Updating GCC

Post by **Quzar** » Mon May 31, 2004 3:20 pm

Can someone please help me? Im on a winbox running cygwin and the version of GCC it comes with is 3.3.1 which is supposed to have problems with sh4. Could someone show me what i need to download and how to install it so that it replaces the older version?

GPF · Post by **GPF** » Mon May 31, 2004 4:43 pm

rerun the cygwin setup and select the newer version of GCC. Or if I misunderstand your question I think you can download new version of GCC from http://gcc.gnu.org/releases.html - just choose the mirror link and select a mirror to download it from.

Troy

itoledo · Post by **itoledo** » Tue Jun 01, 2004 7:38 am

the gcc compiler that you get with cygwin compiles for x86, not sh4. you need to build your 'own' sh4 compiler (sh4-elf-gcc) from the gcc sources. check the tutorial at http://www.hangar-eleven.de/en/devdc-index.html.

SinisterTengu · Post by **SinisterTengu** » Tue Jun 01, 2004 2:32 pm

Yeah, and actually 3.3.1 as well as 3.4.0 should work if you build them for SH4. I've had no problems with it, but apparently people on the KOS list say you should switch -fno-optimize-sibling-calls in the environ_dreamcast.sh file to -fno-crossjumping. I didn't do this and my rumble pack demo still compiled and worked fine, but I think Dan said stuff like FoF wouldn't compile unless he did switched those flags. I used gcc-3.4.0, binutils-2.14 (2.15 didn't work), and newlib-1.12.0, and followed the hangar-eleven guide (I didn't comment out that thing in errno.h though, I don't think thats needed any more because mine built fine without doing that).

Post by **Quzar** » Tue Jun 01, 2004 2:40 pm

hrm... ok well i guess im stuck with whatever i have now because i really dont understand how to update anything... even with that tut.

q_006 · Post by **q_006** » Tue Jun 01, 2004 2:41 pm

is there anyway to make GCC produce better SH-4 asm?
can it be done manually or do we have to wait for the GCC peeps to do such things?

SinisterTengu · Post by **SinisterTengu** » Tue Jun 01, 2004 3:02 pm

You could try different optimization settings, but otherwise, you'll just have to wait

Ian Micheal · Post by **Ian Micheal** » Tue Jun 01, 2004 9:24 pm

Try these together to get better code

-fbranch-probabilities -funroll-loops -frerun-loop-opt -fstrict-aliasing -fomit-frame-pointer -fstrength-reduce -fschedule-insns2 -freduce-all-givs -ffunction-sections -fdata-sections -mieee

Ive found this genrates about as good as you can get.