cmd/internal/gc: increase registerization limits
Also clean up code a little.
Change-Id: I23b7d2b7871b31e0974f1305e54f0c18dcab05d9
Reviewed-on: https://go-review.googlesource.com/7746
Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/cmd/internal/gc/popt.go b/src/cmd/internal/gc/popt.go
index 8dcd1df..ac6dd5e 100644
--- a/src/cmd/internal/gc/popt.go
+++ b/src/cmd/internal/gc/popt.go
@@ -1,44 +1,3 @@
-// Derived from Inferno utils/6c/reg.c
-// http://code.google.com/p/inferno-os/source/browse/utils/6c/reg.c
-//
-// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
-// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
-// Portions Copyright © 1997-1999 Vita Nuova Limited
-// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
-// Portions Copyright © 2004,2006 Bruce Ellis
-// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
-// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
-// Portions Copyright © 2009 The Go Authors. All rights reserved.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-package gc
-
-import (
- "cmd/internal/obj"
- "fmt"
- "sort"
- "strings"
-)
-
-// "Portable" optimizations.
-
// Derived from Inferno utils/6c/gc.h
// http://code.google.com/p/inferno-os/source/browse/utils/6c/gc.h
//
@@ -69,92 +28,17 @@
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
-const (
- CLOAD = 5
- CREF = 5
- CINF = 1000
- LOOP = 3
+// "Portable" optimizations.
+
+package gc
+
+import (
+ "cmd/internal/obj"
+ "fmt"
+ "sort"
+ "strings"
)
-type Reg struct {
- set Bits // regopt variables written by this instruction.
- use1 Bits // regopt variables read by prog->from.
- use2 Bits // regopt variables read by prog->to.
-
- // refahead/refbehind are the regopt variables whose current
- // value may be used in the following/preceding instructions
- // up to a CALL (or the value is clobbered).
- refbehind Bits
- refahead Bits
-
- // calahead/calbehind are similar, but for variables in
- // instructions that are reachable after hitting at least one
- // CALL.
- calbehind Bits
- calahead Bits
-
- regdiff Bits
- act Bits
- regu uint64 // register used bitmap
-}
-
-type Rgn struct {
- enter *Flow
- cost int16
- varno int16
- regno int16
-}
-
-var Z *Node
-
-// A Reg is a wrapper around a single Prog (one instruction) that holds
-// register optimization information while the optimizer runs.
-// r->prog is the instruction.
-
-var R *Reg
-
-const (
- NRGN = 600
-)
-
-// A Rgn represents a single regopt variable over a region of code
-// where a register could potentially be dedicated to that variable.
-// The code encompassed by a Rgn is defined by the flow graph,
-// starting at enter, flood-filling forward while varno is refahead
-// and backward while varno is refbehind, and following branches. A
-// single variable may be represented by multiple disjoint Rgns and
-// each Rgn may choose a different register for that variable.
-// Registers are allocated to regions greedily in order of descending
-// cost.
-
-var zreg Reg
-
-var region [NRGN]Rgn
-
-var rgp *Rgn
-
-var nregion int
-
-var nvar int
-
-var regbits uint64
-
-var externs Bits
-
-var params Bits
-
-var consts Bits
-
-var addrs Bits
-
-var ivar Bits
-
-var ovar Bits
-
-var change int
-
-var maxnr int32
-
type OptStats struct {
Ncvtreg int32
Nspill int32
@@ -354,6 +238,11 @@
var flowmark int
+// MaxFlowProg is the maximum size program (counted in instructions)
+// for which the flow code will build a graph. Functions larger than this limit
+// will not have flow graphs and consequently will not be optimized.
+const MaxFlowProg = 50000
+
func Flowstart(firstp *obj.Prog, newData func() interface{}) *Graph {
// Count and mark instructions to annotate.
nf := 0
@@ -372,8 +261,10 @@
return nil
}
- if nf >= 20000 {
- // fatal("%S is too big (%d instructions)", curfn->nname->sym, nf);
+ if nf >= MaxFlowProg {
+ if Debug['v'] != 0 {
+ Warn("%v is too big (%d instructions)", Sconv(Curfn.Nname.Sym, 0), nf)
+ }
return nil
}
@@ -678,7 +569,7 @@
func mergetemp(firstp *obj.Prog) {
const (
- debugmerge = 1
+ debugmerge = 0
)
g := Flowstart(firstp, nil)
