[cfe-users] Improve compile performance when using Clang 3.6

[Jeffrey Walton]

Hi Everyone,

I just downloaded and built Clang 3.6. It appears performance has
dropped considerably from Clang 3.2 through 3.5 (I've been
building/using it for that long).

Is there anything obvious I am missing that might affect the
performance between 3.5 and 3.6? Like is something enabled that used
to be disabled or missing?

Otherwise, below is what a typical compiler invocation looks like. In
the past, it performed fine. Does it set off any red flags for anyone?

For completeness, I'm trying to run self tests under the sanitizers.
I'm interested in the dynamic analysis at this point, and not static
analysis provided by ccc-analyze and friends.

Thanks in advance.

====================

$ make static
/usr/local/bin/clang++ -DNDEBUG -g3 -Os -fPIC -fsanitize=address
-fsanitize=undefined -Wall -Wno-tautological-compare -Wno-unused-value
-Wno-unused-variable -Wno-unused-parameter -Wno-unused-function
-DCRYPTOPP_DISABLE_ASM -pipe -c 3way.cpp
/usr/local/bin/clang++ -DNDEBUG -g3 -Os -fPIC -fsanitize=address
-fsanitize=undefined -Wall -Wno-tautological-compare -Wno-unused-value
-Wno-unused-variable -Wno-unused-parameter -Wno-unused-function
-DCRYPTOPP_DISABLE_ASM -pipe -c adler32.cpp
...