compiler: emit NOTEQUAL only for numbers

Dispatch based on types similarly to EQUAL.
This commit is contained in:
Evgenii Stratonikov 2020-06-08 11:13:20 +03:00
parent 9d6b0ee4a8
commit cc5b5bff2e
2 changed files with 43 additions and 20 deletions

View file

@ -470,7 +470,6 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
case *ast.SwitchStmt:
ast.Walk(c, n.Tag)
eqOpcode := c.getEqualityOpcode(n.Tag)
switchEnd, label := c.generateLabel(labelEnd)
lastSwitch := c.currentSwitch
@ -490,7 +489,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
for j := range cc.List {
emit.Opcode(c.prog.BinWriter, opcode.DUP)
ast.Walk(c, cc.List[j])
emit.Opcode(c.prog.BinWriter, eqOpcode)
c.emitEquality(n.Tag, token.EQL)
if j == l-1 {
emit.Jmp(c.prog.BinWriter, opcode.JMPIFNOT, lEnd)
} else {
@ -630,19 +629,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
c.prog.Err = errors.New("comparison with `nil` is not supported, use `len(..) == 0` instead")
return nil
}
if n.Op == token.EQL {
// VM has separate opcodes for number and string equality
op := c.getEqualityOpcode(n.X)
emit.Opcode(c.prog.BinWriter, op)
} else {
// VM has separate opcodes for number and string equality
if isStringType(c.typeInfo.Types[n.X].Type) {
emit.Opcode(c.prog.BinWriter, opcode.EQUAL)
emit.Opcode(c.prog.BinWriter, opcode.NOT)
} else {
emit.Opcode(c.prog.BinWriter, opcode.NUMNOTEQUAL)
}
}
c.emitEquality(n.X, n.Op)
default:
c.convertToken(n.Op)
}
@ -988,13 +975,26 @@ func (c *codegen) getLabelOffset(typ labelOffsetType, name string) uint16 {
return c.labels[labelWithType{name: name, typ: typ}]
}
func (c *codegen) getEqualityOpcode(expr ast.Expr) opcode.Opcode {
func (c *codegen) emitEquality(expr ast.Expr, op token.Token) {
t, ok := c.typeInfo.Types[expr].Type.Underlying().(*types.Basic)
if ok && t.Info()&types.IsNumeric != 0 {
return opcode.NUMEQUAL
isNum := ok && t.Info()&types.IsNumeric != 0
switch op {
case token.EQL:
if isNum {
emit.Opcode(c.prog.BinWriter, opcode.NUMEQUAL)
} else {
emit.Opcode(c.prog.BinWriter, opcode.EQUAL)
}
case token.NEQ:
if isNum {
emit.Opcode(c.prog.BinWriter, opcode.NUMNOTEQUAL)
} else {
emit.Opcode(c.prog.BinWriter, opcode.EQUAL)
emit.Opcode(c.prog.BinWriter, opcode.NOT)
}
default:
panic("invalid token in emitEqual()")
}
return opcode.EQUAL
}
// getByteArray returns byte array value from constant expr.

View file

@ -1,6 +1,7 @@
package compiler_test
import (
"fmt"
"math/big"
"testing"
@ -366,3 +367,25 @@ var structTestCases = []testCase{
func TestStructs(t *testing.T) {
runTestCases(t, structTestCases)
}
func TestStructCompare(t *testing.T) {
srcTmpl := `package testcase
type T struct { f int }
func Main() int {
a := T{f: %d}
b := T{f: %d}
if a != b {
return 2
}
return 1
}`
t.Run("Equal", func(t *testing.T) {
src := fmt.Sprintf(srcTmpl, 4, 4)
eval(t, src, big.NewInt(1))
})
t.Run("NotEqual", func(t *testing.T) {
src := fmt.Sprintf(srcTmpl, 4, 5)
eval(t, src, big.NewInt(2))
})
}