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
