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author | whitequark <whitequark@whitequark.org> | 2020-12-13 18:16:55 +0000 |
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committer | whitequark <whitequark@whitequark.org> | 2020-12-15 11:02:38 +0000 |
commit | f75bc6c7aac92c7c1c8954ec7fe5325a94e6e491 (patch) | |
tree | 3470df22d68e3e847981b3413827edaf4981f461 /backends/cxxrtl/cxxrtl_backend.cc | |
parent | 4d40595d644cfe58425a3de023c712641c429010 (diff) | |
download | yosys-f75bc6c7aac92c7c1c8954ec7fe5325a94e6e491.tar.gz yosys-f75bc6c7aac92c7c1c8954ec7fe5325a94e6e491.tar.bz2 yosys-f75bc6c7aac92c7c1c8954ec7fe5325a94e6e491.zip |
cxxrtl: disable optimization of debug_items().
Implementing outlining has greatly increased the amount of debug
information in a typical build, and consequently exposed performance
issues in C++ compilers, which are similar for both GCC and Clang;
the compile time of Minerva SoC SRAM increased almost twofold.
Although one would expect the slowdown to be caused by the increased
use of templates in `debug_eval()`, it is actually almost entirely
attributable to optimizations and codegen for `debug_items()`.
Fortunately, it is neither possible nor desirable to optimize
`debug_items()`: in most cases it is called exactly once, and its
body is a linear sequence of calls with unique arguments.
This commit turns off optimizations for `debug_items()` on GCC and
Clang, improving -Os compile time of Minerva SoC SRAM by ~40% (!)
Diffstat (limited to 'backends/cxxrtl/cxxrtl_backend.cc')
-rw-r--r-- | backends/cxxrtl/cxxrtl_backend.cc | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/backends/cxxrtl/cxxrtl_backend.cc b/backends/cxxrtl/cxxrtl_backend.cc index fa19a8dd6..7bf44626a 100644 --- a/backends/cxxrtl/cxxrtl_backend.cc +++ b/backends/cxxrtl/cxxrtl_backend.cc @@ -2038,6 +2038,7 @@ struct CxxrtlWorker { f << indent << "}\n"; f << "\n"; } + f << indent << "CXXRTL_EXTREMELY_COLD\n"; f << indent << "void " << mangle(module) << "::debug_info(debug_items &items, std::string path) {\n"; dump_debug_info_method(module); f << indent << "}\n"; |