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compiler: make use of extended JMP* opcodes

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This commit is contained in:
Evgenii Stratonikov 2020-08-23 18:00:23 +03:00
parent 51f3baf68e
commit 9dc3edf351
2 changed files with 163 additions and 3 deletions
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67
pkg/compiler/codegen.go
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@ -1087,6 +1087,8 @@ func (c *codegen) emitJumpOnCondition(cond bool, jmpLabel uint16) {
}
}
// emitBoolExpr emits boolean expression. If needJump is true and expression evaluates to `cond`,
// jump to jmpLabel is performed and no item is left on stack.
func (c *codegen) emitBoolExpr(n ast.Expr, needJump bool, cond bool, jmpLabel uint16) {
if be, ok := n.(*ast.BinaryExpr); ok {
c.emitBinaryExpr(be, needJump, cond, jmpLabel)
@ -1098,6 +1100,8 @@ func (c *codegen) emitBoolExpr(n ast.Expr, needJump bool, cond bool, jmpLabel ui
}
}
// emitBinaryExpr emits binary expression. If needJump is true and expression evaluates to `cond`,
// jump to jmpLabel is performed and no item is left on stack.
func (c *codegen) emitBinaryExpr(n *ast.BinaryExpr, needJump bool, cond bool, jmpLabel uint16) {
// The AST package will try to resolve all basic literals for us.
// If the typeinfo.Value is not nil we know that the expr is resolved
@ -1150,10 +1154,21 @@ func (c *codegen) emitBinaryExpr(n *ast.BinaryExpr, needJump bool, cond bool, jm
default:
ast.Walk(c, n.X)
ast.Walk(c, n.Y)
c.emitToken(n.Op, c.typeOf(n.X))
if needJump {
c.emitJumpOnCondition(cond, jmpLabel)
typ := c.typeOf(n.X)
if !needJump {
c.emitToken(n.Op, typ)
return
}
op, ok := getJumpForToken(n.Op, typ)
if !ok {
c.emitToken(n.Op, typ)
c.emitJumpOnCondition(cond, jmpLabel)
return
}
if !cond {
op = negateJmp(op)
}
emit.Jmp(c.prog.BinWriter, op, jmpLabel)
}
}
@ -1214,6 +1229,29 @@ func (c *codegen) getLabelOffset(typ labelOffsetType, name string) uint16 {
return c.labels[labelWithType{name: name, typ: typ}]
}
// For `&&` and `||` it return an opcode which jumps only if result is known:
// false && .. == false, true || .. = true
func getJumpForToken(tok token.Token, typ types.Type) (opcode.Opcode, bool) {
switch tok {
case token.GTR:
return opcode.JMPGTL, true
case token.GEQ:
return opcode.JMPGEL, true
case token.LSS:
return opcode.JMPLTL, true
case token.LEQ:
return opcode.JMPLEL, true
case token.EQL, token.NEQ:
if isNumber(typ) {
if tok == token.EQL {
return opcode.JMPEQL, true
}
return opcode.JMPNEL, true
}
}
return 0, false
}
// getByteArray returns byte array value from constant expr.
// Only literals are supported.
func (c *codegen) getByteArray(expr ast.Expr) []byte {
@ -1766,6 +1804,29 @@ func calcOffsetCorrection(ip, target int, offsets []int) int {
return cnt
}
func negateJmp(op opcode.Opcode) opcode.Opcode {
switch op {
case opcode.JMPIFL:
return opcode.JMPIFNOTL
case opcode.JMPIFNOTL:
return opcode.JMPIFL
case opcode.JMPEQL:
return opcode.JMPNEL
case opcode.JMPNEL:
return opcode.JMPEQL
case opcode.JMPGTL:
return opcode.JMPLEL
case opcode.JMPGEL:
return opcode.JMPLTL
case opcode.JMPLEL:
return opcode.JMPGTL
case opcode.JMPLTL:
return opcode.JMPGEL
default:
panic(fmt.Errorf("invalid opcode in negateJmp: %s", op))
}
}
func toShortForm(op opcode.Opcode) opcode.Opcode {
switch op {
case opcode.JMPL: