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Diffstat (limited to 'results/classifier/semantic-bugs/instruction/2386')
| -rw-r--r-- | results/classifier/semantic-bugs/instruction/2386 | 56 |
1 files changed, 0 insertions, 56 deletions
diff --git a/results/classifier/semantic-bugs/instruction/2386 b/results/classifier/semantic-bugs/instruction/2386 deleted file mode 100644 index 96e88af3..00000000 --- a/results/classifier/semantic-bugs/instruction/2386 +++ /dev/null @@ -1,56 +0,0 @@ -instruction: 0.967 -graphic: 0.899 -socket: 0.812 -device: 0.808 -vnc: 0.803 -network: 0.759 -assembly: 0.688 -mistranslation: 0.640 -semantic: 0.624 -other: 0.616 -boot: 0.615 -KVM: 0.565 - -RISCV - Incorrect behaviour of the SLL instruction -Description of problem: -`SLL` (and probably other similar instructions) produce incorrect results. To quote the [RISCV ISA manual](https://drive.google.com/file/d/1uviu1nH-tScFfgrovvFCrj7Omv8tFtkp/view): - -> SLL, SRL, and SRA perform logical left, logical right, and arithmetic right shifts on the value in register -rs1 by the shift amount held in the lower 5 bits of register rs2. - -This instruction should perform a logical shift left by the shift amount from the lower 5 bits held in the third operand, however, it doesn't seem to be the case. As can be seen from the result of the snippet below: `55c3585000000000`, it seems that it calculates the correct value, but then shifts it by another 32 bits to the left: - -```python -correct_shift_res = (0xDB4D6868655C3585 << (0x69C99AB9B9401024 & 0b11111)) & (2 ** 64 - 1) -incorrect_qemu_produced = (correct_shift_res << 32) & (2 ** 64 - 1) -``` -Steps to reproduce: -1. Compile the attached source file: `riscv64-linux-gnu-gcc -static repro.c -o ./repro.elf` - -```c -#include <stdint.h> -#include <stdio.h> - -int main() { - uint64_t a = 0x69C99AB9B9401024; - uint64_t b = 0xDB4D6868655C3585; - uint64_t c; - - asm volatile("sll %0, %1, %2" : "=r"(c) : "r"(b), "r"(a)); - - printf("s8 : %lx\n", c); - printf("expected: %lx\n", 0xb4d6868655c35850); - - return 0; -} -``` - -2. Run qemu: `./qemu-riscv64 ./repro.elf` -3. You will see the output and what the result of the computation should really be: - -``` -s8 : 55c3585000000000 -expected: b4d6868655c35850 -``` -Additional information: - |