PowerFPU

PowerFPU is a control panel for classic Mac OS from John Neil & Associates that redirected instructions from vintage 68k software to the PowerPC processor when run in emulation.

Functionality
John Neil & Associates' previous product, SoftwareFPU, found use when Apple begin its transition from 68k to PowerPC processors. Though PowerPC processors contained floating-point hardware, the 68k emulator in classic Mac OS only emulated a 68LC040 without floating-point hardware, causing old 68k software that did not perform necessary hardware checks to fail. Though SoftwareFPU 3.0 was available as a fat binary, running floating-point emulation with emulated 68k software was still very slow.

John Neil & Associates then licensed PowerFPU from Todd Pittman, which would directly route such instructions to the appropriate PowerPC-native instructions, enabling performance improvements that was over 10 times faster than SoftwareFPU and approached the speed of Motorola 68881 / 68882 co-processors. PowerFPU was written in a combination of PowerPC assembly language with other routines compiled with CompileIt!