gc: make static initialization more static

Does as much as possible in data layout instead
of during the init function.

Handles var x = y; var y = z as a special case too,
because it is so prevalent in package unicode
(var Greek = _Greek; var _Greek = []...).

Introduces InitPlan description of initialized data
so that it can be traversed multiple times (for example,
in the copy handler).

Cuts package unicode's init function size by 8x.
All that remains there is map initialization, which
is on the chopping block too.

Fixes sinit.go test case.

Aggregate DATA instructions at end of object file.

Checkpoint.  More to come.

R=ken2
CC=golang-dev
https://golang.org/cl/4969051

1 files changed, 187 insertions, 32 deletions

diff --git a/test/sinit.go b/test/sinit.go
index 2adb931e14..5cd3a4567b 100644
--- a/test/sinit.go
+++ b/test/sinit.go
@@ -1,4 +1,4 @@
-// $G -S $D/$F.go | egrep initdone >/dev/null && echo FAIL || true
+// $G -S $D/$F.go | egrep initdone >/dev/null && echo BUG sinit || true
 
 // Copyright 2010 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style
@@ -9,45 +9,45 @@ package p
 // Should be no init func in the assembly.
 // All these initializations should be done at link time.
 
-type	S	struct{ a,b,c int }
-type	SS	struct{ aa,bb,cc S }
-type	SA	struct{ a,b,c [3]int }
-type	SC	struct{ a,b,c []int }
+type S struct{ a, b, c int }
+type SS struct{ aa, bb, cc S }
+type SA struct{ a, b, c [3]int }
+type SC struct{ a, b, c []int }
 
 var (
-	zero = 2
-	one = 1
-	pi = 3.14
-	slice = []byte{1,2,3}
-	sliceInt = []int{1,2,3}
-	hello = "hello, world"
-	bytes = []byte("hello, world")
-	four, five = 4, 5
-	x, y = 0.1, "hello"
-	nilslice []byte = nil
-	nilmap map[string]int = nil
-	nilfunc func() = nil
-	nilchan chan int = nil
-	nilptr *byte = nil
+	zero                      = 2
+	one                       = 1
+	pi                        = 3.14
+	slice                     = []byte{1, 2, 3}
+	sliceInt                  = []int{1, 2, 3}
+	hello                     = "hello, world"
+	bytes                     = []byte("hello, world")
+	four, five                = 4, 5
+	x, y                      = 0.1, "hello"
+	nilslice   []byte         = nil
+	nilmap     map[string]int = nil
+	nilfunc    func()         = nil
+	nilchan    chan int       = nil
+	nilptr     *byte          = nil
 )
 
-var	a	= [3]int{1001, 1002, 1003}
-var	s	= S{1101, 1102, 1103}
-var	c	= []int{1201, 1202, 1203}
+var a = [3]int{1001, 1002, 1003}
+var s = S{1101, 1102, 1103}
+var c = []int{1201, 1202, 1203}
 
-var	aa	= [3][3]int{[3]int{2001,2002,2003}, [3]int{2004,2005,2006}, [3]int{2007,2008,2009}}
-var	as	= [3]S{S{2101,2102,2103},S{2104,2105,2106},S{2107,2108,2109}}
-var	ac	= [3][]int{[]int{2201,2202,2203}, []int{2204,2205,2206}, []int{2207,2208,2209}}
+var aa = [3][3]int{[3]int{2001, 2002, 2003}, [3]int{2004, 2005, 2006}, [3]int{2007, 2008, 2009}}
+var as = [3]S{S{2101, 2102, 2103}, S{2104, 2105, 2106}, S{2107, 2108, 2109}}
+var ac = [3][]int{[]int{2201, 2202, 2203}, []int{2204, 2205, 2206}, []int{2207, 2208, 2209}}
 
-var	sa	= SA{[3]int{3001,3002,3003},[3]int{3004,3005,3006},[3]int{3007,3008,3009}}
-var	ss	= SS{S{3101,3102,3103},S{3104,3105,3106},S{3107,3108,3109}}
-var	sc	= SC{[]int{3201,3202,3203},[]int{3204,3205,3206},[]int{3207,3208,3209}}
+var sa = SA{[3]int{3001, 3002, 3003}, [3]int{3004, 3005, 3006}, [3]int{3007, 3008, 3009}}
+var ss = SS{S{3101, 3102, 3103}, S{3104, 3105, 3106}, S{3107, 3108, 3109}}
+var sc = SC{[]int{3201, 3202, 3203}, []int{3204, 3205, 3206}, []int{3207, 3208, 3209}}
 
-var	ca	= [][3]int{[3]int{4001,4002,4003}, [3]int{4004,4005,4006}, [3]int{4007,4008,4009}}
-var	cs	= []S{S{4101,4102,4103},S{4104,4105,4106},S{4107,4108,4109}}
-var	cc	= [][]int{[]int{4201,4202,4203}, []int{4204,4205,4206}, []int{4207,4208,4209}}
+var ca = [][3]int{[3]int{4001, 4002, 4003}, [3]int{4004, 4005, 4006}, [3]int{4007, 4008, 4009}}
+var cs = []S{S{4101, 4102, 4103}, S{4104, 4105, 4106}, S{4107, 4108, 4109}}
+var cc = [][]int{[]int{4201, 4202, 4203}, []int{4204, 4205, 4206}, []int{4207, 4208, 4209}}
 
-var	answers	= [...]int {
+var answers = [...]int{
 	// s
 	1101, 1102, 1103,
 
@@ -98,3 +98,158 @@ var	answers	= [...]int {
 	2008, 2208, 2308, 4008, 4208, 4308, 5008, 5208, 5308,
 	2009, 2209, 2309, 4009, 4209, 4309, 5009, 5209, 5309,
 }
+
+var (
+	copy_zero = zero
+	copy_one = one
+	copy_pi = pi
+	copy_slice = slice
+	copy_sliceInt = sliceInt
+	copy_hello = hello
+	copy_bytes = bytes
+	copy_four, copy_five = four, five
+	copy_x, copy_y = x, y
+	copy_nilslice = nilslice
+	copy_nilmap = nilmap
+	copy_nilfunc = nilfunc
+	copy_nilchan = nilchan
+	copy_nilptr = nilptr
+)
+
+var copy_a = a
+var copy_s = s
+var copy_c = c
+
+var copy_aa = aa
+var copy_as = as
+var copy_ac = ac
+
+var copy_sa = sa
+var copy_ss = ss
+var copy_sc = sc
+
+var copy_ca = ca
+var copy_cs = cs
+var copy_cc = cc
+
+var copy_answers = answers
+
+var bx bool
+var b0 = false
+var b1 = true
+
+var fx float32
+var f0 = float32(0)
+var f1 = float32(1)
+
+var gx float64
+var g0 = float64(0)
+var g1 = float64(1)
+
+var ix int
+var i0 = 0
+var i1 = 1
+
+var jx uint
+var j0 = uint(0)
+var j1 = uint(1)
+
+var cx complex64
+var c0 = complex64(0)
+var c1 = complex64(1)
+
+var dx complex128
+var d0 = complex128(0)
+var d1 = complex128(1)
+
+var sx []int
+var s0 = []int{0, 0, 0}
+var s1 = []int{1, 2, 3}
+
+func fi() int
+
+var ax [10]int
+var a0 = [10]int{0, 0, 0}
+var a1 = [10]int{1, 2, 3, 4}
+
+type T struct{ X, Y int }
+
+var tx T
+var t0 = T{}
+var t0a = T{0, 0}
+var t0b = T{X: 0}
+var t1 = T{X: 1, Y: 2}
+var t1a = T{3, 4}
+
+var psx *[]int
+var ps0 = &[]int{0, 0, 0}
+var ps1 = &[]int{1, 2, 3}
+
+var pax *[10]int
+var pa0 = &[10]int{0, 0, 0}
+var pa1 = &[10]int{1, 2, 3}
+
+var ptx *T
+var pt0 = &T{}
+var pt0a = &T{0, 0}
+var pt0b = &T{X: 0}
+var pt1 = &T{X: 1, Y: 2}
+var pt1a = &T{3, 4}
+
+var copy_bx = bx
+var copy_b0 = b0
+var copy_b1 = b1
+
+var copy_fx = fx
+var copy_f0 = f0
+var copy_f1 = f1
+
+var copy_gx = gx
+var copy_g0 = g0
+var copy_g1 = g1
+
+var copy_ix = ix
+var copy_i0 = i0
+var copy_i1 = i1
+
+var copy_jx = jx
+var copy_j0 = j0
+var copy_j1 = j1
+
+var copy_cx = cx
+var copy_c0 = c0
+var copy_c1 = c1
+
+var copy_dx = dx
+var copy_d0 = d0
+var copy_d1 = d1
+
+var copy_sx = sx
+var copy_s0 = s0
+var copy_s1 = s1
+
+var copy_ax = ax
+var copy_a0 = a0
+var copy_a1 = a1
+
+var copy_tx = tx
+var copy_t0 = t0
+var copy_t0a = t0a
+var copy_t0b = t0b
+var copy_t1 = t1
+var copy_t1a = t1a
+
+var copy_psx = psx
+var copy_ps0 = ps0
+var copy_ps1 = ps1
+
+var copy_pax = pax
+var copy_pa0 = pa0
+var copy_pa1 = pa1
+
+var copy_ptx = ptx
+var copy_pt0 = pt0
+var copy_pt0a = pt0a
+var copy_pt0b = pt0b
+var copy_pt1 = pt1
+var copy_pt1a = pt1a