1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/patches/glibc/2_9/180-math-tests.patch	Mon Feb 02 22:00:18 2009 +0000
     1.3 @@ -0,0 +1,72 @@
     1.4 +Original patch from: gentoo/src/patchsets/glibc/2.9/0090_all_glibc-math-tests.patch
     1.5 +
     1.6 +-= BEGIN original header =-
     1.7 +From: "Joseph S. Myers" <joseph at codesourcery dot com>
     1.8 +To: libc-alpha at sourceware dot org
     1.9 +Date: Tue, 15 Jul 2008 14:43:04 +0000 (UTC)
    1.10 +Subject: expm1 ulps
    1.11 +
    1.12 +If you test glibc on i686 with GCC 4.3, you get a test-ildoubl failure:
    1.13 +
    1.14 +Failure: Test: expm1 (1) == M_El - 1.0
    1.15 +Result:
    1.16 + is:          1.71828182845904523532e+00   0xd.bf0a8b14576953500000p-3
    1.17 + should be:   1.71828182845904523543e+00   0xd.bf0a8b14576953600000p-3
    1.18 + difference:  1.08420217248550443401e-19   0x8.00000000000000000000p-66
    1.19 + ulp       :  1.0000
    1.20 + max.ulp   :  0.0000
    1.21 +Maximal error of `expm1'
    1.22 + is      : 1 ulp
    1.23 + accepted: 0 ulp
    1.24 +
    1.25 +What happens is that the inline expansion of expm1l uses __builtin_expm1l,
    1.26 +and GCC 4.3 optimizes calls to __builtin_expm1l with constant argument to
    1.27 +a correctly rounded result using MPFR.  The result returned is thus the
    1.28 +value of e-1 rounded once to long double precision.  However, the test
    1.29 +expects M_El - 1.0, and the result of rounding e to long double precision,
    1.30 +then subtracting 1, differs in the last place from the result of rounding
    1.31 +e-1 to long double precision (the latter has smaller exponent, and the
    1.32 +last bit is 1).
    1.33 +
    1.34 +There are two obvious approaches possible to fixing this.  The first patch
    1.35 +below changes the expectation to a decimal expansion for e-1 (taken from
    1.36 +that of M_El) rather than doing arithmetic in the expected value.  This in
    1.37 +turn requires ulps to be set for the out-of-line version of expm1.  It
    1.38 +might also need ulps to be set for the inline version for older compilers
    1.39 +if they should continue to pass the test, and possibly for other targets.
    1.40 +The second patch below takes the alternative approach of keeping the
    1.41 +existing expectation (which has the wrong bit in the last place) and
    1.42 +setting ulps for the inline expansion of expm1, which avoids the risk of
    1.43 +breaking the test for other targets.
    1.44 +
    1.45 +2008-07-15  Joseph Myers  <joseph@codesourcery.com>
    1.46 +
    1.47 +        * sysdeps/i386/fpu/libm-test-ulps: Add inline long double ulps for
    1.48 +        expm1.
    1.49 +
    1.50 +-= END original header =-
    1.51 +
    1.52 +diff -durN glibc-2_9.orig/sysdeps/i386/fpu/libm-test-ulps glibc-2_9/sysdeps/i386/fpu/libm-test-ulps
    1.53 +--- glibc-2_9.orig/sysdeps/i386/fpu/libm-test-ulps	2006-01-15 18:59:37.000000000 +0100
    1.54 ++++ glibc-2_9/sysdeps/i386/fpu/libm-test-ulps	2009-02-02 22:00:47.000000000 +0100
    1.55 +@@ -453,6 +453,10 @@
    1.56 + ildouble: 8
    1.57 + ldouble: 8
    1.58 + 
    1.59 ++# expm1
    1.60 ++Test "expm1 (1) == M_El - 1.0":
    1.61 ++ildouble: 1
    1.62 ++
    1.63 + # gamma
    1.64 + Test "gamma (-0.5) == log(2*sqrt(pi))":
    1.65 + double: 1
    1.66 +@@ -1134,6 +1138,9 @@
    1.67 + ildouble: 8
    1.68 + ldouble: 8
    1.69 + 
    1.70 ++Function: "expm1":
    1.71 ++ildouble: 1
    1.72 ++
    1.73 + Function: "gamma":
    1.74 + double: 1
    1.75 + idouble: 1