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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/mips/math-emu/sp_sqrt.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/math-emu/sp_sqrt.c')
-rw-r--r-- | arch/mips/math-emu/sp_sqrt.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/mips/math-emu/sp_sqrt.c b/arch/mips/math-emu/sp_sqrt.c new file mode 100644 index 0000000000..e9bb60121d --- /dev/null +++ b/arch/mips/math-emu/sp_sqrt.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* IEEE754 floating point arithmetic + * single precision square root + */ +/* + * MIPS floating point support + * Copyright (C) 1994-2000 Algorithmics Ltd. + */ + +#include "ieee754sp.h" + +union ieee754sp ieee754sp_sqrt(union ieee754sp x) +{ + int ix, s, q, m, t, i; + unsigned int r; + COMPXSP; + + /* take care of Inf and NaN */ + + EXPLODEXSP; + ieee754_clearcx(); + FLUSHXSP; + + /* x == INF or NAN? */ + switch (xc) { + case IEEE754_CLASS_SNAN: + return ieee754sp_nanxcpt(x); + + case IEEE754_CLASS_QNAN: + /* sqrt(Nan) = Nan */ + return x; + + case IEEE754_CLASS_ZERO: + /* sqrt(0) = 0 */ + return x; + + case IEEE754_CLASS_INF: + if (xs) { + /* sqrt(-Inf) = Nan */ + ieee754_setcx(IEEE754_INVALID_OPERATION); + return ieee754sp_indef(); + } + /* sqrt(+Inf) = Inf */ + return x; + + case IEEE754_CLASS_DNORM: + case IEEE754_CLASS_NORM: + if (xs) { + /* sqrt(-x) = Nan */ + ieee754_setcx(IEEE754_INVALID_OPERATION); + return ieee754sp_indef(); + } + break; + } + + ix = x.bits; + + /* normalize x */ + m = (ix >> 23); + if (m == 0) { /* subnormal x */ + for (i = 0; (ix & 0x00800000) == 0; i++) + ix <<= 1; + m -= i - 1; + } + m -= 127; /* unbias exponent */ + ix = (ix & 0x007fffff) | 0x00800000; + if (m & 1) /* odd m, double x to make it even */ + ix += ix; + m >>= 1; /* m = [m/2] */ + + /* generate sqrt(x) bit by bit */ + ix += ix; + s = 0; + q = 0; /* q = sqrt(x) */ + r = 0x01000000; /* r = moving bit from right to left */ + + while (r != 0) { + t = s + r; + if (t <= ix) { + s = t + r; + ix -= t; + q += r; + } + ix += ix; + r >>= 1; + } + + if (ix != 0) { + ieee754_setcx(IEEE754_INEXACT); + switch (ieee754_csr.rm) { + case FPU_CSR_RU: + q += 2; + break; + case FPU_CSR_RN: + q += (q & 1); + break; + } + } + ix = (q >> 1) + 0x3f000000; + ix += (m << 23); + x.bits = ix; + return x; +} |