We have --sweep-max-size, it's reasonable to have --sweep-min-size as
well. It can be used when working on the logic for larger sizes, or to
collect a profile for larger sizes only.
Summary:
This patch simply adds the `-fconvergent-functions` flag to the GPU
compilation. This is in relation to the behaviour of SIMT
architectures under divergence. With the flag, we assume every function
is convergent by default and rely on the compiler's divergence analysis
to transform it if possible.
Fixes: https://github.com/llvm/llvm-project/issues/63853
Some float128 systems (specifically the ones used for aarch64 buildbots)
don't respect signs for long double NaNs. This patch disables the printf
test that was failing due to this.
These bugs were found with the new printf long double fuzzing. The long
double inf vs nan bug was introduced when we changed to
get_explicit_exponent. The bitcast msan issue hadn't come up previously,
but isn't a real bug, just a poisoning confusion.
Summary:
We previously had to disable these string functions because they were
not compatible with the definitions coming from the GNU / host
environment. The GPU, when exporting its declarations, has a very
difficult requirement that it be compatible with the host environment as
both sides of the compilation need to agree on definitions and what's
present.
This patch more or less gives up an just copies the definitions as
expected by `glibc` if they are provided that way, otherwise we fall
back to the accepted way. This is the alternative solution to an
existing PR which instead disable's GCC's handling.
Summary:
This patch partially implements the `rand` function on the GPU. This is
partial because the GPU currently doesn't support thread local storage
or static initializers. To implement this on the GPU. I use 1/8th of the
local / shared memory quota to treak the shared memory as thread local
storage. This is done by simply allocating enough storage for each
thread in the block and indexing into this based off of the thread id.
The downside to this is that it does not initialize `srand` correctly to
be `1` as the standard says, it is also wasteful. In the future we
should figure out a way to support TLS on the GPU so that this can be
completely common and less resource intensive.
Summary:
The `fgets` function as implemented is not functional currently when
called with multiple threads. This is because we rely on reapeatedly
polling the character to detect EOF. This doesn't work when there are
multiple threads that may with to poll the characters. this patch pulls
out the logic into a standalone RPC call to handle this in a single
operation such that calling it from multiple threads functions as
expected. It also makes it less slow because we no longer make N RPC
calls for N characters.
This patch populates the GPU version of `libm` with missing vendor entrypoints. The vendor math entrypoints are disabled by default but can be enabled with the CMake option `LIBC_GPU_VENDOR_MATH=ON`.
Summary:
This function follows closely with the pattern of all the other
functions. That is, making a new opcode and forwarding the call to the
host. However, this also required modifying the test somewhat. It seems
that not all `libc` implementations follow the same error rules as are
tested here, and it is not explicit in the standard, so we simply
disable these EOF checks when targeting the GPU.
Recent testing has uncovered some hard-to-find bugs in printf's long
double support. This patch adds an extra long double path to the fuzzer
with minimal extra effort. While a more thorough long double fuzzer
would be useful, it would need to handle the non-standard cases of 80
bit long doubles such as unnormal and pseudo-denormal numbers. For that
reason, a standalone long double fuzzer is left for future development.
C++20 will automatically generate an operator== with reversed operand
order, which is ambiguous with the written operator== when one argument
is marked const and the other isn't.
This operator currently triggers -Wambiguous-reversed-operator at usage
site libc/test/UnitTest/PrintfMatcher.cpp:28.
Summary:
The implementation of `assert` has an if statement so that only the
first thread in the warp prints the assertion. On modern NVPTX
architecture, this can be printed out of order with the abort call. This
would lead to only a portion of the message being printed and then
exiting the program. By adding a mandatory warp sync we force the full
string to be printed before we continue to the abort.
Summary:
Currently, `libc` temporarily provides math by linking against existing
vendor implementations. To use the AMDGPU DeviceRTL we need to define a
handful of control constants that alter behaviour for architecture
specific things. Previously these were marked `extern const` because
they must be present when we link-in the vendor bitcode library.
However, this causes linker errors if more than one math function was
used.
This patch fixes the issue by marking these functions as used and inline
on top of being external. This means that they are linkable, but it
gives us `linkonce_odr` semantics. The downside is that these globals
won't be optimized out, but it allows us to perform constant propagation
on them unlike using `weak`.
Summary:
There were a few tests that weren't enabled on the GPU. This is because
the logic caused them to be skipped as we don't use CPU featured on the
host. This also disables the logic making multiple versions of the
memory functions.
The long double version of float to string's get_negative_block had a
bug in table mode. In table mode, one of the tables is named
"MIN_BLOCK_2" and it stores the number of blocks that are all zeroes
before the digits start for a given index. The check for long doubles
was incorrectly "block_index <= MIN_BLOCK_2[idx]" when it should be
"block_index < MIN_BLOCK_2[idx]" (without the equal sign). This bug
caused an off-by-one error for some long double values. This patch fixes
the bug and adds tests to ensure it doesn't regress.
Explicit braces were added to fix the "suggest explicit braces to avoid
ambiguous ‘else’" warning since the current solution (switch (0) case 0:
default:) doesn't work since gcc 7 (see
https://github.com/google/googletest/issues/1119)
gcc 13 generates about 5000 of these warnings when building libc without
this patch.
Summary:
The GPU build is special in the sense that we always know that
up-to-date `clang` is always going to be the compiler. This allows us to
rely directly on builtins, which allow us to push a lot of this
complexity into the backend. Backend implementations are favored on
the GPU because it allows us to do a lot more target specific
optimizations. This patch changes over the common memory functions to
use builtin versions when building for AMDGPU or NVPTX.
This patch fixes several warnings thrown by clang about an uninitialized
member of struct tm, tm_isdst.
Weirdly, gcc doesn't complain about it, probably this member is never
read in the tests.
This patch fixes a couple of warnings when compiling with gcc 13:
* CPP/type_traits_test.cpp: 'apply' overrides a member function but is
not marked 'override'
* UnitTest/LibcTest.cpp:98: control reaches end of non-void function
* MPFRWrapper/MPFRUtils.cpp:75: control reaches end of non-void function
* smoke/FrexpTest.h:92: backslash-newline at end of file
* __support/float_to_string.h:118: comparison of unsigned expression in ‘>= 0’ is always true
* test/src/__support/CPP/bitset_test.cpp:197: comparison of unsigned expression in ‘>= 0’ is always true
---------
Signed-off-by: Mikhail R. Gadelha <mikhail@igalia.com>
Summary:
This was disabled on the GPU because it conflicted with the definition
in `glibc`. According to information online and in the `glibc`
implementation, the first argument should be a `const void *`. Fixing
this resolves the problem when exporting this to offloading languages.
Summary:
The POSIX standard expects the first argument to this function to be
constant, e.g. https://man7.org/linux/man-pages/man2/nanosleep.2.html.
This fixes that problem and also corrects an obvious problem with
enabling this for offloading.
Summary:
The NVPTX backend is picky about the definitions of functions. Because
we call these functions with these arguments it can cause some problems
when it goes through the backend. This was observed in a different test
for `printf` that hasn't been landed yet. Also adjust the priority.
Summary:
Previously this code was applied to the integration tests but did not
copy the logic that stopped this from being passed to the GPU build.
Copy the full line to avoid the warnings and prevent any libraries from
being included.
Implementing expm1 function for double precision based on exp function
algorithm:
- Reduced x = log2(e) * (hi + mid1 + mid2) + lo, where:
* hi is an integer
* mid1 * 2^-6 is an integer
* mid2 * 2^-12 is an integer
* |lo| < 2^-13 + 2^-30
- Then exp(x) - 1 = 2^hi * 2^mid1 * 2^mid2 * exp(lo) - 1 ~ 2^hi *
(2^mid1 * 2^mid2 * (1 + lo * P(lo)) - 2^(-hi) )
- We evaluate fast pass with P(lo) is a degree-3 Taylor polynomial of
(e^lo - 1) / lo in double precision
- If the Ziv accuracy test fails, we use degree-6 Taylor polynomial of
(e^lo - 1) / lo in double double precision
- If the Ziv accuracy test still fails, we re-evaluate everything in
128-bit precision.
Summary:
These wrapper headers need to work around things in the standard
headers. The existing workarounds didn't correctly handle the macros for
`iscascii` and `toascii`. Additionally, `memrchr` can't be used because
it has a different declaration for C++ mode. Fix this so it can be
compiled.
Summary:
Currently, we use the RPC server to respond to different ports which
each contain a request from some client thread wishing to do work on the
server. This scan starts at zero and continues until its checked all
ports at which point it resets. If we find an active port, we service it
and then restart the search.
This is bad for two reasons. First, it means that we will always bias
the lower ports. If a thread grabs a high port it will be stuck for a
very long time until all the other work is done. Second, it means that
the `handle_server` function can technically run indefinitely as long as
the client is always pushing new work. Because the OpenMP implementation
uses the user thread to service the kernel, this means that it could be
stalled with another asyncrhonous device's kernels.
This patch addresses this by making the server restart at the next port
over. This means we will always do a full scan of the ports before
quitting.
Summary:
This enum previously manually specified the value. This just made it
unnecessarily difficult to add new ones without changing everything.
This patch also makes it compatible with C by removing the `:`
annotation and instead using the `LAST` method.
Summary:
This variable needs a reserved name starting with `__`. It was
mistakenly changed with a mass replace. It happened to work because the
tests still picked up the associated symbol, but it just became a bad
name because it's not reserved anymore.
The name __llvm_libc was mass-replaced with LIBC_NAMESPACE which ended
up changing the "__llvm_libc" prefix of the delete operator linkage names to
"LIBC_NAMESPACE". This change corrects it by changing the namespace prefix
to "__llvm_libc_<version info>".
Other libraries dependent on these libraries will automatically inherit
those compile options. This change in particular affects the compile
option "-DLIBC_COPT_STDIO_USE_SYSTEM_FILE".
This patch enables the compilation of libc for rv32 by unifying the
current rv64 and rv32 implementation into a single rv implementation.
We updated the cmake file to match the new riscv32 arch and force
LIBC_TARGET_ARCHITECTURE to be "riscv" whenever we find "riscv32" or
"riscv64". This is required as LIBC_TARGET_ARCHITECTURE is used in the
path for several platform specific implementations.
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D148797
printf_core.parser is not yet updated to use the printf config options. It
does not use them currently anyway and the corresponding parser_test
should be updated to respect the config options.
Summary:
This patch adds the necessary entrypoints to handle the `fseek`,
`fflush`, and `ftell` functions. These are all very straightfoward, we
simply make RPC calls to the associated function on the other end.
Implementing it this way allows us to more or less borrow the state of
the stream from the server as we intentionally maintain no internal
state on the GPU device. However, this does not implement the `errno`
functinality so that must be ignored.
