This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [tree-ssa] fold-const trick for gzip



On Dec 9, 2003, at 14:41, Andrew Pinski wrote:


In gzip, there is a place where the code could be using unconditional code
instead of conditional code for speed and size (at least on PPC).


It turns (A > (2^n)-1) ? (A - 2^n) : 0 into (-(A >> n))&(A-2^n) where n+1
is the size of the conditional type in bits.


Bootstrapped on powerpc-apple-darwin7.0.0 without any regressions.


ChangeLog:


* fold-const.c (fold): Convert (A > (2^n)-1) ? (A - 2^n) : 0 into (-(A >> n))&(A-2^n).



Patch:



Here is the new patch without the debugging stuff included:




Attachment: gziphack.diff.txt
Description: Text document




Thanks, Andrew Pinski

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]