git: 0bbd0daf4ee5 - stable/12 - Remove unnecessary const and volatile qualifiers from __fp_type_select()

The branch stable/12 has been updated by dim:

URL: https://cgit.FreeBSD.org/src/commit/?id=0bbd0daf4ee5b4b7b8ec7650f2c65c499c0d103d

commit 0bbd0daf4ee5b4b7b8ec7650f2c65c499c0d103d
Author:     Dimitry Andric <dim@FreeBSD.org>
AuthorDate: 2022-07-14 11:20:52 +0000
Commit:     Dimitry Andric <dim@FreeBSD.org>
CommitDate: 2022-07-23 08:57:42 +0000

    Remove unnecessary const and volatile qualifiers from __fp_type_select()
    
    Since https://github.com/llvm/llvm-project/commit/ca75ac5f04f2, clang 15
    has a new warning about _Generic selection expressions, such as used in
    math.h:
    
        lib/libc/gdtoa/_ldtoa.c:82:10: error: due to lvalue conversion of the controlling expression, association of type 'volatile float' will never be selected because it is qualified [-Werror,-Wunreachable-code-generic-assoc]
                switch (fpclassify(u.e)) {
                        ^
        lib/msun/src/math.h:109:2: note: expanded from macro 'fpclassify'
                __fp_type_select(x, __fpclassifyf, __fpclassifyd, __fpclassifyl)
                ^
        lib/msun/src/math.h:85:14: note: expanded from macro '__fp_type_select'
            volatile float: f(x),                                               \
                     ^
    
    This is because the controlling expression always undergoes lvalue
    conversion first, dropping any cv-qualifiers. The 'const', 'volatile',
    and 'volatile const' associations will therefore never be used.
    
    MFC after:      1 week
    Reviewed by:    theraven
    Differential Revision: https://reviews.freebsd.org/D35815
    
    (cherry picked from commit e50027e38d4f93887691f87b024e0abf37e98c78)
---
 lib/msun/src/math.h | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/lib/msun/src/math.h b/lib/msun/src/math.h
index 2a42c14c6cc2..95dc62e9b50b 100644
--- a/lib/msun/src/math.h
+++ b/lib/msun/src/math.h
@@ -81,16 +81,7 @@ extern const union __nan_un {
 #define	__fp_type_select(x, f, d, ld) __extension__ _Generic((x),	\
     float: f(x),							\
     double: d(x),							\
-    long double: ld(x),							\
-    volatile float: f(x),						\
-    volatile double: d(x),						\
-    volatile long double: ld(x),					\
-    volatile const float: f(x),						\
-    volatile const double: d(x),					\
-    volatile const long double: ld(x),					\
-    const float: f(x),							\
-    const double: d(x),							\
-    const long double: ld(x))
+    long double: ld(x))
 #elif __GNUC_PREREQ__(3, 1) && !defined(__cplusplus)
 #define	__fp_type_select(x, f, d, ld) __builtin_choose_expr(		\
     __builtin_types_compatible_p(__typeof(x), long double), ld(x),	\