On 2017-05-07 17:48, G 3 wrote: > I made a diagnostic program for the floating point unit. It will test > various PowerPC floating point instructions for compatibility with the > PowerPC G3 processor. It was tested on a PowerPC G3 and G5 system. The > results of the program in qemu-system-ppc were pretty bad. About every > instruction tested is not implemented correctly.
I don't say that qemu-system-ppc is bug free, but this looks suspicious that about every instruction is buggy. Have you tried to run your program on a real G3 or G5 system? [ snip ] > > Here is the full test results after running this program in qemu-system-ppc > with a Mac OS 10.4 guest: > > > > > fadd test failed > expected answer: 0x3ff3333333333334 > actual answer: 0x8200400000000024 > expected fpscr: 0x82064000 > actual fpscr: 0x82004000 This looks highly suspicious that the actual answer match the expected answer. > actual FPSCR bits set: > bit 17: FPRF - Floating-point greater than or positive > bit 6: XX - Floating-point inexact exception > bit 0: FX - Floating-point exception summary > > expected FPSCR bits set: > bit 17: FPRF - Floating-point greater than or positive > bit 14: FI - Floating-point fraction inexact > bit 13: FR - Floating-point fraction rounded > bit 6: XX - Floating-point inexact exception > bit 0: FX - Floating-point exception summary > > fadds test failed > expected answer: 0x407024d500000000 > actual answer: 0x8200400000000024 > expected fpscr: 0x82064000 > actual fpscr: 0x82004000 Ditto. > actual FPSCR bits set: > bit 17: FPRF - Floating-point greater than or positive > bit 6: XX - Floating-point inexact exception > bit 0: FX - Floating-point exception summary > > expected FPSCR bits set: > bit 17: FPRF - Floating-point greater than or positive > bit 14: FI - Floating-point fraction inexact > bit 13: FR - Floating-point fraction rounded > bit 6: XX - Floating-point inexact exception > bit 0: FX - Floating-point exception summary > > fsub test passed > fsubs test passed > fmul test failed > expected answer: 0x40365c28f5c28f5c > actual answer: 0x8200400000000024 > expected fpscr: 0x82024000 > actual fpscr: 0x82004000 Ditto. > actual FPSCR bits set: > bit 17: FPRF - Floating-point greater than or positive > bit 6: XX - Floating-point inexact exception > bit 0: FX - Floating-point exception summary > > expected FPSCR bits set: > bit 17: FPRF - Floating-point greater than or positive > bit 14: FI - Floating-point fraction inexact > bit 6: XX - Floating-point inexact exception > bit 0: FX - Floating-point exception summary > > fmuls test failed > expected answer: 0x412135a4a0000000 > actual answer: 0x8200400000000024 > expected fpscr: 0x82024000 > actual fpscr: 0x82004000 > > actual FPSCR bits set: > bit 17: FPRF - Floating-point greater than or positive > bit 6: XX - Floating-point inexact exception > bit 0: FX - Floating-point exception summary > > expected FPSCR bits set: > bit 17: FPRF - Floating-point greater than or positive > bit 14: FI - Floating-point fraction inexact > bit 6: XX - Floating-point inexact exception > bit 0: FX - Floating-point exception summary > > fdiv test failed > expected answer: 0x40059f38ee13b48b > actual answer: 0x8200400000000024 > expected fpscr: 0x82064000 > actual fpscr: 0x82004000 Ditto. And so on... -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurel...@aurel32.net http://www.aurel32.net
