From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001
From: upstream source tree <ports@midipix.org>
Date: Sun, 15 Mar 2015 20:14:05 -0400
Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified
 gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream
 tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.
---
 libgo/go/runtime/softfloat64.go | 498 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 498 insertions(+)
 create mode 100644 libgo/go/runtime/softfloat64.go

(limited to 'libgo/go/runtime/softfloat64.go')

diff --git a/libgo/go/runtime/softfloat64.go b/libgo/go/runtime/softfloat64.go
new file mode 100644
index 000000000..d9bbe5def
--- /dev/null
+++ b/libgo/go/runtime/softfloat64.go
@@ -0,0 +1,498 @@
+// Copyright 2010 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Software IEEE754 64-bit floating point.
+// Only referred to (and thus linked in) by arm port
+// and by gotest in this directory.
+
+package runtime
+
+const (
+	mantbits64 uint = 52
+	expbits64  uint = 11
+	bias64     = -1<<(expbits64-1) + 1
+
+	nan64 uint64 = (1<<expbits64-1)<<mantbits64 + 1
+	inf64 uint64 = (1<<expbits64 - 1) << mantbits64
+	neg64 uint64 = 1 << (expbits64 + mantbits64)
+
+	mantbits32 uint = 23
+	expbits32  uint = 8
+	bias32     = -1<<(expbits32-1) + 1
+
+	nan32 uint32 = (1<<expbits32-1)<<mantbits32 + 1
+	inf32 uint32 = (1<<expbits32 - 1) << mantbits32
+	neg32 uint32 = 1 << (expbits32 + mantbits32)
+)
+
+func funpack64(f uint64) (sign, mant uint64, exp int, inf, nan bool) {
+	sign = f & (1 << (mantbits64 + expbits64))
+	mant = f & (1<<mantbits64 - 1)
+	exp = int(f>>mantbits64) & (1<<expbits64 - 1)
+
+	switch exp {
+	case 1<<expbits64 - 1:
+		if mant != 0 {
+			nan = true
+			return
+		}
+		inf = true
+		return
+
+	case 0:
+		// denormalized
+		if mant != 0 {
+			exp += bias64 + 1
+			for mant < 1<<mantbits64 {
+				mant <<= 1
+				exp--
+			}
+		}
+
+	default:
+		// add implicit top bit
+		mant |= 1 << mantbits64
+		exp += bias64
+	}
+	return
+}
+
+func funpack32(f uint32) (sign, mant uint32, exp int, inf, nan bool) {
+	sign = f & (1 << (mantbits32 + expbits32))
+	mant = f & (1<<mantbits32 - 1)
+	exp = int(f>>mantbits32) & (1<<expbits32 - 1)
+
+	switch exp {
+	case 1<<expbits32 - 1:
+		if mant != 0 {
+			nan = true
+			return
+		}
+		inf = true
+		return
+
+	case 0:
+		// denormalized
+		if mant != 0 {
+			exp += bias32 + 1
+			for mant < 1<<mantbits32 {
+				mant <<= 1
+				exp--
+			}
+		}
+
+	default:
+		// add implicit top bit
+		mant |= 1 << mantbits32
+		exp += bias32
+	}
+	return
+}
+
+func fpack64(sign, mant uint64, exp int, trunc uint64) uint64 {
+	mant0, exp0, trunc0 := mant, exp, trunc
+	if mant == 0 {
+		return sign
+	}
+	for mant < 1<<mantbits64 {
+		mant <<= 1
+		exp--
+	}
+	for mant >= 4<<mantbits64 {
+		trunc |= mant & 1
+		mant >>= 1
+		exp++
+	}
+	if mant >= 2<<mantbits64 {
+		if mant&1 != 0 && (trunc != 0 || mant&2 != 0) {
+			mant++
+			if mant >= 4<<mantbits64 {
+				mant >>= 1
+				exp++
+			}
+		}
+		mant >>= 1
+		exp++
+	}
+	if exp >= 1<<expbits64-1+bias64 {
+		return sign ^ inf64
+	}
+	if exp < bias64+1 {
+		if exp < bias64-int(mantbits64) {
+			return sign | 0
+		}
+		// repeat expecting denormal
+		mant, exp, trunc = mant0, exp0, trunc0
+		for exp < bias64 {
+			trunc |= mant & 1
+			mant >>= 1
+			exp++
+		}
+		if mant&1 != 0 && (trunc != 0 || mant&2 != 0) {
+			mant++
+		}
+		mant >>= 1
+		exp++
+		if mant < 1<<mantbits64 {
+			return sign | mant
+		}
+	}
+	return sign | uint64(exp-bias64)<<mantbits64 | mant&(1<<mantbits64-1)
+}
+
+func fpack32(sign, mant uint32, exp int, trunc uint32) uint32 {
+	mant0, exp0, trunc0 := mant, exp, trunc
+	if mant == 0 {
+		return sign
+	}
+	for mant < 1<<mantbits32 {
+		mant <<= 1
+		exp--
+	}
+	for mant >= 4<<mantbits32 {
+		trunc |= mant & 1
+		mant >>= 1
+		exp++
+	}
+	if mant >= 2<<mantbits32 {
+		if mant&1 != 0 && (trunc != 0 || mant&2 != 0) {
+			mant++
+			if mant >= 4<<mantbits32 {
+				mant >>= 1
+				exp++
+			}
+		}
+		mant >>= 1
+		exp++
+	}
+	if exp >= 1<<expbits32-1+bias32 {
+		return sign ^ inf32
+	}
+	if exp < bias32+1 {
+		if exp < bias32-int(mantbits32) {
+			return sign | 0
+		}
+		// repeat expecting denormal
+		mant, exp, trunc = mant0, exp0, trunc0
+		for exp < bias32 {
+			trunc |= mant & 1
+			mant >>= 1
+			exp++
+		}
+		if mant&1 != 0 && (trunc != 0 || mant&2 != 0) {
+			mant++
+		}
+		mant >>= 1
+		exp++
+		if mant < 1<<mantbits32 {
+			return sign | mant
+		}
+	}
+	return sign | uint32(exp-bias32)<<mantbits32 | mant&(1<<mantbits32-1)
+}
+
+func fadd64(f, g uint64) uint64 {
+	fs, fm, fe, fi, fn := funpack64(f)
+	gs, gm, ge, gi, gn := funpack64(g)
+
+	// Special cases.
+	switch {
+	case fn || gn: // NaN + x or x + NaN = NaN
+		return nan64
+
+	case fi && gi && fs != gs: // +Inf + -Inf or -Inf + +Inf = NaN
+		return nan64
+
+	case fi: // ±Inf + g = ±Inf
+		return f
+
+	case gi: // f + ±Inf = ±Inf
+		return g
+
+	case fm == 0 && gm == 0 && fs != 0 && gs != 0: // -0 + -0 = -0
+		return f
+
+	case fm == 0: // 0 + g = g but 0 + -0 = +0
+		if gm == 0 {
+			g ^= gs
+		}
+		return g
+
+	case gm == 0: // f + 0 = f
+		return f
+
+	}
+
+	if fe < ge || fe == ge && fm < gm {
+		f, g, fs, fm, fe, gs, gm, ge = g, f, gs, gm, ge, fs, fm, fe
+	}
+
+	shift := uint(fe - ge)
+	fm <<= 2
+	gm <<= 2
+	trunc := gm & (1<<shift - 1)
+	gm >>= shift
+	if fs == gs {
+		fm += gm
+	} else {
+		fm -= gm
+		if trunc != 0 {
+			fm--
+		}
+	}
+	if fm == 0 {
+		fs = 0
+	}
+	return fpack64(fs, fm, fe-2, trunc)
+}
+
+func fsub64(f, g uint64) uint64 {
+	return fadd64(f, fneg64(g))
+}
+
+func fneg64(f uint64) uint64 {
+	return f ^ (1 << (mantbits64 + expbits64))
+}
+
+func fmul64(f, g uint64) uint64 {
+	fs, fm, fe, fi, fn := funpack64(f)
+	gs, gm, ge, gi, gn := funpack64(g)
+
+	// Special cases.
+	switch {
+	case fn || gn: // NaN * g or f * NaN = NaN
+		return nan64
+
+	case fi && gi: // Inf * Inf = Inf (with sign adjusted)
+		return f ^ gs
+
+	case fi && gm == 0, fm == 0 && gi: // 0 * Inf = Inf * 0 = NaN
+		return nan64
+
+	case fm == 0: // 0 * x = 0 (with sign adjusted)
+		return f ^ gs
+
+	case gm == 0: // x * 0 = 0 (with sign adjusted)
+		return g ^ fs
+	}
+
+	// 53-bit * 53-bit = 107- or 108-bit
+	lo, hi := mullu(fm, gm)
+	shift := mantbits64 - 1
+	trunc := lo & (1<<shift - 1)
+	mant := hi<<(64-shift) | lo>>shift
+	return fpack64(fs^gs, mant, fe+ge-1, trunc)
+}
+
+func fdiv64(f, g uint64) uint64 {
+	fs, fm, fe, fi, fn := funpack64(f)
+	gs, gm, ge, gi, gn := funpack64(g)
+
+	// Special cases.
+	switch {
+	case fn || gn: // NaN / g = f / NaN = NaN
+		return nan64
+
+	case fi && gi: // ±Inf / ±Inf = NaN
+		return nan64
+
+	case !fi && !gi && fm == 0 && gm == 0: // 0 / 0 = NaN
+		return nan64
+
+	case fi, !gi && gm == 0: // Inf / g = f / 0 = Inf
+		return fs ^ gs ^ inf64
+
+	case gi, fm == 0: // f / Inf = 0 / g = Inf
+		return fs ^ gs ^ 0
+	}
+	_, _, _, _ = fi, fn, gi, gn
+
+	// 53-bit<<54 / 53-bit = 53- or 54-bit.
+	shift := mantbits64 + 2
+	q, r := divlu(fm>>(64-shift), fm<<shift, gm)
+	return fpack64(fs^gs, q, fe-ge-2, r)
+}
+
+func f64to32(f uint64) uint32 {
+	fs, fm, fe, fi, fn := funpack64(f)
+	if fn {
+		return nan32
+	}
+	fs32 := uint32(fs >> 32)
+	if fi {
+		return fs32 ^ inf32
+	}
+	const d = mantbits64 - mantbits32 - 1
+	return fpack32(fs32, uint32(fm>>d), fe-1, uint32(fm&(1<<d-1)))
+}
+
+func f32to64(f uint32) uint64 {
+	const d = mantbits64 - mantbits32
+	fs, fm, fe, fi, fn := funpack32(f)
+	if fn {
+		return nan64
+	}
+	fs64 := uint64(fs) << 32
+	if fi {
+		return fs64 ^ inf64
+	}
+	return fpack64(fs64, uint64(fm)<<d, fe, 0)
+}
+
+func fcmp64(f, g uint64) (cmp int, isnan bool) {
+	fs, fm, _, fi, fn := funpack64(f)
+	gs, gm, _, gi, gn := funpack64(g)
+
+	switch {
+	case fn, gn: // flag NaN
+		return 0, true
+
+	case !fi && !gi && fm == 0 && gm == 0: // ±0 == ±0
+		return 0, false
+
+	case fs > gs: // f < 0, g > 0
+		return -1, false
+
+	case fs < gs: // f > 0, g < 0
+		return +1, false
+
+	// Same sign, not NaN.
+	// Can compare encodings directly now.
+	// Reverse for sign.
+	case fs == 0 && f < g, fs != 0 && f > g:
+		return -1, false
+
+	case fs == 0 && f > g, fs != 0 && f < g:
+		return +1, false
+	}
+
+	// f == g
+	return 0, false
+}
+
+func f64toint(f uint64) (val int64, ok bool) {
+	fs, fm, fe, fi, fn := funpack64(f)
+
+	switch {
+	case fi, fn: // NaN
+		return 0, false
+
+	case fe < -1: // f < 0.5
+		return 0, false
+
+	case fe > 63: // f >= 2^63
+		if fs != 0 && fm == 0 { // f == -2^63
+			return -1 << 63, true
+		}
+		if fs != 0 {
+			return 0, false
+		}
+		return 0, false
+	}
+
+	for fe > int(mantbits64) {
+		fe--
+		fm <<= 1
+	}
+	for fe < int(mantbits64) {
+		fe++
+		fm >>= 1
+	}
+	val = int64(fm)
+	if fs != 0 {
+		val = -val
+	}
+	return val, true
+}
+
+func fintto64(val int64) (f uint64) {
+	fs := uint64(val) & (1 << 63)
+	mant := uint64(val)
+	if fs != 0 {
+		mant = -mant
+	}
+	return fpack64(fs, mant, int(mantbits64), 0)
+}
+
+// 64x64 -> 128 multiply.
+// adapted from hacker's delight.
+func mullu(u, v uint64) (lo, hi uint64) {
+	const (
+		s    = 32
+		mask = 1<<s - 1
+	)
+	u0 := u & mask
+	u1 := u >> s
+	v0 := v & mask
+	v1 := v >> s
+	w0 := u0 * v0
+	t := u1*v0 + w0>>s
+	w1 := t & mask
+	w2 := t >> s
+	w1 += u0 * v1
+	return u * v, u1*v1 + w2 + w1>>s
+}
+
+// 128/64 -> 64 quotient, 64 remainder.
+// adapted from hacker's delight
+func divlu(u1, u0, v uint64) (q, r uint64) {
+	const b = 1 << 32
+
+	if u1 >= v {
+		return 1<<64 - 1, 1<<64 - 1
+	}
+
+	// s = nlz(v); v <<= s
+	s := uint(0)
+	for v&(1<<63) == 0 {
+		s++
+		v <<= 1
+	}
+
+	vn1 := v >> 32
+	vn0 := v & (1<<32 - 1)
+	un32 := u1<<s | u0>>(64-s)
+	un10 := u0 << s
+	un1 := un10 >> 32
+	un0 := un10 & (1<<32 - 1)
+	q1 := un32 / vn1
+	rhat := un32 - q1*vn1
+
+again1:
+	if q1 >= b || q1*vn0 > b*rhat+un1 {
+		q1--
+		rhat += vn1
+		if rhat < b {
+			goto again1
+		}
+	}
+
+	un21 := un32*b + un1 - q1*v
+	q0 := un21 / vn1
+	rhat = un21 - q0*vn1
+
+again2:
+	if q0 >= b || q0*vn0 > b*rhat+un0 {
+		q0--
+		rhat += vn1
+		if rhat < b {
+			goto again2
+		}
+	}
+
+	return q1*b + q0, (un21*b + un0 - q0*v) >> s
+}
+
+// callable from C
+
+func fadd64c(f, g uint64, ret *uint64)            { *ret = fadd64(f, g) }
+func fsub64c(f, g uint64, ret *uint64)            { *ret = fsub64(f, g) }
+func fmul64c(f, g uint64, ret *uint64)            { *ret = fmul64(f, g) }
+func fdiv64c(f, g uint64, ret *uint64)            { *ret = fdiv64(f, g) }
+func fneg64c(f uint64, ret *uint64)               { *ret = fneg64(f) }
+func f32to64c(f uint32, ret *uint64)              { *ret = f32to64(f) }
+func f64to32c(f uint64, ret *uint32)              { *ret = f64to32(f) }
+func fcmp64c(f, g uint64, ret *int, retnan *bool) { *ret, *retnan = fcmp64(f, g) }
+func fintto64c(val int64, ret *uint64)            { *ret = fintto64(val) }
+func f64tointc(f uint64, ret *int64, retok *bool) { *ret, *retok = f64toint(f) }
-- 
cgit v1.2.3