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Diffstat (limited to 'results/classifier/gemma3:12b/device/1843651')
| -rw-r--r-- | results/classifier/gemma3:12b/device/1843651 | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/results/classifier/gemma3:12b/device/1843651 b/results/classifier/gemma3:12b/device/1843651 new file mode 100644 index 000000000..689a82fff --- /dev/null +++ b/results/classifier/gemma3:12b/device/1843651 @@ -0,0 +1,81 @@ + +m68k fpu bug + +On gcc123 cfarm machine, +I was testing m68k executables generated by Free Pascal Compiler. + +muller@gcc123:~/pas/check$ cat inf.pp +function get_double(x : double):double; + begin + get_double:=x; + end; + + +var + y : double; + py : pbyte; + i : byte; +begin + y:=1.0/0.0; + py:=@y; +{$ifdef ENDIAN_LITTLE} + write('little endian y='); + for i:=7 downto 0 do +{$else not ENDIAN_LITTLE} + write('big endian y='); + for i:=0 to 7 do +{$endif} + write(hexstr(py[i],2)); + writeln; + y:=get_double(y)+1; +{$ifdef ENDIAN_LITTLE} + write('little endian y='); + for i:=7 downto 0 do +{$else not ENDIAN_LITTLE} + write('big endian y='); + for i:=0 to 7 do +{$endif} + write(hexstr(py[i],2)); + writeln; +end. +muller@gcc123:~/pas/check$ ppc68k inf +Free Pascal Compiler version 3.3.1-r20:42973M [2019/09/11] for m68k +Copyright (c) 1993-2019 by Florian Klaempfl and others +Target OS: Linux for m68k +Compiling inf.pp +Assembling program +Linking inf +33 lines compiled, 0.1 sec +muller@gcc123:~/pas/check$ ./inf +big endian y=7FF0000000000000 +big endian y=7FFFFFFFFFFFFFFF +muller@gcc123:~/pas/check$ qemu-m68k ./inf +big endian y=7FF0000000000000 +big endian y=7FFFFFFFFFFFFFFF +muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k ./inf +qemu-m68k qemu-m68k-fixed +muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k-fixed ./inf +big endian y=7FF0000000000000 +big endian y=7FF0000000000000 + +~/sys-root/bin/qemu-m68k is 4.1.0 release, +~/sys-root/bin/qemu-m68k-fixed is the same source with a unique change: + +gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h:214:#if defined(TARGET_M68K) +gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-215-#define floatx80_infinity_low LIT64(0x0000000000000000) +gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-216-#else +gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-217-#define floatx80_infinity_low LIT64(0x8000000000000000) +gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-218-#endif + +the M68K branch value is set to the same value as the other branch. + +The problem of the M68K specific floatx86_infinity_low values +is that is enters in conflict with +muller@gcc123:~/pas/check$ grep -nA6 invalid_enc /home/muller/gnu/qemu/qemu-4.1.0/include/fpu/softfloat.h +752:static inline bool floatx80_invalid_encoding(floatx80 a) +753-{ +754- return (a.low & (1ULL << 63)) == 0 && (a.high & 0x7FFF) != 0; +755-} + +And thus the m68k variant of floatx80 representing +Infinity is +considered as an invalid encoding, and thus converted into a NaN 7FFFFFFFFFFFFFFF \ No newline at end of file |