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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
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if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
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1 files changed, 363 insertions, 0 deletions

diff --git a/libgo/go/exp/draw/draw.go b/libgo/go/exp/draw/draw.go
new file mode 100644
index 000000000..1d0729d92
--- /dev/null
+++ b/libgo/go/exp/draw/draw.go
@@ -0,0 +1,363 @@
+// Copyright 2009 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.
+
+// Package draw provides basic graphics and drawing primitives,
+// in the style of the Plan 9 graphics library
+// (see http://plan9.bell-labs.com/magic/man2html/2/draw)
+// and the X Render extension.
+package draw
+
+import "image"
+
+// m is the maximum color value returned by image.Color.RGBA.
+const m = 1<<16 - 1
+
+// A Porter-Duff compositing operator.
+type Op int
+
+const (
+	// Over specifies ``(src in mask) over dst''.
+	Over Op = iota
+	// Src specifies ``src in mask''.
+	Src
+)
+
+var zeroColor image.Color = image.AlphaColor{0}
+
+// A draw.Image is an image.Image with a Set method to change a single pixel.
+type Image interface {
+	image.Image
+	Set(x, y int, c image.Color)
+}
+
+// Draw calls DrawMask with a nil mask and an Over op.
+func Draw(dst Image, r image.Rectangle, src image.Image, sp image.Point) {
+	DrawMask(dst, r, src, sp, nil, image.ZP, Over)
+}
+
+// DrawMask aligns r.Min in dst with sp in src and mp in mask and then replaces the rectangle r
+// in dst with the result of a Porter-Duff composition. A nil mask is treated as opaque.
+func DrawMask(dst Image, r image.Rectangle, src image.Image, sp image.Point, mask image.Image, mp image.Point, op Op) {
+	sb := src.Bounds()
+	dx, dy := sb.Max.X-sp.X, sb.Max.Y-sp.Y
+	if mask != nil {
+		mb := mask.Bounds()
+		if dx > mb.Max.X-mp.X {
+			dx = mb.Max.X - mp.X
+		}
+		if dy > mb.Max.Y-mp.Y {
+			dy = mb.Max.Y - mp.Y
+		}
+	}
+	if r.Dx() > dx {
+		r.Max.X = r.Min.X + dx
+	}
+	if r.Dy() > dy {
+		r.Max.Y = r.Min.Y + dy
+	}
+	r = r.Intersect(dst.Bounds())
+	if r.Empty() {
+		return
+	}
+
+	// Fast paths for special cases. If none of them apply, then we fall back to a general but slow implementation.
+	if dst0, ok := dst.(*image.RGBA); ok {
+		if op == Over {
+			if mask == nil {
+				if src0, ok := src.(*image.ColorImage); ok {
+					drawFillOver(dst0, r, src0)
+					return
+				}
+				if src0, ok := src.(*image.RGBA); ok {
+					drawCopyOver(dst0, r, src0, sp)
+					return
+				}
+			} else if mask0, ok := mask.(*image.Alpha); ok {
+				if src0, ok := src.(*image.ColorImage); ok {
+					drawGlyphOver(dst0, r, src0, mask0, mp)
+					return
+				}
+			}
+		} else {
+			if mask == nil {
+				if src0, ok := src.(*image.ColorImage); ok {
+					drawFillSrc(dst0, r, src0)
+					return
+				}
+				if src0, ok := src.(*image.RGBA); ok {
+					drawCopySrc(dst0, r, src0, sp)
+					return
+				}
+			}
+		}
+		drawRGBA(dst0, r, src, sp, mask, mp, op)
+		return
+	}
+
+	x0, x1, dx := r.Min.X, r.Max.X, 1
+	y0, y1, dy := r.Min.Y, r.Max.Y, 1
+	if image.Image(dst) == src && r.Overlaps(r.Add(sp.Sub(r.Min))) {
+		// Rectangles overlap: process backward?
+		if sp.Y < r.Min.Y || sp.Y == r.Min.Y && sp.X < r.Min.X {
+			x0, x1, dx = x1-1, x0-1, -1
+			y0, y1, dy = y1-1, y0-1, -1
+		}
+	}
+
+	var out *image.RGBA64Color
+	sy := sp.Y + y0 - r.Min.Y
+	my := mp.Y + y0 - r.Min.Y
+	for y := y0; y != y1; y, sy, my = y+dy, sy+dy, my+dy {
+		sx := sp.X + x0 - r.Min.X
+		mx := mp.X + x0 - r.Min.X
+		for x := x0; x != x1; x, sx, mx = x+dx, sx+dx, mx+dx {
+			ma := uint32(m)
+			if mask != nil {
+				_, _, _, ma = mask.At(mx, my).RGBA()
+			}
+			switch {
+			case ma == 0:
+				if op == Over {
+					// No-op.
+				} else {
+					dst.Set(x, y, zeroColor)
+				}
+			case ma == m && op == Src:
+				dst.Set(x, y, src.At(sx, sy))
+			default:
+				sr, sg, sb, sa := src.At(sx, sy).RGBA()
+				if out == nil {
+					out = new(image.RGBA64Color)
+				}
+				if op == Over {
+					dr, dg, db, da := dst.At(x, y).RGBA()
+					a := m - (sa * ma / m)
+					out.R = uint16((dr*a + sr*ma) / m)
+					out.G = uint16((dg*a + sg*ma) / m)
+					out.B = uint16((db*a + sb*ma) / m)
+					out.A = uint16((da*a + sa*ma) / m)
+				} else {
+					out.R = uint16(sr * ma / m)
+					out.G = uint16(sg * ma / m)
+					out.B = uint16(sb * ma / m)
+					out.A = uint16(sa * ma / m)
+				}
+				dst.Set(x, y, out)
+			}
+		}
+	}
+}
+
+func drawFillOver(dst *image.RGBA, r image.Rectangle, src *image.ColorImage) {
+	cr, cg, cb, ca := src.RGBA()
+	// The 0x101 is here for the same reason as in drawRGBA.
+	a := (m - ca) * 0x101
+	x0, x1 := r.Min.X, r.Max.X
+	y0, y1 := r.Min.Y, r.Max.Y
+	for y := y0; y != y1; y++ {
+		dbase := y * dst.Stride
+		dpix := dst.Pix[dbase+x0 : dbase+x1]
+		for i, rgba := range dpix {
+			dr := (uint32(rgba.R)*a)/m + cr
+			dg := (uint32(rgba.G)*a)/m + cg
+			db := (uint32(rgba.B)*a)/m + cb
+			da := (uint32(rgba.A)*a)/m + ca
+			dpix[i] = image.RGBAColor{uint8(dr >> 8), uint8(dg >> 8), uint8(db >> 8), uint8(da >> 8)}
+		}
+	}
+}
+
+func drawCopyOver(dst *image.RGBA, r image.Rectangle, src *image.RGBA, sp image.Point) {
+	dx0, dx1 := r.Min.X, r.Max.X
+	dy0, dy1 := r.Min.Y, r.Max.Y
+	nrows := dy1 - dy0
+	sx0, sx1 := sp.X, sp.X+dx1-dx0
+	d0 := dy0*dst.Stride + dx0
+	d1 := dy0*dst.Stride + dx1
+	s0 := sp.Y*src.Stride + sx0
+	s1 := sp.Y*src.Stride + sx1
+	var (
+		ddelta, sdelta int
+		i0, i1, idelta int
+	)
+	if r.Min.Y < sp.Y || r.Min.Y == sp.Y && r.Min.X <= sp.X {
+		ddelta = dst.Stride
+		sdelta = src.Stride
+		i0, i1, idelta = 0, d1-d0, +1
+	} else {
+		// If the source start point is higher than the destination start point, or equal height but to the left,
+		// then we compose the rows in right-to-left, bottom-up order instead of left-to-right, top-down.
+		d0 += (nrows - 1) * dst.Stride
+		d1 += (nrows - 1) * dst.Stride
+		s0 += (nrows - 1) * src.Stride
+		s1 += (nrows - 1) * src.Stride
+		ddelta = -dst.Stride
+		sdelta = -src.Stride
+		i0, i1, idelta = d1-d0-1, -1, -1
+	}
+	for ; nrows > 0; nrows-- {
+		dpix := dst.Pix[d0:d1]
+		spix := src.Pix[s0:s1]
+		for i := i0; i != i1; i += idelta {
+			// For unknown reasons, even though both dpix[i] and spix[i] are
+			// image.RGBAColors, on an x86 CPU it seems fastest to call RGBA
+			// for the source but to do it manually for the destination.
+			sr, sg, sb, sa := spix[i].RGBA()
+			rgba := dpix[i]
+			dr := uint32(rgba.R)
+			dg := uint32(rgba.G)
+			db := uint32(rgba.B)
+			da := uint32(rgba.A)
+			// The 0x101 is here for the same reason as in drawRGBA.
+			a := (m - sa) * 0x101
+			dr = (dr*a)/m + sr
+			dg = (dg*a)/m + sg
+			db = (db*a)/m + sb
+			da = (da*a)/m + sa
+			dpix[i] = image.RGBAColor{uint8(dr >> 8), uint8(dg >> 8), uint8(db >> 8), uint8(da >> 8)}
+		}
+		d0 += ddelta
+		d1 += ddelta
+		s0 += sdelta
+		s1 += sdelta
+	}
+}
+
+func drawGlyphOver(dst *image.RGBA, r image.Rectangle, src *image.ColorImage, mask *image.Alpha, mp image.Point) {
+	x0, x1 := r.Min.X, r.Max.X
+	y0, y1 := r.Min.Y, r.Max.Y
+	cr, cg, cb, ca := src.RGBA()
+	for y, my := y0, mp.Y; y != y1; y, my = y+1, my+1 {
+		dbase := y * dst.Stride
+		dpix := dst.Pix[dbase+x0 : dbase+x1]
+		mbase := my * mask.Stride
+		mpix := mask.Pix[mbase+mp.X:]
+		for i, rgba := range dpix {
+			ma := uint32(mpix[i].A)
+			if ma == 0 {
+				continue
+			}
+			ma |= ma << 8
+			dr := uint32(rgba.R)
+			dg := uint32(rgba.G)
+			db := uint32(rgba.B)
+			da := uint32(rgba.A)
+			// The 0x101 is here for the same reason as in drawRGBA.
+			a := (m - (ca * ma / m)) * 0x101
+			dr = (dr*a + cr*ma) / m
+			dg = (dg*a + cg*ma) / m
+			db = (db*a + cb*ma) / m
+			da = (da*a + ca*ma) / m
+			dpix[i] = image.RGBAColor{uint8(dr >> 8), uint8(dg >> 8), uint8(db >> 8), uint8(da >> 8)}
+		}
+	}
+}
+
+func drawFillSrc(dst *image.RGBA, r image.Rectangle, src *image.ColorImage) {
+	if r.Dy() < 1 {
+		return
+	}
+	cr, cg, cb, ca := src.RGBA()
+	color := image.RGBAColor{uint8(cr >> 8), uint8(cg >> 8), uint8(cb >> 8), uint8(ca >> 8)}
+	// The built-in copy function is faster than a straightforward for loop to fill the destination with
+	// the color, but copy requires a slice source. We therefore use a for loop to fill the first row, and
+	// then use the first row as the slice source for the remaining rows.
+	dx0, dx1 := r.Min.X, r.Max.X
+	dy0, dy1 := r.Min.Y, r.Max.Y
+	dbase := dy0 * dst.Stride
+	i0, i1 := dbase+dx0, dbase+dx1
+	firstRow := dst.Pix[i0:i1]
+	for i := range firstRow {
+		firstRow[i] = color
+	}
+	for y := dy0 + 1; y < dy1; y++ {
+		i0 += dst.Stride
+		i1 += dst.Stride
+		copy(dst.Pix[i0:i1], firstRow)
+	}
+}
+
+func drawCopySrc(dst *image.RGBA, r image.Rectangle, src *image.RGBA, sp image.Point) {
+	dx0, dx1 := r.Min.X, r.Max.X
+	dy0, dy1 := r.Min.Y, r.Max.Y
+	nrows := dy1 - dy0
+	sx0, sx1 := sp.X, sp.X+dx1-dx0
+	d0 := dy0*dst.Stride + dx0
+	d1 := dy0*dst.Stride + dx1
+	s0 := sp.Y*src.Stride + sx0
+	s1 := sp.Y*src.Stride + sx1
+	var ddelta, sdelta int
+	if r.Min.Y <= sp.Y {
+		ddelta = dst.Stride
+		sdelta = src.Stride
+	} else {
+		// If the source start point is higher than the destination start point, then we compose the rows
+		// in bottom-up order instead of top-down. Unlike the drawCopyOver function, we don't have to
+		// check the x co-ordinates because the built-in copy function can handle overlapping slices.
+		d0 += (nrows - 1) * dst.Stride
+		d1 += (nrows - 1) * dst.Stride
+		s0 += (nrows - 1) * src.Stride
+		s1 += (nrows - 1) * src.Stride
+		ddelta = -dst.Stride
+		sdelta = -src.Stride
+	}
+	for ; nrows > 0; nrows-- {
+		copy(dst.Pix[d0:d1], src.Pix[s0:s1])
+		d0 += ddelta
+		d1 += ddelta
+		s0 += sdelta
+		s1 += sdelta
+	}
+}
+
+func drawRGBA(dst *image.RGBA, r image.Rectangle, src image.Image, sp image.Point, mask image.Image, mp image.Point, op Op) {
+	x0, x1, dx := r.Min.X, r.Max.X, 1
+	y0, y1, dy := r.Min.Y, r.Max.Y, 1
+	if image.Image(dst) == src && r.Overlaps(r.Add(sp.Sub(r.Min))) {
+		if sp.Y < r.Min.Y || sp.Y == r.Min.Y && sp.X < r.Min.X {
+			x0, x1, dx = x1-1, x0-1, -1
+			y0, y1, dy = y1-1, y0-1, -1
+		}
+	}
+
+	sy := sp.Y + y0 - r.Min.Y
+	my := mp.Y + y0 - r.Min.Y
+	for y := y0; y != y1; y, sy, my = y+dy, sy+dy, my+dy {
+		sx := sp.X + x0 - r.Min.X
+		mx := mp.X + x0 - r.Min.X
+		dpix := dst.Pix[y*dst.Stride : (y+1)*dst.Stride]
+		for x := x0; x != x1; x, sx, mx = x+dx, sx+dx, mx+dx {
+			ma := uint32(m)
+			if mask != nil {
+				_, _, _, ma = mask.At(mx, my).RGBA()
+			}
+			sr, sg, sb, sa := src.At(sx, sy).RGBA()
+			var dr, dg, db, da uint32
+			if op == Over {
+				rgba := dpix[x]
+				dr = uint32(rgba.R)
+				dg = uint32(rgba.G)
+				db = uint32(rgba.B)
+				da = uint32(rgba.A)
+				// dr, dg, db and da are all 8-bit color at the moment, ranging in [0,255].
+				// We work in 16-bit color, and so would normally do:
+				// dr |= dr << 8
+				// and similarly for dg, db and da, but instead we multiply a
+				// (which is a 16-bit color, ranging in [0,65535]) by 0x101.
+				// This yields the same result, but is fewer arithmetic operations.
+				a := (m - (sa * ma / m)) * 0x101
+				dr = (dr*a + sr*ma) / m
+				dg = (dg*a + sg*ma) / m
+				db = (db*a + sb*ma) / m
+				da = (da*a + sa*ma) / m
+			} else {
+				dr = sr * ma / m
+				dg = sg * ma / m
+				db = sb * ma / m
+				da = sa * ma / m
+			}
+			dpix[x] = image.RGBAColor{uint8(dr >> 8), uint8(dg >> 8), uint8(db >> 8), uint8(da >> 8)}
+		}
+	}
+}