1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
|
<think>
Okay, I'm trying to classify this bug report from QEMU into one of three categories: instruction, syscall, or runtime. Let's break down the information given.
The user mentioned that when running regression tests for Python 3.1.2 with QEMU 0.12.5 on a specific Linux setup, some math tests failed. The errors are in test_cmath, test_float, and test_math.
Looking at the details:
- In test_cmath, the acos function returns a complex number that's slightly off from the expected value. This suggests an issue with floating-point precision or calculation.
- For test_float, there's a discrepancy between the string representation of a float and its expected value, again pointing to precision issues.
- The test_math failure is multiple errors, but without specific details, it's likely related to similar underlying problems.
The user also noted that QEMU's x87 emulation handles trigonometric and other complex operations only at 64-bit precision instead of the full 80-bit. This means that when performing calculations, especially those requiring high precision, QEMU is truncating or approximating values more than a native environment would.
Considering the categories:
- **Instruction**: This refers to issues with specific CPU instructions being faulty. The problem here isn't about an incorrect instruction but rather how operations are handled.
- **Syscall**: This involves errors in system calls. The issue described doesn't relate to syscalls; it's more about computation within the emulator.
- **Runtime**: These are errors that occur during runtime, such as floating-point precision issues or calculation inaccuracies. Since QEMU is not maintaining 80-bit precision for x87 operations, this leads to inaccuracies in math functions, which cause the test failures.
So, the root cause is a runtime error due to insufficient floating-point precision handling in QEMU's emulation.
</think>
runtime
|