 357998
This change adds hierarchical "time trace" profiling blocks that can be visualized in Chrome, in a "flame chart" style. Each profiling block can have a "detail" string that for example indicates the file being processed, template name being instantiated, function being optimized etc.
This is taken from GitHub PR: https://github.com/aras-p/llvm-project-20170507/pull/2
Patch by Aras Pranckevičius.
Differential Revision: https://reviews.llvm.org/D58675
llvm-svn: 357340
Sam McCall