Re: loop unswitching is sensitive to edge order

["Ben Elliston" <bje at au1 dot ibm dot com>]

Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz> writes:

> as far as I am aware, there is no such dependence in unswitching.
> What exactly breaks with your patch?

Numerous GCC test cases at -O3.  For example:

Executing on host: /home/bje/build/head/gcc/xgcc -B/home/bje/build/head/gcc/   -O3 -fomit-frame-pointer  -w -c  -o 20020109-1.o /home/bje/source/gcc-head/gcc/testsuite/gcc.c-torture/compile/20020109-1.c    (timeout = 300)
/home/bje/source/gcc-head/gcc/testsuite/gcc.c-torture/compile/20020109-1.c: In function 'foo':
/home/bje/source/gcc-head/gcc/testsuite/gcc.c-torture/compile/20020109-1.c:15: internal compiler error: in tree_split_edge, at tree-cfg.c:3032
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
compiler exited with status 1

I've attached a patch, as Steven asked, so others can take a look.

Attachment: PATCH.bz2
Description: Binary data

Ben