Part of the _BitInt feature in C2x
(http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2763.pdf) is a new
macro in limits.h named BITINT_MAXWIDTH that can be used to determine
the maximum width of a bit-precise integer type. This macro must expand
to a value that is at least as large as ULLONG_WIDTH.
This adds an implementation-defined macro named __BITINT_MAXWIDTH__ to
specify that value, which is used by limits.h for the standard macro.
This also limits the maximum bit width to 128 bits because backends do
not currently support all mathematical operations (such as division) on
wider types yet. This maximum is expected to be increased in the future.
This completes the implementation of
WG14 N2412 (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2412.pdf),
which standardizes C on a twos complement representation for integer
types. The only work that remained there was to define the correct
macros in the standard headers, which this patch does.
This causes modern glibc to unset math_errhandling MATH_ERRNO. gcc 12
also sets some other macros, but most of them are associated with
flags ignored by clang, so without library examples, it is difficult to
determine whether they should be set. I think setting this one macro is
OK for now.
The intent of this patch is to add support of -fp-model=[source|double|extended] to allow
the compiler to use a wider type for intermediate floating point calculations. As a side
effect to that, the value of FLT_EVAL_METHOD is changed according to the pragma
float_control.
Unfortunately some issue was uncovered with this change in preprocessing. See details in
https://reviews.llvm.org/D93769 . We are therefore reverting this patch until we find a way
to reconcile the value of FLT_EVAL_METHOD, the pragma and the -E flow.
This reverts commit 66ddac22e2.
The Intel compiler ICC supports the option "-fp-model=(source|double|extended)"
which causes the compiler to use a wider type for intermediate floating point
calculations. Also supported is a way to embed this effect in the source
program with #pragma float_control(source|double|extended).
This patch extends pragma float_control syntax, and also adds support
for a new floating point option "-ffp-eval-method=(source|double|extended)".
source: intermediate results use source precision
double: intermediate results use double precision
extended: intermediate results use extended precision
Reviewed By: Aaron Ballman
Differential Revision: https://reviews.llvm.org/D93769
The Intel compiler ICC supports the option "-fp-model=(source|double|extended)"
which causes the compiler to use a wider type for intermediate floating point
calculations. Also supported is a way to embed this effect in the source
program with #pragma float_control(source|double|extended).
This patch extends pragma float_control syntax, and also adds support
for a new floating point option "-ffp-eval-method=(source|double|extended)".
source: intermediate results use source precision
double: intermediate results use double precision
extended: intermediate results use extended precision
Reviewed By: Aaron Ballman
Differential Revision: https://reviews.llvm.org/D93769
Make Clang on aarch64 targets predefine `__AARCH64_CMODEL_SMALL__`
or `__AARCH64_CMODEL_TINY__`, etc. These are the names that GCC
uses for its predefines.
Reviewed By: tamur, MaskRay
Differential Revision: https://reviews.llvm.org/D75002
Jolanta Jensen