"Marshall B. Rogers" <mbr@xxxxx> writes: > Would still be interested in an explanation if somebody has one :-P I think it's a bug. http://gcc.gnu.org/bugs/ Ian > On Mon, Jul 6, 2009 at 11:25 AM, Marshall B. Rogers <mbr@xxxxx> wrote: >> >> Hi, >> >> I am in the process of rewriting some old code from ~1998 that was >> originally built with GCC (don't know the exact version number). The >> goal of the rewrite was to produce faster and more compact code, which >> has been an easy task so far considering how well GCC's optimization >> ability has progressed since then. Unexpectedly, my new program was >> larger than the original, and it turns out that this was due to 32-bit >> floating point constants being thrown into '.rodata', loaded from >> there, and then stored at their target. So, >> lui v0,0x809c >> lwc1 $f0,8192(v0) >> swc1 $f0,424(s0) >> Was being generated, whereas the original 1998 code had this: >> lui at,0x3f00 >> mtc1 at,$f4 >> swc1 $f4,424(s0) >> It's also important to note that the above could be simplified down to: >> lui at,0x3f00 >> sw at,424(s0) >> >> Is there a switch that controls this behavior? If not, when did GCC >> stop behaving this (1998) way, and why? Potential 4-byte instruction >> overhead and 4-byte data overhead seems like a big waste to me! >> >> Regards, >> Marshall
