CVS commit: [netbsd-10] src

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Sun Oct 13 15:05:18 UTC 2024

Modified Files:
        src/distrib/sets/lists/debug [netbsd-10]: mi
        src/distrib/sets/lists/tests [netbsd-10]: mi
        src/lib/libm/src [netbsd-10]: s_nexttoward.c
        src/tests/lib/libm [netbsd-10]: Makefile
Added Files:
        src/tests/lib/libm [netbsd-10]: t_next.c

Log Message:
Pull up following revision(s) (requested by riastradh in ticket #963):

        tests/lib/libm/Makefile: revision 1.49
        distrib/sets/lists/tests/mi: revision 1.1315
        tests/lib/libm/t_next.c: revision 1.1
        tests/lib/libm/t_next.c: revision 1.2
        distrib/sets/lists/debug/mi: revision 1.435
        tests/lib/libm/t_next.c: revision 1.3
        tests/lib/libm/t_next.c: revision 1.4
        tests/lib/libm/t_next.c: revision 1.5
        tests/lib/libm/t_next.c: revision 1.6
        lib/libm/src/s_nexttoward.c: revision 1.3

tests/lib/libm: Test nextafter/nexttoward and variants.

The tests are fairly trivial but should work without any conditionals
about floating-point formats.
tests/lib/libm/t_next: Disable this test on VAX.

But leave a replacement xfail test that fails unconditionally, to
leave a reminder in the tests of PR 57881: vax libm is missing
various symbols.

tests/lib/libm/t_next: Fix stub on VAX.
Tested building the wrong tree, oops.

tests/lib/libm/t_next: Expand substantially.

This covers many more potential problem areas -- and includes a new
xfail test for PR lib/58236: nexttoward(3) is broken on subnormals.
tests/lib/libm/t_next: nexttoward works if it's just nextafter.

It's broken on platforms where long double and double aren't the same
and nexttoward isn't an alias for nextafter.
nexttoward(3): Fix high-word test on small positive subnormals.

By this point in the logic, x can't be zero, so it's either positive
or negative.

The high word hx, however, can be zero, when x is a small positive
subnormal.  This means x is a small positive subnormal, so if x > y
we are computing nextDown, and if x < y we are computing nextUp.
hx is a (signed 32-bit) integer, not a double floating-point number,
so it's a little silly to compare hx > 0.0.  But that on its own
isn't enough to trigger the bug because all signed 32-bit integers
can be represented by double on all NetBSD architectures.
PR lib/58236


To generate a diff of this commit:
cvs rdiff -u -r1.394.2.12 -r1.394.2.13 src/distrib/sets/lists/debug/mi
cvs rdiff -u -r1.1238.2.14 -r1.1238.2.15 src/distrib/sets/lists/tests/mi
cvs rdiff -u -r1.2 -r1.2.36.1 src/lib/libm/src/s_nexttoward.c
cvs rdiff -u -r1.48.2.2 -r1.48.2.3 src/tests/lib/libm/Makefile
cvs rdiff -u -r0 -r1.7.4.2 src/tests/lib/libm/t_next.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.