+++ /dev/null
-/*
- * Routines to emulate some Altivec/VMX instructions, specifically
- * those that can trap when given denormalized operands in Java mode.
- */
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <asm/ptrace.h>
-#include <asm/processor.h>
-#include <asm/uaccess.h>
-
-/* Functions in vector.S */
-extern void vaddfp(vector128 *dst, vector128 *a, vector128 *b);
-extern void vsubfp(vector128 *dst, vector128 *a, vector128 *b);
-extern void vmaddfp(vector128 *dst, vector128 *a, vector128 *b, vector128 *c);
-extern void vnmsubfp(vector128 *dst, vector128 *a, vector128 *b, vector128 *c);
-extern void vrefp(vector128 *dst, vector128 *src);
-extern void vrsqrtefp(vector128 *dst, vector128 *src);
-extern void vexptep(vector128 *dst, vector128 *src);
-
-static unsigned int exp2s[8] = {
- 0x800000,
- 0x8b95c2,
- 0x9837f0,
- 0xa5fed7,
- 0xb504f3,
- 0xc5672a,
- 0xd744fd,
- 0xeac0c7
-};
-
-/*
- * Computes an estimate of 2^x. The `s' argument is the 32-bit
- * single-precision floating-point representation of x.
- */
-static unsigned int eexp2(unsigned int s)
-{
- int exp, pwr;
- unsigned int mant, frac;
-
- /* extract exponent field from input */
- exp = ((s >> 23) & 0xff) - 127;
- if (exp > 7) {
- /* check for NaN input */
- if (exp == 128 && (s & 0x7fffff) != 0)
- return s | 0x400000; /* return QNaN */
- /* 2^-big = 0, 2^+big = +Inf */
- return (s & 0x80000000)? 0: 0x7f800000; /* 0 or +Inf */
- }
- if (exp < -23)
- return 0x3f800000; /* 1.0 */
-
- /* convert to fixed point integer in 9.23 representation */
- pwr = (s & 0x7fffff) | 0x800000;
- if (exp > 0)
- pwr <<= exp;
- else
- pwr >>= -exp;
- if (s & 0x80000000)
- pwr = -pwr;
-
- /* extract integer part, which becomes exponent part of result */
- exp = (pwr >> 23) + 126;
- if (exp >= 254)
- return 0x7f800000;
- if (exp < -23)
- return 0;
-
- /* table lookup on top 3 bits of fraction to get mantissa */
- mant = exp2s[(pwr >> 20) & 7];
-
- /* linear interpolation using remaining 20 bits of fraction */
- asm("mulhwu %0,%1,%2" : "=r" (frac)
- : "r" (pwr << 12), "r" (0x172b83ff));
- asm("mulhwu %0,%1,%2" : "=r" (frac) : "r" (frac), "r" (mant));
- mant += frac;
-
- if (exp >= 0)
- return mant + (exp << 23);
-
- /* denormalized result */
- exp = -exp;
- mant += 1 << (exp - 1);
- return mant >> exp;
-}
-
-/*
- * Computes an estimate of log_2(x). The `s' argument is the 32-bit
- * single-precision floating-point representation of x.
- */
-static unsigned int elog2(unsigned int s)
-{
- int exp, mant, lz, frac;
-
- exp = s & 0x7f800000;
- mant = s & 0x7fffff;
- if (exp == 0x7f800000) { /* Inf or NaN */
- if (mant != 0)
- s |= 0x400000; /* turn NaN into QNaN */
- return s;
- }
- if ((exp | mant) == 0) /* +0 or -0 */
- return 0xff800000; /* return -Inf */
-
- if (exp == 0) {
- /* denormalized */
- asm("cntlzw %0,%1" : "=r" (lz) : "r" (mant));
- mant <<= lz - 8;
- exp = (-118 - lz) << 23;
- } else {
- mant |= 0x800000;
- exp -= 127 << 23;
- }
-
- if (mant >= 0xb504f3) { /* 2^0.5 * 2^23 */
- exp |= 0x400000; /* 0.5 * 2^23 */
- asm("mulhwu %0,%1,%2" : "=r" (mant)
- : "r" (mant), "r" (0xb504f334)); /* 2^-0.5 * 2^32 */
- }
- if (mant >= 0x9837f0) { /* 2^0.25 * 2^23 */
- exp |= 0x200000; /* 0.25 * 2^23 */
- asm("mulhwu %0,%1,%2" : "=r" (mant)
- : "r" (mant), "r" (0xd744fccb)); /* 2^-0.25 * 2^32 */
- }
- if (mant >= 0x8b95c2) { /* 2^0.125 * 2^23 */
- exp |= 0x100000; /* 0.125 * 2^23 */
- asm("mulhwu %0,%1,%2" : "=r" (mant)
- : "r" (mant), "r" (0xeac0c6e8)); /* 2^-0.125 * 2^32 */
- }
- if (mant > 0x800000) { /* 1.0 * 2^23 */
- /* calculate (mant - 1) * 1.381097463 */
- /* 1.381097463 == 0.125 / (2^0.125 - 1) */
- asm("mulhwu %0,%1,%2" : "=r" (frac)
- : "r" ((mant - 0x800000) << 1), "r" (0xb0c7cd3a));
- exp += frac;
- }
- s = exp & 0x80000000;
- if (exp != 0) {
- if (s)
- exp = -exp;
- asm("cntlzw %0,%1" : "=r" (lz) : "r" (exp));
- lz = 8 - lz;
- if (lz > 0)
- exp >>= lz;
- else if (lz < 0)
- exp <<= -lz;
- s += ((lz + 126) << 23) + exp;
- }
- return s;
-}
-
-#define VSCR_SAT 1
-
-static int ctsxs(unsigned int x, int scale, unsigned int *vscrp)
-{
- int exp, mant;
-
- exp = (x >> 23) & 0xff;
- mant = x & 0x7fffff;
- if (exp == 255 && mant != 0)
- return 0; /* NaN -> 0 */
- exp = exp - 127 + scale;
- if (exp < 0)
- return 0; /* round towards zero */
- if (exp >= 31) {
- /* saturate, unless the result would be -2^31 */
- if (x + (scale << 23) != 0xcf000000)
- *vscrp |= VSCR_SAT;
- return (x & 0x80000000)? 0x80000000: 0x7fffffff;
- }
- mant |= 0x800000;
- mant = (mant << 7) >> (30 - exp);
- return (x & 0x80000000)? -mant: mant;
-}
-
-static unsigned int ctuxs(unsigned int x, int scale, unsigned int *vscrp)
-{
- int exp;
- unsigned int mant;
-
- exp = (x >> 23) & 0xff;
- mant = x & 0x7fffff;
- if (exp == 255 && mant != 0)
- return 0; /* NaN -> 0 */
- exp = exp - 127 + scale;
- if (exp < 0)
- return 0; /* round towards zero */
- if (x & 0x80000000) {
- /* negative => saturate to 0 */
- *vscrp |= VSCR_SAT;
- return 0;
- }
- if (exp >= 32) {
- /* saturate */
- *vscrp |= VSCR_SAT;
- return 0xffffffff;
- }
- mant |= 0x800000;
- mant = (mant << 8) >> (31 - exp);
- return mant;
-}
-
-/* Round to floating integer, towards 0 */
-static unsigned int rfiz(unsigned int x)
-{
- int exp;
-
- exp = ((x >> 23) & 0xff) - 127;
- if (exp == 128 && (x & 0x7fffff) != 0)
- return x | 0x400000; /* NaN -> make it a QNaN */
- if (exp >= 23)
- return x; /* it's an integer already (or Inf) */
- if (exp < 0)
- return x & 0x80000000; /* |x| < 1.0 rounds to 0 */
- return x & ~(0x7fffff >> exp);
-}
-
-/* Round to floating integer, towards +/- Inf */
-static unsigned int rfii(unsigned int x)
-{
- int exp, mask;
-
- exp = ((x >> 23) & 0xff) - 127;
- if (exp == 128 && (x & 0x7fffff) != 0)
- return x | 0x400000; /* NaN -> make it a QNaN */
- if (exp >= 23)
- return x; /* it's an integer already (or Inf) */
- if ((x & 0x7fffffff) == 0)
- return x; /* +/-0 -> +/-0 */
- if (exp < 0)
- /* 0 < |x| < 1.0 rounds to +/- 1.0 */
- return (x & 0x80000000) | 0x3f800000;
- mask = 0x7fffff >> exp;
- /* mantissa overflows into exponent - that's OK,
- it can't overflow into the sign bit */
- return (x + mask) & ~mask;
-}
-
-/* Round to floating integer, to nearest */
-static unsigned int rfin(unsigned int x)
-{
- int exp, half;
-
- exp = ((x >> 23) & 0xff) - 127;
- if (exp == 128 && (x & 0x7fffff) != 0)
- return x | 0x400000; /* NaN -> make it a QNaN */
- if (exp >= 23)
- return x; /* it's an integer already (or Inf) */
- if (exp < -1)
- return x & 0x80000000; /* |x| < 0.5 -> +/-0 */
- if (exp == -1)
- /* 0.5 <= |x| < 1.0 rounds to +/- 1.0 */
- return (x & 0x80000000) | 0x3f800000;
- half = 0x400000 >> exp;
- /* add 0.5 to the magnitude and chop off the fraction bits */
- return (x + half) & ~(0x7fffff >> exp);
-}
-
-int
-emulate_altivec(struct pt_regs *regs)
-{
- unsigned int instr, i;
- unsigned int va, vb, vc, vd;
- vector128 *vrs;
-
- if (get_user(instr, (unsigned int __user *) regs->nip))
- return -EFAULT;
- if ((instr >> 26) != 4)
- return -EINVAL; /* not an altivec instruction */
- vd = (instr >> 21) & 0x1f;
- va = (instr >> 16) & 0x1f;
- vb = (instr >> 11) & 0x1f;
- vc = (instr >> 6) & 0x1f;
-
- vrs = current->thread.vr;
- switch (instr & 0x3f) {
- case 10:
- switch (vc) {
- case 0: /* vaddfp */
- vaddfp(&vrs[vd], &vrs[va], &vrs[vb]);
- break;
- case 1: /* vsubfp */
- vsubfp(&vrs[vd], &vrs[va], &vrs[vb]);
- break;
- case 4: /* vrefp */
- vrefp(&vrs[vd], &vrs[vb]);
- break;
- case 5: /* vrsqrtefp */
- vrsqrtefp(&vrs[vd], &vrs[vb]);
- break;
- case 6: /* vexptefp */
- for (i = 0; i < 4; ++i)
- vrs[vd].u[i] = eexp2(vrs[vb].u[i]);
- break;
- case 7: /* vlogefp */
- for (i = 0; i < 4; ++i)
- vrs[vd].u[i] = elog2(vrs[vb].u[i]);
- break;
- case 8: /* vrfin */
- for (i = 0; i < 4; ++i)
- vrs[vd].u[i] = rfin(vrs[vb].u[i]);
- break;
- case 9: /* vrfiz */
- for (i = 0; i < 4; ++i)
- vrs[vd].u[i] = rfiz(vrs[vb].u[i]);
- break;
- case 10: /* vrfip */
- for (i = 0; i < 4; ++i) {
- u32 x = vrs[vb].u[i];
- x = (x & 0x80000000)? rfiz(x): rfii(x);
- vrs[vd].u[i] = x;
- }
- break;
- case 11: /* vrfim */
- for (i = 0; i < 4; ++i) {
- u32 x = vrs[vb].u[i];
- x = (x & 0x80000000)? rfii(x): rfiz(x);
- vrs[vd].u[i] = x;
- }
- break;
- case 14: /* vctuxs */
- for (i = 0; i < 4; ++i)
- vrs[vd].u[i] = ctuxs(vrs[vb].u[i], va,
- ¤t->thread.vscr.u[3]);
- break;
- case 15: /* vctsxs */
- for (i = 0; i < 4; ++i)
- vrs[vd].u[i] = ctsxs(vrs[vb].u[i], va,
- ¤t->thread.vscr.u[3]);
- break;
- default:
- return -EINVAL;
- }
- break;
- case 46: /* vmaddfp */
- vmaddfp(&vrs[vd], &vrs[va], &vrs[vb], &vrs[vc]);
- break;
- case 47: /* vnmsubfp */
- vnmsubfp(&vrs[vd], &vrs[va], &vrs[vb], &vrs[vc]);
- break;
- default:
- return -EINVAL;
- }
-
- return 0;
-}
projects / linux-2.6 / commitdiff