micropython/tests
Damien George 0a59938574 py/mpz: Fix overflow of borrow in mpn_div.
For certain operands to mpn_div, the existing code path for
`DIG_SIZE == MPZ_DBL_DIG_SIZE / 2` had a bug in it where borrow could still
overflow in the `(x >= *n || *n - x <= borrow)` branch, ie
`borrow + x - (mpz_dbl_dig_t)*n` overflows the borrow variable.  In such
cases the subsequent right-shift of borrow would not bring in the overflow
bit, leading to an error in the result.  An example division that had
overflow when MPZ_DIG_SIZE = 16 is `(2 ** 48 - 1) ** 2 // (2 ** 48 - 1)`.

This is fixed in this commit by simplifying the code and handling the low
digits of borrow first, and then the upper bits (to shift down) separately.
There is no longer a distinction between `DIG_SIZE < MPZ_DBL_DIG_SIZE / 2`
and `DIG_SIZE == MPZ_DBL_DIG_SIZE / 2`.

This commit also simplifies the second part of the calculation so that
borrow does not need to be negated (instead the code just works knowing
that borrow is negative and using + instead of - in calculations involving
borrow).

Fixes #6777.

Signed-off-by: Damien George <damien@micropython.org>
2021-02-08 11:50:05 +11:00
..
basics py/mpz: Fix overflow of borrow in mpn_div. 2021-02-08 11:50:05 +11:00
cmdline unix/variants: Enable MICROPY_DEBUG_PARSE_RULE_NAME on coverage build. 2020-10-01 15:26:43 +10:00
cpydiff tests/cpydiff: Add CPy diff test for assignment expression behaviour. 2020-06-16 22:06:47 +10:00
esp32 esp32/modsocket: Fix getaddrinfo to raise on error. 2020-05-09 16:43:48 +10:00
extmod tests/extmod/utime_time_ns.py: Relax bounds on time_ns measurement. 2021-02-01 18:44:28 +11:00
feature_check all: Rename "sys" module to "usys". 2020-09-04 00:10:24 +10:00
float py: Fix handling of NaN in certain pow implementations. 2020-09-11 10:04:57 +10:00
import tests: Move .mpy import tests from import/ to micropython/ dir. 2020-07-26 22:04:31 +10:00
inlineasm tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
internal_bench tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
io all: Rename "sys" module to "usys". 2020-09-04 00:10:24 +10:00
jni tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
micropython tests: Move native for test from pybnative to micropython. 2021-01-29 23:57:10 +11:00
misc tests/misc/sys_settrace_features.py: Fix running with non-dflt encoding. 2020-12-18 13:57:17 +11:00
multi_bluetooth tests/multi_bluetooth: Add multitests for BLE pairing and bonding. 2020-12-02 14:44:55 +11:00
multi_net extmod/uasyncio: Add StreamReader.readexactly(n) method. 2020-07-25 23:10:05 +10:00
net_hosted tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
net_inet extmod/modussl_mbedtls: Integrate shorter error strings. 2020-07-21 00:31:05 +10:00
perf_bench tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
pyb tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
pybnative tests: Move native for test from pybnative to micropython. 2021-01-29 23:57:10 +11:00
qemu-arm qemu-arm: Add testing of frozen native modules. 2019-08-20 15:14:08 +10:00
stress tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
thread tests/thread/stress_schedule.py: Assign globals before running test. 2020-10-28 00:54:30 +11:00
unicode tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
unix py/mpprint: Fix length calculation for strings with precision-modifier. 2020-12-07 23:32:06 +11:00
wipy tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
README tests: Make run-tests help and README be more descriptive of behaviour. 2020-01-22 16:35:24 +11:00
run-internalbench.py tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
run-multitests.py tests/run-multitests.py: Add a -p flag to run permutations of instances. 2020-11-13 17:19:05 +11:00
run-natmodtests.py all: Rename "sys" module to "usys". 2020-09-04 00:10:24 +10:00
run-perfbench.py tests: Format all Python code with black, except tests in basics subdir. 2020-03-30 13:21:58 +11:00
run-tests tests/run-tests: Change default Python command used on Windows. 2021-02-02 21:32:20 +11:00
run-tests-exp.py all: Rename "sys" module to "usys". 2020-09-04 00:10:24 +10:00
run-tests-exp.sh run-tests-exp.sh: Typo fix in comment. 2015-02-21 03:22:33 +02:00

README

This directory contains tests for various functionality areas of MicroPython.
To run all stable tests, run "run-tests" script in this directory.

Tests of capabilities not supported on all platforms should be written
to check for the capability being present. If it is not, the test
should merely output 'SKIP' followed by the line terminator, and call
sys.exit() to raise SystemExit, instead of attempting to test the
missing capability. The testing framework (run-tests in this
directory, test_main.c in qemu_arm) recognizes this as a skipped test.

There are a few features for which this mechanism cannot be used to
condition a test. The run-tests script uses small scripts in the
feature_check directory to check whether each such feature is present,
and skips the relevant tests if not.

Tests are generally verified by running the test both in MicroPython and
in CPython and comparing the outputs. If the output differs the test fails
and the outputs are saved in a .out and a .exp file respectively.
For tests that cannot be run in CPython, for example because they use
the machine module, a .exp file can be provided next to the test's .py
file. A convenient way to generate that is to run the test, let it fail
(because CPython cannot run it) and then copy the .out file (but not
before checking it manually!)

When creating new tests, anything that relies on float support should go in the
float/ subdirectory.  Anything that relies on import x, where x is not a built-in
module, should go in the import/ subdirectory.