cmd/compile: start using reflect.Value.IsZero

We now require Go 1.17.13 to bootstrap via make.bash,
and since reflect.Value.IsZero was added in Go 1.13,
we can now use it directly to save a bit of copy pasting.

Change-Id: I77eef782cbbf86c72a4505c8b4866c9658914a24
Reviewed-on: https://go-review.googlesource.com/c/go/+/479395
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>

diff --git a/src/cmd/compile/internal/ir/dump.go b/src/cmd/compile/internal/ir/dump.go
index 59914baa5cc04cfe367fcfb51328805604e91e08..4c218682ea6c758d8d8c757826478a067b77fc64 100644 (file)
--- a/src/cmd/compile/internal/ir/dump.go
+++ b/src/cmd/compile/internal/ir/dump.go
@@ -218,7 +218,7 @@ func (p *dumper) dump(x reflect.Value, depth int) {
                                        continue // Op field already printed for Nodes
                                }
                                x := x.Field(i)
-                               if isZeroVal(x) {
+                               if x.IsZero() {
                                        omitted = true
                                        continue // exclude zero-valued fields
                                }
@@ -248,22 +248,6 @@ func (p *dumper) dump(x reflect.Value, depth int) {
        }
 }
 
-func isZeroVal(x reflect.Value) bool {
-       switch x.Kind() {
-       case reflect.Bool:
-               return !x.Bool()
-       case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-               return x.Int() == 0
-       case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-               return x.Uint() == 0
-       case reflect.String:
-               return x.String() == ""
-       case reflect.Interface, reflect.Ptr, reflect.Slice:
-               return x.IsNil()
-       }
-       return false
-}
-
 func commonPrefixLen(a, b string) (i int) {
        for i < len(a) && i < len(b) && a[i] == b[i] {
                i++

diff --git a/src/cmd/compile/internal/ir/fmt.go b/src/cmd/compile/internal/ir/fmt.go
index 83f45234254e3a95cd6f89c011b9ef900e75bf59..dcb8988b66e2d6137c544ffcf332a4159bd57ce2 100644 (file)
--- a/src/cmd/compile/internal/ir/fmt.go
+++ b/src/cmd/compile/internal/ir/fmt.go
@@ -9,7 +9,6 @@ import (
        "fmt"
        "go/constant"
        "io"
-       "math"
        "os"
        "path/filepath"
        "reflect"
@@ -1022,7 +1021,7 @@ func dumpNodeHeader(w io.Writer, n Node) {
                        name := strings.TrimSuffix(tf.Name, "_")
                        vf := v.Field(i)
                        vfi := vf.Interface()
-                       if name == "Offset" && vfi == types.BADWIDTH || name != "Offset" && isZero(vf) {
+                       if name == "Offset" && vfi == types.BADWIDTH || name != "Offset" && vf.IsZero() {
                                continue
                        }
                        if vfi == true {
@@ -1261,40 +1260,3 @@ func dumpNodes(w io.Writer, list Nodes, depth int) {
                dumpNode(w, n, depth)
        }
 }
-
-// reflect.IsZero is not available in Go 1.4 (added in Go 1.13), so we use this copy instead.
-func isZero(v reflect.Value) bool {
-       switch v.Kind() {
-       case reflect.Bool:
-               return !v.Bool()
-       case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-               return v.Int() == 0
-       case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-               return v.Uint() == 0
-       case reflect.Float32, reflect.Float64:
-               return math.Float64bits(v.Float()) == 0
-       case reflect.Complex64, reflect.Complex128:
-               c := v.Complex()
-               return math.Float64bits(real(c)) == 0 && math.Float64bits(imag(c)) == 0
-       case reflect.Array:
-               for i := 0; i < v.Len(); i++ {
-                       if !isZero(v.Index(i)) {
-                               return false
-                       }
-               }
-               return true
-       case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice, reflect.UnsafePointer:
-               return v.IsNil()
-       case reflect.String:
-               return v.Len() == 0
-       case reflect.Struct:
-               for i := 0; i < v.NumField(); i++ {
-                       if !isZero(v.Field(i)) {
-                               return false
-                       }
-               }
-               return true
-       default:
-               return false
-       }
-}