The rounding during type conversion uses multiple conversions, selecting
between them to try to discover if rounding occurred. This appears to
not have been tested, since it would generate code of the form:
float convert_float_rtp(char x)
{
float r = convert_float(x);
char y = convert_char(y);
[...]
}
which will access uninitialised data. The idea appears to have been to
have done a char -> float -> char roundtrip in order to discover the
rounding, so do this.
Discovered by inspection.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed By: jvesely
Differential Revision: https://reviews.llvm.org/D81999
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libclc
------
libclc is an open source, BSD licensed implementation of the library
requirements of the OpenCL C programming language, as specified by the
OpenCL 1.1 Specification. The following sections of the specification
impose library requirements:
*6.1: Supported Data Types
*6.2.3: Explicit Conversions
*6.2.4.2: Reinterpreting Types Using as_type() and as_typen()
*6.9: Preprocessor Directives and Macros
*6.11: Built-in Functions
*9.3: Double Precision Floating-Point
*9.4: 64-bit Atomics
*9.5: Writing to 3D image memory objects
*9.6: Half Precision Floating-Point
libclc is intended to be used with the Clang compiler's OpenCL frontend.
libclc is designed to be portable and extensible. To this end, it provides
generic implementations of most library requirements, allowing the target
to override the generic implementation at the granularity of individual
functions.
libclc currently only supports the PTX target, but support for more
targets is welcome.
Compiling and installing with Make
----------------------------------
$ ./configure.py --with-llvm-config=/path/to/llvm-config && make
$ make install
Note you can use the DESTDIR Makefile variable to do staged installs.
$ make install DESTDIR=/path/for/staged/install
Compiling and installing with Ninja
-----------------------------------
$ ./configure.py -g ninja --with-llvm-config=/path/to/llvm-config && ninja
$ ninja install
Note you can use the DESTDIR environment variable to do staged installs.
$ DESTDIR=/path/for/staged/install ninja install
Website
-------
https://libclc.llvm.org/
59510c4212