// 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.
// This program generates a test to verify that the standard arithmetic
// operators properly handle constant folding. The test file should be
// generated with a known working version of go.
// launch with `go run constFoldGen.go` a file called constFold_test.go
// will be written into the grandparent directory containing the tests.
package main
import (
"bytes"
"fmt"
"go/format"
"io/ioutil"
"log"
)
type op struct {
name, symbol string
}
type szD struct {
name string
sn string
u []uint64
i []int64
}
var szs []szD = []szD{
szD{name: "uint64", sn: "64", u: []uint64{0, 1, 4294967296, 0xffffFFFFffffFFFF}},
szD{name: "int64", sn: "64", i: []int64{-0x8000000000000000, -0x7FFFFFFFFFFFFFFF,
-4294967296, -1, 0, 1, 4294967296, 0x7FFFFFFFFFFFFFFE, 0x7FFFFFFFFFFFFFFF}},
szD{name: "uint32", sn: "32", u: []uint64{0, 1, 4294967295}},
szD{name: "int32", sn: "32", i: []int64{-0x80000000, -0x7FFFFFFF, -1, 0,
1, 0x7FFFFFFF}},
szD{name: "uint16", sn: "16", u: []uint64{0, 1, 65535}},
szD{name: "int16", sn: "16", i: []int64{-32768, -32767, -1, 0, 1, 32766, 32767}},
szD{name: "uint8", sn: "8", u: []uint64{0, 1, 255}},
szD{name: "int8", sn: "8", i: []int64{-128, -127, -1, 0, 1, 126, 127}},
}
var ops = []op{
op{"add", "+"}, op{"sub", "-"}, op{"div", "/"}, op{"mul", "*"},
op{"lsh", "<<"}, op{"rsh", ">>"}, op{"mod", "%"},
}
// compute the result of i op j, cast as type t.
func ansU(i, j uint64, t, op string) string {
var ans uint64
switch op {
case "+":
ans = i + j
case "-":
ans = i - j
case "*":
ans = i * j
case "/":
if j != 0 {
ans = i / j
}
case "%":
if j != 0 {
ans = i % j
}
case "<<":
ans = i << j
case ">>":
ans = i >> j
}
switch t {
case "uint32":
ans = uint64(uint32(ans))
case "uint16":
ans = uint64(uint16(ans))
case "uint8":
ans = uint64(uint8(ans))
}
return fmt.Sprintf("%d", ans)
}
// compute the result of i op j, cast as type t.
func ansS(i, j int64, t, op string) string {
var ans int64
switch op {
case "+":
ans = i + j
case "-":
ans = i - j
case "*":
ans = i * j
case "/":
if j != 0 {
ans = i / j
}
case "%":
if j != 0 {
ans = i % j
}
case "<<":
ans = i << uint64(j)
case ">>":
ans = i >> uint64(j)
}
switch t {
case "int32":
ans = int64(int32(ans))
case "int16":
ans = int64(int16(ans))
case "int8":
ans = int64(int8(ans))
}
return fmt.Sprintf("%d", ans)
}
func main() {
w := new(bytes.Buffer)
fmt.Fprintf(w, "// run\n")
fmt.Fprintf(w, "// Code generated by gen/constFoldGen.go. DO NOT EDIT.\n\n")
fmt.Fprintf(w, "package gc\n")
fmt.Fprintf(w, "import \"testing\"\n")
for _, s := range szs {
for _, o := range ops {
if o.symbol == "<<" || o.symbol == ">>" {
// shifts handled separately below, as they can have
// different types on the LHS and RHS.
continue
}
fmt.Fprintf(w, "func TestConstFold%s%s(t *testing.T) {\n", s.name, o.name)
fmt.Fprintf(w, "\tvar x, y, r %s\n", s.name)
// unsigned test cases
for _, c := range s.u {
fmt.Fprintf(w, "\tx = %d\n", c)
for _, d := range s.u {
if d == 0 && (o.symbol == "/" || o.symbol == "%") {
continue
}
fmt.Fprintf(w, "\ty = %d\n", d)
fmt.Fprintf(w, "\tr = x %s y\n", o.symbol)
want := ansU(c, d, s.name, o.symbol)
fmt.Fprintf(w, "\tif r != %s {\n", want)
fmt.Fprintf(w, "\t\tt.Errorf(\"%d %%s %d = %%d, want %s\", %q, r)\n", c, d, want, o.symbol)
fmt.Fprintf(w, "\t}\n")
}
}
// signed test cases
for _, c := range s.i {
fmt.Fprintf(w, "\tx = %d\n", c)
for _, d := range s.i {
if d == 0 && (o.symbol == "/" || o.symbol == "%") {
continue
}
fmt.Fprintf(w, "\ty = %d\n", d)
fmt.Fprintf(w, "\tr = x %s y\n", o.symbol)
want := ansS(c, d, s.name, o.symbol)
fmt.Fprintf(w, "\tif r != %s {\n", want)
fmt.Fprintf(w, "\t\tt.Errorf(\"%d %%s %d = %%d, want %s\", %q, r)\n", c, d, want, o.symbol)
fmt.Fprintf(w, "\t}\n")
}
}
fmt.Fprintf(w, "}\n")
}
}
// Special signed/unsigned cases for shifts
for _, ls := range szs {
for _, rs := range szs {
if rs.name[0] != 'u' {
continue
}
for _, o := range ops {
if o.symbol != "<<" && o.symbol != ">>" {
continue
}
fmt.Fprintf(w, "func TestConstFold%s%s%s(t *testing.T) {\n", ls.name, rs.name, o.name)
fmt.Fprintf(w, "\tvar x, r %s\n", ls.name)
fmt.Fprintf(w, "\tvar y %s\n", rs.name)
// unsigned LHS
for _, c := range ls.u {
fmt.Fprintf(w, "\tx = %d\n", c)
for _, d := range rs.u {
fmt.Fprintf(w, "\ty = %d\n", d)
fmt.Fprintf(w, "\tr = x %s y\n", o.symbol)
want := ansU(c, d, ls.name, o.symbol)
fmt.Fprintf(w, "\tif r != %s {\n", want)
fmt.Fprintf(w, "\t\tt.Errorf(\"%d %%s %d = %%d, want %s\", %q, r)\n", c, d, want, o.symbol)
fmt.Fprintf(w, "\t}\n")
}
}
// signed LHS
for _, c := range ls.i {
fmt.Fprintf(w, "\tx = %d\n", c)
for _, d := range rs.u {
fmt.Fprintf(w, "\ty = %d\n", d)
fmt.Fprintf(w, "\tr = x %s y\n", o.symbol)
want := ansS(c, int64(d), ls.name, o.symbol)
fmt.Fprintf(w, "\tif r != %s {\n", want)
fmt.Fprintf(w, "\t\tt.Errorf(\"%d %%s %d = %%d, want %s\", %q, r)\n", c, d, want, o.symbol)
fmt.Fprintf(w, "\t}\n")
}
}
fmt.Fprintf(w, "}\n")
}
}
}
// Constant folding for comparisons
for _, s := range szs {
fmt.Fprintf(w, "func TestConstFoldCompare%s(t *testing.T) {\n", s.name)
for _, x := range s.i {
for _, y := range s.i {
fmt.Fprintf(w, "\t{\n")
fmt.Fprintf(w, "\t\tvar x %s = %d\n", s.name, x)
fmt.Fprintf(w, "\t\tvar y %s = %d\n", s.name, y)
if x == y {
fmt.Fprintf(w, "\t\tif !(x == y) { t.Errorf(\"!(%%d == %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x == y { t.Errorf(\"%%d == %%d\", x, y) }\n")
}
if x != y {
fmt.Fprintf(w, "\t\tif !(x != y) { t.Errorf(\"!(%%d != %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x != y { t.Errorf(\"%%d != %%d\", x, y) }\n")
}
if x < y {
fmt.Fprintf(w, "\t\tif !(x < y) { t.Errorf(\"!(%%d < %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x < y { t.Errorf(\"%%d < %%d\", x, y) }\n")
}
if x > y {
fmt.Fprintf(w, "\t\tif !(x > y) { t.Errorf(\"!(%%d > %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x > y { t.Errorf(\"%%d > %%d\", x, y) }\n")
}
if x <= y {
fmt.Fprintf(w, "\t\tif !(x <= y) { t.Errorf(\"!(%%d <= %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x <= y { t.Errorf(\"%%d <= %%d\", x, y) }\n")
}
if x >= y {
fmt.Fprintf(w, "\t\tif !(x >= y) { t.Errorf(\"!(%%d >= %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x >= y { t.Errorf(\"%%d >= %%d\", x, y) }\n")
}
fmt.Fprintf(w, "\t}\n")
}
}
for _, x := range s.u {
for _, y := range s.u {
fmt.Fprintf(w, "\t{\n")
fmt.Fprintf(w, "\t\tvar x %s = %d\n", s.name, x)
fmt.Fprintf(w, "\t\tvar y %s = %d\n", s.name, y)
if x == y {
fmt.Fprintf(w, "\t\tif !(x == y) { t.Errorf(\"!(%%d == %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x == y { t.Errorf(\"%%d == %%d\", x, y) }\n")
}
if x != y {
fmt.Fprintf(w, "\t\tif !(x != y) { t.Errorf(\"!(%%d != %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x != y { t.Errorf(\"%%d != %%d\", x, y) }\n")
}
if x < y {
fmt.Fprintf(w, "\t\tif !(x < y) { t.Errorf(\"!(%%d < %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x < y { t.Errorf(\"%%d < %%d\", x, y) }\n")
}
if x > y {
fmt.Fprintf(w, "\t\tif !(x > y) { t.Errorf(\"!(%%d > %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x > y { t.Errorf(\"%%d > %%d\", x, y) }\n")
}
if x <= y {
fmt.Fprintf(w, "\t\tif !(x <= y) { t.Errorf(\"!(%%d <= %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x <= y { t.Errorf(\"%%d <= %%d\", x, y) }\n")
}
if x >= y {
fmt.Fprintf(w, "\t\tif !(x >= y) { t.Errorf(\"!(%%d >= %%d)\", x, y) }\n")
} else {
fmt.Fprintf(w, "\t\tif x >= y { t.Errorf(\"%%d >= %%d\", x, y) }\n")
}
fmt.Fprintf(w, "\t}\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("../../constFold_test.go", src, 0666)
if err != nil {
log.Fatalf("can't write output: %v\n", err)
}
}
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