Fix powl inaccuracy for x86_64 and x86 (bug 13881).

1 files changed, 31 insertions, 4 deletions

diff --git a/math/libm-test.inc b/math/libm-test.inc
index c0265113ca..21590645f9 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -8431,7 +8431,6 @@ pow_test (void)
 #endif
   TEST_ff_f (pow, -min_value, max_value, plus_zero, UNDERFLOW_EXCEPTION);
 
-#ifndef TEST_LDOUBLE /* Bug 13881.  */
   TEST_ff_f (pow, 0x0.ffffffp0, 10, 0.999999403953712118183885036774764444747L);
   TEST_ff_f (pow, 0x0.ffffffp0, 100, 0.999994039553108359406305079606228341585L);
   TEST_ff_f (pow, 0x0.ffffffp0, 1000, 0.9999403971297699052276650144650733772182L);
@@ -8447,16 +8446,44 @@ pow_test (void)
   TEST_ff_f (pow, 0x1.000002p0, 0x1p24, 7.3890552180866447284268641248075832310141L);
   TEST_ff_f (pow, 0x1.000002p0, 0x1.234566p29, 4.2107033006507495188536371520637025716256e+31L);
   TEST_ff_f (pow, 0x1.000002p0, -0x1.234566p29, 2.3749001736727769098946062325205705312166e-32L);
-#endif
 
-  /* Bug 13881: powl inaccurate so these tests disabled for long double.  */
-#if !defined TEST_FLOAT && !defined TEST_LDOUBLE
+#if !defined TEST_FLOAT
   TEST_ff_f (pow, 0x0.fffffffffffff8p0L, 0x1.23456789abcdfp62L, 1.0118762747827252817436395051178295138220e-253L);
   TEST_ff_f (pow, 0x0.fffffffffffff8p0L, -0x1.23456789abcdfp62L, 9.8826311568054561811190162420900667121992e+252L);
   TEST_ff_f (pow, 0x1.0000000000001p0L, 0x1.23456789abcdfp61L, 9.8826311568044974397135026217687399395481e+252L);
   TEST_ff_f (pow, 0x1.0000000000001p0L, -0x1.23456789abcdfp61L, 1.0118762747828234466621210689458255908670e-253L);
 #endif
 
+#if defined TEST_LDOUBLE && LDBL_MANT_DIG >= 64 && LDBL_MAX_EXP >= 16384
+  TEST_ff_f (pow, 0x0.ffffffffffffffffp0L, 0x1.23456789abcdef0ep77L, 1.2079212226420368189981778807634890018840e-4048L);
+  TEST_ff_f (pow, 0x0.ffffffffffffffffp0L, -0x1.23456789abcdef0ep77L, 8.2786855736563746280496724205839522148001e+4047L);
+  TEST_ff_f (pow, 0x1.0000000000000002p0L, 0x1.23456789abcdef0ep76L, 8.2786855736563683535324500168799315131570e+4047L);
+  TEST_ff_f (pow, 0x1.0000000000000002p0L, -0x1.23456789abcdef0ep76L, 1.2079212226420377344964713407722652880280e-4048L);
+#endif
+
+#if defined TEST_LDOUBLE && LDBL_MANT_DIG >= 113
+  TEST_ff_f (pow, 0x0.ffffffffffffffffffffffffffff8p0L, 0x1.23456789abcdef0123456789abcdp126L, 1.2079212226420440237790185999151440179953e-4048L);
+  TEST_ff_f (pow, 0x0.ffffffffffffffffffffffffffff8p0L, -0x1.23456789abcdef0123456789abcdp126L, 8.2786855736563252489063231915535105363602e+4047L);
+  TEST_ff_f (pow, 0x1.0000000000000000000000000001p0L, 0x1.23456789abcdef0123456789abcdp125L, 8.2786855736563252489063231915423647547782e+4047L);
+  TEST_ff_f (pow, 0x1.0000000000000000000000000001p0L, -0x1.23456789abcdef0123456789abcdp125L, 1.2079212226420440237790185999167702696503e-4048L);
+#endif
+
+#if defined TEST_LDOUBLE && LDBL_MAX_EXP >= 16384
+  TEST_ff_f (pow, 1e4932L, 0.75L, 1e3699L);
+  TEST_ff_f (pow, 1e4928L, 0.75L, 1e3696L);
+  TEST_ff_f (pow, 1e4924L, 0.75L, 1e3693L);
+  TEST_ff_f (pow, 1e4920L, 0.75L, 1e3690L);
+  TEST_ff_f (pow, 10.0L, 4932.0L, 1e4932L);
+  TEST_ff_f (pow, 10.0L, 4931.0L, 1e4931L);
+  TEST_ff_f (pow, 10.0L, 4930.0L, 1e4930L);
+  TEST_ff_f (pow, 10.0L, 4929.0L, 1e4929L);
+  TEST_ff_f (pow, 10.0L, -4931.0L, 1e-4931L);
+  TEST_ff_f (pow, 10.0L, -4930.0L, 1e-4930L);
+  TEST_ff_f (pow, 10.0L, -4929.0L, 1e-4929L);
+  TEST_ff_f (pow, 1e27L, 182.0L, 1e4914L);
+  TEST_ff_f (pow, 1e27L, -182.0L, 1e-4914L);
+#endif
+
   TEST_ff_f (pow, min_subnorm_value, min_subnorm_value, 1.0L);
   TEST_ff_f (pow, min_subnorm_value, -min_subnorm_value, 1.0L);
   TEST_ff_f (pow, max_value, min_subnorm_value, 1.0L);