| // Copyright 2015 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. |
| |
| // +build gen |
| |
| // This program generates Go code that applies rewrite rules to a Value. |
| // The generated code implements a function of type func (v *Value) bool |
| // which reports whether if did something. |
| // Ideas stolen from Swift: http://www.hpl.hp.com/techreports/Compaq-DEC/WRL-2000-2.html |
| |
| package main |
| |
| import ( |
| "bufio" |
| "bytes" |
| "flag" |
| "fmt" |
| "go/format" |
| "io" |
| "io/ioutil" |
| "log" |
| "os" |
| "regexp" |
| "sort" |
| "strings" |
| ) |
| |
| // rule syntax: |
| // sexpr [&& extra conditions] -> [@block] sexpr |
| // |
| // sexpr are s-expressions (lisp-like parenthesized groupings) |
| // sexpr ::= [variable:](opcode sexpr*) |
| // | variable |
| // | <type> |
| // | [auxint] |
| // | {aux} |
| // |
| // aux ::= variable | {code} |
| // type ::= variable | {code} |
| // variable ::= some token |
| // opcode ::= one of the opcodes from the *Ops.go files |
| |
| // extra conditions is just a chunk of Go that evaluates to a boolean. It may use |
| // variables declared in the matching sexpr. The variable "v" is predefined to be |
| // the value matched by the entire rule. |
| |
| // If multiple rules match, the first one in file order is selected. |
| |
| var ( |
| genLog = flag.Bool("log", false, "generate code that logs; for debugging only") |
| ) |
| |
| type Rule struct { |
| rule string |
| loc string // file name & line number |
| } |
| |
| func (r Rule) String() string { |
| return fmt.Sprintf("rule %q at %s", r.rule, r.loc) |
| } |
| |
| func normalizeSpaces(s string) string { |
| return strings.Join(strings.Fields(strings.TrimSpace(s)), " ") |
| } |
| |
| // parse returns the matching part of the rule, additional conditions, and the result. |
| func (r Rule) parse() (match, cond, result string) { |
| s := strings.Split(r.rule, "->") |
| if len(s) != 2 { |
| log.Fatalf("no arrow in %s", r) |
| } |
| match = normalizeSpaces(s[0]) |
| result = normalizeSpaces(s[1]) |
| cond = "" |
| if i := strings.Index(match, "&&"); i >= 0 { |
| cond = normalizeSpaces(match[i+2:]) |
| match = normalizeSpaces(match[:i]) |
| } |
| return match, cond, result |
| } |
| |
| func genRules(arch arch) { |
| // Open input file. |
| text, err := os.Open(arch.name + ".rules") |
| if err != nil { |
| log.Fatalf("can't read rule file: %v", err) |
| } |
| |
| // oprules contains a list of rules for each block and opcode |
| blockrules := map[string][]Rule{} |
| oprules := map[string][]Rule{} |
| |
| // read rule file |
| scanner := bufio.NewScanner(text) |
| rule := "" |
| var lineno int |
| var ruleLineno int // line number of "->" |
| for scanner.Scan() { |
| lineno++ |
| line := scanner.Text() |
| if i := strings.Index(line, "//"); i >= 0 { |
| // Remove comments. Note that this isn't string safe, so |
| // it will truncate lines with // inside strings. Oh well. |
| line = line[:i] |
| } |
| rule += " " + line |
| rule = strings.TrimSpace(rule) |
| if rule == "" { |
| continue |
| } |
| if !strings.Contains(rule, "->") { |
| continue |
| } |
| if ruleLineno == 0 { |
| ruleLineno = lineno |
| } |
| if strings.HasSuffix(rule, "->") { |
| continue |
| } |
| if unbalanced(rule) { |
| continue |
| } |
| |
| loc := fmt.Sprintf("%s.rules:%d", arch.name, ruleLineno) |
| for _, rule2 := range expandOr(rule) { |
| for _, rule3 := range commute(rule2, arch) { |
| r := Rule{rule: rule3, loc: loc} |
| if rawop := strings.Split(rule3, " ")[0][1:]; isBlock(rawop, arch) { |
| blockrules[rawop] = append(blockrules[rawop], r) |
| } else { |
| // Do fancier value op matching. |
| match, _, _ := r.parse() |
| op, oparch, _, _, _, _ := parseValue(match, arch, loc) |
| opname := fmt.Sprintf("Op%s%s", oparch, op.name) |
| oprules[opname] = append(oprules[opname], r) |
| } |
| } |
| } |
| rule = "" |
| ruleLineno = 0 |
| } |
| if err := scanner.Err(); err != nil { |
| log.Fatalf("scanner failed: %v\n", err) |
| } |
| if unbalanced(rule) { |
| log.Fatalf("%s.rules:%d: unbalanced rule: %v\n", arch.name, lineno, rule) |
| } |
| |
| // Order all the ops. |
| var ops []string |
| for op := range oprules { |
| ops = append(ops, op) |
| } |
| sort.Strings(ops) |
| |
| // Start output buffer, write header. |
| w := new(bytes.Buffer) |
| fmt.Fprintf(w, "// Code generated from gen/%s.rules; DO NOT EDIT.\n", arch.name) |
| fmt.Fprintln(w, "// generated with: cd gen; go run *.go") |
| fmt.Fprintln(w) |
| fmt.Fprintln(w, "package ssa") |
| fmt.Fprintln(w, "import \"fmt\"") |
| fmt.Fprintln(w, "import \"math\"") |
| fmt.Fprintln(w, "import \"cmd/internal/obj\"") |
| fmt.Fprintln(w, "import \"cmd/internal/objabi\"") |
| fmt.Fprintln(w, "import \"cmd/compile/internal/types\"") |
| fmt.Fprintln(w, "var _ = fmt.Println // in case not otherwise used") |
| fmt.Fprintln(w, "var _ = math.MinInt8 // in case not otherwise used") |
| fmt.Fprintln(w, "var _ = obj.ANOP // in case not otherwise used") |
| fmt.Fprintln(w, "var _ = objabi.GOROOT // in case not otherwise used") |
| fmt.Fprintln(w, "var _ = types.TypeMem // in case not otherwise used") |
| fmt.Fprintln(w) |
| |
| const chunkSize = 10 |
| // Main rewrite routine is a switch on v.Op. |
| fmt.Fprintf(w, "func rewriteValue%s(v *Value) bool {\n", arch.name) |
| fmt.Fprintf(w, "switch v.Op {\n") |
| for _, op := range ops { |
| fmt.Fprintf(w, "case %s:\n", op) |
| fmt.Fprint(w, "return ") |
| for chunk := 0; chunk < len(oprules[op]); chunk += chunkSize { |
| if chunk > 0 { |
| fmt.Fprint(w, " || ") |
| } |
| fmt.Fprintf(w, "rewriteValue%s_%s_%d(v)", arch.name, op, chunk) |
| } |
| fmt.Fprintln(w) |
| } |
| fmt.Fprintf(w, "}\n") |
| fmt.Fprintf(w, "return false\n") |
| fmt.Fprintf(w, "}\n") |
| |
| // Generate a routine per op. Note that we don't make one giant routine |
| // because it is too big for some compilers. |
| for _, op := range ops { |
| for chunk := 0; chunk < len(oprules[op]); chunk += chunkSize { |
| buf := new(bytes.Buffer) |
| var canFail bool |
| endchunk := chunk + chunkSize |
| if endchunk > len(oprules[op]) { |
| endchunk = len(oprules[op]) |
| } |
| for i, rule := range oprules[op][chunk:endchunk] { |
| match, cond, result := rule.parse() |
| fmt.Fprintf(buf, "// match: %s\n", match) |
| fmt.Fprintf(buf, "// cond: %s\n", cond) |
| fmt.Fprintf(buf, "// result: %s\n", result) |
| |
| canFail = false |
| fmt.Fprintf(buf, "for {\n") |
| pos, matchCanFail := genMatch(buf, arch, match, rule.loc) |
| if pos == "" { |
| pos = "v.Pos" |
| } |
| if matchCanFail { |
| canFail = true |
| } |
| |
| if cond != "" { |
| fmt.Fprintf(buf, "if !(%s) {\nbreak\n}\n", cond) |
| canFail = true |
| } |
| if !canFail && i+chunk != len(oprules[op])-1 { |
| log.Fatalf("unconditional rule %s is followed by other rules", match) |
| } |
| |
| genResult(buf, arch, result, rule.loc, pos) |
| if *genLog { |
| fmt.Fprintf(buf, "logRule(\"%s\")\n", rule.loc) |
| } |
| fmt.Fprintf(buf, "return true\n") |
| |
| fmt.Fprintf(buf, "}\n") |
| } |
| if canFail { |
| fmt.Fprintf(buf, "return false\n") |
| } |
| |
| body := buf.String() |
| // Do a rough match to predict whether we need b, config, fe, and/or types. |
| // It's not precise--thus the blank assignments--but it's good enough |
| // to avoid generating needless code and doing pointless nil checks. |
| hasb := strings.Contains(body, "b.") |
| hasconfig := strings.Contains(body, "config.") || strings.Contains(body, "config)") |
| hasfe := strings.Contains(body, "fe.") |
| hastyps := strings.Contains(body, "typ.") |
| fmt.Fprintf(w, "func rewriteValue%s_%s_%d(v *Value) bool {\n", arch.name, op, chunk) |
| if hasb || hasconfig || hasfe || hastyps { |
| fmt.Fprintln(w, "b := v.Block") |
| fmt.Fprintln(w, "_ = b") |
| } |
| if hasconfig { |
| fmt.Fprintln(w, "config := b.Func.Config") |
| fmt.Fprintln(w, "_ = config") |
| } |
| if hasfe { |
| fmt.Fprintln(w, "fe := b.Func.fe") |
| fmt.Fprintln(w, "_ = fe") |
| } |
| if hastyps { |
| fmt.Fprintln(w, "typ := &b.Func.Config.Types") |
| fmt.Fprintln(w, "_ = typ") |
| } |
| fmt.Fprint(w, body) |
| fmt.Fprintf(w, "}\n") |
| } |
| } |
| |
| // Generate block rewrite function. There are only a few block types |
| // so we can make this one function with a switch. |
| fmt.Fprintf(w, "func rewriteBlock%s(b *Block) bool {\n", arch.name) |
| fmt.Fprintln(w, "config := b.Func.Config") |
| fmt.Fprintln(w, "_ = config") |
| fmt.Fprintln(w, "fe := b.Func.fe") |
| fmt.Fprintln(w, "_ = fe") |
| fmt.Fprintln(w, "typ := &config.Types") |
| fmt.Fprintln(w, "_ = typ") |
| fmt.Fprintf(w, "switch b.Kind {\n") |
| ops = nil |
| for op := range blockrules { |
| ops = append(ops, op) |
| } |
| sort.Strings(ops) |
| for _, op := range ops { |
| fmt.Fprintf(w, "case %s:\n", blockName(op, arch)) |
| for _, rule := range blockrules[op] { |
| match, cond, result := rule.parse() |
| fmt.Fprintf(w, "// match: %s\n", match) |
| fmt.Fprintf(w, "// cond: %s\n", cond) |
| fmt.Fprintf(w, "// result: %s\n", result) |
| |
| fmt.Fprintf(w, "for {\n") |
| |
| _, _, _, aux, s := extract(match) // remove parens, then split |
| |
| // check match of control value |
| pos := "" |
| if s[0] != "nil" { |
| fmt.Fprintf(w, "v := b.Control\n") |
| if strings.Contains(s[0], "(") { |
| pos, _ = genMatch0(w, arch, s[0], "v", map[string]struct{}{}, false, rule.loc) |
| } else { |
| fmt.Fprintf(w, "_ = v\n") // in case we don't use v |
| fmt.Fprintf(w, "%s := b.Control\n", s[0]) |
| } |
| } |
| if aux != "" { |
| fmt.Fprintf(w, "%s := b.Aux\n", aux) |
| } |
| |
| if cond != "" { |
| fmt.Fprintf(w, "if !(%s) {\nbreak\n}\n", cond) |
| } |
| |
| // Rule matches. Generate result. |
| outop, _, _, aux, t := extract(result) // remove parens, then split |
| newsuccs := t[1:] |
| |
| // Check if newsuccs is the same set as succs. |
| succs := s[1:] |
| m := map[string]bool{} |
| for _, succ := range succs { |
| if m[succ] { |
| log.Fatalf("can't have a repeat successor name %s in %s", succ, rule) |
| } |
| m[succ] = true |
| } |
| for _, succ := range newsuccs { |
| if !m[succ] { |
| log.Fatalf("unknown successor %s in %s", succ, rule) |
| } |
| delete(m, succ) |
| } |
| if len(m) != 0 { |
| log.Fatalf("unmatched successors %v in %s", m, rule) |
| } |
| |
| fmt.Fprintf(w, "b.Kind = %s\n", blockName(outop, arch)) |
| if t[0] == "nil" { |
| fmt.Fprintf(w, "b.SetControl(nil)\n") |
| } else { |
| if pos == "" { |
| pos = "v.Pos" |
| } |
| fmt.Fprintf(w, "b.SetControl(%s)\n", genResult0(w, arch, t[0], new(int), false, false, rule.loc, pos)) |
| } |
| if aux != "" { |
| fmt.Fprintf(w, "b.Aux = %s\n", aux) |
| } else { |
| fmt.Fprintln(w, "b.Aux = nil") |
| } |
| |
| succChanged := false |
| for i := 0; i < len(succs); i++ { |
| if succs[i] != newsuccs[i] { |
| succChanged = true |
| } |
| } |
| if succChanged { |
| if len(succs) != 2 { |
| log.Fatalf("changed successors, len!=2 in %s", rule) |
| } |
| if succs[0] != newsuccs[1] || succs[1] != newsuccs[0] { |
| log.Fatalf("can only handle swapped successors in %s", rule) |
| } |
| fmt.Fprintln(w, "b.swapSuccessors()") |
| } |
| |
| if *genLog { |
| fmt.Fprintf(w, "logRule(\"%s\")\n", rule.loc) |
| } |
| fmt.Fprintf(w, "return true\n") |
| |
| fmt.Fprintf(w, "}\n") |
| } |
| } |
| fmt.Fprintf(w, "}\n") |
| fmt.Fprintf(w, "return false\n") |
| fmt.Fprintf(w, "}\n") |
| |
| // gofmt result |
| b := w.Bytes() |
| src, err := format.Source(b) |
| if err != nil { |
| fmt.Printf("%s\n", b) |
| panic(err) |
| } |
| |
| // Write to file |
| err = ioutil.WriteFile("../rewrite"+arch.name+".go", src, 0666) |
| if err != nil { |
| log.Fatalf("can't write output: %v\n", err) |
| } |
| } |
| |
| // genMatch returns the variable whose source position should be used for the |
| // result (or "" if no opinion), and a boolean that reports whether the match can fail. |
| func genMatch(w io.Writer, arch arch, match string, loc string) (string, bool) { |
| return genMatch0(w, arch, match, "v", map[string]struct{}{}, true, loc) |
| } |
| |
| func genMatch0(w io.Writer, arch arch, match, v string, m map[string]struct{}, top bool, loc string) (string, bool) { |
| if match[0] != '(' || match[len(match)-1] != ')' { |
| panic("non-compound expr in genMatch0: " + match) |
| } |
| pos := "" |
| canFail := false |
| |
| op, oparch, typ, auxint, aux, args := parseValue(match, arch, loc) |
| |
| // check op |
| if !top { |
| fmt.Fprintf(w, "if %s.Op != Op%s%s {\nbreak\n}\n", v, oparch, op.name) |
| canFail = true |
| } |
| if op.faultOnNilArg0 || op.faultOnNilArg1 { |
| // Prefer the position of an instruction which could fault. |
| pos = v + ".Pos" |
| } |
| |
| if typ != "" { |
| if !isVariable(typ) { |
| // code. We must match the results of this code. |
| fmt.Fprintf(w, "if %s.Type != %s {\nbreak\n}\n", v, typ) |
| canFail = true |
| } else { |
| // variable |
| if _, ok := m[typ]; ok { |
| // must match previous variable |
| fmt.Fprintf(w, "if %s.Type != %s {\nbreak\n}\n", v, typ) |
| canFail = true |
| } else { |
| m[typ] = struct{}{} |
| fmt.Fprintf(w, "%s := %s.Type\n", typ, v) |
| } |
| } |
| } |
| |
| if auxint != "" { |
| if !isVariable(auxint) { |
| // code |
| fmt.Fprintf(w, "if %s.AuxInt != %s {\nbreak\n}\n", v, auxint) |
| canFail = true |
| } else { |
| // variable |
| if _, ok := m[auxint]; ok { |
| fmt.Fprintf(w, "if %s.AuxInt != %s {\nbreak\n}\n", v, auxint) |
| canFail = true |
| } else { |
| m[auxint] = struct{}{} |
| fmt.Fprintf(w, "%s := %s.AuxInt\n", auxint, v) |
| } |
| } |
| } |
| |
| if aux != "" { |
| |
| if !isVariable(aux) { |
| // code |
| fmt.Fprintf(w, "if %s.Aux != %s {\nbreak\n}\n", v, aux) |
| canFail = true |
| } else { |
| // variable |
| if _, ok := m[aux]; ok { |
| fmt.Fprintf(w, "if %s.Aux != %s {\nbreak\n}\n", v, aux) |
| canFail = true |
| } else { |
| m[aux] = struct{}{} |
| fmt.Fprintf(w, "%s := %s.Aux\n", aux, v) |
| } |
| } |
| } |
| |
| if n := len(args); n > 1 { |
| fmt.Fprintf(w, "_ = %s.Args[%d]\n", v, n-1) // combine some bounds checks |
| } |
| for i, arg := range args { |
| if arg == "_" { |
| continue |
| } |
| if !strings.Contains(arg, "(") { |
| // leaf variable |
| if _, ok := m[arg]; ok { |
| // variable already has a definition. Check whether |
| // the old definition and the new definition match. |
| // For example, (add x x). Equality is just pointer equality |
| // on Values (so cse is important to do before lowering). |
| fmt.Fprintf(w, "if %s != %s.Args[%d] {\nbreak\n}\n", arg, v, i) |
| canFail = true |
| } else { |
| // remember that this variable references the given value |
| m[arg] = struct{}{} |
| fmt.Fprintf(w, "%s := %s.Args[%d]\n", arg, v, i) |
| } |
| continue |
| } |
| // compound sexpr |
| var argname string |
| colon := strings.Index(arg, ":") |
| openparen := strings.Index(arg, "(") |
| if colon >= 0 && openparen >= 0 && colon < openparen { |
| // rule-specified name |
| argname = arg[:colon] |
| arg = arg[colon+1:] |
| } else { |
| // autogenerated name |
| argname = fmt.Sprintf("%s_%d", v, i) |
| } |
| fmt.Fprintf(w, "%s := %s.Args[%d]\n", argname, v, i) |
| argPos, argCanFail := genMatch0(w, arch, arg, argname, m, false, loc) |
| if argPos != "" { |
| // Keep the argument in preference to the parent, as the |
| // argument is normally earlier in program flow. |
| // Keep the argument in preference to an earlier argument, |
| // as that prefers the memory argument which is also earlier |
| // in the program flow. |
| pos = argPos |
| } |
| if argCanFail { |
| canFail = true |
| } |
| } |
| |
| if op.argLength == -1 { |
| fmt.Fprintf(w, "if len(%s.Args) != %d {\nbreak\n}\n", v, len(args)) |
| canFail = true |
| } |
| return pos, canFail |
| } |
| |
| func genResult(w io.Writer, arch arch, result string, loc string, pos string) { |
| move := false |
| if result[0] == '@' { |
| // parse @block directive |
| s := strings.SplitN(result[1:], " ", 2) |
| fmt.Fprintf(w, "b = %s\n", s[0]) |
| result = s[1] |
| move = true |
| } |
| genResult0(w, arch, result, new(int), true, move, loc, pos) |
| } |
| func genResult0(w io.Writer, arch arch, result string, alloc *int, top, move bool, loc string, pos string) string { |
| // TODO: when generating a constant result, use f.constVal to avoid |
| // introducing copies just to clean them up again. |
| if result[0] != '(' { |
| // variable |
| if top { |
| // It in not safe in general to move a variable between blocks |
| // (and particularly not a phi node). |
| // Introduce a copy. |
| fmt.Fprintf(w, "v.reset(OpCopy)\n") |
| fmt.Fprintf(w, "v.Type = %s.Type\n", result) |
| fmt.Fprintf(w, "v.AddArg(%s)\n", result) |
| } |
| return result |
| } |
| |
| op, oparch, typ, auxint, aux, args := parseValue(result, arch, loc) |
| |
| // Find the type of the variable. |
| typeOverride := typ != "" |
| if typ == "" && op.typ != "" { |
| typ = typeName(op.typ) |
| } |
| |
| var v string |
| if top && !move { |
| v = "v" |
| fmt.Fprintf(w, "v.reset(Op%s%s)\n", oparch, op.name) |
| if typeOverride { |
| fmt.Fprintf(w, "v.Type = %s\n", typ) |
| } |
| } else { |
| if typ == "" { |
| log.Fatalf("sub-expression %s (op=Op%s%s) at %s must have a type", result, oparch, op.name, loc) |
| } |
| v = fmt.Sprintf("v%d", *alloc) |
| *alloc++ |
| fmt.Fprintf(w, "%s := b.NewValue0(%s, Op%s%s, %s)\n", v, pos, oparch, op.name, typ) |
| if move && top { |
| // Rewrite original into a copy |
| fmt.Fprintf(w, "v.reset(OpCopy)\n") |
| fmt.Fprintf(w, "v.AddArg(%s)\n", v) |
| } |
| } |
| |
| if auxint != "" { |
| fmt.Fprintf(w, "%s.AuxInt = %s\n", v, auxint) |
| } |
| if aux != "" { |
| fmt.Fprintf(w, "%s.Aux = %s\n", v, aux) |
| } |
| for _, arg := range args { |
| x := genResult0(w, arch, arg, alloc, false, move, loc, pos) |
| fmt.Fprintf(w, "%s.AddArg(%s)\n", v, x) |
| } |
| |
| return v |
| } |
| |
| func split(s string) []string { |
| var r []string |
| |
| outer: |
| for s != "" { |
| d := 0 // depth of ({[< |
| var open, close byte // opening and closing markers ({[< or )}]> |
| nonsp := false // found a non-space char so far |
| for i := 0; i < len(s); i++ { |
| switch { |
| case d == 0 && s[i] == '(': |
| open, close = '(', ')' |
| d++ |
| case d == 0 && s[i] == '<': |
| open, close = '<', '>' |
| d++ |
| case d == 0 && s[i] == '[': |
| open, close = '[', ']' |
| d++ |
| case d == 0 && s[i] == '{': |
| open, close = '{', '}' |
| d++ |
| case d == 0 && (s[i] == ' ' || s[i] == '\t'): |
| if nonsp { |
| r = append(r, strings.TrimSpace(s[:i])) |
| s = s[i:] |
| continue outer |
| } |
| case d > 0 && s[i] == open: |
| d++ |
| case d > 0 && s[i] == close: |
| d-- |
| default: |
| nonsp = true |
| } |
| } |
| if d != 0 { |
| panic("imbalanced expression: " + s) |
| } |
| if nonsp { |
| r = append(r, strings.TrimSpace(s)) |
| } |
| break |
| } |
| return r |
| } |
| |
| // isBlock reports whether this op is a block opcode. |
| func isBlock(name string, arch arch) bool { |
| for _, b := range genericBlocks { |
| if b.name == name { |
| return true |
| } |
| } |
| for _, b := range arch.blocks { |
| if b.name == name { |
| return true |
| } |
| } |
| return false |
| } |
| |
| func extract(val string) (op string, typ string, auxint string, aux string, args []string) { |
| val = val[1 : len(val)-1] // remove () |
| |
| // Split val up into regions. |
| // Split by spaces/tabs, except those contained in (), {}, [], or <>. |
| s := split(val) |
| |
| // Extract restrictions and args. |
| op = s[0] |
| for _, a := range s[1:] { |
| switch a[0] { |
| case '<': |
| typ = a[1 : len(a)-1] // remove <> |
| case '[': |
| auxint = a[1 : len(a)-1] // remove [] |
| case '{': |
| aux = a[1 : len(a)-1] // remove {} |
| default: |
| args = append(args, a) |
| } |
| } |
| return |
| } |
| |
| // parseValue parses a parenthesized value from a rule. |
| // The value can be from the match or the result side. |
| // It returns the op and unparsed strings for typ, auxint, and aux restrictions and for all args. |
| // oparch is the architecture that op is located in, or "" for generic. |
| func parseValue(val string, arch arch, loc string) (op opData, oparch string, typ string, auxint string, aux string, args []string) { |
| // Resolve the op. |
| var s string |
| s, typ, auxint, aux, args = extract(val) |
| |
| // match reports whether x is a good op to select. |
| // If strict is true, rule generation might succeed. |
| // If strict is false, rule generation has failed, |
| // but we're trying to generate a useful error. |
| // Doing strict=true then strict=false allows |
| // precise op matching while retaining good error messages. |
| match := func(x opData, strict bool, archname string) bool { |
| if x.name != s { |
| return false |
| } |
| if x.argLength != -1 && int(x.argLength) != len(args) { |
| if strict { |
| return false |
| } else { |
| log.Printf("%s: op %s (%s) should have %d args, has %d", loc, s, archname, x.argLength, len(args)) |
| } |
| } |
| return true |
| } |
| |
| for _, x := range genericOps { |
| if match(x, true, "generic") { |
| op = x |
| break |
| } |
| } |
| if arch.name != "generic" { |
| for _, x := range arch.ops { |
| if match(x, true, arch.name) { |
| if op.name != "" { |
| log.Fatalf("%s: matches for op %s found in both generic and %s", loc, op.name, arch.name) |
| } |
| op = x |
| oparch = arch.name |
| break |
| } |
| } |
| } |
| |
| if op.name == "" { |
| // Failed to find the op. |
| // Run through everything again with strict=false |
| // to generate useful diagnosic messages before failing. |
| for _, x := range genericOps { |
| match(x, false, "generic") |
| } |
| for _, x := range arch.ops { |
| match(x, false, arch.name) |
| } |
| log.Fatalf("%s: unknown op %s", loc, s) |
| } |
| |
| // Sanity check aux, auxint. |
| if auxint != "" { |
| switch op.aux { |
| case "Bool", "Int8", "Int16", "Int32", "Int64", "Int128", "Float32", "Float64", "SymOff", "SymValAndOff", "SymInt32", "TypSize": |
| default: |
| log.Fatalf("%s: op %s %s can't have auxint", loc, op.name, op.aux) |
| } |
| } |
| if aux != "" { |
| switch op.aux { |
| case "String", "Sym", "SymOff", "SymValAndOff", "SymInt32", "Typ", "TypSize", "CCop": |
| default: |
| log.Fatalf("%s: op %s %s can't have aux", loc, op.name, op.aux) |
| } |
| } |
| |
| return |
| } |
| |
| func blockName(name string, arch arch) string { |
| for _, b := range genericBlocks { |
| if b.name == name { |
| return "Block" + name |
| } |
| } |
| return "Block" + arch.name + name |
| } |
| |
| // typeName returns the string to use to generate a type. |
| func typeName(typ string) string { |
| if typ[0] == '(' { |
| ts := strings.Split(typ[1:len(typ)-1], ",") |
| if len(ts) != 2 { |
| panic("Tuple expect 2 arguments") |
| } |
| return "types.NewTuple(" + typeName(ts[0]) + ", " + typeName(ts[1]) + ")" |
| } |
| switch typ { |
| case "Flags", "Mem", "Void", "Int128": |
| return "types.Type" + typ |
| default: |
| return "typ." + typ |
| } |
| } |
| |
| // unbalanced reports whether there aren't the same number of ( and ) in the string. |
| func unbalanced(s string) bool { |
| var left, right int |
| for _, c := range s { |
| if c == '(' { |
| left++ |
| } |
| if c == ')' { |
| right++ |
| } |
| } |
| return left != right |
| } |
| |
| // isVariable reports whether s is a single Go alphanumeric identifier. |
| func isVariable(s string) bool { |
| b, err := regexp.MatchString("^[A-Za-z_][A-Za-z_0-9]*$", s) |
| if err != nil { |
| panic("bad variable regexp") |
| } |
| return b |
| } |
| |
| // opRegexp is a regular expression to find the opcode portion of s-expressions. |
| var opRegexp = regexp.MustCompile(`[(]\w*[(](\w+[|])+\w+[)]\w* `) |
| |
| // expandOr converts a rule into multiple rules by expanding | ops. |
| func expandOr(r string) []string { |
| // Find every occurrence of |-separated things at the opcode position. |
| // They look like (MOV(B|W|L|Q|SS|SD)load |
| // Note: there might be false positives in parts of rules that are Go code |
| // (e.g. && conditions, AuxInt expressions, etc.). There are currently no |
| // such false positives, so I'm not too worried about it. |
| // Generate rules selecting one case from each |-form. |
| |
| // Count width of |-forms. They must match. |
| n := 1 |
| for _, s := range opRegexp.FindAllString(r, -1) { |
| c := strings.Count(s, "|") + 1 |
| if c == 1 { |
| continue |
| } |
| if n > 1 && n != c { |
| log.Fatalf("'|' count doesn't match in %s: both %d and %d\n", r, n, c) |
| } |
| n = c |
| } |
| if n == 1 { |
| // No |-form in this rule. |
| return []string{r} |
| } |
| res := make([]string, n) |
| for i := 0; i < n; i++ { |
| res[i] = opRegexp.ReplaceAllStringFunc(r, func(s string) string { |
| if strings.Count(s, "|") == 0 { |
| return s |
| } |
| s = s[1 : len(s)-1] // remove leading "(" and trailing " " |
| x, y := strings.Index(s, "("), strings.Index(s, ")") |
| return "(" + s[:x] + strings.Split(s[x+1:y], "|")[i] + s[y+1:] + " " |
| }) |
| } |
| return res |
| } |
| |
| // commute returns all equivalent rules to r after applying all possible |
| // argument swaps to the commutable ops in r. |
| // Potentially exponential, be careful. |
| func commute(r string, arch arch) []string { |
| match, cond, result := Rule{rule: r}.parse() |
| a := commute1(match, varCount(match), arch) |
| for i, m := range a { |
| if cond != "" { |
| m += " && " + cond |
| } |
| m += " -> " + result |
| a[i] = m |
| } |
| if len(a) == 1 && normalizeWhitespace(r) != normalizeWhitespace(a[0]) { |
| fmt.Println(normalizeWhitespace(r)) |
| fmt.Println(normalizeWhitespace(a[0])) |
| panic("commute() is not the identity for noncommuting rule") |
| } |
| if false && len(a) > 1 { |
| fmt.Println(r) |
| for _, x := range a { |
| fmt.Println(" " + x) |
| } |
| } |
| return a |
| } |
| |
| func commute1(m string, cnt map[string]int, arch arch) []string { |
| if m[0] == '<' || m[0] == '[' || m[0] == '{' || isVariable(m) { |
| return []string{m} |
| } |
| // Split up input. |
| var prefix string |
| colon := strings.Index(m, ":") |
| if colon >= 0 && isVariable(m[:colon]) { |
| prefix = m[:colon+1] |
| m = m[colon+1:] |
| } |
| if m[0] != '(' || m[len(m)-1] != ')' { |
| panic("non-compound expr in commute1: " + m) |
| } |
| s := split(m[1 : len(m)-1]) |
| op := s[0] |
| |
| // Figure out if the op is commutative or not. |
| commutative := false |
| for _, x := range genericOps { |
| if op == x.name { |
| if x.commutative { |
| commutative = true |
| } |
| break |
| } |
| } |
| if arch.name != "generic" { |
| for _, x := range arch.ops { |
| if op == x.name { |
| if x.commutative { |
| commutative = true |
| } |
| break |
| } |
| } |
| } |
| var idx0, idx1 int |
| if commutative { |
| // Find indexes of two args we can swap. |
| for i, arg := range s { |
| if i == 0 || arg[0] == '<' || arg[0] == '[' || arg[0] == '{' { |
| continue |
| } |
| if idx0 == 0 { |
| idx0 = i |
| continue |
| } |
| if idx1 == 0 { |
| idx1 = i |
| break |
| } |
| } |
| if idx1 == 0 { |
| panic("couldn't find first two args of commutative op " + s[0]) |
| } |
| if cnt[s[idx0]] == 1 && cnt[s[idx1]] == 1 || s[idx0] == s[idx1] && cnt[s[idx0]] == 2 { |
| // When we have (Add x y) with no other uses of x and y in the matching rule, |
| // then we can skip the commutative match (Add y x). |
| commutative = false |
| } |
| } |
| |
| // Recursively commute arguments. |
| a := make([][]string, len(s)) |
| for i, arg := range s { |
| a[i] = commute1(arg, cnt, arch) |
| } |
| |
| // Choose all possibilities from all args. |
| r := crossProduct(a) |
| |
| // If commutative, do that again with its two args reversed. |
| if commutative { |
| a[idx0], a[idx1] = a[idx1], a[idx0] |
| r = append(r, crossProduct(a)...) |
| } |
| |
| // Construct result. |
| for i, x := range r { |
| r[i] = prefix + "(" + x + ")" |
| } |
| return r |
| } |
| |
| // varCount returns a map which counts the number of occurrences of |
| // Value variables in m. |
| func varCount(m string) map[string]int { |
| cnt := map[string]int{} |
| varCount1(m, cnt) |
| return cnt |
| } |
| func varCount1(m string, cnt map[string]int) { |
| if m[0] == '<' || m[0] == '[' || m[0] == '{' { |
| return |
| } |
| if isVariable(m) { |
| cnt[m]++ |
| return |
| } |
| // Split up input. |
| colon := strings.Index(m, ":") |
| if colon >= 0 && isVariable(m[:colon]) { |
| cnt[m[:colon]]++ |
| m = m[colon+1:] |
| } |
| if m[0] != '(' || m[len(m)-1] != ')' { |
| panic("non-compound expr in commute1: " + m) |
| } |
| s := split(m[1 : len(m)-1]) |
| for _, arg := range s[1:] { |
| varCount1(arg, cnt) |
| } |
| } |
| |
| // crossProduct returns all possible values |
| // x[0][i] + " " + x[1][j] + " " + ... + " " + x[len(x)-1][k] |
| // for all valid values of i, j, ..., k. |
| func crossProduct(x [][]string) []string { |
| if len(x) == 1 { |
| return x[0] |
| } |
| var r []string |
| for _, tail := range crossProduct(x[1:]) { |
| for _, first := range x[0] { |
| r = append(r, first+" "+tail) |
| } |
| } |
| return r |
| } |
| |
| // normalizeWhitespace replaces 2+ whitespace sequences with a single space. |
| func normalizeWhitespace(x string) string { |
| x = strings.Join(strings.Fields(x), " ") |
| x = strings.Replace(x, "( ", "(", -1) |
| x = strings.Replace(x, " )", ")", -1) |
| return x |
| } |
