https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106680
--- Comment #11 from Kewen Lin <linkw at gcc dot gnu.org> --- (In reply to Sebastian Huber from comment #8) > Yes, it seems that -mcpu=e6500 -mno-powerpc64 yields the right code for the > attached test case (with or without the -m32). The default is -m32 I guess? :) > > I am now a bit confused what the purpose of the -m32 and -m64 options is. For -m32/-m64, the manual says: Generate code for 32-bit or 64-bit environments of Darwin and SVR4 targets (including GNU/Linux). The 32-bit environment sets int, long and pointer to 32 bits and generates code that runs on any PowerPC variant. The 64-bit environment sets int to 32 bits and long and pointer to 64 bits, and generates code for PowerPC64, as for -mpowerpc64. But it's possible to interact with option powerpc64, like cpu e6500 which by default supports powerpc64 and if applied OS is able to support the necessary context switches, we want -mpowerpc64 kept and it's able to generate more efficient code (leveraging insns guarded with powerpc64 flag).
