// Copyright 2016 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.

package ssa

import (
	"math/big"
	"math/bits"
)

// So you want to compute x / c for some constant c?
// Machine division instructions are slow, so we try to
// compute this division with a multiplication + a few
// other cheap instructions instead.

// pkg.test's arguments.
// We allow known flags both before and after the package name list,
// to allow both
//
//	go test fmt -custom-flag-for-fmt-test
//	go test -x math
func testFlags(args []string) (packageNames, passToTest []string) {
	base.SetFromGOFLAGS(&CmdTest.Flag)
	addFromGOFLAGS := map[string]bool{}
	CmdTest.Flag.Visit(func(f *flag.Flag) {

(OffPtr [off] ptr) => (ADD (MOVDconst [off]) ptr)

(Const(64|32|16|8) [val]) => (MOVDconst [int64(val)])
(Const32F [val]) => (FMVSX (MOVDconst [int64(math.Float32bits(val))]))
(Const64F [val]) => (FMVDX (MOVDconst [int64(math.Float64bits(val))]))
(ConstNil) => (MOVDconst [0])
(ConstBool [val]) => (MOVDconst [int64(b2i(val))])

(Addr {sym} base) => (MOVaddr {sym} [0] base)

pkg math (linux-amd64-cgo), const MinInt = -9223372036854775808
pkg math (linux-arm), const MaxInt = 2147483647
pkg math (linux-arm), const MaxUint = 4294967295
pkg math (linux-arm), const MinInt = -2147483648
pkg math (linux-arm-cgo), const MaxInt = 2147483647
pkg math (linux-arm-cgo), const MaxUint = 4294967295
pkg math (linux-arm-cgo), const MinInt = -2147483648
pkg math (netbsd-386), const MaxInt = 2147483647

		{math.MaxInt64, "0000000\x00", false},
		{math.MaxInt64, "\x80\x00\x00\x00\x7f\xff\xff\xff\xff\xff\xff\xff", true},
		{math.MinInt64, "0000000\x00", false},
		{math.MinInt64, "\xff\xff\xff\xff\x80\x00\x00\x00\x00\x00\x00\x00", true},
		{math.MaxInt64, "\x80\x7f\xff\xff\xff\xff\xff\xff\xff", true},
		{math.MinInt64, "\xff\x80\x00\x00\x00\x00\x00\x00\x00", true},
	}

			"flag.mustBeExported",
			"flag.kind",
			"flag.ro",
		},
		"regexp": {
			"(*bitState).push",
		},
		"math/big": {
			"bigEndianWord",
			// The following functions require the math_big_pure_go build tag.
			"addVW",
			"subVW",
		},
		"math/rand": {
			"(*rngSource).Int63",
			"(*rngSource).Uint64",
		},
		"net": {
			"(*UDPConn).ReadFromUDP",
		},
		"sync": {

pkg io, const SeekCurrent = 1
pkg io, const SeekCurrent ideal-int
pkg io, const SeekEnd = 2
pkg io, const SeekEnd ideal-int
pkg io, const SeekStart = 0
pkg io, const SeekStart ideal-int
pkg math/big, method (*Float) GobDecode([]uint8) error
pkg math/big, method (*Float) GobEncode() ([]uint8, error)
pkg net, method (*Dialer) DialContext(context.Context, string, string) (Conn, error)
pkg net/http, const StatusAlreadyReported = 208

	auxUInt8                  // auxInt is an 8-bit unsigned integer
	auxFloat32                // auxInt is a float32 (encoded with math.Float64bits)
	auxFloat64                // auxInt is a float64 (encoded with math.Float64bits)
	auxFlagConstant           // auxInt is a flagConstant
	auxCCop                   // auxInt is a ssa.Op that represents a flags-to-bool conversion (e.g. LessThan)

// The gen command generates Go code (in the parent directory) for all
// the architecture-specific opcodes, blocks, and rewrites.
package main

import (
	"bytes"
	"flag"
	"fmt"
	"go/format"
	"log"
	"math/bits"
	"os"
	"path"
	"regexp"
	"runtime"
	"runtime/pprof"
	"runtime/trace"
	"sort"
	"strings"
	"sync"
)

// TODO: capitalize these types, so that we can more easily tell variable names

(Mod16u x y) => (Select0 (DIVU (ZeroExt16to32 x) (ZeroExt16to32 y)))
(Mod8 x y) => (Select0 (DIV (SignExt8to32 x) (SignExt8to32 y)))
(Mod8u x y) => (Select0 (DIVU (ZeroExt8to32 x) (ZeroExt8to32 y)))

// math package intrinsics
(Abs ...) => (ABSD ...)

// (x + y) / 2 with x>=y  becomes  (x - y) / 2 + y
(Avg32u <t> x y) => (ADD (SRLconst <t> (SUB <t> x y) [1]) y)

(And(32|16|8) ...) => (AND ...)
(Or(32|16|8) ...) => (OR ...)