README.PORTING

--------------------------------------------------------------------------
Notes for building Mednafen's code outside of Mednafen's own build system:
    (though you should get most of this if you read configure.ac)

 Last updated November 28, 2014
--------------------------------------------------------------------------

gcc or LLVM(clang) is generally required, and ICC may work.  Other compilers will
require signficant changes to the codebase due to widespread usage of GNU extensions.

Compile with -fwrapv

Compile "ngp" module(Neo Geo Pop emulation) with -fno-strict-aliasing

Compile with -fomit-frame-pointer(at least on x86/x86_64).

Compile with -fsigned-char.

Compile with -fno-aggressive-loop-optimizations on newer versions of gcc that support it.

Compile in tests.cpp, and the call to the math test function, at least in your debug builds,
as it contains important compiler sanity checks.

Compile the PSX module with -mmmx -msse -msse2 on 32-bit x86 for better performance.

Compile with -fno-pic -fno-pie on 32-bit x86.

Define ARCH_X86(to 1) when compiling for 32-bit and 64-bit x86, and ARCH_X86_32 for 32-bit x86 and
ARCH_X86_64 for 64-bit x86_64.

Define ARCH_POWERPC and ARCH_POWERPC_ALTIVEC when compiling for POWER/PowerPC.

Do NOT compile with LTO, unless you use -fno-strict-aliasing(and that may negate the performance
benefits LTO provides).

Do NOT compile with -ffast-math, some relatively recent versions of gcc are buggy
and will produce completely wrong machine code for some common constructs
when -ffast-math is used.