[Bug tree-optimization/56175] Issue with combine phase on x86.

[ysrumyan at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56175

--- Comment #11 from Yuri Rumyantsev <ysrumyan at gmail dot com> 2013-02-14 12:03:37 UTC ---
I did measurements of 3 possible fixes:

1. Comment out 2 patterns related to type sinking.
2. Comment out 1st pattern only.
3. Prohibit type sinking if source type (of def_arg1) is short type.

Measuremnets were done on eembc 2.0 suite at base optset and they showed that
the 3rd fix is more profitable for x86 in 32-bit mode.

Since I hear nothing from the code owner I assume that we will add new target
hook returning true/false for type sinkning in the both patterns that will
anaylze the source type and likely destination type of operand.

Richard, what is your opinion?