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1206 lines
28 KiB
1206 lines
28 KiB
/* |
|
* linux/arch/arm/vfp/vfpdouble.c |
|
* |
|
* This code is derived in part from John R. Housers softfloat library, which |
|
* carries the following notice: |
|
* |
|
* =========================================================================== |
|
* This C source file is part of the SoftFloat IEC/IEEE Floating-point |
|
* Arithmetic Package, Release 2. |
|
* |
|
* Written by John R. Hauser. This work was made possible in part by the |
|
* International Computer Science Institute, located at Suite 600, 1947 Center |
|
* Street, Berkeley, California 94704. Funding was partially provided by the |
|
* National Science Foundation under grant MIP-9311980. The original version |
|
* of this code was written as part of a project to build a fixed-point vector |
|
* processor in collaboration with the University of California at Berkeley, |
|
* overseen by Profs. Nelson Morgan and John Wawrzynek. More information |
|
* is available through the web page `http://HTTP.CS.Berkeley.EDU/~jhauser/ |
|
* arithmetic/softfloat.html'. |
|
* |
|
* THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort |
|
* has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT |
|
* TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO |
|
* PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY |
|
* AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE. |
|
* |
|
* Derivative works are acceptable, even for commercial purposes, so long as |
|
* (1) they include prominent notice that the work is derivative, and (2) they |
|
* include prominent notice akin to these three paragraphs for those parts of |
|
* this code that are retained. |
|
* =========================================================================== |
|
*/ |
|
#include <linux/kernel.h> |
|
#include <linux/bitops.h> |
|
|
|
#include <asm/div64.h> |
|
#include <asm/vfp.h> |
|
|
|
#include "vfpinstr.h" |
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#include "vfp.h" |
|
|
|
static struct vfp_double vfp_double_default_qnan = { |
|
.exponent = 2047, |
|
.sign = 0, |
|
.significand = VFP_DOUBLE_SIGNIFICAND_QNAN, |
|
}; |
|
|
|
static void vfp_double_dump(const char *str, struct vfp_double *d) |
|
{ |
|
pr_debug("VFP: %s: sign=%d exponent=%d significand=%016llx\n", |
|
str, d->sign != 0, d->exponent, d->significand); |
|
} |
|
|
|
static void vfp_double_normalise_denormal(struct vfp_double *vd) |
|
{ |
|
int bits = 31 - fls(vd->significand >> 32); |
|
if (bits == 31) |
|
bits = 63 - fls(vd->significand); |
|
|
|
vfp_double_dump("normalise_denormal: in", vd); |
|
|
|
if (bits) { |
|
vd->exponent -= bits - 1; |
|
vd->significand <<= bits; |
|
} |
|
|
|
vfp_double_dump("normalise_denormal: out", vd); |
|
} |
|
|
|
u32 vfp_double_normaliseround(int dd, struct vfp_double *vd, u32 fpscr, u32 exceptions, const char *func) |
|
{ |
|
u64 significand, incr; |
|
int exponent, shift, underflow; |
|
u32 rmode; |
|
|
|
vfp_double_dump("pack: in", vd); |
|
|
|
/* |
|
* Infinities and NaNs are a special case. |
|
*/ |
|
if (vd->exponent == 2047 && (vd->significand == 0 || exceptions)) |
|
goto pack; |
|
|
|
/* |
|
* Special-case zero. |
|
*/ |
|
if (vd->significand == 0) { |
|
vd->exponent = 0; |
|
goto pack; |
|
} |
|
|
|
exponent = vd->exponent; |
|
significand = vd->significand; |
|
|
|
shift = 32 - fls(significand >> 32); |
|
if (shift == 32) |
|
shift = 64 - fls(significand); |
|
if (shift) { |
|
exponent -= shift; |
|
significand <<= shift; |
|
} |
|
|
|
#ifdef DEBUG |
|
vd->exponent = exponent; |
|
vd->significand = significand; |
|
vfp_double_dump("pack: normalised", vd); |
|
#endif |
|
|
|
/* |
|
* Tiny number? |
|
*/ |
|
underflow = exponent < 0; |
|
if (underflow) { |
|
significand = vfp_shiftright64jamming(significand, -exponent); |
|
exponent = 0; |
|
#ifdef DEBUG |
|
vd->exponent = exponent; |
|
vd->significand = significand; |
|
vfp_double_dump("pack: tiny number", vd); |
|
#endif |
|
if (!(significand & ((1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1))) |
|
underflow = 0; |
|
} |
|
|
|
/* |
|
* Select rounding increment. |
|
*/ |
|
incr = 0; |
|
rmode = fpscr & FPSCR_RMODE_MASK; |
|
|
|
if (rmode == FPSCR_ROUND_NEAREST) { |
|
incr = 1ULL << VFP_DOUBLE_LOW_BITS; |
|
if ((significand & (1ULL << (VFP_DOUBLE_LOW_BITS + 1))) == 0) |
|
incr -= 1; |
|
} else if (rmode == FPSCR_ROUND_TOZERO) { |
|
incr = 0; |
|
} else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vd->sign != 0)) |
|
incr = (1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1; |
|
|
|
pr_debug("VFP: rounding increment = 0x%08llx\n", incr); |
|
|
|
/* |
|
* Is our rounding going to overflow? |
|
*/ |
|
if ((significand + incr) < significand) { |
|
exponent += 1; |
|
significand = (significand >> 1) | (significand & 1); |
|
incr >>= 1; |
|
#ifdef DEBUG |
|
vd->exponent = exponent; |
|
vd->significand = significand; |
|
vfp_double_dump("pack: overflow", vd); |
|
#endif |
|
} |
|
|
|
/* |
|
* If any of the low bits (which will be shifted out of the |
|
* number) are non-zero, the result is inexact. |
|
*/ |
|
if (significand & ((1 << (VFP_DOUBLE_LOW_BITS + 1)) - 1)) |
|
exceptions |= FPSCR_IXC; |
|
|
|
/* |
|
* Do our rounding. |
|
*/ |
|
significand += incr; |
|
|
|
/* |
|
* Infinity? |
|
*/ |
|
if (exponent >= 2046) { |
|
exceptions |= FPSCR_OFC | FPSCR_IXC; |
|
if (incr == 0) { |
|
vd->exponent = 2045; |
|
vd->significand = 0x7fffffffffffffffULL; |
|
} else { |
|
vd->exponent = 2047; /* infinity */ |
|
vd->significand = 0; |
|
} |
|
} else { |
|
if (significand >> (VFP_DOUBLE_LOW_BITS + 1) == 0) |
|
exponent = 0; |
|
if (exponent || significand > 0x8000000000000000ULL) |
|
underflow = 0; |
|
if (underflow) |
|
exceptions |= FPSCR_UFC; |
|
vd->exponent = exponent; |
|
vd->significand = significand >> 1; |
|
} |
|
|
|
pack: |
|
vfp_double_dump("pack: final", vd); |
|
{ |
|
s64 d = vfp_double_pack(vd); |
|
pr_debug("VFP: %s: d(d%d)=%016llx exceptions=%08x\n", func, |
|
dd, d, exceptions); |
|
vfp_put_double(d, dd); |
|
} |
|
return exceptions; |
|
} |
|
|
|
/* |
|
* Propagate the NaN, setting exceptions if it is signalling. |
|
* 'n' is always a NaN. 'm' may be a number, NaN or infinity. |
|
*/ |
|
static u32 |
|
vfp_propagate_nan(struct vfp_double *vdd, struct vfp_double *vdn, |
|
struct vfp_double *vdm, u32 fpscr) |
|
{ |
|
struct vfp_double *nan; |
|
int tn, tm = 0; |
|
|
|
tn = vfp_double_type(vdn); |
|
|
|
if (vdm) |
|
tm = vfp_double_type(vdm); |
|
|
|
if (fpscr & FPSCR_DEFAULT_NAN) |
|
/* |
|
* Default NaN mode - always returns a quiet NaN |
|
*/ |
|
nan = &vfp_double_default_qnan; |
|
else { |
|
/* |
|
* Contemporary mode - select the first signalling |
|
* NAN, or if neither are signalling, the first |
|
* quiet NAN. |
|
*/ |
|
if (tn == VFP_SNAN || (tm != VFP_SNAN && tn == VFP_QNAN)) |
|
nan = vdn; |
|
else |
|
nan = vdm; |
|
/* |
|
* Make the NaN quiet. |
|
*/ |
|
nan->significand |= VFP_DOUBLE_SIGNIFICAND_QNAN; |
|
} |
|
|
|
*vdd = *nan; |
|
|
|
/* |
|
* If one was a signalling NAN, raise invalid operation. |
|
*/ |
|
return tn == VFP_SNAN || tm == VFP_SNAN ? FPSCR_IOC : VFP_NAN_FLAG; |
|
} |
|
|
|
/* |
|
* Extended operations |
|
*/ |
|
static u32 vfp_double_fabs(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
vfp_put_double(vfp_double_packed_abs(vfp_get_double(dm)), dd); |
|
return 0; |
|
} |
|
|
|
static u32 vfp_double_fcpy(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
vfp_put_double(vfp_get_double(dm), dd); |
|
return 0; |
|
} |
|
|
|
static u32 vfp_double_fneg(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
vfp_put_double(vfp_double_packed_negate(vfp_get_double(dm)), dd); |
|
return 0; |
|
} |
|
|
|
static u32 vfp_double_fsqrt(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdm, vdd; |
|
int ret, tm; |
|
|
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
tm = vfp_double_type(&vdm); |
|
if (tm & (VFP_NAN|VFP_INFINITY)) { |
|
struct vfp_double *vdp = &vdd; |
|
|
|
if (tm & VFP_NAN) |
|
ret = vfp_propagate_nan(vdp, &vdm, NULL, fpscr); |
|
else if (vdm.sign == 0) { |
|
sqrt_copy: |
|
vdp = &vdm; |
|
ret = 0; |
|
} else { |
|
sqrt_invalid: |
|
vdp = &vfp_double_default_qnan; |
|
ret = FPSCR_IOC; |
|
} |
|
vfp_put_double(vfp_double_pack(vdp), dd); |
|
return ret; |
|
} |
|
|
|
/* |
|
* sqrt(+/- 0) == +/- 0 |
|
*/ |
|
if (tm & VFP_ZERO) |
|
goto sqrt_copy; |
|
|
|
/* |
|
* Normalise a denormalised number |
|
*/ |
|
if (tm & VFP_DENORMAL) |
|
vfp_double_normalise_denormal(&vdm); |
|
|
|
/* |
|
* sqrt(<0) = invalid |
|
*/ |
|
if (vdm.sign) |
|
goto sqrt_invalid; |
|
|
|
vfp_double_dump("sqrt", &vdm); |
|
|
|
/* |
|
* Estimate the square root. |
|
*/ |
|
vdd.sign = 0; |
|
vdd.exponent = ((vdm.exponent - 1023) >> 1) + 1023; |
|
vdd.significand = (u64)vfp_estimate_sqrt_significand(vdm.exponent, vdm.significand >> 32) << 31; |
|
|
|
vfp_double_dump("sqrt estimate1", &vdd); |
|
|
|
vdm.significand >>= 1 + (vdm.exponent & 1); |
|
vdd.significand += 2 + vfp_estimate_div128to64(vdm.significand, 0, vdd.significand); |
|
|
|
vfp_double_dump("sqrt estimate2", &vdd); |
|
|
|
/* |
|
* And now adjust. |
|
*/ |
|
if ((vdd.significand & VFP_DOUBLE_LOW_BITS_MASK) <= 5) { |
|
if (vdd.significand < 2) { |
|
vdd.significand = ~0ULL; |
|
} else { |
|
u64 termh, terml, remh, reml; |
|
vdm.significand <<= 2; |
|
mul64to128(&termh, &terml, vdd.significand, vdd.significand); |
|
sub128(&remh, &reml, vdm.significand, 0, termh, terml); |
|
while ((s64)remh < 0) { |
|
vdd.significand -= 1; |
|
shift64left(&termh, &terml, vdd.significand); |
|
terml |= 1; |
|
add128(&remh, &reml, remh, reml, termh, terml); |
|
} |
|
vdd.significand |= (remh | reml) != 0; |
|
} |
|
} |
|
vdd.significand = vfp_shiftright64jamming(vdd.significand, 1); |
|
|
|
return vfp_double_normaliseround(dd, &vdd, fpscr, 0, "fsqrt"); |
|
} |
|
|
|
/* |
|
* Equal := ZC |
|
* Less than := N |
|
* Greater than := C |
|
* Unordered := CV |
|
*/ |
|
static u32 vfp_compare(int dd, int signal_on_qnan, int dm, u32 fpscr) |
|
{ |
|
s64 d, m; |
|
u32 ret = 0; |
|
|
|
m = vfp_get_double(dm); |
|
if (vfp_double_packed_exponent(m) == 2047 && vfp_double_packed_mantissa(m)) { |
|
ret |= FPSCR_C | FPSCR_V; |
|
if (signal_on_qnan || !(vfp_double_packed_mantissa(m) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1)))) |
|
/* |
|
* Signalling NaN, or signalling on quiet NaN |
|
*/ |
|
ret |= FPSCR_IOC; |
|
} |
|
|
|
d = vfp_get_double(dd); |
|
if (vfp_double_packed_exponent(d) == 2047 && vfp_double_packed_mantissa(d)) { |
|
ret |= FPSCR_C | FPSCR_V; |
|
if (signal_on_qnan || !(vfp_double_packed_mantissa(d) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1)))) |
|
/* |
|
* Signalling NaN, or signalling on quiet NaN |
|
*/ |
|
ret |= FPSCR_IOC; |
|
} |
|
|
|
if (ret == 0) { |
|
if (d == m || vfp_double_packed_abs(d | m) == 0) { |
|
/* |
|
* equal |
|
*/ |
|
ret |= FPSCR_Z | FPSCR_C; |
|
} else if (vfp_double_packed_sign(d ^ m)) { |
|
/* |
|
* different signs |
|
*/ |
|
if (vfp_double_packed_sign(d)) |
|
/* |
|
* d is negative, so d < m |
|
*/ |
|
ret |= FPSCR_N; |
|
else |
|
/* |
|
* d is positive, so d > m |
|
*/ |
|
ret |= FPSCR_C; |
|
} else if ((vfp_double_packed_sign(d) != 0) ^ (d < m)) { |
|
/* |
|
* d < m |
|
*/ |
|
ret |= FPSCR_N; |
|
} else if ((vfp_double_packed_sign(d) != 0) ^ (d > m)) { |
|
/* |
|
* d > m |
|
*/ |
|
ret |= FPSCR_C; |
|
} |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static u32 vfp_double_fcmp(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
return vfp_compare(dd, 0, dm, fpscr); |
|
} |
|
|
|
static u32 vfp_double_fcmpe(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
return vfp_compare(dd, 1, dm, fpscr); |
|
} |
|
|
|
static u32 vfp_double_fcmpz(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
return vfp_compare(dd, 0, VFP_REG_ZERO, fpscr); |
|
} |
|
|
|
static u32 vfp_double_fcmpez(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
return vfp_compare(dd, 1, VFP_REG_ZERO, fpscr); |
|
} |
|
|
|
static u32 vfp_double_fcvts(int sd, int unused, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdm; |
|
struct vfp_single vsd; |
|
int tm; |
|
u32 exceptions = 0; |
|
|
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
|
|
tm = vfp_double_type(&vdm); |
|
|
|
/* |
|
* If we have a signalling NaN, signal invalid operation. |
|
*/ |
|
if (tm == VFP_SNAN) |
|
exceptions = FPSCR_IOC; |
|
|
|
if (tm & VFP_DENORMAL) |
|
vfp_double_normalise_denormal(&vdm); |
|
|
|
vsd.sign = vdm.sign; |
|
vsd.significand = vfp_hi64to32jamming(vdm.significand); |
|
|
|
/* |
|
* If we have an infinity or a NaN, the exponent must be 255 |
|
*/ |
|
if (tm & (VFP_INFINITY|VFP_NAN)) { |
|
vsd.exponent = 255; |
|
if (tm == VFP_QNAN) |
|
vsd.significand |= VFP_SINGLE_SIGNIFICAND_QNAN; |
|
goto pack_nan; |
|
} else if (tm & VFP_ZERO) |
|
vsd.exponent = 0; |
|
else |
|
vsd.exponent = vdm.exponent - (1023 - 127); |
|
|
|
return vfp_single_normaliseround(sd, &vsd, fpscr, exceptions, "fcvts"); |
|
|
|
pack_nan: |
|
vfp_put_float(vfp_single_pack(&vsd), sd); |
|
return exceptions; |
|
} |
|
|
|
static u32 vfp_double_fuito(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdm; |
|
u32 m = vfp_get_float(dm); |
|
|
|
vdm.sign = 0; |
|
vdm.exponent = 1023 + 63 - 1; |
|
vdm.significand = (u64)m; |
|
|
|
return vfp_double_normaliseround(dd, &vdm, fpscr, 0, "fuito"); |
|
} |
|
|
|
static u32 vfp_double_fsito(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdm; |
|
u32 m = vfp_get_float(dm); |
|
|
|
vdm.sign = (m & 0x80000000) >> 16; |
|
vdm.exponent = 1023 + 63 - 1; |
|
vdm.significand = vdm.sign ? -m : m; |
|
|
|
return vfp_double_normaliseround(dd, &vdm, fpscr, 0, "fsito"); |
|
} |
|
|
|
static u32 vfp_double_ftoui(int sd, int unused, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdm; |
|
u32 d, exceptions = 0; |
|
int rmode = fpscr & FPSCR_RMODE_MASK; |
|
int tm; |
|
|
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
|
|
/* |
|
* Do we have a denormalised number? |
|
*/ |
|
tm = vfp_double_type(&vdm); |
|
if (tm & VFP_DENORMAL) |
|
exceptions |= FPSCR_IDC; |
|
|
|
if (tm & VFP_NAN) |
|
vdm.sign = 0; |
|
|
|
if (vdm.exponent >= 1023 + 32) { |
|
d = vdm.sign ? 0 : 0xffffffff; |
|
exceptions = FPSCR_IOC; |
|
} else if (vdm.exponent >= 1023 - 1) { |
|
int shift = 1023 + 63 - vdm.exponent; |
|
u64 rem, incr = 0; |
|
|
|
/* |
|
* 2^0 <= m < 2^32-2^8 |
|
*/ |
|
d = (vdm.significand << 1) >> shift; |
|
rem = vdm.significand << (65 - shift); |
|
|
|
if (rmode == FPSCR_ROUND_NEAREST) { |
|
incr = 0x8000000000000000ULL; |
|
if ((d & 1) == 0) |
|
incr -= 1; |
|
} else if (rmode == FPSCR_ROUND_TOZERO) { |
|
incr = 0; |
|
} else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) { |
|
incr = ~0ULL; |
|
} |
|
|
|
if ((rem + incr) < rem) { |
|
if (d < 0xffffffff) |
|
d += 1; |
|
else |
|
exceptions |= FPSCR_IOC; |
|
} |
|
|
|
if (d && vdm.sign) { |
|
d = 0; |
|
exceptions |= FPSCR_IOC; |
|
} else if (rem) |
|
exceptions |= FPSCR_IXC; |
|
} else { |
|
d = 0; |
|
if (vdm.exponent | vdm.significand) { |
|
exceptions |= FPSCR_IXC; |
|
if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0) |
|
d = 1; |
|
else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign) { |
|
d = 0; |
|
exceptions |= FPSCR_IOC; |
|
} |
|
} |
|
} |
|
|
|
pr_debug("VFP: ftoui: d(s%d)=%08x exceptions=%08x\n", sd, d, exceptions); |
|
|
|
vfp_put_float(d, sd); |
|
|
|
return exceptions; |
|
} |
|
|
|
static u32 vfp_double_ftouiz(int sd, int unused, int dm, u32 fpscr) |
|
{ |
|
return vfp_double_ftoui(sd, unused, dm, FPSCR_ROUND_TOZERO); |
|
} |
|
|
|
static u32 vfp_double_ftosi(int sd, int unused, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdm; |
|
u32 d, exceptions = 0; |
|
int rmode = fpscr & FPSCR_RMODE_MASK; |
|
int tm; |
|
|
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
vfp_double_dump("VDM", &vdm); |
|
|
|
/* |
|
* Do we have denormalised number? |
|
*/ |
|
tm = vfp_double_type(&vdm); |
|
if (tm & VFP_DENORMAL) |
|
exceptions |= FPSCR_IDC; |
|
|
|
if (tm & VFP_NAN) { |
|
d = 0; |
|
exceptions |= FPSCR_IOC; |
|
} else if (vdm.exponent >= 1023 + 32) { |
|
d = 0x7fffffff; |
|
if (vdm.sign) |
|
d = ~d; |
|
exceptions |= FPSCR_IOC; |
|
} else if (vdm.exponent >= 1023 - 1) { |
|
int shift = 1023 + 63 - vdm.exponent; /* 58 */ |
|
u64 rem, incr = 0; |
|
|
|
d = (vdm.significand << 1) >> shift; |
|
rem = vdm.significand << (65 - shift); |
|
|
|
if (rmode == FPSCR_ROUND_NEAREST) { |
|
incr = 0x8000000000000000ULL; |
|
if ((d & 1) == 0) |
|
incr -= 1; |
|
} else if (rmode == FPSCR_ROUND_TOZERO) { |
|
incr = 0; |
|
} else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) { |
|
incr = ~0ULL; |
|
} |
|
|
|
if ((rem + incr) < rem && d < 0xffffffff) |
|
d += 1; |
|
if (d > 0x7fffffff + (vdm.sign != 0)) { |
|
d = 0x7fffffff + (vdm.sign != 0); |
|
exceptions |= FPSCR_IOC; |
|
} else if (rem) |
|
exceptions |= FPSCR_IXC; |
|
|
|
if (vdm.sign) |
|
d = -d; |
|
} else { |
|
d = 0; |
|
if (vdm.exponent | vdm.significand) { |
|
exceptions |= FPSCR_IXC; |
|
if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0) |
|
d = 1; |
|
else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign) |
|
d = -1; |
|
} |
|
} |
|
|
|
pr_debug("VFP: ftosi: d(s%d)=%08x exceptions=%08x\n", sd, d, exceptions); |
|
|
|
vfp_put_float((s32)d, sd); |
|
|
|
return exceptions; |
|
} |
|
|
|
static u32 vfp_double_ftosiz(int dd, int unused, int dm, u32 fpscr) |
|
{ |
|
return vfp_double_ftosi(dd, unused, dm, FPSCR_ROUND_TOZERO); |
|
} |
|
|
|
|
|
static struct op fops_ext[32] = { |
|
[FEXT_TO_IDX(FEXT_FCPY)] = { vfp_double_fcpy, 0 }, |
|
[FEXT_TO_IDX(FEXT_FABS)] = { vfp_double_fabs, 0 }, |
|
[FEXT_TO_IDX(FEXT_FNEG)] = { vfp_double_fneg, 0 }, |
|
[FEXT_TO_IDX(FEXT_FSQRT)] = { vfp_double_fsqrt, 0 }, |
|
[FEXT_TO_IDX(FEXT_FCMP)] = { vfp_double_fcmp, OP_SCALAR }, |
|
[FEXT_TO_IDX(FEXT_FCMPE)] = { vfp_double_fcmpe, OP_SCALAR }, |
|
[FEXT_TO_IDX(FEXT_FCMPZ)] = { vfp_double_fcmpz, OP_SCALAR }, |
|
[FEXT_TO_IDX(FEXT_FCMPEZ)] = { vfp_double_fcmpez, OP_SCALAR }, |
|
[FEXT_TO_IDX(FEXT_FCVT)] = { vfp_double_fcvts, OP_SCALAR|OP_SD }, |
|
[FEXT_TO_IDX(FEXT_FUITO)] = { vfp_double_fuito, OP_SCALAR|OP_SM }, |
|
[FEXT_TO_IDX(FEXT_FSITO)] = { vfp_double_fsito, OP_SCALAR|OP_SM }, |
|
[FEXT_TO_IDX(FEXT_FTOUI)] = { vfp_double_ftoui, OP_SCALAR|OP_SD }, |
|
[FEXT_TO_IDX(FEXT_FTOUIZ)] = { vfp_double_ftouiz, OP_SCALAR|OP_SD }, |
|
[FEXT_TO_IDX(FEXT_FTOSI)] = { vfp_double_ftosi, OP_SCALAR|OP_SD }, |
|
[FEXT_TO_IDX(FEXT_FTOSIZ)] = { vfp_double_ftosiz, OP_SCALAR|OP_SD }, |
|
}; |
|
|
|
|
|
|
|
|
|
static u32 |
|
vfp_double_fadd_nonnumber(struct vfp_double *vdd, struct vfp_double *vdn, |
|
struct vfp_double *vdm, u32 fpscr) |
|
{ |
|
struct vfp_double *vdp; |
|
u32 exceptions = 0; |
|
int tn, tm; |
|
|
|
tn = vfp_double_type(vdn); |
|
tm = vfp_double_type(vdm); |
|
|
|
if (tn & tm & VFP_INFINITY) { |
|
/* |
|
* Two infinities. Are they different signs? |
|
*/ |
|
if (vdn->sign ^ vdm->sign) { |
|
/* |
|
* different signs -> invalid |
|
*/ |
|
exceptions = FPSCR_IOC; |
|
vdp = &vfp_double_default_qnan; |
|
} else { |
|
/* |
|
* same signs -> valid |
|
*/ |
|
vdp = vdn; |
|
} |
|
} else if (tn & VFP_INFINITY && tm & VFP_NUMBER) { |
|
/* |
|
* One infinity and one number -> infinity |
|
*/ |
|
vdp = vdn; |
|
} else { |
|
/* |
|
* 'n' is a NaN of some type |
|
*/ |
|
return vfp_propagate_nan(vdd, vdn, vdm, fpscr); |
|
} |
|
*vdd = *vdp; |
|
return exceptions; |
|
} |
|
|
|
static u32 |
|
vfp_double_add(struct vfp_double *vdd, struct vfp_double *vdn, |
|
struct vfp_double *vdm, u32 fpscr) |
|
{ |
|
u32 exp_diff; |
|
u64 m_sig; |
|
|
|
if (vdn->significand & (1ULL << 63) || |
|
vdm->significand & (1ULL << 63)) { |
|
pr_info("VFP: bad FP values in %s\n", __func__); |
|
vfp_double_dump("VDN", vdn); |
|
vfp_double_dump("VDM", vdm); |
|
} |
|
|
|
/* |
|
* Ensure that 'n' is the largest magnitude number. Note that |
|
* if 'n' and 'm' have equal exponents, we do not swap them. |
|
* This ensures that NaN propagation works correctly. |
|
*/ |
|
if (vdn->exponent < vdm->exponent) { |
|
struct vfp_double *t = vdn; |
|
vdn = vdm; |
|
vdm = t; |
|
} |
|
|
|
/* |
|
* Is 'n' an infinity or a NaN? Note that 'm' may be a number, |
|
* infinity or a NaN here. |
|
*/ |
|
if (vdn->exponent == 2047) |
|
return vfp_double_fadd_nonnumber(vdd, vdn, vdm, fpscr); |
|
|
|
/* |
|
* We have two proper numbers, where 'vdn' is the larger magnitude. |
|
* |
|
* Copy 'n' to 'd' before doing the arithmetic. |
|
*/ |
|
*vdd = *vdn; |
|
|
|
/* |
|
* Align 'm' with the result. |
|
*/ |
|
exp_diff = vdn->exponent - vdm->exponent; |
|
m_sig = vfp_shiftright64jamming(vdm->significand, exp_diff); |
|
|
|
/* |
|
* If the signs are different, we are really subtracting. |
|
*/ |
|
if (vdn->sign ^ vdm->sign) { |
|
m_sig = vdn->significand - m_sig; |
|
if ((s64)m_sig < 0) { |
|
vdd->sign = vfp_sign_negate(vdd->sign); |
|
m_sig = -m_sig; |
|
} else if (m_sig == 0) { |
|
vdd->sign = (fpscr & FPSCR_RMODE_MASK) == |
|
FPSCR_ROUND_MINUSINF ? 0x8000 : 0; |
|
} |
|
} else { |
|
m_sig += vdn->significand; |
|
} |
|
vdd->significand = m_sig; |
|
|
|
return 0; |
|
} |
|
|
|
static u32 |
|
vfp_double_multiply(struct vfp_double *vdd, struct vfp_double *vdn, |
|
struct vfp_double *vdm, u32 fpscr) |
|
{ |
|
vfp_double_dump("VDN", vdn); |
|
vfp_double_dump("VDM", vdm); |
|
|
|
/* |
|
* Ensure that 'n' is the largest magnitude number. Note that |
|
* if 'n' and 'm' have equal exponents, we do not swap them. |
|
* This ensures that NaN propagation works correctly. |
|
*/ |
|
if (vdn->exponent < vdm->exponent) { |
|
struct vfp_double *t = vdn; |
|
vdn = vdm; |
|
vdm = t; |
|
pr_debug("VFP: swapping M <-> N\n"); |
|
} |
|
|
|
vdd->sign = vdn->sign ^ vdm->sign; |
|
|
|
/* |
|
* If 'n' is an infinity or NaN, handle it. 'm' may be anything. |
|
*/ |
|
if (vdn->exponent == 2047) { |
|
if (vdn->significand || (vdm->exponent == 2047 && vdm->significand)) |
|
return vfp_propagate_nan(vdd, vdn, vdm, fpscr); |
|
if ((vdm->exponent | vdm->significand) == 0) { |
|
*vdd = vfp_double_default_qnan; |
|
return FPSCR_IOC; |
|
} |
|
vdd->exponent = vdn->exponent; |
|
vdd->significand = 0; |
|
return 0; |
|
} |
|
|
|
/* |
|
* If 'm' is zero, the result is always zero. In this case, |
|
* 'n' may be zero or a number, but it doesn't matter which. |
|
*/ |
|
if ((vdm->exponent | vdm->significand) == 0) { |
|
vdd->exponent = 0; |
|
vdd->significand = 0; |
|
return 0; |
|
} |
|
|
|
/* |
|
* We add 2 to the destination exponent for the same reason |
|
* as the addition case - though this time we have +1 from |
|
* each input operand. |
|
*/ |
|
vdd->exponent = vdn->exponent + vdm->exponent - 1023 + 2; |
|
vdd->significand = vfp_hi64multiply64(vdn->significand, vdm->significand); |
|
|
|
vfp_double_dump("VDD", vdd); |
|
return 0; |
|
} |
|
|
|
#define NEG_MULTIPLY (1 << 0) |
|
#define NEG_SUBTRACT (1 << 1) |
|
|
|
static u32 |
|
vfp_double_multiply_accumulate(int dd, int dn, int dm, u32 fpscr, u32 negate, char *func) |
|
{ |
|
struct vfp_double vdd, vdp, vdn, vdm; |
|
u32 exceptions; |
|
|
|
vfp_double_unpack(&vdn, vfp_get_double(dn)); |
|
if (vdn.exponent == 0 && vdn.significand) |
|
vfp_double_normalise_denormal(&vdn); |
|
|
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
if (vdm.exponent == 0 && vdm.significand) |
|
vfp_double_normalise_denormal(&vdm); |
|
|
|
exceptions = vfp_double_multiply(&vdp, &vdn, &vdm, fpscr); |
|
if (negate & NEG_MULTIPLY) |
|
vdp.sign = vfp_sign_negate(vdp.sign); |
|
|
|
vfp_double_unpack(&vdn, vfp_get_double(dd)); |
|
if (vdn.exponent == 0 && vdn.significand) |
|
vfp_double_normalise_denormal(&vdn); |
|
if (negate & NEG_SUBTRACT) |
|
vdn.sign = vfp_sign_negate(vdn.sign); |
|
|
|
exceptions |= vfp_double_add(&vdd, &vdn, &vdp, fpscr); |
|
|
|
return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, func); |
|
} |
|
|
|
/* |
|
* Standard operations |
|
*/ |
|
|
|
/* |
|
* sd = sd + (sn * sm) |
|
*/ |
|
static u32 vfp_double_fmac(int dd, int dn, int dm, u32 fpscr) |
|
{ |
|
return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, 0, "fmac"); |
|
} |
|
|
|
/* |
|
* sd = sd - (sn * sm) |
|
*/ |
|
static u32 vfp_double_fnmac(int dd, int dn, int dm, u32 fpscr) |
|
{ |
|
return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_MULTIPLY, "fnmac"); |
|
} |
|
|
|
/* |
|
* sd = -sd + (sn * sm) |
|
*/ |
|
static u32 vfp_double_fmsc(int dd, int dn, int dm, u32 fpscr) |
|
{ |
|
return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT, "fmsc"); |
|
} |
|
|
|
/* |
|
* sd = -sd - (sn * sm) |
|
*/ |
|
static u32 vfp_double_fnmsc(int dd, int dn, int dm, u32 fpscr) |
|
{ |
|
return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT | NEG_MULTIPLY, "fnmsc"); |
|
} |
|
|
|
/* |
|
* sd = sn * sm |
|
*/ |
|
static u32 vfp_double_fmul(int dd, int dn, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdd, vdn, vdm; |
|
u32 exceptions; |
|
|
|
vfp_double_unpack(&vdn, vfp_get_double(dn)); |
|
if (vdn.exponent == 0 && vdn.significand) |
|
vfp_double_normalise_denormal(&vdn); |
|
|
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
if (vdm.exponent == 0 && vdm.significand) |
|
vfp_double_normalise_denormal(&vdm); |
|
|
|
exceptions = vfp_double_multiply(&vdd, &vdn, &vdm, fpscr); |
|
return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fmul"); |
|
} |
|
|
|
/* |
|
* sd = -(sn * sm) |
|
*/ |
|
static u32 vfp_double_fnmul(int dd, int dn, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdd, vdn, vdm; |
|
u32 exceptions; |
|
|
|
vfp_double_unpack(&vdn, vfp_get_double(dn)); |
|
if (vdn.exponent == 0 && vdn.significand) |
|
vfp_double_normalise_denormal(&vdn); |
|
|
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
if (vdm.exponent == 0 && vdm.significand) |
|
vfp_double_normalise_denormal(&vdm); |
|
|
|
exceptions = vfp_double_multiply(&vdd, &vdn, &vdm, fpscr); |
|
vdd.sign = vfp_sign_negate(vdd.sign); |
|
|
|
return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fnmul"); |
|
} |
|
|
|
/* |
|
* sd = sn + sm |
|
*/ |
|
static u32 vfp_double_fadd(int dd, int dn, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdd, vdn, vdm; |
|
u32 exceptions; |
|
|
|
vfp_double_unpack(&vdn, vfp_get_double(dn)); |
|
if (vdn.exponent == 0 && vdn.significand) |
|
vfp_double_normalise_denormal(&vdn); |
|
|
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
if (vdm.exponent == 0 && vdm.significand) |
|
vfp_double_normalise_denormal(&vdm); |
|
|
|
exceptions = vfp_double_add(&vdd, &vdn, &vdm, fpscr); |
|
|
|
return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fadd"); |
|
} |
|
|
|
/* |
|
* sd = sn - sm |
|
*/ |
|
static u32 vfp_double_fsub(int dd, int dn, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdd, vdn, vdm; |
|
u32 exceptions; |
|
|
|
vfp_double_unpack(&vdn, vfp_get_double(dn)); |
|
if (vdn.exponent == 0 && vdn.significand) |
|
vfp_double_normalise_denormal(&vdn); |
|
|
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
if (vdm.exponent == 0 && vdm.significand) |
|
vfp_double_normalise_denormal(&vdm); |
|
|
|
/* |
|
* Subtraction is like addition, but with a negated operand. |
|
*/ |
|
vdm.sign = vfp_sign_negate(vdm.sign); |
|
|
|
exceptions = vfp_double_add(&vdd, &vdn, &vdm, fpscr); |
|
|
|
return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fsub"); |
|
} |
|
|
|
/* |
|
* sd = sn / sm |
|
*/ |
|
static u32 vfp_double_fdiv(int dd, int dn, int dm, u32 fpscr) |
|
{ |
|
struct vfp_double vdd, vdn, vdm; |
|
u32 exceptions = 0; |
|
int tm, tn; |
|
|
|
vfp_double_unpack(&vdn, vfp_get_double(dn)); |
|
vfp_double_unpack(&vdm, vfp_get_double(dm)); |
|
|
|
vdd.sign = vdn.sign ^ vdm.sign; |
|
|
|
tn = vfp_double_type(&vdn); |
|
tm = vfp_double_type(&vdm); |
|
|
|
/* |
|
* Is n a NAN? |
|
*/ |
|
if (tn & VFP_NAN) |
|
goto vdn_nan; |
|
|
|
/* |
|
* Is m a NAN? |
|
*/ |
|
if (tm & VFP_NAN) |
|
goto vdm_nan; |
|
|
|
/* |
|
* If n and m are infinity, the result is invalid |
|
* If n and m are zero, the result is invalid |
|
*/ |
|
if (tm & tn & (VFP_INFINITY|VFP_ZERO)) |
|
goto invalid; |
|
|
|
/* |
|
* If n is infinity, the result is infinity |
|
*/ |
|
if (tn & VFP_INFINITY) |
|
goto infinity; |
|
|
|
/* |
|
* If m is zero, raise div0 exceptions |
|
*/ |
|
if (tm & VFP_ZERO) |
|
goto divzero; |
|
|
|
/* |
|
* If m is infinity, or n is zero, the result is zero |
|
*/ |
|
if (tm & VFP_INFINITY || tn & VFP_ZERO) |
|
goto zero; |
|
|
|
if (tn & VFP_DENORMAL) |
|
vfp_double_normalise_denormal(&vdn); |
|
if (tm & VFP_DENORMAL) |
|
vfp_double_normalise_denormal(&vdm); |
|
|
|
/* |
|
* Ok, we have two numbers, we can perform division. |
|
*/ |
|
vdd.exponent = vdn.exponent - vdm.exponent + 1023 - 1; |
|
vdm.significand <<= 1; |
|
if (vdm.significand <= (2 * vdn.significand)) { |
|
vdn.significand >>= 1; |
|
vdd.exponent++; |
|
} |
|
vdd.significand = vfp_estimate_div128to64(vdn.significand, 0, vdm.significand); |
|
if ((vdd.significand & 0x1ff) <= 2) { |
|
u64 termh, terml, remh, reml; |
|
mul64to128(&termh, &terml, vdm.significand, vdd.significand); |
|
sub128(&remh, &reml, vdn.significand, 0, termh, terml); |
|
while ((s64)remh < 0) { |
|
vdd.significand -= 1; |
|
add128(&remh, &reml, remh, reml, 0, vdm.significand); |
|
} |
|
vdd.significand |= (reml != 0); |
|
} |
|
return vfp_double_normaliseround(dd, &vdd, fpscr, 0, "fdiv"); |
|
|
|
vdn_nan: |
|
exceptions = vfp_propagate_nan(&vdd, &vdn, &vdm, fpscr); |
|
pack: |
|
vfp_put_double(vfp_double_pack(&vdd), dd); |
|
return exceptions; |
|
|
|
vdm_nan: |
|
exceptions = vfp_propagate_nan(&vdd, &vdm, &vdn, fpscr); |
|
goto pack; |
|
|
|
zero: |
|
vdd.exponent = 0; |
|
vdd.significand = 0; |
|
goto pack; |
|
|
|
divzero: |
|
exceptions = FPSCR_DZC; |
|
infinity: |
|
vdd.exponent = 2047; |
|
vdd.significand = 0; |
|
goto pack; |
|
|
|
invalid: |
|
vfp_put_double(vfp_double_pack(&vfp_double_default_qnan), dd); |
|
return FPSCR_IOC; |
|
} |
|
|
|
static struct op fops[16] = { |
|
[FOP_TO_IDX(FOP_FMAC)] = { vfp_double_fmac, 0 }, |
|
[FOP_TO_IDX(FOP_FNMAC)] = { vfp_double_fnmac, 0 }, |
|
[FOP_TO_IDX(FOP_FMSC)] = { vfp_double_fmsc, 0 }, |
|
[FOP_TO_IDX(FOP_FNMSC)] = { vfp_double_fnmsc, 0 }, |
|
[FOP_TO_IDX(FOP_FMUL)] = { vfp_double_fmul, 0 }, |
|
[FOP_TO_IDX(FOP_FNMUL)] = { vfp_double_fnmul, 0 }, |
|
[FOP_TO_IDX(FOP_FADD)] = { vfp_double_fadd, 0 }, |
|
[FOP_TO_IDX(FOP_FSUB)] = { vfp_double_fsub, 0 }, |
|
[FOP_TO_IDX(FOP_FDIV)] = { vfp_double_fdiv, 0 }, |
|
}; |
|
|
|
#define FREG_BANK(x) ((x) & 0x0c) |
|
#define FREG_IDX(x) ((x) & 3) |
|
|
|
u32 vfp_double_cpdo(u32 inst, u32 fpscr) |
|
{ |
|
u32 op = inst & FOP_MASK; |
|
u32 exceptions = 0; |
|
unsigned int dest; |
|
unsigned int dn = vfp_get_dn(inst); |
|
unsigned int dm; |
|
unsigned int vecitr, veclen, vecstride; |
|
struct op *fop; |
|
|
|
vecstride = (1 + ((fpscr & FPSCR_STRIDE_MASK) == FPSCR_STRIDE_MASK)); |
|
|
|
fop = (op == FOP_EXT) ? &fops_ext[FEXT_TO_IDX(inst)] : &fops[FOP_TO_IDX(op)]; |
|
|
|
/* |
|
* fcvtds takes an sN register number as destination, not dN. |
|
* It also always operates on scalars. |
|
*/ |
|
if (fop->flags & OP_SD) |
|
dest = vfp_get_sd(inst); |
|
else |
|
dest = vfp_get_dd(inst); |
|
|
|
/* |
|
* f[us]ito takes a sN operand, not a dN operand. |
|
*/ |
|
if (fop->flags & OP_SM) |
|
dm = vfp_get_sm(inst); |
|
else |
|
dm = vfp_get_dm(inst); |
|
|
|
/* |
|
* If destination bank is zero, vector length is always '1'. |
|
* ARM DDI0100F C5.1.3, C5.3.2. |
|
*/ |
|
if ((fop->flags & OP_SCALAR) || (FREG_BANK(dest) == 0)) |
|
veclen = 0; |
|
else |
|
veclen = fpscr & FPSCR_LENGTH_MASK; |
|
|
|
pr_debug("VFP: vecstride=%u veclen=%u\n", vecstride, |
|
(veclen >> FPSCR_LENGTH_BIT) + 1); |
|
|
|
if (!fop->fn) |
|
goto invalid; |
|
|
|
for (vecitr = 0; vecitr <= veclen; vecitr += 1 << FPSCR_LENGTH_BIT) { |
|
u32 except; |
|
char type; |
|
|
|
type = fop->flags & OP_SD ? 's' : 'd'; |
|
if (op == FOP_EXT) |
|
pr_debug("VFP: itr%d (%c%u) = op[%u] (d%u)\n", |
|
vecitr >> FPSCR_LENGTH_BIT, |
|
type, dest, dn, dm); |
|
else |
|
pr_debug("VFP: itr%d (%c%u) = (d%u) op[%u] (d%u)\n", |
|
vecitr >> FPSCR_LENGTH_BIT, |
|
type, dest, dn, FOP_TO_IDX(op), dm); |
|
|
|
except = fop->fn(dest, dn, dm, fpscr); |
|
pr_debug("VFP: itr%d: exceptions=%08x\n", |
|
vecitr >> FPSCR_LENGTH_BIT, except); |
|
|
|
exceptions |= except; |
|
|
|
/* |
|
* CHECK: It appears to be undefined whether we stop when |
|
* we encounter an exception. We continue. |
|
*/ |
|
dest = FREG_BANK(dest) + ((FREG_IDX(dest) + vecstride) & 3); |
|
dn = FREG_BANK(dn) + ((FREG_IDX(dn) + vecstride) & 3); |
|
if (FREG_BANK(dm) != 0) |
|
dm = FREG_BANK(dm) + ((FREG_IDX(dm) + vecstride) & 3); |
|
} |
|
return exceptions; |
|
|
|
invalid: |
|
return ~0; |
|
}
|
|
|