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Diffstat (limited to 'results/classifier/108/other/2318')
| -rw-r--r-- | results/classifier/108/other/2318 | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/results/classifier/108/other/2318 b/results/classifier/108/other/2318 new file mode 100644 index 000000000..58c00aaf7 --- /dev/null +++ b/results/classifier/108/other/2318 @@ -0,0 +1,49 @@ +device: 0.679 +graphic: 0.495 +vnc: 0.479 +semantic: 0.460 +permissions: 0.424 +performance: 0.363 +boot: 0.291 +socket: 0.281 +network: 0.239 +PID: 0.217 +debug: 0.212 +files: 0.176 +other: 0.133 +KVM: 0.006 + +SH4: SUBV instruction not emulated properly +Description of problem: +SUBV opcode is emulated incorrectly. + +The documentation says: + +`SUBV Rm, Rn Rn - Rm -> Rn, underflow -> T` + +Qemu seems to perform the subtraction correctly, but will not detect an underflow. +Steps to reproduce: +```c +#include <stdio.h> + +int main(void) +{ + register unsigned int a asm("r8") = 0x80000001; + register unsigned int b asm("r9") = 0x2; + register unsigned int c asm("r10"); + + asm volatile("subv %2,%0\n" + "movt %1\n" + : "+r"(a), "=r"(c) : "r"(b) :); + + printf("Values: a=0x%x b=0x%x c=0x%x\n", a, b, c); + + return 0; +} +``` +Additional information: +Tested on real hardware (SEGA Dreamcast, GCC 15.0), the program above prints: +`Values: a=0x7fffffff b=0x2 c=0x1` + +Running with Qemu (and GCC 13.0), the same program prints: +`Values: a=0x7fffffff b=0x2 c=0x0` |