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fpu/softfloat: re-factor div

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We can now add float16_div and use the common decompose and
canonicalize functions to have a single implementation for
float16/32/64 versions.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Alex Bennée 2017-11-27 16:13:36 +00:00
parent 74d707e2cc
commit cf07323d49
3 changed files with 137 additions and 148 deletions
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48
fpu/softfloat-macros.h
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@ -625,6 +625,54 @@ static uint64_t estimateDiv128To64( uint64_t a0, uint64_t a1, uint64_t b )
}
/* From the GNU Multi Precision Library - longlong.h __udiv_qrnnd
* (https://gmplib.org/repo/gmp/file/tip/longlong.h)
*
* Licensed under the GPLv2/LGPLv3
*/
static uint64_t div128To64(uint64_t n0, uint64_t n1, uint64_t d)
{
uint64_t d0, d1, q0, q1, r1, r0, m;
d0 = (uint32_t)d;
d1 = d >> 32;
r1 = n1 % d1;
q1 = n1 / d1;
m = q1 * d0;
r1 = (r1 << 32) | (n0 >> 32);
if (r1 < m) {
q1 -= 1;
r1 += d;
if (r1 >= d) {
if (r1 < m) {
q1 -= 1;
r1 += d;
}
}
}
r1 -= m;
r0 = r1 % d1;
q0 = r1 / d1;
m = q0 * d0;
r0 = (r0 << 32) | (uint32_t)n0;
if (r0 < m) {
q0 -= 1;
r0 += d;
if (r0 >= d) {
if (r0 < m) {
q0 -= 1;
r0 += d;
}
}
}
r0 -= m;
/* Return remainder in LSB */
return (q1 << 32) | q0 | (r0 != 0);
}
/*----------------------------------------------------------------------------
| Returns an approximation to the square root of the 32-bit significand given
| by `a'. Considered as an integer, `a' must be at least 2^31. If bit 0 of