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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-07-06 16:43:19 +0000 |
|---|---|---|
| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-07-06 16:43:19 +0000 |
| commit | 238ec2b7cc1557d6f34c33cc482e4d0cd3e266dd (patch) | |
| tree | cd8a1b75ba7b3543eb7fe6857f408e7be4d9fd0b /results/classifier/gemma3:27b/instruction/2318 | |
| parent | 96049c939b1916d80532630d63c14e04d5244f1d (diff) | |
| download | emulator-bug-study-238ec2b7cc1557d6f34c33cc482e4d0cd3e266dd.tar.gz emulator-bug-study-238ec2b7cc1557d6f34c33cc482e4d0cd3e266dd.zip | |
add results
Diffstat (limited to 'results/classifier/gemma3:27b/instruction/2318')
| -rw-r--r-- | results/classifier/gemma3:27b/instruction/2318 | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/results/classifier/gemma3:27b/instruction/2318 b/results/classifier/gemma3:27b/instruction/2318 new file mode 100644 index 00000000..9ed785f0 --- /dev/null +++ b/results/classifier/gemma3:27b/instruction/2318 @@ -0,0 +1,37 @@ + + + +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` |