diff options
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | NEWS | 24 | ||||
| -rw-r--r-- | math/libm-test.inc | 26 | ||||
| -rw-r--r-- | sysdeps/i386/fpu/e_pow.S | 53 | ||||
| -rw-r--r-- | sysdeps/x86_64/fpu/libm-test-ulps | 15 |
5 files changed, 112 insertions, 16 deletions
diff --git a/ChangeLog b/ChangeLog index 6154bb4da7..6c4bd0732a 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2012-04-09 Joseph Myers <joseph@codesourcery.com> + + [BZ #706] + * sysdeps/i386/fpu/e_pow.S (p10): New object. + (__ieee754_pow): Use iterative multiplication algorithm only for + integer exponents with absolute value below 1024. Check for odd + integer exponents when using algorithm for real exponents. + * math/libm-test.inc (pow_test): Add more tests. + * sysdeps/x86_64/fpu/libm-test-ulps: Update. + 2012-04-08 Joseph Myers <joseph@codesourcery.com> [BZ #13705] diff --git a/NEWS b/NEWS index d55fc294a0..5bd167709b 100644 --- a/NEWS +++ b/NEWS @@ -9,18 +9,18 @@ Version 2.16 * The following bugs are resolved with this release: - 174, 350, 369, 411, 2541, 2547, 2548, 2551, 2552, 2553, 2554, 2562, 2563, - 2565, 2566, 2576, 2678, 3335, 3866, 3868, 3976, 3992, 4026, 4108, 4596, - 4822, 5077, 5461, 5805, 5993, 6471, 6486, 6578, 6649, 6730, 6770, 6884, - 6890, 6895, 6907, 6911, 9739, 9902, 10110, 10135, 10140, 10153, 10210, - 10346, 10545, 10716, 11174, 11322, 11365, 11451, 11494, 12047, 12340, - 13058, 13525, 13526, 13527, 13528, 13529, 13530, 13531, 13532, 13533, - 13547, 13551, 13552, 13553, 13555, 13559, 13566, 13583, 13592, 13618, - 13637, 13656, 13658, 13673, 13691, 13695, 13704, 13705, 13706, 13726, - 13738, 13760, 13761, 13786, 13792, 13806, 13824, 13840, 13841, 13844, - 13846, 13851, 13852, 13854, 13871, 13879, 13883, 13892, 13895, 13908, - 13910, 13911, 13912, 13913, 13915, 13916, 13917, 13918, 13919, 13920, - 13921, 13926, 13928, 13938 + 174, 350, 369, 411, 706, 2541, 2547, 2548, 2551, 2552, 2553, 2554, 2562, + 2563, 2565, 2566, 2576, 2678, 3335, 3866, 3868, 3976, 3992, 4026, 4108, + 4596, 4822, 5077, 5461, 5805, 5993, 6471, 6486, 6578, 6649, 6730, 6770, + 6884, 6890, 6895, 6907, 6911, 9739, 9902, 10110, 10135, 10140, 10153, + 10210, 10346, 10545, 10716, 11174, 11322, 11365, 11451, 11494, 12047, + 12340, 13058, 13525, 13526, 13527, 13528, 13529, 13530, 13531, 13532, + 13533, 13547, 13551, 13552, 13553, 13555, 13559, 13566, 13583, 13592, + 13618, 13637, 13656, 13658, 13673, 13691, 13695, 13704, 13705, 13706, + 13726, 13738, 13760, 13761, 13786, 13792, 13806, 13824, 13840, 13841, + 13844, 13846, 13851, 13852, 13854, 13871, 13879, 13883, 13892, 13895, + 13908, 13910, 13911, 13912, 13913, 13915, 13916, 13917, 13918, 13919, + 13920, 13921, 13926, 13928, 13938 * ISO C11 support: diff --git a/math/libm-test.inc b/math/libm-test.inc index 35d014b72f..b9ff9f3ad2 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -6070,6 +6070,32 @@ pow_test (void) /* Bug 13872: spurious OVERFLOW exception may be present. */ TEST_ff_f (pow, -min_value, max_value, plus_zero, OVERFLOW_EXCEPTION_OK); +#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); + TEST_ff_f (pow, 0x0.ffffffp0, 0x1p24, 0.3678794302077803437135155590023422899744L); + TEST_ff_f (pow, 0x0.ffffffp0, 0x1p30, 1.603807831524924233828134753069728224044e-28L); + TEST_ff_f (pow, 0x0.ffffffp0, 0x1.234566p30, 2.374884712135295099971443365381007297732e-32L); + TEST_ff_f (pow, 0x0.ffffffp0, -10, 1.000000596046643153205170848674671339688L); + TEST_ff_f (pow, 0x0.ffffffp0, -100, 1.000005960482418779499387594989252621451L); + TEST_ff_f (pow, 0x0.ffffffp0, -1000, 1.000059606422943986382898964231519867906L); + TEST_ff_f (pow, 0x0.ffffffp0, -0x1p24, 2.7182819094701610539628664526874952929416L); + TEST_ff_f (pow, 0x0.ffffffp0, -0x1p30, 6.2351609734265057988914412331288163636075e+27L); + TEST_ff_f (pow, 0x0.ffffffp0, -0x1.234566p30, 4.2107307141696353498921307077142537353515e+31L); + 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 + 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 + END (pow); } diff --git a/sysdeps/i386/fpu/e_pow.S b/sysdeps/i386/fpu/e_pow.S index b61a946082..73d2421162 100644 --- a/sysdeps/i386/fpu/e_pow.S +++ b/sysdeps/i386/fpu/e_pow.S @@ -32,6 +32,9 @@ limit: .double 0.29 ASM_TYPE_DIRECTIVE(p63,@object) p63: .byte 0, 0, 0, 0, 0, 0, 0xe0, 0x43 ASM_SIZE_DIRECTIVE(p63) + ASM_TYPE_DIRECTIVE(p10,@object) +p10: .byte 0, 0, 0, 0, 0, 0, 0x90, 0x40 + ASM_SIZE_DIRECTIVE(p10) .section .rodata.cst16,"aM",@progbits,16 @@ -116,7 +119,15 @@ ENTRY(__ieee754_pow) sahf jne 3f - /* OK, we have an integer value for y. */ + /* OK, we have an integer value for y. If large enough that + errors may propagate out of the 11 bits excess precision, use + the algorithm for real exponent instead. */ + fld %st // y : y : x + fabs // |y| : y : x + fcompl MO(p10) // y : x + fnstsw + sahf + jnc 2f popl %eax cfi_adjust_cfa_offset (-4) popl %edx @@ -157,7 +168,9 @@ ENTRY(__ieee754_pow) cfi_adjust_cfa_offset (8) .align ALIGNARG(4) -2: /* y is a large integer (so even). */ +2: // y is a large integer (absolute value at least 1L<<10), but + // may be odd unless at least 1L<<64. So it may be necessary + // to adjust the sign of a negative result afterwards. fxch // x : y fabs // |x| : y fxch // y : x @@ -187,9 +200,41 @@ ENTRY(__ieee754_pow) f2xm1 // 2^fract(y*log2(x))-1 : int(y*log2(x)) faddl MO(one) // 2^fract(y*log2(x)) : int(y*log2(x)) fscale // 2^fract(y*log2(x))*2^int(y*log2(x)) : int(y*log2(x)) - addl $8, %esp - cfi_adjust_cfa_offset (-8) fstp %st(1) // 2^fract(y*log2(x))*2^int(y*log2(x)) + testb $2, %dh + jz 292f + // x is negative. If y is an odd integer, negate the result. + fldl 20(%esp) // y : abs(result) + fld %st // y : y : abs(result) + fabs // |y| : y : abs(result) + fcompl MO(p63) // y : abs(result) + fnstsw + sahf + jnc 291f + + // We must find out whether y is an odd integer. + fld %st // y : y : abs(result) + fistpll (%esp) // y : abs(result) + fildll (%esp) // int(y) : y : abs(result) + fucompp // abs(result) + fnstsw + sahf + jne 292f + + // OK, the value is an integer, but is it odd? + popl %eax + cfi_adjust_cfa_offset (-4) + popl %edx + cfi_adjust_cfa_offset (-4) + andb $1, %al + jz 290f // jump if not odd + // It's an odd integer. + fchs +290: ret + cfi_adjust_cfa_offset (8) +291: fstp %st(0) // abs(result) +292: addl $8, %esp + cfi_adjust_cfa_offset (-8) ret diff --git a/sysdeps/x86_64/fpu/libm-test-ulps b/sysdeps/x86_64/fpu/libm-test-ulps index d43955aff8..dce60cfb5b 100644 --- a/sysdeps/x86_64/fpu/libm-test-ulps +++ b/sysdeps/x86_64/fpu/libm-test-ulps @@ -1444,6 +1444,17 @@ Test "log1p (-0.25) == -0.287682072451780927439219005993827432": float: 1 ifloat: 1 +# pow +Test "pow (0x0.ffffffp0, -0x1p24) == 2.7182819094701610539628664526874952929416": +float: 1 +ifloat: 1 +Test "pow (0x0.ffffffp0, 0x1p24) == 0.3678794302077803437135155590023422899744": +float: 1 +ifloat: 1 +Test "pow (0x1.000002p0, 0x1p24) == 7.3890552180866447284268641248075832310141": +float: 1 +ifloat: 1 + # pow_downward Test "pow_downward (1.0625, 1.125) == 1.070582293028761362162622578677070098674": ildouble: 1 @@ -2413,6 +2424,10 @@ Function: "log1p": float: 1 ifloat: 1 +Function: "pow": +float: 1 +ifloat: 1 + Function: "pow_downward": float: 1 ifloat: 1 |