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Diffstat (limited to 'results/classifier/118/none/1815423')
| -rw-r--r-- | results/classifier/118/none/1815423 | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/results/classifier/118/none/1815423 b/results/classifier/118/none/1815423 new file mode 100644 index 000000000..c47c69c80 --- /dev/null +++ b/results/classifier/118/none/1815423 @@ -0,0 +1,101 @@ +TCG: 0.785 +x86: 0.771 +files: 0.577 +architecture: 0.490 +performance: 0.465 +graphic: 0.458 +debug: 0.446 +device: 0.442 +ppc: 0.401 +vnc: 0.394 +register: 0.394 +socket: 0.392 +network: 0.375 +risc-v: 0.361 +arm: 0.343 +boot: 0.337 +semantic: 0.333 +mistranslation: 0.326 +permissions: 0.317 +PID: 0.298 +assembly: 0.284 +hypervisor: 0.263 +user-level: 0.259 +i386: 0.217 +kernel: 0.213 +peripherals: 0.168 +VMM: 0.155 +KVM: 0.144 +virtual: 0.124 + +x86_64 TCG: Incorrect floating point cast to int. + +I used exaample from: +https://stackoverflow.com/questions/3986795/what-is-the-result-of-casting-float-inf-inf-and-nan-to-integer-in-c + +#include <stdio.h> +#include <math.h> + +int main(int argc, char** argv) { + float a = INFINITY; + float b = -INFINITY; + float c = NAN; + + printf("float %f %f %f\n", a, b, c); + printf("int %d %d %d\n", (int) a, (int) b, (int) c); + printf("uint %u %u %u\n", (unsigned int) a, (unsigned int) b, (unsigned int) c); + printf("lint %ld %ld %ld\n", (long int) a, (long int) b, (long int) b); + printf("luint %lu %lu %lu\n", (unsigned long int) a, (unsigned long int) b, (unsigned long int) c); + + return 0; +} + +And got different results on real computer and on qemu. + +output from real HW is the same as on stackoverflow: + +$ gcc test.c && ./a.out +float inf -inf nan +int -2147483648 -2147483648 -2147483648 +uint 0 0 0 +lint -9223372036854775808 -9223372036854775808 -9223372036854775808 +luint 0 9223372036854775808 9223372036854775808 + + +But on qemu I got another results: + +float inf -inf nan +int 2147483647 -2147483648 2147483647 +uint 4294967295 0 4294967295 +lint 9223372036854775807 -9223372036854775808 -9223372036854775808 +luint 18446744073709551615 9223372036854775808 9223372036854775807 + +qemu launch string: +/qemu-system-x86_64 -m 1024 -cpu core2duo -serial stdio -netdev user,id=network0 -device e1000,netdev=network0 -kernel my_kernel + + +qemu version: +x86_64-softmmu/qemu-system-x86_64 --version +QEMU emulator version 3.1.50 (v3.1.0-1676-ge47f81b617-dirty) +Copyright (c) 2003-2019 Fabrice Bellard and the QEMU Project developers + + +This bug affect some javascript (surprise) calculations: + +var conversion = "01234567890"; +var x; +var result = conversion[x & 42]; +console.log(result) + + +In example, var x is "undefined" +and when do calculation "x & 42" on js we should get 0 (it is documented feature), but actually got "42" + +and "result" sould be "0" but actually we got "undefined" + +https://<email address hidden>/ is a patch which fixes the C test case (and may also fix the node.js case, though I don't have a setup to test that). + + +This should be fixed by commit 1e8a98b53867f61da9, which will be in the 4.2 release. + + |