qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-23 01:30:02 -07:00
Code Releases Activity

cmd/compile: remove typecheck.EvalConst

Browse Source 
types2 has already done most of the constant folding parts. The only
case left is unsafe.{Alignoff,Offsetof,Sizeof} with variable size
argument, which is handled separately during typecheck.

Change-Id: I8050b7613a16b19b91751726ac07253333177f73
Reviewed-on: https://go-review.googlesource.com/c/go/+/469595
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
This commit is contained in:
Cuong Manh Le 2023-02-20 12:49:03 +07:00 committed by Gopher Robot
parent 13f0b8f421
commit 25bc96dbd2
2 changed files with 0 additions and 191 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

184
src/cmd/compile/internal/typecheck/const.go
View File

@ -11,7 +11,6 @@ import (
"internal/types/errors" "internal/types/errors"
"math" "math"
"math/big" "math/big"
"strings"
"unicode" "unicode"
"cmd/compile/internal/base" "cmd/compile/internal/base"
@ -349,178 +348,6 @@ var tokenForOp = [...]token.Token{
ir.ORSH: token.SHR, ir.ORSH: token.SHR,
} }
// EvalConst returns a constant-evaluated expression equivalent to n.
// If n is not a constant, EvalConst returns n.
// Otherwise, EvalConst returns a new OLITERAL with the same value as n,
// and with .Orig pointing back to n.
func EvalConst(n ir.Node) ir.Node {
// Pick off just the opcodes that can be constant evaluated.
switch n.Op() {
case ir.OPLUS, ir.ONEG, ir.OBITNOT, ir.ONOT:
n := n.(*ir.UnaryExpr)
nl := n.X
if nl.Op() == ir.OLITERAL {
var prec uint
if n.Type().IsUnsigned() {
prec = uint(n.Type().Size() * 8)
}
return OrigConst(n, constant.UnaryOp(tokenForOp[n.Op()], nl.Val(), prec))
}
case ir.OADD, ir.OSUB, ir.OMUL, ir.ODIV, ir.OMOD, ir.OOR, ir.OXOR, ir.OAND, ir.OANDNOT:
n := n.(*ir.BinaryExpr)
nl, nr := n.X, n.Y
if nl.Op() == ir.OLITERAL && nr.Op() == ir.OLITERAL {
rval := nr.Val()
// check for divisor underflow in complex division (see issue 20227)
if n.Op() == ir.ODIV && n.Type().IsComplex() && constant.Sign(square(constant.Real(rval))) == 0 && constant.Sign(square(constant.Imag(rval))) == 0 {
base.Errorf("complex division by zero")
n.SetType(nil)
return n
}
if (n.Op() == ir.ODIV || n.Op() == ir.OMOD) && constant.Sign(rval) == 0 {
base.Errorf("division by zero")
n.SetType(nil)
return n
}
tok := tokenForOp[n.Op()]
if n.Op() == ir.ODIV && n.Type().IsInteger() {
tok = token.QUO_ASSIGN // integer division
}
return OrigConst(n, constant.BinaryOp(nl.Val(), tok, rval))
}
case ir.OOROR, ir.OANDAND:
n := n.(*ir.LogicalExpr)
nl, nr := n.X, n.Y
if nl.Op() == ir.OLITERAL && nr.Op() == ir.OLITERAL {
return OrigConst(n, constant.BinaryOp(nl.Val(), tokenForOp[n.Op()], nr.Val()))
}
case ir.OEQ, ir.ONE, ir.OLT, ir.OLE, ir.OGT, ir.OGE:
n := n.(*ir.BinaryExpr)
nl, nr := n.X, n.Y
if nl.Op() == ir.OLITERAL && nr.Op() == ir.OLITERAL {
return OrigBool(n, constant.Compare(nl.Val(), tokenForOp[n.Op()], nr.Val()))
}
case ir.OLSH, ir.ORSH:
n := n.(*ir.BinaryExpr)
nl, nr := n.X, n.Y
if nl.Op() == ir.OLITERAL && nr.Op() == ir.OLITERAL {
// shiftBound from go/types; "so we can express smallestFloat64" (see issue #44057)
const shiftBound = 1023 - 1 + 52
s, ok := constant.Uint64Val(nr.Val())
if !ok || s > shiftBound {
base.Errorf("invalid shift count %v", nr)
n.SetType(nil)
break
}
return OrigConst(n, constant.Shift(toint(nl.Val()), tokenForOp[n.Op()], uint(s)))
}
case ir.OCONV, ir.ORUNESTR:
n := n.(*ir.ConvExpr)
nl := n.X
if ir.OKForConst[n.Type().Kind()] && nl.Op() == ir.OLITERAL {
return OrigConst(n, convertVal(nl.Val(), n.Type(), true))
}
case ir.OCONVNOP:
n := n.(*ir.ConvExpr)
nl := n.X
if ir.OKForConst[n.Type().Kind()] && nl.Op() == ir.OLITERAL {
// set so n.Orig gets OCONV instead of OCONVNOP
n.SetOp(ir.OCONV)
return OrigConst(n, nl.Val())
}
case ir.OADDSTR:
// Merge adjacent constants in the argument list.
n := n.(*ir.AddStringExpr)
s := n.List
need := 0
for i := 0; i < len(s); i++ {
if i == 0 || !ir.IsConst(s[i-1], constant.String) || !ir.IsConst(s[i], constant.String) {
// Can't merge s[i] into s[i-1]; need a slot in the list.
need++
}
}
if need == len(s) {
return n
}
if need == 1 {
var strs []string
for _, c := range s {
strs = append(strs, ir.StringVal(c))
}
return OrigConst(n, constant.MakeString(strings.Join(strs, "")))
}
newList := make([]ir.Node, 0, need)
for i := 0; i < len(s); i++ {
if ir.IsConst(s[i], constant.String) && i+1 < len(s) && ir.IsConst(s[i+1], constant.String) {
// merge from i up to but not including i2
var strs []string
i2 := i
for i2 < len(s) && ir.IsConst(s[i2], constant.String) {
strs = append(strs, ir.StringVal(s[i2]))
i2++
}
nl := ir.Copy(n).(*ir.AddStringExpr)
nl.List = s[i:i2]
newList = append(newList, OrigConst(nl, constant.MakeString(strings.Join(strs, ""))))
i = i2 - 1
} else {
newList = append(newList, s[i])
}
}
nn := ir.Copy(n).(*ir.AddStringExpr)
nn.List = newList
return nn
case ir.OCAP, ir.OLEN:
n := n.(*ir.UnaryExpr)
nl := n.X
switch nl.Type().Kind() {
case types.TSTRING:
if ir.IsConst(nl, constant.String) {
return OrigInt(n, int64(len(ir.StringVal(nl))))
}
case types.TARRAY:
if !anyCallOrChan(nl) {
return OrigInt(n, nl.Type().NumElem())
}
}
case ir.OREAL:
n := n.(*ir.UnaryExpr)
nl := n.X
if nl.Op() == ir.OLITERAL {
return OrigConst(n, constant.Real(nl.Val()))
}
case ir.OIMAG:
n := n.(*ir.UnaryExpr)
nl := n.X
if nl.Op() == ir.OLITERAL {
return OrigConst(n, constant.Imag(nl.Val()))
}
case ir.OCOMPLEX:
n := n.(*ir.BinaryExpr)
nl, nr := n.X, n.Y
if nl.Op() == ir.OLITERAL && nr.Op() == ir.OLITERAL {
return OrigConst(n, makeComplex(nl.Val(), nr.Val()))
}
}
return n
}
func makeFloat64(f float64) constant.Value { func makeFloat64(f float64) constant.Value {
if math.IsInf(f, 0) { if math.IsInf(f, 0) {
base.Fatalf("infinity is not a valid constant") base.Fatalf("infinity is not a valid constant")
@ -532,10 +359,6 @@ func makeComplex(real, imag constant.Value) constant.Value {
return constant.BinaryOp(constant.ToFloat(real), token.ADD, constant.MakeImag(constant.ToFloat(imag))) return constant.BinaryOp(constant.ToFloat(real), token.ADD, constant.MakeImag(constant.ToFloat(imag)))
} }
func square(x constant.Value) constant.Value {
return constant.BinaryOp(x, token.MUL, x)
}
// For matching historical "constant OP overflow" error messages. // For matching historical "constant OP overflow" error messages.
// TODO(mdempsky): Replace with error messages like go/types uses. // TODO(mdempsky): Replace with error messages like go/types uses.
var overflowNames = [...]string{ var overflowNames = [...]string{
@ -733,13 +556,6 @@ func callOrChan(n ir.Node) bool {
return false return false
} }
// anyCallOrChan reports whether n contains any calls or channel operations.
func anyCallOrChan(n ir.Node) bool {
return ir.Any(n, func(n ir.Node) bool {
return callOrChan(n)
})
}
// evalunsafe evaluates a package unsafe operation and returns the result. // evalunsafe evaluates a package unsafe operation and returns the result.
func evalunsafe(n ir.Node) int64 { func evalunsafe(n ir.Node) int64 {
switch n.Op() { switch n.Op() {

7
src/cmd/compile/internal/typecheck/typecheck.go
View File

@ -355,10 +355,6 @@ func typecheck(n ir.Node, top int) (res ir.Node) {
types.CheckSize(t) types.CheckSize(t)
} }
} }
if t != nil {
n = EvalConst(n)
t = n.Type()
}
// TODO(rsc): Lots of the complexity here is because typecheck can // TODO(rsc): Lots of the complexity here is because typecheck can
// see OTYPE, ONAME, and OLITERAL nodes multiple times. // see OTYPE, ONAME, and OLITERAL nodes multiple times.
@ -516,9 +512,6 @@ func typecheck1(n ir.Node, top int) ir.Node {
if t != nil { if t != nil {
n.X, n.Y = l, r n.X, n.Y = l, r
n.SetType(types.UntypedBool) n.SetType(types.UntypedBool)
if con := EvalConst(n); con.Op() == ir.OLITERAL {
return con
}
n.X, n.Y = defaultlit2(l, r, true) n.X, n.Y = defaultlit2(l, r, true)
} }
return n return n