Summary:
The AMDGPU architecture does not use a fixed frequency for all of its
architectures. However, the newer GPUs tend to have one that's
consistent between them (Except for Vega10). This was set up but not
actually used, so the implementation was just defaulting to whatever
value the global was being set to. Fix.
`FPBits` is currently implemented as a general case and a specialization
for `long double` when `long double` is x86 80-bit extended precision.
This patch is a first of a series to provide an implementation based on
`FPType` instead of the C++ float type (which implementation is
architecture dependent).
As part of startup refactoring, this patch adds a function to merge
multiple objects into a single relocatable object:
cc -r obj1.o obj2.o -o obj.o
A relocatable object is an object file that is not fully linked into an
executable or a shared library. It is an intermediate file format that
can be passed into the linker.
A crt object can have arch-specific code and arch-agnostic code. To
reduce code cohesion, the implementation is splitted into multiple
units. As a result, we need to merge them into a single relocatable
object.
Use a size smaller than the smallest supported page size so that we
don't
clobber over any guard pages, which may result in a segfault before
__stack_chk_fail can be called.
Also, move __stack_chk_fail outside of our namespace.
__stack_chk_fail should be provided by libc.a, not startup files.
Add __stack_chk_fail to existing linux and arm entrypoints. On Windows
(when
not targeting MinGW), it seems that the corresponding function
identifier is
__security_check_cookie, so no entrypoint is added for Windows.
Baremetal
targets also ought to be compileable with `-fstack-protector*`
There is no common header for this prototype, since calls to
__stack_chk_fail
are meant to be inserted by the compiler upon function return when
compiled
`-fstack-protector*`.
This patch lifts aux vector related definitions to app.h. Because
startup's refactoring is in progress, this patch still contains
duplicated changes. This problem will be addressed very soon in an
incoming patch.
Profiling cmake shows that a significant time configuring `libc` folder
is spent on running `get_object_files_for_test` in the `test` folder (13
sec in `libc/test` folder / 16 sec in `libc` folder). By caching all
needed objects for each target instead of resolving every time, the time
cmake spends on configuring `libc/test` folder is reduced to ~1s.
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
This one might be a bit controversial since the terminology has been
introduced from the start but I think `FRACTION_LEN` is a better name
here. AFAICT it really is "the number of bits after the decimal dot when
the number is in normal form."
`MANTISSA_WIDTH` is less precise as it's unclear whether we take the
leading bit into account.
This patch also renames most of the properties to use the `_LEN` suffix
and fixes useless casts or variables.
Internal builds of the unittests with msan flagged mempcpy_test.
==6862==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x55e34d7d734a in length
llvm-project/libc/src/__support/CPP/string_view.h:41:11
#1 0x55e34d7d734a in string_view
llvm-project/libc/src/__support/CPP/string_view.h:71:24
#2 0x55e34d7d734a in
__llvm_libc_9999_0_0_git::testing::Test::testStrEq(char const*, char
const*, char const*, char const*,
__llvm_libc_9999_0_0_git::testing::internal::Location)
llvm-project/libc/test/UnitTest/LibcTest.cpp:284:13
#3 0x55e34d7d4e09 in LlvmLibcMempcpyTest_Simple::Run()
llvm-project/libc/test/src/string/mempcpy_test.cpp:20:3
#4 0x55e34d7d6dff in
__llvm_libc_9999_0_0_git::testing::Test::runTests(char const*)
llvm-project/libc/test/UnitTest/LibcTest.cpp:133:8
#5 0x55e34d7d86e0 in main
llvm-project/libc/test/UnitTest/LibcTestMain.cpp:21:10
SUMMARY: MemorySanitizer: use-of-uninitialized-value
llvm-project/libc/src/__support/CPP/string_view.h:41:11 in length
What's going on here is that mempcpy_test.cpp's Simple test is using
ASSERT_STREQ with a partially initialized char array. ASSERT_STREQ calls
Test::testStrEq which constructs a cpp:string_view. That constructor
calls the
private method cpp::string_view::length. When built with msan, the loop
is
transformed into multi-byte access, which then fails upon access.
I took a look at libc++'s __constexpr_strlen which just calls
__builtin_strlen(). Replacing the implementation of
cpp::string_view::length
with a call to __builtin_strlen() may still result in out of bounds
access when
the test is built with msan.
It's not safe to use ASSERT_STREQ with a partially initialized array.
Initialize the whole array so that the test passes.
When building with compiler-rt enabled, warnings such as the following
are
observed:
llvm-project/llvm/build/projects/compiler-rt/../libc/include/llvm-libc-macros/linux/sys-stat-macros.h:46:9:
warning: 'S_IXOTH' macro redefined [-Wmacro-redefined]
#define S_IXOTH 00001
^
llvm-project/llvm/build/projects/compiler-rt/../libc/include/llvm-libc-macros/linux/fcntl-macros.h:61:9:
note: previous definition is here
#define S_IXOTH 01
^
It looks like we have these multiply defined. Deduplicate these flags;
users
should expect to find them in sys/stat.h. S_FIFO was wrong anyways
(should
have been S_IFIFO).
Also make type naming consistent by using `UIntType` instead of
`intU_t`.
This patch is a reland of #75196 but does not include the "use `FPBits`
instead of `FPBits_t`, `FPB`" part. This needs more work.
Reverts llvm/llvm-project#75196
GCC complains about change of meaning for `FPBits`
```
/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian-fullbuild/libc-x86_64-debian-gcc-fullbuild-dbg/llvm-project/libc/src/__support/FPUtil/generic/FMod.h:188:9: error: declaration of ‘using FPBits = struct __llvm_libc_18_0_0_git::fputil::FPBits<T>’ changes meaning of ‘FPBits’ [-fpermissive]
188 | using FPBits = FPBits<T>;
| ^~~~~~
```
I'll reland with a different name.
This patch fixes cmake configuration when building with
LLVM_LIBC_INCLUDE_SCUDO. In libc, LIBC_TARGET_ARCHITECTURE is renamed
from `riscv64` to `riscv`. However, `compiler-rt`, hence `scudo`,
distinguishes `riscv32` and `riscv64` in the support list. As a result,
we need to translate the architecture name accordingly.
If a function is declared with stack-protector, the compiler may try to
load the TLS. However, inside certain runtime functions, TLS may not be
available. This patch disables stack protectors for such routines to fix
the problem.
Closes#74487.
This patch sinks `EXPLICIT_BIT_MASK` into `get_explicit_mantissa` - the
only function using it. Then it sinks the content of
`FPCommonProperties` directly into `FPProperties`.
An unsigned integer was being initialized with -1 to set all its bits to
1, but this doesn't work for the BigInt class which may be used as an
integer type on systems that don't support uint128 natively. This patch
moves the initialization to use ~T(0) instead.
This is a follow up on #74481 that migrates code from all
specializations into `FPCommonProperties` (except for
`EXPLICIT_BIT_MASK` in the `X86_Binary80` specialization)
