sys-devel/gcc-4.4.* have bug with sse (and subbug vith tree-vectorizer). In theory, all versions of gcc have sse-related bug, based on stack aligning. This bug mostly active with tree-vectoriser and was fixed for 4.2+ (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32893). But in 4.4+ branches this bug was reanimated by author of this: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40838 (reanimated in other place, read history). There are 2 (known to me) patches/solutions against this problem, published here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40985 - second patch solve THIS (zlib-related) problem near regression 32893 state, but I have more stable environment with -mfpmath=sse,387 with both patches (according to comments to 40838, first patch may not solve all problems with vectorizer). May be you are will understand more, reading this 3 upstream threads... PS All solutions may violate SysV ABI standard. But second was alredy applyed in 4.3.* Reproducible: Always
*** This bug has been marked as a duplicate of bug 270120 ***
