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![Catalin Marinas](/assets/img/avatar_default.png)
This patch adds ptrace support for setting and getting the VFP registers using PTRACE_SETVFPREGS and PTRACE_GETVFPREGS. The user_vfp structure defined in asm/user.h contains 32 double registers (to cover VFPv3 and Neon hardware) and the FPSCR register. Cc: Paul Brook <paul@codesourcery.com> Cc: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
380 lines
9.4 KiB
C
380 lines
9.4 KiB
C
/*
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* linux/arch/arm/vfp/vfp.h
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*
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* Copyright (C) 2004 ARM Limited.
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* Written by Deep Blue Solutions Limited.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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static inline u32 vfp_shiftright32jamming(u32 val, unsigned int shift)
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{
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if (shift) {
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if (shift < 32)
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val = val >> shift | ((val << (32 - shift)) != 0);
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else
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val = val != 0;
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}
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return val;
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}
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static inline u64 vfp_shiftright64jamming(u64 val, unsigned int shift)
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{
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if (shift) {
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if (shift < 64)
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val = val >> shift | ((val << (64 - shift)) != 0);
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else
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val = val != 0;
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}
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return val;
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}
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static inline u32 vfp_hi64to32jamming(u64 val)
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{
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u32 v;
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asm(
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"cmp %Q1, #1 @ vfp_hi64to32jamming\n\t"
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"movcc %0, %R1\n\t"
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"orrcs %0, %R1, #1"
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: "=r" (v) : "r" (val) : "cc");
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return v;
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}
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static inline void add128(u64 *resh, u64 *resl, u64 nh, u64 nl, u64 mh, u64 ml)
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{
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asm( "adds %Q0, %Q2, %Q4\n\t"
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"adcs %R0, %R2, %R4\n\t"
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"adcs %Q1, %Q3, %Q5\n\t"
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"adc %R1, %R3, %R5"
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: "=r" (nl), "=r" (nh)
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: "0" (nl), "1" (nh), "r" (ml), "r" (mh)
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: "cc");
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*resh = nh;
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*resl = nl;
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}
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static inline void sub128(u64 *resh, u64 *resl, u64 nh, u64 nl, u64 mh, u64 ml)
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{
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asm( "subs %Q0, %Q2, %Q4\n\t"
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"sbcs %R0, %R2, %R4\n\t"
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"sbcs %Q1, %Q3, %Q5\n\t"
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"sbc %R1, %R3, %R5\n\t"
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: "=r" (nl), "=r" (nh)
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: "0" (nl), "1" (nh), "r" (ml), "r" (mh)
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: "cc");
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*resh = nh;
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*resl = nl;
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}
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static inline void mul64to128(u64 *resh, u64 *resl, u64 n, u64 m)
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{
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u32 nh, nl, mh, ml;
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u64 rh, rma, rmb, rl;
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nl = n;
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ml = m;
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rl = (u64)nl * ml;
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nh = n >> 32;
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rma = (u64)nh * ml;
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mh = m >> 32;
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rmb = (u64)nl * mh;
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rma += rmb;
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rh = (u64)nh * mh;
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rh += ((u64)(rma < rmb) << 32) + (rma >> 32);
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rma <<= 32;
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rl += rma;
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rh += (rl < rma);
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*resl = rl;
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*resh = rh;
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}
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static inline void shift64left(u64 *resh, u64 *resl, u64 n)
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{
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*resh = n >> 63;
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*resl = n << 1;
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}
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static inline u64 vfp_hi64multiply64(u64 n, u64 m)
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{
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u64 rh, rl;
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mul64to128(&rh, &rl, n, m);
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return rh | (rl != 0);
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}
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static inline u64 vfp_estimate_div128to64(u64 nh, u64 nl, u64 m)
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{
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u64 mh, ml, remh, reml, termh, terml, z;
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if (nh >= m)
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return ~0ULL;
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mh = m >> 32;
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if (mh << 32 <= nh) {
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z = 0xffffffff00000000ULL;
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} else {
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z = nh;
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do_div(z, mh);
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z <<= 32;
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}
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mul64to128(&termh, &terml, m, z);
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sub128(&remh, &reml, nh, nl, termh, terml);
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ml = m << 32;
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while ((s64)remh < 0) {
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z -= 0x100000000ULL;
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add128(&remh, &reml, remh, reml, mh, ml);
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}
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remh = (remh << 32) | (reml >> 32);
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if (mh << 32 <= remh) {
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z |= 0xffffffff;
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} else {
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do_div(remh, mh);
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z |= remh;
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}
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return z;
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}
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/*
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* Operations on unpacked elements
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*/
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#define vfp_sign_negate(sign) (sign ^ 0x8000)
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/*
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* Single-precision
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*/
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struct vfp_single {
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s16 exponent;
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u16 sign;
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u32 significand;
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};
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extern s32 vfp_get_float(unsigned int reg);
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extern void vfp_put_float(s32 val, unsigned int reg);
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/*
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* VFP_SINGLE_MANTISSA_BITS - number of bits in the mantissa
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* VFP_SINGLE_EXPONENT_BITS - number of bits in the exponent
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* VFP_SINGLE_LOW_BITS - number of low bits in the unpacked significand
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* which are not propagated to the float upon packing.
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*/
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#define VFP_SINGLE_MANTISSA_BITS (23)
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#define VFP_SINGLE_EXPONENT_BITS (8)
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#define VFP_SINGLE_LOW_BITS (32 - VFP_SINGLE_MANTISSA_BITS - 2)
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#define VFP_SINGLE_LOW_BITS_MASK ((1 << VFP_SINGLE_LOW_BITS) - 1)
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/*
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* The bit in an unpacked float which indicates that it is a quiet NaN
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*/
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#define VFP_SINGLE_SIGNIFICAND_QNAN (1 << (VFP_SINGLE_MANTISSA_BITS - 1 + VFP_SINGLE_LOW_BITS))
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/*
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* Operations on packed single-precision numbers
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*/
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#define vfp_single_packed_sign(v) ((v) & 0x80000000)
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#define vfp_single_packed_negate(v) ((v) ^ 0x80000000)
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#define vfp_single_packed_abs(v) ((v) & ~0x80000000)
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#define vfp_single_packed_exponent(v) (((v) >> VFP_SINGLE_MANTISSA_BITS) & ((1 << VFP_SINGLE_EXPONENT_BITS) - 1))
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#define vfp_single_packed_mantissa(v) ((v) & ((1 << VFP_SINGLE_MANTISSA_BITS) - 1))
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/*
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* Unpack a single-precision float. Note that this returns the magnitude
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* of the single-precision float mantissa with the 1. if necessary,
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* aligned to bit 30.
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*/
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static inline void vfp_single_unpack(struct vfp_single *s, s32 val)
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{
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u32 significand;
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s->sign = vfp_single_packed_sign(val) >> 16,
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s->exponent = vfp_single_packed_exponent(val);
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significand = (u32) val;
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significand = (significand << (32 - VFP_SINGLE_MANTISSA_BITS)) >> 2;
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if (s->exponent && s->exponent != 255)
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significand |= 0x40000000;
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s->significand = significand;
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}
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/*
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* Re-pack a single-precision float. This assumes that the float is
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* already normalised such that the MSB is bit 30, _not_ bit 31.
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*/
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static inline s32 vfp_single_pack(struct vfp_single *s)
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{
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u32 val;
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val = (s->sign << 16) +
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(s->exponent << VFP_SINGLE_MANTISSA_BITS) +
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(s->significand >> VFP_SINGLE_LOW_BITS);
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return (s32)val;
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}
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#define VFP_NUMBER (1<<0)
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#define VFP_ZERO (1<<1)
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#define VFP_DENORMAL (1<<2)
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#define VFP_INFINITY (1<<3)
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#define VFP_NAN (1<<4)
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#define VFP_NAN_SIGNAL (1<<5)
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#define VFP_QNAN (VFP_NAN)
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#define VFP_SNAN (VFP_NAN|VFP_NAN_SIGNAL)
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static inline int vfp_single_type(struct vfp_single *s)
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{
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int type = VFP_NUMBER;
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if (s->exponent == 255) {
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if (s->significand == 0)
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type = VFP_INFINITY;
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else if (s->significand & VFP_SINGLE_SIGNIFICAND_QNAN)
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type = VFP_QNAN;
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else
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type = VFP_SNAN;
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} else if (s->exponent == 0) {
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if (s->significand == 0)
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type |= VFP_ZERO;
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else
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type |= VFP_DENORMAL;
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}
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return type;
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}
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#ifndef DEBUG
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#define vfp_single_normaliseround(sd,vsd,fpscr,except,func) __vfp_single_normaliseround(sd,vsd,fpscr,except)
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u32 __vfp_single_normaliseround(int sd, struct vfp_single *vs, u32 fpscr, u32 exceptions);
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#else
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u32 vfp_single_normaliseround(int sd, struct vfp_single *vs, u32 fpscr, u32 exceptions, const char *func);
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#endif
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/*
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* Double-precision
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*/
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struct vfp_double {
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s16 exponent;
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u16 sign;
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u64 significand;
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};
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/*
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* VFP_REG_ZERO is a special register number for vfp_get_double
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* which returns (double)0.0. This is useful for the compare with
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* zero instructions.
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*/
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#ifdef CONFIG_VFPv3
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#define VFP_REG_ZERO 32
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#else
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#define VFP_REG_ZERO 16
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#endif
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extern u64 vfp_get_double(unsigned int reg);
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extern void vfp_put_double(u64 val, unsigned int reg);
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#define VFP_DOUBLE_MANTISSA_BITS (52)
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#define VFP_DOUBLE_EXPONENT_BITS (11)
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#define VFP_DOUBLE_LOW_BITS (64 - VFP_DOUBLE_MANTISSA_BITS - 2)
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#define VFP_DOUBLE_LOW_BITS_MASK ((1 << VFP_DOUBLE_LOW_BITS) - 1)
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/*
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* The bit in an unpacked double which indicates that it is a quiet NaN
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*/
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#define VFP_DOUBLE_SIGNIFICAND_QNAN (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1 + VFP_DOUBLE_LOW_BITS))
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/*
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* Operations on packed single-precision numbers
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*/
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#define vfp_double_packed_sign(v) ((v) & (1ULL << 63))
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#define vfp_double_packed_negate(v) ((v) ^ (1ULL << 63))
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#define vfp_double_packed_abs(v) ((v) & ~(1ULL << 63))
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#define vfp_double_packed_exponent(v) (((v) >> VFP_DOUBLE_MANTISSA_BITS) & ((1 << VFP_DOUBLE_EXPONENT_BITS) - 1))
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#define vfp_double_packed_mantissa(v) ((v) & ((1ULL << VFP_DOUBLE_MANTISSA_BITS) - 1))
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/*
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* Unpack a double-precision float. Note that this returns the magnitude
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* of the double-precision float mantissa with the 1. if necessary,
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* aligned to bit 62.
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*/
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static inline void vfp_double_unpack(struct vfp_double *s, s64 val)
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{
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u64 significand;
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s->sign = vfp_double_packed_sign(val) >> 48;
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s->exponent = vfp_double_packed_exponent(val);
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significand = (u64) val;
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significand = (significand << (64 - VFP_DOUBLE_MANTISSA_BITS)) >> 2;
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if (s->exponent && s->exponent != 2047)
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significand |= (1ULL << 62);
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s->significand = significand;
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}
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/*
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* Re-pack a double-precision float. This assumes that the float is
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* already normalised such that the MSB is bit 30, _not_ bit 31.
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*/
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static inline s64 vfp_double_pack(struct vfp_double *s)
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{
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u64 val;
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val = ((u64)s->sign << 48) +
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((u64)s->exponent << VFP_DOUBLE_MANTISSA_BITS) +
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(s->significand >> VFP_DOUBLE_LOW_BITS);
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return (s64)val;
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}
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static inline int vfp_double_type(struct vfp_double *s)
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{
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int type = VFP_NUMBER;
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if (s->exponent == 2047) {
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if (s->significand == 0)
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type = VFP_INFINITY;
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else if (s->significand & VFP_DOUBLE_SIGNIFICAND_QNAN)
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type = VFP_QNAN;
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else
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type = VFP_SNAN;
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} else if (s->exponent == 0) {
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if (s->significand == 0)
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type |= VFP_ZERO;
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else
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type |= VFP_DENORMAL;
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}
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return type;
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}
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u32 vfp_double_normaliseround(int dd, struct vfp_double *vd, u32 fpscr, u32 exceptions, const char *func);
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u32 vfp_estimate_sqrt_significand(u32 exponent, u32 significand);
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/*
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* A special flag to tell the normalisation code not to normalise.
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*/
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#define VFP_NAN_FLAG 0x100
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/*
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* A bit pattern used to indicate the initial (unset) value of the
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* exception mask, in case nothing handles an instruction. This
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* doesn't include the NAN flag, which get masked out before
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* we check for an error.
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*/
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#define VFP_EXCEPTION_ERROR ((u32)-1 & ~VFP_NAN_FLAG)
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/*
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* A flag to tell vfp instruction type.
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* OP_SCALAR - this operation always operates in scalar mode
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* OP_SD - the instruction exceptionally writes to a single precision result.
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* OP_DD - the instruction exceptionally writes to a double precision result.
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* OP_SM - the instruction exceptionally reads from a single precision operand.
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*/
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#define OP_SCALAR (1 << 0)
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#define OP_SD (1 << 1)
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#define OP_DD (1 << 1)
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#define OP_SM (1 << 2)
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struct op {
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u32 (* const fn)(int dd, int dn, int dm, u32 fpscr);
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u32 flags;
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};
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extern void vfp_save_state(void *location, u32 fpexc);
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