diff options
Diffstat (limited to 'toolchain/glibc/patches/2.26/0006-Let-fpclassify-use-the-builtin-when-optimizing-for-s.patch')
| -rw-r--r-- | toolchain/glibc/patches/2.26/0006-Let-fpclassify-use-the-builtin-when-optimizing-for-s.patch | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/toolchain/glibc/patches/2.26/0006-Let-fpclassify-use-the-builtin-when-optimizing-for-s.patch b/toolchain/glibc/patches/2.26/0006-Let-fpclassify-use-the-builtin-when-optimizing-for-s.patch new file mode 100644 index 000000000..37807c459 --- /dev/null +++ b/toolchain/glibc/patches/2.26/0006-Let-fpclassify-use-the-builtin-when-optimizing-for-s.patch @@ -0,0 +1,63 @@ +From 33f54cf4f81a51e5c8cbfb2408edd439bdee9435 Mon Sep 17 00:00:00 2001 +From: "Gabriel F. T. Gomes" <gabriel@inconstante.eti.br> +Date: Wed, 20 Sep 2017 15:10:26 -0300 +Subject: [PATCH] Let fpclassify use the builtin when optimizing for size in + C++ mode (bug 22146) + +When optimization for size is on (-Os), fpclassify does not use the +type-generic __builtin_fpclassify builtin, instead it uses __MATH_TG. +However, when library support for float128 is available, __MATH_TG uses +__builtin_types_compatible_p, which is not available in C++ mode. + +On the other hand, libstdc++ undefines (in cmath) many macros from +math.h, including fpclassify, so that it can provide its own functions. +However, during its configure tests, libstdc++ just tests for the +availability of the macros (it does not undefine them, nor does it +provide its own functions). + +Finally, when libstdc++ is configured with optimization for size +enabled, its configure tests include math.h and get the definition of +fpclassify that uses __MATH_TG (and __builtin_types_compatible_p). +Since libstdc++ does not undefine the macros during its configure tests, +they fail. + +This patch lets fpclassify use the builtin in C++ mode, even when +optimization for size is on. This allows the configure test in +libstdc++ to work. + +Tested for powerpc64le and x86_64. + + [BZ #22146] + math/math.h: Let fpclassify use the builtin in C++ mode, even + when optimazing for size. + +(cherry picked from commit c5c4a626098ec884b8527356abdf2a4bb7b6bf27) + +[Romain rebase on glibc 2.26) +Signed-off-by: Romain Naour <romain.naour@gmail.com> +--- + math/math.h | 8 +++++++- + 1 file changed, 7 insertions(+), 1 deletion(-) + +diff --git a/math/math.h b/math/math.h +index 7c0fc6d..f9348ec 100644 +--- a/math/math.h ++++ b/math/math.h +@@ -402,7 +402,13 @@ enum + + /* Return number of classification appropriate for X. */ + # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__ \ +- && !defined __OPTIMIZE_SIZE__ ++ && (!defined __OPTIMIZE_SIZE__ || defined __cplusplus) ++ /* The check for __cplusplus allows the use of the builtin, even ++ when optimization for size is on. This is provided for ++ libstdc++, only to let its configure test work when it is built ++ with -Os. No further use of this definition of fpclassify is ++ expected in C++ mode, since libstdc++ provides its own version ++ of fpclassify in cmath (which undefines fpclassify). */ + # define fpclassify(x) __builtin_fpclassify (FP_NAN, FP_INFINITE, \ + FP_NORMAL, FP_SUBNORMAL, FP_ZERO, x) + # else +-- +2.9.5 + |