| // 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) | |
| } | |
| } |