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| author | Joseph Myers <joseph@codesourcery.com> | 2014-01-03 02:05:44 +0000 |
|---|---|---|
| committer | Joseph Myers <jsm28@gcc.gnu.org> | 2014-01-03 02:05:44 +0000 |
| commit | a02e7bddb8b6e631048c93a7463278f6079532a2 (patch) | |
| tree | 600f5ab6116c9a7fad8b0f87b548b842bbf02f7f | |
| parent | 927734cfafbc115c51401621f37d17b56b162d2a (diff) | |
| download | gcc-a02e7bddb8b6e631048c93a7463278f6079532a2.zip gcc-a02e7bddb8b6e631048c93a7463278f6079532a2.tar.gz gcc-a02e7bddb8b6e631048c93a7463278f6079532a2.tar.bz2 | |
ibm-ldouble.c (__gcc_qdiv): Scale up arguments in case of small numerator and finite nonzero result.
libgcc:
* config/rs6000/ibm-ldouble.c (__gcc_qdiv): Scale up arguments in
case of small numerator and finite nonzero result.
gcc/testsuite:
* gcc.target/powerpc/rs6000-ldouble-3.c: New test.
From-SVN: r206310
| -rw-r--r-- | gcc/testsuite/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/powerpc/rs6000-ldouble-3.c | 21 | ||||
| -rw-r--r-- | libgcc/ChangeLog | 5 | ||||
| -rw-r--r-- | libgcc/config/rs6000/ibm-ldouble.c | 11 |
4 files changed, 40 insertions, 1 deletions
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 359421a..ebc453d 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2014-01-02 Joseph Myers <joseph@codesourcery.com> + + * gcc.target/powerpc/rs6000-ldouble-3.c: New test. + 2014-01-02 Marc Glisse <marc.glisse@inria.fr> PR c++/59641 diff --git a/gcc/testsuite/gcc.target/powerpc/rs6000-ldouble-3.c b/gcc/testsuite/gcc.target/powerpc/rs6000-ldouble-3.c new file mode 100644 index 0000000..1c78052 --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/rs6000-ldouble-3.c @@ -0,0 +1,21 @@ +/* Test accuracy of long double division (glibc bug 15396). */ +/* { dg-do run { target powerpc*-*-linux* powerpc*-*-darwin* powerpc*-*-aix* rs6000-*-* } } */ +/* { dg-options "-mlong-double-128" } */ + +extern void exit (int); +extern void abort (void); + +volatile long double a = 0x1p-1024L; +volatile long double b = 0x3p-53L; +volatile long double r; +volatile long double expected = 0x1.55555555555555555555555555p-973L; + +int +main (void) +{ + r = a / b; + /* Allow error up to 2ulp. */ + if (__builtin_fabsl (r - expected) > 0x1p-1073L) + abort (); + exit (0); +} diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index 0c32652..7fc4bd0 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,8 @@ +2014-01-02 Joseph Myers <joseph@codesourcery.com> + + * config/rs6000/ibm-ldouble.c (__gcc_qdiv): Scale up arguments in + case of small numerator and finite nonzero result. + 2014-01-02 Richard Sandiford <rdsandiford@googlemail.com> Update copyright years diff --git a/libgcc/config/rs6000/ibm-ldouble.c b/libgcc/config/rs6000/ibm-ldouble.c index 089de7d..abcd3c5 100644 --- a/libgcc/config/rs6000/ibm-ldouble.c +++ b/libgcc/config/rs6000/ibm-ldouble.c @@ -190,7 +190,16 @@ __gcc_qdiv (double a, double b, double c, double d) || nonfinite (t)) return t; - /* Finite nonzero result requires corrections to the highest order term. */ + /* Finite nonzero result requires corrections to the highest order + term. These corrections require the low part of c * t to be + exactly represented in double. */ + if (fabs (a) <= 0x1p-969) + { + a *= 0x1p106; + b *= 0x1p106; + c *= 0x1p106; + d *= 0x1p106; + } s = c * t; /* (s,sigma) = c*t exactly. */ w = -(-b + d * t); /* Written to get fnmsub for speed, but not |