cmd/compile: rearrange fields between ssa.Func, ssa.Cache, and ssa.Config

This makes ssa.Func, ssa.Cache, and ssa.Config fulfill
the roles laid out for them in CL 38160.

The only non-trivial change in this CL is how cached
values and blocks get IDs. Prior to this CL, their IDs were
assigned as part of resetting the cache, and only modified
IDs were reset. This required knowing how many values and
blocks were modified, which required a tight coupling between
ssa.Func and ssa.Config. To eliminate that coupling,
we now zero values and blocks during reset,
and assign their IDs when they are used.
Since unused values and blocks have ID == 0,
we can efficiently find the last used value/block,
to avoid zeroing everything.
Bulk zeroing is efficient, but not efficient enough
to obviate the need to avoid zeroing everything every time.
As a happy side-effect, ssa.Func.Free is no longer necessary.

DebugHashMatch and friends now belong in func.go.
They have been left in place for clarity and review.
I will move them in a subsequent CL.

Passes toolstash -cmp. No compiler performance impact.
No change in 'go test cmd/compile/internal/ssa' execution time.

Change-Id: I2eb7af58da067ef6a36e815a6f386cfe8634d098
Reviewed-on: https://go-review.googlesource.com/38167
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/gc/main.go

@@ -483,6 +483,11 @@ func Main() {
 			}
 		}
 
+		// Prepare for SSA compilation.
+		// This must be before peekitabs, because peekitabs
+		// can trigger function compilation.
+		initssaconfig()
+
 		// Just before compilation, compile itabs found on
 		// the right side of OCONVIFACE so that methods
 		// can be de-virtualized during compilation.

src/cmd/compile/internal/gc/pgen.go

@@ -411,7 +411,6 @@ func compile(fn *Node) {
 	gclocals := makefuncdatasym("gclocals·", obj.FUNCDATA_LocalsPointerMaps)
 
 	genssa(ssafn, ptxt, gcargs, gclocals)
-	ssafn.Free()
 
 	obj.Flushplist(Ctxt, plist) // convert from Prog list to machine code
 	ptxt = nil                  // nil to prevent misuse; Prog may have been freed by Flushplist

src/cmd/compile/internal/gc/ssa.go

@@ -20,16 +20,14 @@ import (
 
 var ssaConfig *ssa.Config
 var ssaExp ssaExport
+var ssaCache *ssa.Cache
 
-func initssa() *ssa.Config {
-	if ssaConfig == nil {
+func initssaconfig() {
 	ssaConfig = ssa.NewConfig(Thearch.LinkArch.Name, &ssaExp, Ctxt, Debug['N'] == 0)
 	if Thearch.LinkArch.Name == "386" {
 		ssaConfig.Set387(Thearch.Use387)
 	}
-	}
-	ssaConfig.HTML = nil
-	return ssaConfig
+	ssaCache = new(ssa.Cache)
 }
 
 // buildssa builds an SSA function.
@@ -51,12 +49,15 @@ func buildssa(fn *Node) *ssa.Func {
 	if fn.Func.Pragma&CgoUnsafeArgs != 0 {
 		s.cgoUnsafeArgs = true
 	}
-	// TODO(khr): build config just once at the start of the compiler binary
 
 	ssaExp.log = printssa
 
-	s.config = initssa()
-	s.f = s.config.NewFunc()
+	s.f = ssa.NewFunc()
+	s.config = ssaConfig
+	s.f.Config = ssaConfig
+	s.f.Cache = ssaCache
+	s.f.Cache.Reset()
+	s.f.DebugTest = s.f.DebugHashMatch("GOSSAHASH", name)
 	s.f.Name = name
 	if fn.Func.Pragma&Nosplit != 0 {
 		s.f.NoSplit = true
@@ -71,12 +72,9 @@ func buildssa(fn *Node) *ssa.Func {
 	}()
 	s.exitCode = fn.Func.Exit
 	s.panics = map[funcLine]*ssa.Block{}
-	s.config.DebugTest = s.config.DebugHashMatch("GOSSAHASH", name)
 
 	if name == os.Getenv("GOSSAFUNC") {
-		// TODO: tempfile? it is handy to have the location
-		// of this file be stable, so you can just reload in the browser.
-		s.config.HTML = ssa.NewHTMLWriter("ssa.html", s.config, name)
+		s.f.HTMLWriter = ssa.NewHTMLWriter("ssa.html", ssaConfig, name)
 		// TODO: generate and print a mapping from nodes to values and blocks
 	}
 
@@ -140,7 +138,6 @@ func buildssa(fn *Node) *ssa.Func {
 	}
 
 	if nerrors > 0 {
-		s.f.Free()
 		return nil
 	}
 
@@ -152,7 +149,6 @@ func buildssa(fn *Node) *ssa.Func {
 	// Main call to ssa package to compile function
 	ssa.Compile(s.f)
 	if nerrors > 0 {
-		s.f.Free()
 		return nil
 	}
 
@@ -4287,7 +4283,7 @@ func genssa(f *ssa.Func, ptxt *obj.Prog, gcargs, gclocals *Sym) {
 			}
 			f.Logf("%s\t%s\n", s, p)
 		}
-		if f.Config.HTML != nil {
+		if f.HTMLWriter != nil {
 			// LineHist is defunct now - this code won't do
 			// anything.
 			// TODO: fix this (ideally without a global variable)
@@ -4311,7 +4307,7 @@ func genssa(f *ssa.Func, ptxt *obj.Prog, gcargs, gclocals *Sym) {
 			}
 			buf.WriteString("</dl>")
 			buf.WriteString("</code>")
-			f.Config.HTML.WriteColumn("genssa", buf.String())
+			f.HTMLWriter.WriteColumn("genssa", buf.String())
 			// ptxt.Ctxt.LineHist.PrintFilenameOnly = saved
 		}
 	}
@@ -4328,8 +4324,8 @@ func genssa(f *ssa.Func, ptxt *obj.Prog, gcargs, gclocals *Sym) {
 	// Remove leftover instrumentation from the instruction stream.
 	removevardef(ptxt)
 
-	f.Config.HTML.Close()
-	f.Config.HTML = nil
+	f.HTMLWriter.Close()
+	f.HTMLWriter = nil
 }
 
 type FloatingEQNEJump struct {

src/cmd/compile/internal/ssa/cache.go

@@ -4,7 +4,38 @@
 
 package ssa
 
+import "sort"
+
 // A Cache holds reusable compiler state.
 // It is intended to be re-used for multiple Func compilations.
 type Cache struct {
+	// Storage for low-numbered values and blocks.
+	values [2000]Value
+	blocks [200]Block
+	locs   [2000]Location
+
+	// Reusable stackAllocState.
+	// See stackalloc.go's {new,put}StackAllocState.
+	stackAllocState *stackAllocState
+
+	domblockstore []ID         // scratch space for computing dominators
+	scrSparse     []*sparseSet // scratch sparse sets to be re-used.
+}
+
+func (c *Cache) Reset() {
+	nv := sort.Search(len(c.values), func(i int) bool { return c.values[i].ID == 0 })
+	xv := c.values[:nv]
+	for i := range xv {
+		xv[i] = Value{}
+	}
+	nb := sort.Search(len(c.blocks), func(i int) bool { return c.blocks[i].ID == 0 })
+	xb := c.blocks[:nb]
+	for i := range xb {
+		xb[i] = Block{}
+	}
+	nl := sort.Search(len(c.locs), func(i int) bool { return c.locs[i] == nil })
+	xl := c.locs[:nl]
+	for i := range xl {
+		xl[i] = nil
+	}
 }

src/cmd/compile/internal/ssa/compile.go

@@ -43,7 +43,7 @@ func Compile(f *Func) {
 
 	// Run all the passes
 	printFunc(f)
-	f.Config.HTML.WriteFunc("start", f)
+	f.HTMLWriter.WriteFunc("start", f)
 	if BuildDump != "" && BuildDump == f.Name {
 		f.dumpFile("build")
 	}
@@ -71,7 +71,7 @@ func Compile(f *Func) {
 		tEnd := time.Now()
 
 		// Need something less crude than "Log the whole intermediate result".
-		if f.Log() || f.Config.HTML != nil {
+		if f.Log() || f.HTMLWriter != nil {
 			time := tEnd.Sub(tStart).Nanoseconds()
 			var stats string
 			if logMemStats {
@@ -86,7 +86,7 @@ func Compile(f *Func) {
 
 			f.Logf("  pass %s end %s\n", p.name, stats)
 			printFunc(f)
-			f.Config.HTML.WriteFunc(fmt.Sprintf("after %s <span class=\"stats\">%s</span>", phaseName, stats), f)
+			f.HTMLWriter.WriteFunc(fmt.Sprintf("after %s <span class=\"stats\">%s</span>", phaseName, stats), f)
 		}
 		if p.time || p.mem {
 			// Surround timing information w/ enough context to allow comparisons.

src/cmd/compile/internal/ssa/config.go

@@ -32,7 +32,6 @@ type Config struct {
 	LinkReg         int8                       // register number of link register if it is a general purpose register, -1 if not used
 	hasGReg         bool                       // has hardware g register
 	fe              Frontend                   // callbacks into compiler frontend
-	HTML            *HTMLWriter                // html writer, for debugging
 	ctxt            *obj.Link                  // Generic arch information
 	optimize        bool                       // Do optimization
 	noDuffDevice    bool                       // Don't use Duff's device
@@ -41,27 +40,7 @@ type Config struct {
 	OldArch         bool                       // True for older versions of architecture, e.g. true for PPC64BE, false for PPC64LE
 	NeedsFpScratch  bool                       // No direct move between GP and FP register sets
 	BigEndian       bool                       //
-	DebugTest       bool                       // default true unless $GOSSAHASH != ""; as a debugging aid, make new code conditional on this and use GOSSAHASH to binary search for failing cases
 	sparsePhiCutoff uint64                     // Sparse phi location algorithm used above this #blocks*#variables score
-	curFunc         *Func
-
-	// TODO: more stuff. Compiler flags of interest, ...
-
-	// Given an environment variable used for debug hash match,
-	// what file (if any) receives the yes/no logging?
-	logfiles map[string]*os.File
-
-	// Storage for low-numbered values and blocks.
-	values [2000]Value
-	blocks [200]Block
-	locs   [2000]Location
-
-	// Reusable stackAllocState.
-	// See stackalloc.go's {new,put}StackAllocState.
-	stackAllocState *stackAllocState
-
-	domblockstore []ID         // scratch space for computing dominators
-	scrSparse     []*sparseSet // scratch sparse sets to be re-used.
 }
 
 type TypeSource interface {
@@ -304,16 +283,6 @@ func NewConfig(arch string, fe Frontend, ctxt *obj.Link, optimize bool) *Config
 		opcodeTable[OpARMCALLudiv].reg.clobbers |= 1 << 12 // R12
 	}
 
-	// Assign IDs to preallocated values/blocks.
-	for i := range c.values {
-		c.values[i].ID = ID(i)
-	}
-	for i := range c.blocks {
-		c.blocks[i].ID = ID(i)
-	}
-
-	c.logfiles = make(map[string]*os.File)
-
 	// cutoff is compared with product of numblocks and numvalues,
 	// if product is smaller than cutoff, use old non-sparse method.
 	// cutoff == 0 implies all sparse.
@@ -342,18 +311,6 @@ func (c *Config) Frontend() Frontend      { return c.fe }
 func (c *Config) SparsePhiCutoff() uint64 { return c.sparsePhiCutoff }
 func (c *Config) Ctxt() *obj.Link         { return c.ctxt }
 
-// NewFunc returns a new, empty function object.
-// Caller must call f.Free() before calling NewFunc again.
-func (c *Config) NewFunc() *Func {
-	// TODO(khr): should this function take name, type, etc. as arguments?
-	if c.curFunc != nil {
-		c.Fatalf(src.NoXPos, "NewFunc called without previous Free")
-	}
-	f := &Func{Config: c, NamedValues: map[LocalSlot][]*Value{}}
-	c.curFunc = f
-	return f
-}
-
 func (c *Config) Logf(msg string, args ...interface{})                 { c.fe.Logf(msg, args...) }
 func (c *Config) Log() bool                                            { return c.fe.Log() }
 func (c *Config) Fatalf(pos src.XPos, msg string, args ...interface{}) { c.fe.Fatalf(pos, msg, args...) }
@@ -362,8 +319,11 @@ func (c *Config) Warnl(pos src.XPos, msg string, args ...interface{})  { c.fe.Wa
 func (c *Config) Debug_checknil() bool                                 { return c.fe.Debug_checknil() }
 func (c *Config) Debug_wb() bool                                       { return c.fe.Debug_wb() }
 
-func (c *Config) logDebugHashMatch(evname, name string) {
-	file := c.logfiles[evname]
+func (f *Func) logDebugHashMatch(evname, name string) {
+	if f.logfiles == nil {
+		f.logfiles = make(map[string]*os.File)
+	}
+	file := f.logfiles[evname]
 	if file == nil {
 		file = os.Stdout
 		tmpfile := os.Getenv("GSHS_LOGFILE")
@@ -371,10 +331,10 @@ func (c *Config) logDebugHashMatch(evname, name string) {
 			var ok error
 			file, ok = os.Create(tmpfile)
 			if ok != nil {
-				c.Fatalf(src.NoXPos, "Could not open hash-testing logfile %s", tmpfile)
+				f.Fatalf("could not open hash-testing logfile %s", tmpfile)
 			}
 		}
-		c.logfiles[evname] = file
+		f.logfiles[evname] = file
 	}
 	s := fmt.Sprintf("%s triggered %s\n", evname, name)
 	file.WriteString(s)
@@ -395,14 +355,13 @@ func (c *Config) logDebugHashMatch(evname, name string) {
 //  GSHS_LOGFILE
 // or standard out if that is empty or there is an error
 // opening the file.
-
-func (c *Config) DebugHashMatch(evname, name string) bool {
+func (f *Func) DebugHashMatch(evname, name string) bool {
 	evhash := os.Getenv(evname)
 	if evhash == "" {
 		return true // default behavior with no EV is "on"
 	}
 	if evhash == "y" || evhash == "Y" {
-		c.logDebugHashMatch(evname, name)
+		f.logDebugHashMatch(evname, name)
 		return true
 	}
 	if evhash == "n" || evhash == "N" {
@@ -417,7 +376,7 @@ func (c *Config) DebugHashMatch(evname, name string) bool {
 	}
 
 	if strings.HasSuffix(hstr, evhash) {
-		c.logDebugHashMatch(evname, name)
+		f.logDebugHashMatch(evname, name)
 		return true
 	}
 
@@ -430,13 +389,13 @@ func (c *Config) DebugHashMatch(evname, name string) bool {
 			break
 		}
 		if strings.HasSuffix(hstr, evv) {
-			c.logDebugHashMatch(ev, name)
+			f.logDebugHashMatch(ev, name)
 			return true
 		}
 	}
 	return false
 }
 
-func (c *Config) DebugNameMatch(evname, name string) bool {
+func DebugNameMatch(evname, name string) bool {
 	return os.Getenv(evname) == name
 }

src/cmd/compile/internal/ssa/copyelim_test.go

@@ -36,6 +36,5 @@ func benchmarkCopyElim(b *testing.B, n int) {
 	for i := 0; i < b.N; i++ {
 		fun := Fun(c, "entry", Bloc("entry", values...))
 		Copyelim(fun.f)
-		fun.f.Free()
 	}
 }

src/cmd/compile/internal/ssa/deadcode_test.go

@@ -154,7 +154,6 @@ func BenchmarkDeadCode(b *testing.B) {
 			for i := 0; i < b.N; i++ {
 				fun := Fun(c, "entry", blocks...)
 				Deadcode(fun.f)
-				fun.f.Free()
 			}
 		})
 	}

src/cmd/compile/internal/ssa/dom.go

@@ -70,9 +70,9 @@ const nscratchslices = 7
 // in make.bash.
 const minscratchblocks = 512
 
-func (cfg *Config) scratchBlocksForDom(maxBlockID int) (a, b, c, d, e, f, g []ID) {
+func (cache *Cache) scratchBlocksForDom(maxBlockID int) (a, b, c, d, e, f, g []ID) {
 	tot := maxBlockID * nscratchslices
-	scratch := cfg.domblockstore
+	scratch := cache.domblockstore
 	if len(scratch) < tot {
 		// req = min(1.5*tot, nscratchslices*minscratchblocks)
 		// 50% padding allows for graph growth in later phases.
@@ -81,7 +81,7 @@ func (cfg *Config) scratchBlocksForDom(maxBlockID int) (a, b, c, d, e, f, g []ID
 			req = nscratchslices * minscratchblocks
 		}
 		scratch = make([]ID, req)
-		cfg.domblockstore = scratch
+		cache.domblockstore = scratch
 	} else {
 		// Clear as much of scratch as we will (re)use
 		scratch = scratch[0:tot]
@@ -117,7 +117,7 @@ func (f *Func) dominatorsLTOrig(entry *Block, predFn linkedBlocks, succFn linked
 	// Adapted directly from the original TOPLAS article's "simple" algorithm
 
 	maxBlockID := entry.Func.NumBlocks()
-	semi, vertex, label, parent, ancestor, bucketHead, bucketLink := f.Config.scratchBlocksForDom(maxBlockID)
+	semi, vertex, label, parent, ancestor, bucketHead, bucketLink := f.Cache.scratchBlocksForDom(maxBlockID)
 
 	// This version uses integers for most of the computation,
 	// to make the work arrays smaller and pointer-free.

src/cmd/compile/internal/ssa/func.go

@@ -8,6 +8,7 @@ import (
 	"cmd/internal/src"
 	"fmt"
 	"math"
+	"os"
 	"strings"
 )
 
@@ -16,6 +17,7 @@ import (
 // Funcs are single-use; a new Func must be created for every compiled function.
 type Func struct {
 	Config *Config  // architecture information
+	Cache  *Cache   // re-usable cache
 	pass   *pass    // current pass information (name, options, etc.)
 	Name   string   // e.g. bytes·Compare
 	Type   Type     // type signature of the function.
@@ -24,6 +26,12 @@ type Func struct {
 	bid    idAlloc  // block ID allocator
 	vid    idAlloc  // value ID allocator
 
+	// Given an environment variable used for debug hash match,
+	// what file (if any) receives the yes/no logging?
+	logfiles   map[string]*os.File
+	HTMLWriter *HTMLWriter // html writer, for debugging
+	DebugTest  bool        // default true unless $GOSSAHASH != ""; as a debugging aid, make new code conditional on this and use GOSSAHASH to binary search for failing cases
+
 	scheduled bool // Values in Blocks are in final order
 	NoSplit   bool // true if function is marked as nosplit.  Used by schedule check pass.
 
@@ -52,6 +60,12 @@ type Func struct {
 	constants map[int64][]*Value // constants cache, keyed by constant value; users must check value's Op and Type
 }
 
+// NewFunc returns a new, empty function object.
+// Caller must set f.Config and f.Cache before using f.
+func NewFunc() *Func {
+	return &Func{NamedValues: make(map[LocalSlot][]*Value)}
+}
+
 // NumBlocks returns an integer larger than the id of any Block in the Func.
 func (f *Func) NumBlocks() int {
 	return f.bid.num()
@@ -64,9 +78,9 @@ func (f *Func) NumValues() int {
 
 // newSparseSet returns a sparse set that can store at least up to n integers.
 func (f *Func) newSparseSet(n int) *sparseSet {
-	for i, scr := range f.Config.scrSparse {
+	for i, scr := range f.Cache.scrSparse {
 		if scr != nil && scr.cap() >= n {
-			f.Config.scrSparse[i] = nil
+			f.Cache.scrSparse[i] = nil
 			scr.clear()
 			return scr
 		}
@@ -76,13 +90,13 @@ func (f *Func) newSparseSet(n int) *sparseSet {
 
 // retSparseSet returns a sparse set to the config's cache of sparse sets to be reused by f.newSparseSet.
 func (f *Func) retSparseSet(ss *sparseSet) {
-	for i, scr := range f.Config.scrSparse {
+	for i, scr := range f.Cache.scrSparse {
 		if scr == nil {
-			f.Config.scrSparse[i] = ss
+			f.Cache.scrSparse[i] = ss
 			return
 		}
 	}
-	f.Config.scrSparse = append(f.Config.scrSparse, ss)
+	f.Cache.scrSparse = append(f.Cache.scrSparse, ss)
 }
 
 // newValue allocates a new Value with the given fields and places it at the end of b.Values.
@@ -94,8 +108,9 @@ func (f *Func) newValue(op Op, t Type, b *Block, pos src.XPos) *Value {
 		v.argstorage[0] = nil
 	} else {
 		ID := f.vid.get()
-		if int(ID) < len(f.Config.values) {
-			v = &f.Config.values[ID]
+		if int(ID) < len(f.Cache.values) {
+			v = &f.Cache.values[ID]
+			v.ID = ID
 		} else {
 			v = &Value{ID: ID}
 		}
@@ -120,8 +135,9 @@ func (f *Func) newValueNoBlock(op Op, t Type, pos src.XPos) *Value {
 		v.argstorage[0] = nil
 	} else {
 		ID := f.vid.get()
-		if int(ID) < len(f.Config.values) {
-			v = &f.Config.values[ID]
+		if int(ID) < len(f.Cache.values) {
+			v = &f.Cache.values[ID]
+			v.ID = ID
 		} else {
 			v = &Value{ID: ID}
 		}
@@ -190,8 +206,9 @@ func (f *Func) NewBlock(kind BlockKind) *Block {
 		b.succstorage[0].b = nil
 	} else {
 		ID := f.bid.get()
-		if int(ID) < len(f.Config.blocks) {
-			b = &f.Config.blocks[ID]
+		if int(ID) < len(f.Cache.blocks) {
+			b = &f.Cache.blocks[ID]
+			b.ID = ID
 		} else {
 			b = &Block{ID: ID}
 		}
@@ -468,48 +485,6 @@ func (f *Func) Logf(msg string, args ...interface{})   { f.Config.Logf(msg, args
 func (f *Func) Log() bool                              { return f.Config.Log() }
 func (f *Func) Fatalf(msg string, args ...interface{}) { f.Config.Fatalf(f.Entry.Pos, msg, args...) }
 
-func (f *Func) Free() {
-	// Clear cached CFG info.
-	f.invalidateCFG()
-
-	// Clear values.
-	n := f.vid.num()
-	if n > len(f.Config.values) {
-		n = len(f.Config.values)
-	}
-	for i := 1; i < n; i++ {
-		f.Config.values[i] = Value{}
-		f.Config.values[i].ID = ID(i)
-	}
-
-	// Clear blocks.
-	n = f.bid.num()
-	if n > len(f.Config.blocks) {
-		n = len(f.Config.blocks)
-	}
-	for i := 1; i < n; i++ {
-		f.Config.blocks[i] = Block{}
-		f.Config.blocks[i].ID = ID(i)
-	}
-
-	// Clear locs.
-	n = len(f.RegAlloc)
-	if n > len(f.Config.locs) {
-		n = len(f.Config.locs)
-	}
-	head := f.Config.locs[:n]
-	for i := range head {
-		head[i] = nil
-	}
-
-	// Unregister from config.
-	if f.Config.curFunc != f {
-		f.Fatalf("free of function which isn't the last one allocated")
-	}
-	f.Config.curFunc = nil
-	*f = Func{} // just in case
-}
-
 // postorder returns the reachable blocks in f in a postorder traversal.
 func (f *Func) postorder() []*Block {
 	if f.cachedPostorder == nil {

src/cmd/compile/internal/ssa/func_test.go

@@ -144,7 +144,12 @@ var emptyPass pass = pass{
 // supplied to one of the Bloc functions. Each of the bloc names and
 // valu names should be unique across the Fun.
 func Fun(c *Config, entry string, blocs ...bloc) fun {
-	f := c.NewFunc()
+	f := NewFunc()
+	f.Config = c
+	// TODO: Either mark some SSA tests as t.Parallel,
+	// or set up a shared Cache and Reset it between tests.
+	// But not both.
+	f.Cache = new(Cache)
 	f.pass = &emptyPass
 
 	blocks := make(map[string]*Block)

src/cmd/compile/internal/ssa/fuse_test.go

@@ -162,7 +162,6 @@ func BenchmarkFuse(b *testing.B) {
 			for i := 0; i < b.N; i++ {
 				fun := Fun(c, "entry", blocks...)
 				fuse(fun.f)
-				fun.f.Free()
 			}
 		})
 	}

src/cmd/compile/internal/ssa/loop_test.go

@@ -82,6 +82,4 @@ func TestLoopConditionS390X(t *testing.T) {
 		OpS390XCMP:       1,
 		OpS390XCMPWconst: 0,
 	})
-
-	fun.f.Free()
 }

src/cmd/compile/internal/ssa/regalloc.go

@@ -495,7 +495,7 @@ func isLeaf(f *Func) bool {
 
 func (s *regAllocState) init(f *Func) {
 	s.f = f
-	s.f.RegAlloc = s.f.Config.locs[:0]
+	s.f.RegAlloc = s.f.Cache.locs[:0]
 	s.registers = f.Config.registers
 	if nr := len(s.registers); nr == 0 || nr > int(noRegister) || nr > int(unsafe.Sizeof(regMask(0))*8) {
 		s.f.Fatalf("bad number of registers: %d", nr)

src/cmd/compile/internal/ssa/shift_test.go

@@ -12,22 +12,21 @@ func TestShiftConstAMD64(t *testing.T) {
 	c := testConfig(t)
 	fun := makeConstShiftFunc(c, 18, OpLsh64x64, TypeUInt64)
 	checkOpcodeCounts(t, fun.f, map[Op]int{OpAMD64SHLQconst: 1, OpAMD64CMPQconst: 0, OpAMD64ANDQconst: 0})
-	fun.f.Free()
+
 	fun = makeConstShiftFunc(c, 66, OpLsh64x64, TypeUInt64)
 	checkOpcodeCounts(t, fun.f, map[Op]int{OpAMD64SHLQconst: 0, OpAMD64CMPQconst: 0, OpAMD64ANDQconst: 0})
-	fun.f.Free()
+
 	fun = makeConstShiftFunc(c, 18, OpRsh64Ux64, TypeUInt64)
 	checkOpcodeCounts(t, fun.f, map[Op]int{OpAMD64SHRQconst: 1, OpAMD64CMPQconst: 0, OpAMD64ANDQconst: 0})
-	fun.f.Free()
+
 	fun = makeConstShiftFunc(c, 66, OpRsh64Ux64, TypeUInt64)
 	checkOpcodeCounts(t, fun.f, map[Op]int{OpAMD64SHRQconst: 0, OpAMD64CMPQconst: 0, OpAMD64ANDQconst: 0})
-	fun.f.Free()
+
 	fun = makeConstShiftFunc(c, 18, OpRsh64x64, TypeInt64)
 	checkOpcodeCounts(t, fun.f, map[Op]int{OpAMD64SARQconst: 1, OpAMD64CMPQconst: 0})
-	fun.f.Free()
+
 	fun = makeConstShiftFunc(c, 66, OpRsh64x64, TypeInt64)
 	checkOpcodeCounts(t, fun.f, map[Op]int{OpAMD64SARQconst: 1, OpAMD64CMPQconst: 0})
-	fun.f.Free()
 }
 
 func makeConstShiftFunc(c *Config, amount int64, op Op, typ Type) fun {
@@ -80,7 +79,6 @@ func TestShiftToExtensionAMD64(t *testing.T) {
 	for _, tc := range tests {
 		fun := makeShiftExtensionFunc(c, tc.amount, tc.left, tc.right, tc.typ)
 		checkOpcodeCounts(t, fun.f, ops)
-		fun.f.Free()
 	}
 }
 

src/cmd/compile/internal/ssa/stackalloc.go

@@ -35,7 +35,7 @@ type stackAllocState struct {
 }
 
 func newStackAllocState(f *Func) *stackAllocState {
-	s := f.Config.stackAllocState
+	s := f.Cache.stackAllocState
 	if s == nil {
 		return new(stackAllocState)
 	}
@@ -61,7 +61,7 @@ func putStackAllocState(s *stackAllocState) {
 	for i := range s.used {
 		s.used[i] = false
 	}
-	s.f.Config.stackAllocState = s
+	s.f.Cache.stackAllocState = s
 	s.f = nil
 	s.live = nil
 	s.nArgSlot, s.nNotNeed, s.nNamedSlot, s.nReuse, s.nAuto, s.nSelfInterfere = 0, 0, 0, 0, 0, 0