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Fix ldbl-128 j1l spurious underflows (bug 18612).

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The ldbl-128 implementation of j1l produces spurious underflow
exceptions for some small arguments, as a result of squaring the
argument.  This patch fixes it just to use a linear approximation for
sufficiently small arguments, and then to force an underflow exception
only in the cases where it is required.

Tested for mips64.

	[BZ #18612]
	* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_j1l): For small
	arguments, just return 0.5 times the argument, with underflow
	forced as needed.
	* math/auto-libm-test-in: Add more tests of j1.
	* math/auto-libm-test-out: Regenerated.
This commit is contained in:
Joseph Myers 2015-06-29 17:51:32 +00:00
parent 63dbe5f322
commit 4aa10d01b6
5 changed files with 196 additions and 1 deletions
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7
ChangeLog
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@ -1,5 +1,12 @@
2015-06-29 Joseph Myers <joseph@codesourcery.com>
[BZ #18612]
* sysdeps/ieee754/ldbl-128/e_j1l.c (__ieee754_j1l): For small
arguments, just return 0.5 times the argument, with underflow
forced as needed.
* math/auto-libm-test-in: Add more tests of j1.
* math/auto-libm-test-out: Regenerated.
[BZ #16559]
* sysdeps/ieee754/dbl-64/e_j1.c: Include <float.h>.
(__ieee754_j1): Force underflow exception for small results.

2
NEWS
View File

@ -25,7 +25,7 @@ Version 2.22
18497, 18498, 18502, 18507, 18512, 18513, 18519, 18520, 18522, 18527,
18528, 18529, 18530, 18532, 18533, 18534, 18536, 18539, 18540, 18542,
18544, 18545, 18546, 18547, 18549, 18553, 18558, 18569, 18583, 18585,
18586, 18593, 18594, 18602.
18586, 18593, 18594, 18602, 18612.
* Cache information can be queried via sysconf() function on s390 e.g. with
_SC_LEVEL1_ICACHE_SIZE as argument.

3
math/auto-libm-test-in
View File

@ -1812,6 +1812,9 @@ j1 0x1.ff00000000002p+840
j1 0x1p1023
j1 0x1p16382
j1 0x1p16383
j1 0x1p-100
j1 0x1p-600
j1 0x1p-10000
# Bug 18611: errno setting may be missing.
j1 min missing-errno
j1 -min missing-errno

175
math/auto-libm-test-out
View File

@ -142437,6 +142437,181 @@ j1 0x1p16383
= j1 tonearest ldbl-128ibm 0xf.ffffffffffffbffffffffffffcp+1020L : -0x5.34b8be56c9cb044a0ef191b026p-516L : inexact-ok
= j1 towardzero ldbl-128ibm 0xf.ffffffffffffbffffffffffffcp+1020L : -0x5.34b8be56c9cb044a0ef191b024p-516L : inexact-ok
= j1 upward ldbl-128ibm 0xf.ffffffffffffbffffffffffffcp+1020L : -0x5.34b8be56c9cb044a0ef191b024p-516L : inexact-ok
j1 0x1p-100
= j1 downward flt-32 0x1p-100f : 0x7.fffff8p-104f : inexact-ok
= j1 tonearest flt-32 0x1p-100f : 0x8p-104f : inexact-ok
= j1 towardzero flt-32 0x1p-100f : 0x7.fffff8p-104f : inexact-ok
= j1 upward flt-32 0x1p-100f : 0x8p-104f : inexact-ok
= j1 downward dbl-64 0x1p-100 : 0x7.ffffffffffffcp-104 : inexact-ok
= j1 tonearest dbl-64 0x1p-100 : 0x8p-104 : inexact-ok
= j1 towardzero dbl-64 0x1p-100 : 0x7.ffffffffffffcp-104 : inexact-ok
= j1 upward dbl-64 0x1p-100 : 0x8p-104 : inexact-ok
= j1 downward ldbl-96-intel 0x1p-100L : 0x7.fffffffffffffff8p-104L : inexact-ok
= j1 tonearest ldbl-96-intel 0x1p-100L : 0x8p-104L : inexact-ok
= j1 towardzero ldbl-96-intel 0x1p-100L : 0x7.fffffffffffffff8p-104L : inexact-ok
= j1 upward ldbl-96-intel 0x1p-100L : 0x8p-104L : inexact-ok
= j1 downward ldbl-96-m68k 0x1p-100L : 0x7.fffffffffffffff8p-104L : inexact-ok
= j1 tonearest ldbl-96-m68k 0x1p-100L : 0x8p-104L : inexact-ok
= j1 towardzero ldbl-96-m68k 0x1p-100L : 0x7.fffffffffffffff8p-104L : inexact-ok
= j1 upward ldbl-96-m68k 0x1p-100L : 0x8p-104L : inexact-ok
= j1 downward ldbl-128 0x1p-100L : 0x7.fffffffffffffffffffffffffffcp-104L : inexact-ok
= j1 tonearest ldbl-128 0x1p-100L : 0x8p-104L : inexact-ok
= j1 towardzero ldbl-128 0x1p-100L : 0x7.fffffffffffffffffffffffffffcp-104L : inexact-ok
= j1 upward ldbl-128 0x1p-100L : 0x8p-104L : inexact-ok
= j1 downward ldbl-128ibm 0x1p-100L : 0x7.fffffffffffffffffffffffffep-104L : inexact-ok
= j1 tonearest ldbl-128ibm 0x1p-100L : 0x8p-104L : inexact-ok
= j1 towardzero ldbl-128ibm 0x1p-100L : 0x7.fffffffffffffffffffffffffep-104L : inexact-ok
= j1 upward ldbl-128ibm 0x1p-100L : 0x8p-104L : inexact-ok
j1 0x1p-600
= j1 downward flt-32 0x8p-152f : 0x0p+0f : inexact-ok underflow errno-erange
= j1 tonearest flt-32 0x8p-152f : 0x0p+0f : inexact-ok underflow errno-erange
= j1 towardzero flt-32 0x8p-152f : 0x0p+0f : inexact-ok underflow errno-erange
= j1 upward flt-32 0x8p-152f : 0x8p-152f : inexact-ok underflow errno-erange-ok
= j1 downward dbl-64 0x8p-152 : 0x3.ffffffffffffep-152 : inexact-ok
= j1 tonearest dbl-64 0x8p-152 : 0x4p-152 : inexact-ok
= j1 towardzero dbl-64 0x8p-152 : 0x3.ffffffffffffep-152 : inexact-ok
= j1 upward dbl-64 0x8p-152 : 0x4p-152 : inexact-ok
= j1 downward ldbl-96-intel 0x8p-152L : 0x3.fffffffffffffffcp-152L : inexact-ok
= j1 tonearest ldbl-96-intel 0x8p-152L : 0x4p-152L : inexact-ok
= j1 towardzero ldbl-96-intel 0x8p-152L : 0x3.fffffffffffffffcp-152L : inexact-ok
= j1 upward ldbl-96-intel 0x8p-152L : 0x4p-152L : inexact-ok
= j1 downward ldbl-96-m68k 0x8p-152L : 0x3.fffffffffffffffcp-152L : inexact-ok
= j1 tonearest ldbl-96-m68k 0x8p-152L : 0x4p-152L : inexact-ok
= j1 towardzero ldbl-96-m68k 0x8p-152L : 0x3.fffffffffffffffcp-152L : inexact-ok
= j1 upward ldbl-96-m68k 0x8p-152L : 0x4p-152L : inexact-ok
= j1 downward ldbl-128 0x8p-152L : 0x3.fffffffffffffffffffffffffffep-152L : inexact-ok
= j1 tonearest ldbl-128 0x8p-152L : 0x4p-152L : inexact-ok
= j1 towardzero ldbl-128 0x8p-152L : 0x3.fffffffffffffffffffffffffffep-152L : inexact-ok
= j1 upward ldbl-128 0x8p-152L : 0x4p-152L : inexact-ok
= j1 downward ldbl-128ibm 0x8p-152L : 0x3.ffffffffffffffffffffffffffp-152L : inexact-ok
= j1 tonearest ldbl-128ibm 0x8p-152L : 0x4p-152L : inexact-ok
= j1 towardzero ldbl-128ibm 0x8p-152L : 0x3.ffffffffffffffffffffffffffp-152L : inexact-ok
= j1 upward ldbl-128ibm 0x8p-152L : 0x4p-152L : inexact-ok
= j1 downward flt-32 0x0p+0f : 0x0p+0f : inexact-ok
= j1 tonearest flt-32 0x0p+0f : 0x0p+0f : inexact-ok
= j1 towardzero flt-32 0x0p+0f : 0x0p+0f : inexact-ok
= j1 upward flt-32 0x0p+0f : 0x0p+0f : inexact-ok
= j1 downward dbl-64 0x0p+0 : 0x0p+0 : inexact-ok
= j1 tonearest dbl-64 0x0p+0 : 0x0p+0 : inexact-ok
= j1 towardzero dbl-64 0x0p+0 : 0x0p+0 : inexact-ok
= j1 upward dbl-64 0x0p+0 : 0x0p+0 : inexact-ok
= j1 downward ldbl-96-intel 0x0p+0L : 0x0p+0L : inexact-ok
= j1 tonearest ldbl-96-intel 0x0p+0L : 0x0p+0L : inexact-ok
= j1 towardzero ldbl-96-intel 0x0p+0L : 0x0p+0L : inexact-ok
= j1 upward ldbl-96-intel 0x0p+0L : 0x0p+0L : inexact-ok
= j1 downward ldbl-96-m68k 0x0p+0L : 0x0p+0L : inexact-ok
= j1 tonearest ldbl-96-m68k 0x0p+0L : 0x0p+0L : inexact-ok
= j1 towardzero ldbl-96-m68k 0x0p+0L : 0x0p+0L : inexact-ok
= j1 upward ldbl-96-m68k 0x0p+0L : 0x0p+0L : inexact-ok
= j1 downward ldbl-128 0x0p+0L : 0x0p+0L : inexact-ok
= j1 tonearest ldbl-128 0x0p+0L : 0x0p+0L : inexact-ok
= j1 towardzero ldbl-128 0x0p+0L : 0x0p+0L : inexact-ok
= j1 upward ldbl-128 0x0p+0L : 0x0p+0L : inexact-ok
= j1 downward ldbl-128ibm 0x0p+0L : 0x0p+0L : inexact-ok
= j1 tonearest ldbl-128ibm 0x0p+0L : 0x0p+0L : inexact-ok
= j1 towardzero ldbl-128ibm 0x0p+0L : 0x0p+0L : inexact-ok
= j1 upward ldbl-128ibm 0x0p+0L : 0x0p+0L : inexact-ok
= j1 downward dbl-64 0x1p-600 : 0x7.ffffffffffffcp-604 : inexact-ok
= j1 tonearest dbl-64 0x1p-600 : 0x8p-604 : inexact-ok
= j1 towardzero dbl-64 0x1p-600 : 0x7.ffffffffffffcp-604 : inexact-ok
= j1 upward dbl-64 0x1p-600 : 0x8p-604 : inexact-ok
= j1 downward ldbl-96-intel 0x1p-600L : 0x7.fffffffffffffff8p-604L : inexact-ok
= j1 tonearest ldbl-96-intel 0x1p-600L : 0x8p-604L : inexact-ok
= j1 towardzero ldbl-96-intel 0x1p-600L : 0x7.fffffffffffffff8p-604L : inexact-ok
= j1 upward ldbl-96-intel 0x1p-600L : 0x8p-604L : inexact-ok
= j1 downward ldbl-96-m68k 0x1p-600L : 0x7.fffffffffffffff8p-604L : inexact-ok
= j1 tonearest ldbl-96-m68k 0x1p-600L : 0x8p-604L : inexact-ok
= j1 towardzero ldbl-96-m68k 0x1p-600L : 0x7.fffffffffffffff8p-604L : inexact-ok
= j1 upward ldbl-96-m68k 0x1p-600L : 0x8p-604L : inexact-ok
= j1 downward ldbl-128 0x1p-600L : 0x7.fffffffffffffffffffffffffffcp-604L : inexact-ok
= j1 tonearest ldbl-128 0x1p-600L : 0x8p-604L : inexact-ok
= j1 towardzero ldbl-128 0x1p-600L : 0x7.fffffffffffffffffffffffffffcp-604L : inexact-ok
= j1 upward ldbl-128 0x1p-600L : 0x8p-604L : inexact-ok
= j1 downward ldbl-128ibm 0x1p-600L : 0x7.fffffffffffffffffffffffffep-604L : inexact-ok
= j1 tonearest ldbl-128ibm 0x1p-600L : 0x8p-604L : inexact-ok
= j1 towardzero ldbl-128ibm 0x1p-600L : 0x7.fffffffffffffffffffffffffep-604L : inexact-ok
= j1 upward ldbl-128ibm 0x1p-600L : 0x8p-604L : inexact-ok
j1 0x1p-10000
= j1 downward flt-32 0x8p-152f : 0x0p+0f : inexact-ok underflow errno-erange
= j1 tonearest flt-32 0x8p-152f : 0x0p+0f : inexact-ok underflow errno-erange
= j1 towardzero flt-32 0x8p-152f : 0x0p+0f : inexact-ok underflow errno-erange
= j1 upward flt-32 0x8p-152f : 0x8p-152f : inexact-ok underflow errno-erange-ok
= j1 downward dbl-64 0x8p-152 : 0x3.ffffffffffffep-152 : inexact-ok
= j1 tonearest dbl-64 0x8p-152 : 0x4p-152 : inexact-ok
= j1 towardzero dbl-64 0x8p-152 : 0x3.ffffffffffffep-152 : inexact-ok
= j1 upward dbl-64 0x8p-152 : 0x4p-152 : inexact-ok
= j1 downward ldbl-96-intel 0x8p-152L : 0x3.fffffffffffffffcp-152L : inexact-ok
= j1 tonearest ldbl-96-intel 0x8p-152L : 0x4p-152L : inexact-ok
= j1 towardzero ldbl-96-intel 0x8p-152L : 0x3.fffffffffffffffcp-152L : inexact-ok
= j1 upward ldbl-96-intel 0x8p-152L : 0x4p-152L : inexact-ok
= j1 downward ldbl-96-m68k 0x8p-152L : 0x3.fffffffffffffffcp-152L : inexact-ok
= j1 tonearest ldbl-96-m68k 0x8p-152L : 0x4p-152L : inexact-ok
= j1 towardzero ldbl-96-m68k 0x8p-152L : 0x3.fffffffffffffffcp-152L : inexact-ok
= j1 upward ldbl-96-m68k 0x8p-152L : 0x4p-152L : inexact-ok
= j1 downward ldbl-128 0x8p-152L : 0x3.fffffffffffffffffffffffffffep-152L : inexact-ok
= j1 tonearest ldbl-128 0x8p-152L : 0x4p-152L : inexact-ok
= j1 towardzero ldbl-128 0x8p-152L : 0x3.fffffffffffffffffffffffffffep-152L : inexact-ok
= j1 upward ldbl-128 0x8p-152L : 0x4p-152L : inexact-ok
= j1 downward ldbl-128ibm 0x8p-152L : 0x3.ffffffffffffffffffffffffffp-152L : inexact-ok
= j1 tonearest ldbl-128ibm 0x8p-152L : 0x4p-152L : inexact-ok
= j1 towardzero ldbl-128ibm 0x8p-152L : 0x3.ffffffffffffffffffffffffffp-152L : inexact-ok
= j1 upward ldbl-128ibm 0x8p-152L : 0x4p-152L : inexact-ok
= j1 downward flt-32 0x0p+0f : 0x0p+0f : inexact-ok
= j1 tonearest flt-32 0x0p+0f : 0x0p+0f : inexact-ok
= j1 towardzero flt-32 0x0p+0f : 0x0p+0f : inexact-ok
= j1 upward flt-32 0x0p+0f : 0x0p+0f : inexact-ok
= j1 downward dbl-64 0x0p+0 : 0x0p+0 : inexact-ok
= j1 tonearest dbl-64 0x0p+0 : 0x0p+0 : inexact-ok
= j1 towardzero dbl-64 0x0p+0 : 0x0p+0 : inexact-ok
= j1 upward dbl-64 0x0p+0 : 0x0p+0 : inexact-ok
= j1 downward ldbl-96-intel 0x0p+0L : 0x0p+0L : inexact-ok
= j1 tonearest ldbl-96-intel 0x0p+0L : 0x0p+0L : inexact-ok
= j1 towardzero ldbl-96-intel 0x0p+0L : 0x0p+0L : inexact-ok
= j1 upward ldbl-96-intel 0x0p+0L : 0x0p+0L : inexact-ok
= j1 downward ldbl-96-m68k 0x0p+0L : 0x0p+0L : inexact-ok
= j1 tonearest ldbl-96-m68k 0x0p+0L : 0x0p+0L : inexact-ok
= j1 towardzero ldbl-96-m68k 0x0p+0L : 0x0p+0L : inexact-ok
= j1 upward ldbl-96-m68k 0x0p+0L : 0x0p+0L : inexact-ok
= j1 downward ldbl-128 0x0p+0L : 0x0p+0L : inexact-ok
= j1 tonearest ldbl-128 0x0p+0L : 0x0p+0L : inexact-ok
= j1 towardzero ldbl-128 0x0p+0L : 0x0p+0L : inexact-ok
= j1 upward ldbl-128 0x0p+0L : 0x0p+0L : inexact-ok
= j1 downward ldbl-128ibm 0x0p+0L : 0x0p+0L : inexact-ok
= j1 tonearest ldbl-128ibm 0x0p+0L : 0x0p+0L : inexact-ok
= j1 towardzero ldbl-128ibm 0x0p+0L : 0x0p+0L : inexact-ok
= j1 upward ldbl-128ibm 0x0p+0L : 0x0p+0L : inexact-ok
= j1 downward dbl-64 0x4p-1076 : 0x0p+0 : inexact-ok underflow errno-erange
= j1 tonearest dbl-64 0x4p-1076 : 0x0p+0 : inexact-ok underflow errno-erange
= j1 towardzero dbl-64 0x4p-1076 : 0x0p+0 : inexact-ok underflow errno-erange
= j1 upward dbl-64 0x4p-1076 : 0x4p-1076 : inexact-ok underflow errno-erange-ok
= j1 downward ldbl-96-intel 0x4p-1076L : 0x1.fffffffffffffffep-1076L : inexact-ok
= j1 tonearest ldbl-96-intel 0x4p-1076L : 0x2p-1076L : inexact-ok
= j1 towardzero ldbl-96-intel 0x4p-1076L : 0x1.fffffffffffffffep-1076L : inexact-ok
= j1 upward ldbl-96-intel 0x4p-1076L : 0x2p-1076L : inexact-ok
= j1 downward ldbl-96-m68k 0x4p-1076L : 0x1.fffffffffffffffep-1076L : inexact-ok
= j1 tonearest ldbl-96-m68k 0x4p-1076L : 0x2p-1076L : inexact-ok
= j1 towardzero ldbl-96-m68k 0x4p-1076L : 0x1.fffffffffffffffep-1076L : inexact-ok
= j1 upward ldbl-96-m68k 0x4p-1076L : 0x2p-1076L : inexact-ok
= j1 downward ldbl-128 0x4p-1076L : 0x1.ffffffffffffffffffffffffffffp-1076L : inexact-ok
= j1 tonearest ldbl-128 0x4p-1076L : 0x2p-1076L : inexact-ok
= j1 towardzero ldbl-128 0x4p-1076L : 0x1.ffffffffffffffffffffffffffffp-1076L : inexact-ok
= j1 upward ldbl-128 0x4p-1076L : 0x2p-1076L : inexact-ok
= j1 downward ldbl-128ibm 0x4p-1076L : 0x0p+0L : inexact-ok underflow errno-erange
= j1 tonearest ldbl-128ibm 0x4p-1076L : 0x0p+0L : inexact-ok underflow errno-erange
= j1 towardzero ldbl-128ibm 0x4p-1076L : 0x0p+0L : inexact-ok underflow errno-erange
= j1 upward ldbl-128ibm 0x4p-1076L : 0x4p-1076L : inexact-ok underflow errno-erange-ok
= j1 downward ldbl-96-intel 0x1p-10000L : 0x7.fffffffffffffff8p-10004L : inexact-ok
= j1 tonearest ldbl-96-intel 0x1p-10000L : 0x8p-10004L : inexact-ok
= j1 towardzero ldbl-96-intel 0x1p-10000L : 0x7.fffffffffffffff8p-10004L : inexact-ok
= j1 upward ldbl-96-intel 0x1p-10000L : 0x8p-10004L : inexact-ok
= j1 downward ldbl-96-m68k 0x1p-10000L : 0x7.fffffffffffffff8p-10004L : inexact-ok
= j1 tonearest ldbl-96-m68k 0x1p-10000L : 0x8p-10004L : inexact-ok
= j1 towardzero ldbl-96-m68k 0x1p-10000L : 0x7.fffffffffffffff8p-10004L : inexact-ok
= j1 upward ldbl-96-m68k 0x1p-10000L : 0x8p-10004L : inexact-ok
= j1 downward ldbl-128 0x1p-10000L : 0x7.fffffffffffffffffffffffffffcp-10004L : inexact-ok
= j1 tonearest ldbl-128 0x1p-10000L : 0x8p-10004L : inexact-ok
= j1 towardzero ldbl-128 0x1p-10000L : 0x7.fffffffffffffffffffffffffffcp-10004L : inexact-ok
= j1 upward ldbl-128 0x1p-10000L : 0x8p-10004L : inexact-ok
j1 min missing-errno
= j1 downward flt-32 0x4p-128f : 0x1.fffff8p-128f : inexact-ok underflow errno-erange-ok
= j1 tonearest flt-32 0x4p-128f : 0x2p-128f : inexact-ok underflow errno-erange-ok

10
sysdeps/ieee754/ldbl-128/e_j1l.c
View File

@ -697,6 +697,16 @@ __ieee754_j1l (long double x)
if (x == 0.0L)
return x;
xx = fabsl (x);
if (xx <= 0x1p-58L)
{
long double ret = x * 0.5L;
if (fabsl (ret) < LDBL_MIN)
{
long double force_underflow = ret * ret;
math_force_eval (force_underflow);
}
return ret;
}
if (xx <= 2.0L)
{
/* 0 <= x <= 2 */