Add dependencies for code generator

vendor/gonum.org/v1/gonum/lapack/gonum/dlasq5.go

@@ -0,0 +1,140 @@
+// Copyright ©2015 The Gonum Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package gonum
+
+import "math"
+
+// Dlasq5 computes one dqds transform in ping-pong form.
+// i0 and n0 are zero-indexed.
+//
+// Dlasq5 is an internal routine. It is exported for testing purposes.
+func (impl Implementation) Dlasq5(i0, n0 int, z []float64, pp int, tau, sigma float64) (i0Out, n0Out, ppOut int, tauOut, sigmaOut, dmin, dmin1, dmin2, dn, dnm1, dnm2 float64) {
+	// The lapack function has inputs for ieee and eps, but Go requires ieee so
+	// these are unnecessary.
+
+	switch {
+	case i0 < 0:
+		panic(i0LT0)
+	case n0 < 0:
+		panic(n0LT0)
+	case len(z) < 4*n0:
+		panic(shortZ)
+	case pp != 0 && pp != 1:
+		panic(badPp)
+	}
+
+	if n0-i0-1 <= 0 {
+		return i0, n0, pp, tau, sigma, dmin, dmin1, dmin2, dn, dnm1, dnm2
+	}
+
+	eps := dlamchP
+	dthresh := eps * (sigma + tau)
+	if tau < dthresh*0.5 {
+		tau = 0
+	}
+	var j4 int
+	var emin float64
+	if tau != 0 {
+		j4 = 4*i0 + pp
+		emin = z[j4+4]
+		d := z[j4] - tau
+		dmin = d
+		// In the reference there are code paths that actually return this value.
+		// dmin1 = -z[j4]
+		if pp == 0 {
+			for j4loop := 4 * (i0 + 1); j4loop <= 4*((n0+1)-3); j4loop += 4 {
+				j4 := j4loop - 1
+				z[j4-2] = d + z[j4-1]
+				tmp := z[j4+1] / z[j4-2]
+				d = d*tmp - tau
+				dmin = math.Min(dmin, d)
+				z[j4] = z[j4-1] * tmp
+				emin = math.Min(z[j4], emin)
+			}
+		} else {
+			for j4loop := 4 * (i0 + 1); j4loop <= 4*((n0+1)-3); j4loop += 4 {
+				j4 := j4loop - 1
+				z[j4-3] = d + z[j4]
+				tmp := z[j4+2] / z[j4-3]
+				d = d*tmp - tau
+				dmin = math.Min(dmin, d)
+				z[j4-1] = z[j4] * tmp
+				emin = math.Min(z[j4-1], emin)
+			}
+		}
+		// Unroll the last two steps.
+		dnm2 = d
+		dmin2 = dmin
+		j4 = 4*((n0+1)-2) - pp - 1
+		j4p2 := j4 + 2*pp - 1
+		z[j4-2] = dnm2 + z[j4p2]
+		z[j4] = z[j4p2+2] * (z[j4p2] / z[j4-2])
+		dnm1 = z[j4p2+2]*(dnm2/z[j4-2]) - tau
+		dmin = math.Min(dmin, dnm1)
+
+		dmin1 = dmin
+		j4 += 4
+		j4p2 = j4 + 2*pp - 1
+		z[j4-2] = dnm1 + z[j4p2]
+		z[j4] = z[j4p2+2] * (z[j4p2] / z[j4-2])
+		dn = z[j4p2+2]*(dnm1/z[j4-2]) - tau
+		dmin = math.Min(dmin, dn)
+	} else {
+		// This is the version that sets d's to zero if they are small enough.
+		j4 = 4*(i0+1) + pp - 4
+		emin = z[j4+4]
+		d := z[j4] - tau
+		dmin = d
+		// In the reference there are code paths that actually return this value.
+		// dmin1 = -z[j4]
+		if pp == 0 {
+			for j4loop := 4 * (i0 + 1); j4loop <= 4*((n0+1)-3); j4loop += 4 {
+				j4 := j4loop - 1
+				z[j4-2] = d + z[j4-1]
+				tmp := z[j4+1] / z[j4-2]
+				d = d*tmp - tau
+				if d < dthresh {
+					d = 0
+				}
+				dmin = math.Min(dmin, d)
+				z[j4] = z[j4-1] * tmp
+				emin = math.Min(z[j4], emin)
+			}
+		} else {
+			for j4loop := 4 * (i0 + 1); j4loop <= 4*((n0+1)-3); j4loop += 4 {
+				j4 := j4loop - 1
+				z[j4-3] = d + z[j4]
+				tmp := z[j4+2] / z[j4-3]
+				d = d*tmp - tau
+				if d < dthresh {
+					d = 0
+				}
+				dmin = math.Min(dmin, d)
+				z[j4-1] = z[j4] * tmp
+				emin = math.Min(z[j4-1], emin)
+			}
+		}
+		// Unroll the last two steps.
+		dnm2 = d
+		dmin2 = dmin
+		j4 = 4*((n0+1)-2) - pp - 1
+		j4p2 := j4 + 2*pp - 1
+		z[j4-2] = dnm2 + z[j4p2]
+		z[j4] = z[j4p2+2] * (z[j4p2] / z[j4-2])
+		dnm1 = z[j4p2+2]*(dnm2/z[j4-2]) - tau
+		dmin = math.Min(dmin, dnm1)
+
+		dmin1 = dmin
+		j4 += 4
+		j4p2 = j4 + 2*pp - 1
+		z[j4-2] = dnm1 + z[j4p2]
+		z[j4] = z[j4p2+2] * (z[j4p2] / z[j4-2])
+		dn = z[j4p2+2]*(dnm1/z[j4-2]) - tau
+		dmin = math.Min(dmin, dn)
+	}
+	z[j4+2] = dn
+	z[4*(n0+1)-pp-1] = emin
+	return i0, n0, pp, tau, sigma, dmin, dmin1, dmin2, dn, dnm1, dnm2
+}