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Diffstat (limited to 'results/classifier/zero-shot/118/user-level/1821515')
| -rw-r--r-- | results/classifier/zero-shot/118/user-level/1821515 | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/results/classifier/zero-shot/118/user-level/1821515 b/results/classifier/zero-shot/118/user-level/1821515 new file mode 100644 index 000000000..f2dbc11d5 --- /dev/null +++ b/results/classifier/zero-shot/118/user-level/1821515 @@ -0,0 +1,148 @@ +user-level: 0.838 +permissions: 0.836 +graphic: 0.800 +virtual: 0.796 +semantic: 0.746 +debug: 0.716 +register: 0.709 +assembly: 0.693 +device: 0.642 +arm: 0.620 +PID: 0.616 +hypervisor: 0.607 +architecture: 0.587 +peripherals: 0.582 +TCG: 0.582 +mistranslation: 0.567 +performance: 0.566 +kernel: 0.538 +ppc: 0.535 +risc-v: 0.524 +files: 0.494 +x86: 0.452 +boot: 0.441 +VMM: 0.397 +network: 0.370 +socket: 0.369 +vnc: 0.364 +KVM: 0.357 +i386: 0.234 +-------------------- +user-level: 0.976 +ppc: 0.816 +debug: 0.097 +files: 0.072 +TCG: 0.017 +hypervisor: 0.016 +virtual: 0.010 +PID: 0.007 +assembly: 0.007 +kernel: 0.005 +register: 0.005 +semantic: 0.004 +device: 0.004 +graphic: 0.003 +VMM: 0.002 +performance: 0.002 +architecture: 0.001 +network: 0.001 +peripherals: 0.001 +x86: 0.001 +boot: 0.001 +vnc: 0.001 +socket: 0.001 +mistranslation: 0.001 +permissions: 0.001 +risc-v: 0.000 +KVM: 0.000 +arm: 0.000 +i386: 0.000 + +qemu-ppc (user) incorrectly converts float(nan)->double(non-nan) + +Noticed on qemu-3.1.0 on GHC test suite where float32 comparisons didn't work on NaNs. +Here is the minimal reproducer: + +```c +// cat a.c +#include <stdio.h> +#include <math.h> +#include <stdint.h> + +int main() { + volatile float f1 = NAN; + volatile float f2 = NAN; + printf ("f1 (%e, %#x) >= f2 (%e, %#x): %s\n", + f1, *(volatile uint32_t*)&f1, + f2, *(volatile uint32_t*)&f2, + (f1 >= f2) ? "True" + : "False"); + volatile double d = f1; + printf ("d (%e, %#llx)\n", + d, *(volatile uint64_t*)&d); +} +``` + +``` +# incorrect execution: +$ powerpc-unknown-linux-gnu-gcc -O2 a.c -o a -static && qemu-ppc ./a +f1 (5.104236e+38, 0x7fc00000) >= f2 (5.104236e+38, 0x7fc00000): True +d (5.104236e+38, 0x47f8000000000000) + +# correct execution +$ scp a timberdoodle.ppc64.dev.gentoo.org:~/; ssh timberdoodle.ppc64.dev.gentoo.org ./a +f1 (nan, 0x7fc00000) >= f2 (nan, 0x7fc00000): False +d (nan, 0x7ff8000000000000) +``` + +Note: qemu-ppc handled float32 extension as it was not a NaN (exp=111..1111) but a normalized number. + + + +The bug is in the same area as https://bugs.launchpad.net/qemu/+bug/1821444 but in another branch of 'uint64_t helper_todouble(uint32_t arg=0x1)'. + +We also hit this regression when testing CompCert for e5500 with qemu 3.1.0. + +The minimal example +> #include <stdio.h> +> #include <math.h> +> +> union C { float f; unsigned long l; }; +> int main (void) { +> union C c; +> c.f = NAN; +> printf("Float: %f\n Hex: 0x%x\n", c.f, c.l); +> printf("The above float is %s NAN\n", c.f == NAN ? "==" : "!="); +> return 0; +> } + +does not exhibit the error with GCC 6.3.0, since that statically optimizes the c.f == NAN to always be false. But CompCert doesn't do this optimization and thus triggers the regression in the float compare. + +With qemu 3.0.0 the example outputs (whether built with compcert or gcc): +> Float: nan +> Hex: 0x7fc00000 +> The above float is != NAN + +The example works well with qemu 3.0.0 and we stumbled over this with qemu 3.1.0; both build from the released source tarballs. My native system is a x86_64 GNU/Linux (openSUSE Tumbleweed with Kernel 4.20.13-1-default). + +Output with qemu 3.1.0 and built with GCC: +> $ ./qemu-ppc64abi32-3.1.0 bug25310.gcc.elf +> Float: 510423550381407695195061911147652317184.000000 +> Hex: 0x7fc00000 +> The above float is != NAN + +qemu 3.1.0 and example built with CompCert: +> $ ./qemu-ppc64abi32-3.1.0 bug25310.ccomp.elf +> Float: 510423550381407695195061911147652317184.000000 +> Hex: 0x7fc00000 +> The above float is == NAN + +I attached example binaries (statically built): +> $ ../../compcert_internal_ppc/bin/ccomp --version +> The CompCert C verified compiler, Release: 18.10i, Build: 4503984, Tag: auto/2019/02/11/1924 +> $ ../../compcert_internal_ppc/bin/ccomp -target e5500-linux -g -static bug25310.c -o bug25310.ccomp.elf +> +> $ ../../compcert_internal_ppc/gcc/bin/powerpc-unknown-linux-gnu-gcc --version +> powerpc-unknown-linux-gnu-gcc (crosstool-NG crosstool-ng-1.23.0) 6.3.0 +> $ ../../compcert_internal_ppc/gcc/bin/powerpc-unknown-linux-gnu-gcc bug25310.c -g -static -O0 -o bug25310.gcc.elf -mcpu=e5500 + |