mirror of
https://github.com/golang/go
synced 2024-11-26 03:37:57 -07:00
first step toward cgo tool.
can extract import "C" doc comment and all references to C package. ; cgo gmp.go | sort #include <gmp.h> gmp.go:197:4: mpz_t as type gmp.go:205:2: mpz_init as call gmp.go:206:2: mpz_set as call gmp.go:221:2: mpz_init as call gmp.go:227:7: size_t as call gmp.go:228:2: mpz_export as call gmp.go:235:13: mpz_sizeinbase as call gmp.go:241:2: mpz_set as call gmp.go:252:3: mpz_import as call gmp.go:261:2: mpz_set_si as call gmp.go:273:5: mpz_set_str as call gmp.go:282:9: mpz_get_str as call gmp.go:287:3: mpz_clear as call gmp.go:302:2: mpz_add as call gmp.go:311:2: mpz_sub as call gmp.go:320:2: mpz_mul as call gmp.go:329:2: mpz_tdiv_q as call gmp.go:339:2: mpz_tdiv_r as call gmp.go:348:2: mpz_mul_2exp as call gmp.go:356:2: mpz_div_2exp as call gmp.go:367:3: mpz_pow as call gmp.go:369:3: mpz_powm as call gmp.go:378:2: mpz_neg as call gmp.go:386:2: mpz_abs as call gmp.go:404:9: mpz_cmp as call gmp.go:413:2: mpz_tdiv_qr as call gmp.go:426:2: mpz_gcdext as call ; R=r DELTA=746 (746 added, 0 deleted, 0 changed) OCL=34710 CL=34714
This commit is contained in:
Russ Cox
parent
11df49c43f
commit
0b7878a96e
11
src/cmd/cgo/Makefile
Normal file
11
src/cmd/cgo/Makefile
Normal file
@ -0,0 +1,11 @@
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# Copyright 2009 The Go Authors. All rights reserved.
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# Use of this source code is governed by a BSD-style
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# license that can be found in the LICENSE file.
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include $(GOROOT)/src/Make.$(GOARCH)
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TARG=cgo
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GOFILES=\
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cgo.go\
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include $(GOROOT)/src/Make.cmd
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308
src/cmd/cgo/cgo.go
Normal file
308
src/cmd/cgo/cgo.go
Normal file
@ -0,0 +1,308 @@
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Cgo; see gmp.go for an overview.
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// TODO(rsc):
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// Emit correct line number annotations.
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// Make 6g understand the annotations.
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package main
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import (
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"bufio";
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"container/vector";
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"debug/dwarf";
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"debug/elf";
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"flag";
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"fmt";
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"go/ast";
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"go/doc";
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"go/parser";
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"go/scanner";
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"go/token";
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"io";
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"os";
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)
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// Map of uses of C.xxx. The key is the pointer
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// to the use (a pointer so it can be rewritten)
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// and the value is the context ("call", "expr", "type").
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type cmap map[*ast.Expr] string
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var noPos token.Position
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func usage() {
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fmt.Fprint(os.Stderr, "usage: cgo [options] file.cgo\n");
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flag.PrintDefaults();
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}
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func main() {
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flag.Usage = usage;
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flag.Parse();
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args := flag.Args();
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if len(args) != 1 {
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flag.Usage();
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}
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filename := args[0];
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prog, err := parser.ParsePkgFile("", filename, parser.ParseComments);
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if err != nil {
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fatal(err);
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}
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// Find the import "C" line and get any extra C preamble.
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preamble := "";
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found := false;
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for _, d := range prog.Decls {
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d, ok := d.(*ast.GenDecl);
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if !ok {
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continue;
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}
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for _, s := range d.Specs {
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s, ok := s.(*ast.ImportSpec);
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if !ok {
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continue;
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}
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if len(s.Path) != 1 || string(s.Path[0].Value) != `"C"` {
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continue;
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}
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found = true;
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if s.Name != nil {
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error(s.Path[0].Pos(), `cannot rename import "C"`);
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}
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if s.Doc != nil {
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preamble += doc.CommentText(s.Doc) + "\n";
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}
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else if len(d.Specs) == 1 && d.Doc != nil {
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preamble += doc.CommentText(d.Doc) + "\n";
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}
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}
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}
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if !found {
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error(noPos, `cannot find import "C"`);
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}
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// Accumulate pointers to uses of C.x.
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m := make(cmap);
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walk(prog, m, "prog");
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fmt.Print(preamble);
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for p, context := range m {
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sel := (*p).(*ast.SelectorExpr);
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fmt.Printf("%s: %s as %s\n", sel.Pos(), sel.Sel.Value, context);
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}
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}
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func walk(x interface{}, m cmap, context string) {
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switch n := x.(type) {
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case *ast.Expr:
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if sel, ok := (*n).(*ast.SelectorExpr); ok {
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// For now, assume that the only instance of capital C is
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// when used as the imported package identifier.
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// The parser should take care of scoping in the future,
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// so that we will be able to distinguish a "top-level C"
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// from a local C.
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if l, ok := sel.X.(*ast.Ident); ok && l.Value == "C" {
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m[n] = context;
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break;
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}
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}
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walk(*n, m, context);
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// everything else just recurs
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default:
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error(noPos, "unexpected type %T in walk", x);
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panic();
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case nil:
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// These are ordered and grouped to match ../../pkg/go/ast/ast.go
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case *ast.Field:
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walk(&n.Type, m, "type");
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case *ast.BadExpr:
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case *ast.Ident:
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case *ast.Ellipsis:
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case *ast.BasicLit:
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case *ast.StringList:
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case *ast.FuncLit:
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walk(n.Type, m, "type");
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walk(n.Body, m, "stmt");
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case *ast.CompositeLit:
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walk(&n.Type, m, "type");
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walk(n.Elts, m, "expr");
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case *ast.ParenExpr:
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walk(&n.X, m, context);
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case *ast.SelectorExpr:
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walk(&n.X, m, "selector");
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case *ast.IndexExpr:
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walk(&n.X, m, "expr");
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walk(&n.Index, m, "expr");
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if n.End != nil {
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walk(&n.End, m, "expr");
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}
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case *ast.TypeAssertExpr:
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walk(&n.X, m, "expr");
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walk(&n.Type, m, "type");
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case *ast.CallExpr:
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walk(&n.Fun, m, "call");
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walk(n.Args, m, "expr");
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case *ast.StarExpr:
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walk(&n.X, m, context);
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case *ast.UnaryExpr:
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walk(&n.X, m, "expr");
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case *ast.BinaryExpr:
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walk(&n.X, m, "expr");
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walk(&n.Y, m, "expr");
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case *ast.KeyValueExpr:
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walk(&n.Key, m, "expr");
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walk(&n.Value, m, "expr");
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case *ast.ArrayType:
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walk(&n.Len, m, "expr");
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walk(&n.Elt, m, "type");
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case *ast.StructType:
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walk(n.Fields, m, "field");
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case *ast.FuncType:
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walk(n.Params, m, "field");
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walk(n.Results, m, "field");
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case *ast.InterfaceType:
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walk(n.Methods, m, "field");
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case *ast.MapType:
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walk(&n.Key, m, "type");
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walk(&n.Value, m, "type");
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case *ast.ChanType:
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walk(&n.Value, m, "type");
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case *ast.BadStmt:
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case *ast.DeclStmt:
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walk(n.Decl, m, "decl");
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case *ast.EmptyStmt:
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case *ast.LabeledStmt:
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walk(n.Stmt, m, "stmt");
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case *ast.ExprStmt:
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walk(&n.X, m, "expr");
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case *ast.IncDecStmt:
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walk(&n.X, m, "expr");
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case *ast.AssignStmt:
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walk(n.Lhs, m, "expr");
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walk(n.Rhs, m, "expr");
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case *ast.GoStmt:
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walk(&n.Call, m, "expr");
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case *ast.DeferStmt:
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walk(&n.Call, m, "expr");
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case *ast.ReturnStmt:
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walk(n.Results, m, "expr");
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case *ast.BranchStmt:
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case *ast.BlockStmt:
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walk(n.List, m, "stmt");
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case *ast.IfStmt:
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walk(n.Init, m, "stmt");
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walk(&n.Cond, m, "expr");
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walk(n.Body, m, "stmt");
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walk(n.Else, m, "stmt");
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case *ast.CaseClause:
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walk(n.Values, m, "expr");
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walk(n.Body, m, "stmt");
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case *ast.SwitchStmt:
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walk(n.Init, m, "stmt");
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walk(&n.Tag, m, "expr");
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walk(n.Body, m, "stmt");
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case *ast.TypeCaseClause:
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walk(n.Types, m, "type");
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walk(n.Body, m, "stmt");
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case *ast.TypeSwitchStmt:
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walk(n.Init, m, "stmt");
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walk(n.Assign, m, "stmt");
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walk(n.Body, m, "stmt");
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case *ast.CommClause:
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walk(n.Lhs, m, "expr");
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walk(n.Rhs, m, "expr");
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walk(n.Body, m, "stmt");
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case *ast.SelectStmt:
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walk(n.Body, m, "stmt");
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case *ast.ForStmt:
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walk(n.Init, m, "stmt");
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walk(&n.Cond, m, "expr");
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walk(n.Post, m, "stmt");
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walk(n.Body, m, "stmt");
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case *ast.RangeStmt:
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walk(&n.Key, m, "expr");
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walk(&n.Value, m, "expr");
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walk(&n.X, m, "expr");
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walk(n.Body, m, "stmt");
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case *ast.ImportSpec:
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case *ast.ValueSpec:
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walk(&n.Type, m, "type");
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walk(n.Values, m, "expr");
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case *ast.TypeSpec:
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walk(&n.Type, m, "type");
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case *ast.BadDecl:
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case *ast.GenDecl:
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walk(n.Specs, m, "spec");
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case *ast.FuncDecl:
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if n.Recv != nil {
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walk(n.Recv, m, "field");
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}
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walk(n.Type, m, "type");
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walk(n.Body, m, "stmt");
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case *ast.File:
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walk(n.Decls, m, "decl");
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case *ast.Package:
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for _, f := range n.Files {
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walk(f, m, "file");
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}
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case []ast.Decl:
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for _, d := range n {
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walk(d, m, context);
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}
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case []ast.Expr:
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for i := range n {
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walk(&n[i], m, context);
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}
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case []*ast.Field:
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for _, f := range n {
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walk(f, m, context);
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}
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case []ast.Stmt:
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for _, s := range n {
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walk(s, m, context);
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}
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case []ast.Spec:
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for _, s := range n {
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walk(s, m, context);
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}
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}
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}
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func fatal(err os.Error) {
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// If err is a scanner.ErrorList, its String will print just
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// the first error and then (+n more errors).
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// Instead, turn it into a new Error that will return
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// details for all the errors.
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if list, ok := err.(scanner.ErrorList); ok {
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for _, e := range list {
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fmt.Fprintln(os.Stderr, e);
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}
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} else {
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fmt.Fprintln(os.Stderr, err);
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||||
}
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os.Exit(2);
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||||
}
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||||
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var nerrors int
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||||
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||||
func error(pos token.Position, msg string, args ...) {
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||||
nerrors++;
|
||||
if pos.IsValid() {
|
||||
fmt.Fprintf(os.Stderr, "%s: ", pos);
|
||||
}
|
||||
fmt.Fprintf(os.Stderr, msg, args);
|
||||
fmt.Fprintf(os.Stderr, "\n");
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||||
}
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427
src/cmd/cgo/gmp.go
Normal file
427
src/cmd/cgo/gmp.go
Normal file
@ -0,0 +1,427 @@
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// 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.
|
||||
|
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/*
|
||||
An example of wrapping a C library in Go. This is the GNU
|
||||
multiprecision library gmp's integer type mpz_t wrapped to look like
|
||||
the Go package big's integer type Int.
|
||||
|
||||
This is a syntactically valid Go program—it can be parsed with the Go
|
||||
parser and processed by godoc—but it is not compiled directly by 6g.
|
||||
Instead, a separate tool, cgo, processes it to produce three output
|
||||
files. The first two, 6g.go and 6c.c, are a Go source file for 6g and
|
||||
a C source file for 6c; both compile as part of the named package
|
||||
(gmp, in this example). The third, gcc.c, is a C source file for gcc;
|
||||
it compiles into a shared object (.so) that is dynamically linked into
|
||||
any 6.out that imports the first two files.
|
||||
|
||||
The stanza
|
||||
|
||||
// #include <gmp.h>
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import "C"
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||||
|
||||
is a signal to cgo. The doc comment on the import of "C" provides
|
||||
additional context for the C file. Here it is just a single #include
|
||||
but it could contain arbitrary C definitions to be imported and used.
|
||||
|
||||
Cgo recognizes any use of a qualified identifier C.xxx and uses gcc to
|
||||
find the definition of xxx. If xxx is a type, cgo replaces C.xxx with
|
||||
a Go translation. C arithmetic types translate to precisely-sized Go
|
||||
arithmetic types. A C struct translates to a Go struct, field by
|
||||
field; unrepresentable fields are replaced with opaque byte arrays. A
|
||||
C union translates into a struct containing the first union member and
|
||||
perhaps additional padding. C arrays become Go arrays. C pointers
|
||||
become Go pointers. C function pointers and void pointers become Go's
|
||||
*byte.
|
||||
|
||||
For example, mpz_t is defined in <gmp.h> as:
|
||||
|
||||
typedef unsigned long int mp_limb_t;
|
||||
|
||||
typedef struct
|
||||
{
|
||||
int _mp_alloc;
|
||||
int _mp_size;
|
||||
mp_limb_t *_mp_d;
|
||||
} __mpz_struct;
|
||||
|
||||
typedef __mpz_struct mpz_t[1];
|
||||
|
||||
Cgo generates:
|
||||
|
||||
type _C_int int32
|
||||
type _C_mp_limb_t uint64
|
||||
type _C___mpz_struct struct {
|
||||
_mp_alloc _C_int;
|
||||
_mp_size _C_int;
|
||||
_mp_d *_C_mp_limb_t;
|
||||
}
|
||||
type _C_mpz_t [1]_C___mpz_struct
|
||||
|
||||
and then replaces each occurrence of a type C.xxx with _C_xxx.
|
||||
|
||||
If xxx is data, cgo arranges for C.xxx to refer to the C variable,
|
||||
with the type translated as described above. To do this, cgo must
|
||||
introduce a Go variable that points at the C variable (the linker can
|
||||
be told to initialize this pointer). For example, if the gmp library
|
||||
provided
|
||||
|
||||
mpz_t zero;
|
||||
|
||||
then cgo would rewrite a reference to C.zero by introducing
|
||||
|
||||
var _C_zero *C.mpz_t
|
||||
|
||||
and then replacing all instances of C.zero with (*_C_zero).
|
||||
|
||||
Cgo's most interesting translation is for functions. If xxx is a C
|
||||
function, then cgo rewrites C.xxx into a new function _C_xxx that
|
||||
calls the C xxx in a standard pthread. The new function translates
|
||||
its arguments, calls xxx, and translates the return value.
|
||||
|
||||
Translation of parameters and the return value follows the type
|
||||
translation above with one extension: a function expecting a char*
|
||||
will change to expect a string, and a function returning a char* will
|
||||
change to return a string. The wrapper that cgo generates for the
|
||||
first case allocates a new C string, passes that pointer to the C
|
||||
function, and then frees the string when the function returns. The
|
||||
wrapper for the second case assumes the char* being returned is
|
||||
pointer that must be freed. It makes a Go string with a copy of the
|
||||
contents and then frees the pointer. The char* conventions are a
|
||||
useful heuristic; there should be some way to override them but isn't
|
||||
yet. One can also imagine wrapping Go functions being passed into C
|
||||
functions so that C can call them.
|
||||
|
||||
Garbage collection is the big problem. It is fine for the Go world to
|
||||
have pointers into the C world and to free those pointers when they
|
||||
are no longer needed. To help, the garbage collector calls an
|
||||
object's destroy() method prior to collecting it. C pointers can be
|
||||
wrapped by Go objects with appropriate destroy methods.
|
||||
|
||||
It is much more difficult for the C world to have pointers into the Go
|
||||
world, because the Go garbage collector is unaware of the memory
|
||||
allocated by C. I think the most important consideration is not to
|
||||
constrain future implementations, so the rule is basically that Go
|
||||
code can hand a Go pointer to C code but must separately arrange for
|
||||
Go to hang on to a reference to the pointer until C is done with it.
|
||||
|
||||
Note: the sketches assume that the char* <-> string conversions described
|
||||
above have been thrown away. Otherwise one can't pass nil as the first
|
||||
argument to mpz_get_str.
|
||||
|
||||
Sketch of 6c.c:
|
||||
|
||||
// NOTE: Maybe cgo is smart enough to figure out that
|
||||
// mpz_init's real C name is __gmpz_init and use that instead.
|
||||
|
||||
// Tell dynamic linker to initialize _cgo_mpz_init in this file
|
||||
// to point at the function of the same name in gcc.c.
|
||||
#pragma dynld _cgo_mpz_init _cgo_mpz_init "gmp.so"
|
||||
#pragma dynld _cgo_mpz_get_str _cgo_mpz_get_str "gmp.so"
|
||||
|
||||
void (*_cgo_mpz_init)(void*);
|
||||
void (*_cgo_mpz_get_str)(void*);
|
||||
|
||||
// implementation of Go function called as C.mpz_init below.
|
||||
void
|
||||
gmp·_C_mpz_init(struct { char x[8]; } p) // dummy struct, same size as 6g parameter frame
|
||||
{
|
||||
cgocall(_cgo_mpz_init, &p);
|
||||
}
|
||||
|
||||
void
|
||||
gmp·_C_mpz_get_str(struct { char x[32]; } p)
|
||||
{
|
||||
cgocall(_cgo_mpz_get_str, &p);
|
||||
}
|
||||
|
||||
Sketch of 6g.go:
|
||||
|
||||
// Type declarations from above, omitted.
|
||||
|
||||
// Extern declarations for 6c.c functions
|
||||
func _C_mpz_init(*_C_mpz_t)
|
||||
func _C_mpz_get_str(*_C_char, int32, *_C_mpz_t) *_C_char
|
||||
|
||||
// Original Go source with C.xxx replaced by _C_xxx
|
||||
// as described above.
|
||||
|
||||
Sketch of gcc.c:
|
||||
|
||||
void
|
||||
_cgo_mpz_init(void *v)
|
||||
{
|
||||
struct {
|
||||
__mpz_struct *p1; // not mpz_t because of C array passing rule
|
||||
} *a = v;
|
||||
mpz_init(a->p1);
|
||||
}
|
||||
|
||||
void
|
||||
_cgo_mpz_get_str(void *v)
|
||||
{
|
||||
struct {
|
||||
char *p1;
|
||||
int32 p2;
|
||||
in32 _pad1;
|
||||
__mpz_struct *p3;
|
||||
char *p4;
|
||||
} *a = v;
|
||||
a->p4 = mpz_get_str(a->p1, a->p2, a->p3);
|
||||
}
|
||||
|
||||
Gmp defines mpz_t as __mpz_struct[1], meaning that if you
|
||||
declare one it takes up a struct worth of space, but when you
|
||||
pass one to a function, it passes a pointer to the space instead
|
||||
of copying it. This can't be modeled directly in Go or in C structs
|
||||
so some rewriting happens in the generated files. In Go,
|
||||
the functions take *_C_mpz_t instead of _C_mpz_t, and in the
|
||||
GCC structs, the parameters are __mpz_struct* instead of mpz_t.
|
||||
|
||||
*/
|
||||
|
||||
package gmp
|
||||
|
||||
// #include <gmp.h>
|
||||
import "C"
|
||||
|
||||
|
||||
/*
|
||||
* one of a kind
|
||||
*/
|
||||
|
||||
// An Int represents a signed multi-precision integer.
|
||||
// The zero value for an Int represents the value 0.
|
||||
type Int struct {
|
||||
i C.mpz_t;
|
||||
init bool;
|
||||
}
|
||||
|
||||
// NewInt returns a new Int initialized to x.
|
||||
func NewInt(x int64) *Int {
|
||||
z := new(Int);
|
||||
z.init = true;
|
||||
C.mpz_init(&z.i);
|
||||
C.mpz_set(&z.i, x);
|
||||
return z;
|
||||
}
|
||||
|
||||
// Int promises that the zero value is a 0, but in gmp
|
||||
// the zero value is a crash. To bridge the gap, the
|
||||
// init bool says whether this is a valid gmp value.
|
||||
// doinit initializes z.i if it needs it. This is not inherent
|
||||
// to FFI, just a mismatch between Go's convention of
|
||||
// making zero values useful and gmp's decision not to.
|
||||
func (z *Int) doinit() {
|
||||
if z.init {
|
||||
return;
|
||||
}
|
||||
z.init = true;
|
||||
C.mpz_init(&z.i);
|
||||
}
|
||||
|
||||
// Bytes returns z's representation as a big-endian byte array.
|
||||
func (z *Int) Bytes() []byte {
|
||||
b := make([]byte, (z.Len() + 7) / 8);
|
||||
n := C.size_t(len(b));
|
||||
C.mpz_export(&b[0], &n, 1, 1, 1, 0, &z.i);
|
||||
return b[0:n];
|
||||
}
|
||||
|
||||
// Len returns the length of z in bits. 0 is considered to have length 1.
|
||||
func (z *Int) Len() int {
|
||||
z.doinit();
|
||||
return int(C.mpz_sizeinbase(&z.i, 2));
|
||||
}
|
||||
|
||||
// Set sets z = x and returns z.
|
||||
func (z *Int) Set(x *Int) *Int {
|
||||
z.doinit();
|
||||
C.mpz_set(&z.i, x);
|
||||
return z;
|
||||
}
|
||||
|
||||
// SetBytes interprets b as the bytes of a big-endian integer
|
||||
// and sets z to that value.
|
||||
func (z *Int) SetBytes(b []byte) *Int {
|
||||
z.doinit();
|
||||
if len(b) == 0 {
|
||||
z.SetInt64(0);
|
||||
} else {
|
||||
C.mpz_import(&z.i, len(b), 1, 1, 1, 0, &b[0]);
|
||||
}
|
||||
return z;
|
||||
}
|
||||
|
||||
// SetInt64 sets z = x and returns z.
|
||||
func (z *Int) SetInt64(x int64) *Int {
|
||||
z.doinit();
|
||||
// TODO(rsc): more work on 32-bit platforms
|
||||
C.mpz_set_si(z, x);
|
||||
return z;
|
||||
}
|
||||
|
||||
// SetString interprets s as a number in the given base
|
||||
// and sets z to that value. The base must be in the range [2,36].
|
||||
// SetString returns an error if s cannot be parsed or the base is invalid.
|
||||
func (z *Int) SetString(s string, base int) os.Error {
|
||||
z.doinit();
|
||||
if base < 2 || base > 36 {
|
||||
return os.EINVAL;
|
||||
}
|
||||
if C.mpz_set_str(&z.i, s, base) < 0 {
|
||||
return os.EINVAL;
|
||||
}
|
||||
return z;
|
||||
}
|
||||
|
||||
// String returns the decimal representation of z.
|
||||
func (z *Int) String() string {
|
||||
z.doinit();
|
||||
return C.mpz_get_str(nil, 10, &z.i);
|
||||
}
|
||||
|
||||
func (z *Int) destroy() {
|
||||
if z.init {
|
||||
C.mpz_clear(z);
|
||||
}
|
||||
z.init = false;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* arithmetic
|
||||
*/
|
||||
|
||||
// Add sets z = x + y and returns z.
|
||||
func (z *Int) Add(x, y *Int) *Int {
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
z.doinit();
|
||||
C.mpz_add(&z.i, &x.i, &y.i);
|
||||
return z;
|
||||
}
|
||||
|
||||
// Sub sets z = x - y and returns z.
|
||||
func (z *Int) Sub(x, y *Int) *Int {
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
z.doinit();
|
||||
C.mpz_sub(&z.i, &x.i, &y.i);
|
||||
return z;
|
||||
}
|
||||
|
||||
// Mul sets z = x * y and returns z.
|
||||
func (z *Int) Mul(x, y *Int) *Int {
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
z.doinit();
|
||||
C.mpz_mul(&z.i, &x.i, &y.i);
|
||||
return z;
|
||||
}
|
||||
|
||||
// Div sets z = x / y, rounding toward zero, and returns z.
|
||||
func (z *Int) Div(x, y *Int) *Int {
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
z.doinit();
|
||||
C.mpz_tdiv_q(&z.i, &x.i, &y.i);
|
||||
return z;
|
||||
}
|
||||
|
||||
// Mod sets z = x % y and returns z.
|
||||
// XXX Unlike in Go, the result is always positive.
|
||||
func (z *Int) Mod(x, y *Int) *Int {
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
z.doinit();
|
||||
C.mpz_tdiv_r(&z.i, &x.i, &y.i);
|
||||
return z;
|
||||
}
|
||||
|
||||
// Lsh sets z = x << s and returns z.
|
||||
func (z *Int) Lsh(x *Int, s uint) *Int {
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
z.doinit();
|
||||
C.mpz_mul_2exp(&z.i, &x.i, s);
|
||||
}
|
||||
|
||||
// Rsh sets z = x >> s and returns z.
|
||||
func (z *Int) Rsh(x *int, s uint) *Int {
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
z.doinit();
|
||||
C.mpz_div_2exp(&z.i, &x.i, s);
|
||||
}
|
||||
|
||||
// Exp sets z = x^y % m and returns z.
|
||||
// If m == nil, Exp sets z = x^y.
|
||||
func (z *Int) Exp(x, y, m *Int) *Int {
|
||||
m.doinit();
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
z.doinit();
|
||||
if m == nil {
|
||||
C.mpz_pow(&z.i, &x.i, &y.i);
|
||||
} else {
|
||||
C.mpz_powm(&z.i, &x.i, &y.i, &m.i);
|
||||
}
|
||||
return z;
|
||||
}
|
||||
|
||||
// Neg sets z = -x and returns z.
|
||||
func (z *Int) Neg(x *Int) *Int {
|
||||
x.doinit();
|
||||
z.doinit();
|
||||
C.mpz_neg(&z.i, &x.i);
|
||||
return z;
|
||||
}
|
||||
|
||||
// Abs sets z to the absolute value of x and returns z.
|
||||
func (z *Int) Abs(x *Int) *Int {
|
||||
x.doinit();
|
||||
z.doinit();
|
||||
C.mpz_abs(&z.i, &x.i);
|
||||
return z;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* functions without a clear receiver
|
||||
*/
|
||||
|
||||
// CmpInt compares x and y. The result is
|
||||
//
|
||||
// -1 if x < y
|
||||
// 0 if x == y
|
||||
// +1 if x > y
|
||||
//
|
||||
func CmpInt(x, y *Int) int {
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
return C.mpz_cmp(&x.i, &y.i);
|
||||
}
|
||||
|
||||
// DivModInt sets q = x / y and r = x % y.
|
||||
func DivModInt(q, r, x, y *Int) {
|
||||
q.doinit();
|
||||
r.doinit();
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
C.mpz_tdiv_qr(&q.i, &r.i, &x.i, &y.i);
|
||||
}
|
||||
|
||||
// GcdInt sets d to the greatest common divisor of a and b,
|
||||
// which must be positive numbers.
|
||||
// If x and y are not nil, GcdInt sets x and y such that d = a*x + b*y.
|
||||
// If either a or b is not positive, GcdInt sets d = x = y = 0.
|
||||
func GcdInt(d, x, y, a, b *Int) {
|
||||
d.doinit();
|
||||
x.doinit();
|
||||
y.doinit();
|
||||
a.doinit();
|
||||
b.doinit();
|
||||
C.mpz_gcdext(&d.i, &x.i, &y.i, &a.i, &b.i);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user