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core/vm: reduced big int allocations

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Reduced big int allocation by making stack items modifiable. Instead of
adding items such as `common.Big0` to the stack, `new(big.Int)` is
added instead. One must expect that any item that is added to the stack
might change.
This commit is contained in:
Jeffrey Wilcke
2015-08-06 23:06:47 +02:00
parent 184e9ae9a8
commit ac697326a6
4 changed files with 78 additions and 123 deletions
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171
core/vm/instructions.go
View File

@ -46,40 +46,33 @@ func opStaticJump(instr instruction, ret *big.Int, env Environment, context *Con
func opAdd(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opAdd(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
stack.push(U256(x.Add(x, y)))
stack.push(U256(new(big.Int).Add(x, y)))
} }
func opSub(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opSub(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
stack.push(U256(x.Sub(x, y)))
stack.push(U256(new(big.Int).Sub(x, y)))
} }
func opMul(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opMul(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
stack.push(U256(x.Mul(x, y)))
stack.push(U256(new(big.Int).Mul(x, y)))
} }
func opDiv(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opDiv(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
base := new(big.Int)
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
if y.Cmp(common.Big0) != 0 { if y.Cmp(common.Big0) != 0 {
base.Div(x, y) stack.push(U256(x.Div(x, y)))
} else {
stack.push(new(big.Int))
} }
// pop result back on the stack
stack.push(U256(base))
} }
func opSdiv(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opSdiv(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
base := new(big.Int)
x, y := S256(stack.pop()), S256(stack.pop()) x, y := S256(stack.pop()), S256(stack.pop())
if y.Cmp(common.Big0) == 0 { if y.Cmp(common.Big0) == 0 {
base.Set(common.Big0) stack.push(new(big.Int))
return
} else { } else {
n := new(big.Int) n := new(big.Int)
if new(big.Int).Mul(x, y).Cmp(common.Big0) < 0 { if new(big.Int).Mul(x, y).Cmp(common.Big0) < 0 {
@ -88,35 +81,27 @@ func opSdiv(instr instruction, env Environment, context *Context, memory *Memory
n.SetInt64(1) n.SetInt64(1)
} }
base.Div(x.Abs(x), y.Abs(y)).Mul(base, n) res := x.Div(x.Abs(x), y.Abs(y))
res.Mul(res, n)
U256(base) stack.push(U256(res))
} }
stack.push(base)
} }
func opMod(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opMod(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
base := new(big.Int)
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
if y.Cmp(common.Big0) == 0 { if y.Cmp(common.Big0) == 0 {
base.Set(common.Big0) stack.push(new(big.Int))
} else { } else {
base.Mod(x, y) stack.push(U256(x.Mod(x, y)))
} }
U256(base)
stack.push(base)
} }
func opSmod(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opSmod(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
base := new(big.Int)
x, y := S256(stack.pop()), S256(stack.pop()) x, y := S256(stack.pop()), S256(stack.pop())
if y.Cmp(common.Big0) == 0 { if y.Cmp(common.Big0) == 0 {
base.Set(common.Big0) stack.push(new(big.Int))
} else { } else {
n := new(big.Int) n := new(big.Int)
if x.Cmp(common.Big0) < 0 { if x.Cmp(common.Big0) < 0 {
@ -125,23 +110,16 @@ func opSmod(instr instruction, env Environment, context *Context, memory *Memory
n.SetInt64(1) n.SetInt64(1)
} }
base.Mod(x.Abs(x), y.Abs(y)).Mul(base, n) res := x.Mod(x.Abs(x), y.Abs(y))
res.Mul(res, n)
U256(base) stack.push(U256(res))
} }
stack.push(base)
} }
func opExp(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opExp(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
base := new(big.Int)
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
stack.push(U256(x.Exp(x, y, Pow256)))
base.Exp(x, y, Pow256)
U256(base)
stack.push(base)
} }
func opSignExtend(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opSignExtend(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
@ -149,7 +127,7 @@ func opSignExtend(instr instruction, env Environment, context *Context, memory *
if back.Cmp(big.NewInt(31)) < 0 { if back.Cmp(big.NewInt(31)) < 0 {
bit := uint(back.Uint64()*8 + 7) bit := uint(back.Uint64()*8 + 7)
num := stack.pop() num := stack.pop()
mask := new(big.Int).Lsh(common.Big1, bit) mask := back.Lsh(common.Big1, bit)
mask.Sub(mask, common.Big1) mask.Sub(mask, common.Big1)
if common.BitTest(num, int(bit)) { if common.BitTest(num, int(bit)) {
num.Or(num, mask.Not(mask)) num.Or(num, mask.Not(mask))
@ -157,145 +135,116 @@ func opSignExtend(instr instruction, env Environment, context *Context, memory *
num.And(num, mask) num.And(num, mask)
} }
num = U256(num) stack.push(U256(num))
stack.push(num)
} }
} }
func opNot(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opNot(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
stack.push(U256(new(big.Int).Not(stack.pop()))) x := stack.pop()
stack.push(U256(x.Not(x)))
} }
func opLt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opLt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
// x < y
if x.Cmp(y) < 0 { if x.Cmp(y) < 0 {
stack.push(common.BigTrue) stack.push(big.NewInt(1))
} else { } else {
stack.push(common.BigFalse) stack.push(new(big.Int))
} }
} }
func opGt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opGt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
// x > y
if x.Cmp(y) > 0 { if x.Cmp(y) > 0 {
stack.push(common.BigTrue) stack.push(big.NewInt(1))
} else { } else {
stack.push(common.BigFalse) stack.push(new(big.Int))
} }
} }
func opSlt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opSlt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := S256(stack.pop()), S256(stack.pop()) x, y := S256(stack.pop()), S256(stack.pop())
// x < y
if x.Cmp(S256(y)) < 0 { if x.Cmp(S256(y)) < 0 {
stack.push(common.BigTrue) stack.push(big.NewInt(1))
} else { } else {
stack.push(common.BigFalse) stack.push(new(big.Int))
} }
} }
func opSgt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opSgt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := S256(stack.pop()), S256(stack.pop()) x, y := S256(stack.pop()), S256(stack.pop())
// x > y
if x.Cmp(y) > 0 { if x.Cmp(y) > 0 {
stack.push(common.BigTrue) stack.push(big.NewInt(1))
} else { } else {
stack.push(common.BigFalse) stack.push(new(big.Int))
} }
} }
func opEq(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opEq(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
// x == y
if x.Cmp(y) == 0 { if x.Cmp(y) == 0 {
stack.push(common.BigTrue) stack.push(big.NewInt(1))
} else { } else {
stack.push(common.BigFalse) stack.push(new(big.Int))
} }
} }
func opIszero(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opIszero(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x := stack.pop() x := stack.pop()
if x.Cmp(common.BigFalse) > 0 { if x.Cmp(common.Big0) > 0 {
stack.push(common.BigFalse) stack.push(new(big.Int))
} else { } else {
stack.push(common.BigTrue) stack.push(big.NewInt(1))
} }
} }
func opAnd(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opAnd(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
stack.push(x.And(x, y))
stack.push(new(big.Int).And(x, y))
} }
func opOr(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opOr(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
stack.push(x.Or(x, y))
stack.push(new(big.Int).Or(x, y))
} }
func opXor(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opXor(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop() x, y := stack.pop(), stack.pop()
stack.push(x.Xor(x, y))
stack.push(new(big.Int).Xor(x, y))
} }
func opByte(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opByte(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
base := new(big.Int)
th, val := stack.pop(), stack.pop() th, val := stack.pop(), stack.pop()
if th.Cmp(big.NewInt(32)) < 0 { if th.Cmp(big.NewInt(32)) < 0 {
byt := big.NewInt(int64(common.LeftPadBytes(val.Bytes(), 32)[th.Int64()])) byte := big.NewInt(int64(common.LeftPadBytes(val.Bytes(), 32)[th.Int64()]))
stack.push(byte)
base.Set(byt)
} else { } else {
base.Set(common.BigFalse) stack.push(new(big.Int))
} }
stack.push(base)
} }
func opAddmod(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opAddmod(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
base := new(big.Int) x, y, z := stack.pop(), stack.pop(), stack.pop()
x := stack.pop()
y := stack.pop()
z := stack.pop()
if z.Cmp(Zero) > 0 { if z.Cmp(Zero) > 0 {
add := new(big.Int).Add(x, y) add := x.Add(x, y)
base.Mod(add, z) add.Mod(add, z)
stack.push(U256(add))
base = U256(base) } else {
stack.push(new(big.Int))
} }
stack.push(base)
} }
func opMulmod(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opMulmod(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
base := new(big.Int) x, y, z := stack.pop(), stack.pop(), stack.pop()
x := stack.pop()
y := stack.pop()
z := stack.pop()
if z.Cmp(Zero) > 0 { if z.Cmp(Zero) > 0 {
mul := new(big.Int).Mul(x, y) mul := x.Mul(x, y)
base.Mod(mul, z) mul.Mod(mul, z)
stack.push(U256(mul))
U256(base) } else {
stack.push(new(big.Int))
} }
stack.push(base)
} }
func opSha3(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opSha3(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
offset, size := stack.pop(), stack.pop() offset, size := stack.pop(), stack.pop()
hash := crypto.Sha3(memory.Get(offset.Int64(), size.Int64())) hash := crypto.Sha3(memory.Get(offset.Int64(), size.Int64()))
stack.push(common.BigD(hash)) stack.push(common.BytesToBig(hash))
} }
func opAddress(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) { func opAddress(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
@ -383,7 +332,7 @@ func opBlockhash(instr instruction, env Environment, context *Context, memory *M
if num.Cmp(n) > 0 && num.Cmp(env.BlockNumber()) < 0 { if num.Cmp(n) > 0 && num.Cmp(env.BlockNumber()) < 0 {
stack.push(env.GetHash(num.Uint64()).Big()) stack.push(env.GetHash(num.Uint64()).Big())
} else { } else {
stack.push(common.Big0) stack.push(new(big.Int))
} }
} }
@ -497,7 +446,7 @@ func opCreate(instr instruction, env Environment, context *Context, memory *Memo
context.UseGas(context.Gas) context.UseGas(context.Gas)
ret, suberr, ref := env.Create(context, input, gas, context.Price, value) ret, suberr, ref := env.Create(context, input, gas, context.Price, value)
if suberr != nil { if suberr != nil {
stack.push(common.BigFalse) stack.push(new(big.Int))
} else { } else {
// gas < len(ret) * Createinstr.dataGas == NO_CODE // gas < len(ret) * Createinstr.dataGas == NO_CODE
@ -535,10 +484,10 @@ func opCall(instr instruction, env Environment, context *Context, memory *Memory
ret, err := env.Call(context, address, args, gas, context.Price, value) ret, err := env.Call(context, address, args, gas, context.Price, value)
if err != nil { if err != nil {
stack.push(common.BigFalse) stack.push(new(big.Int))
} else { } else {
stack.push(common.BigTrue) stack.push(big.NewInt(1))
memory.Set(retOffset.Uint64(), retSize.Uint64(), ret) memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
} }
@ -566,10 +515,10 @@ func opCallCode(instr instruction, env Environment, context *Context, memory *Me
ret, err := env.CallCode(context, address, args, gas, context.Price, value) ret, err := env.CallCode(context, address, args, gas, context.Price, value)
if err != nil { if err != nil {
stack.push(common.BigFalse) stack.push(new(big.Int))
} else { } else {
stack.push(common.BigTrue) stack.push(big.NewInt(1))
memory.Set(retOffset.Uint64(), retSize.Uint64(), ret) memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
} }

17
core/vm/jit.go
View File

@ -404,9 +404,10 @@ func jitCalculateGasAndSize(env Environment, context *Context, caller ContextRef
mSize, mStart := stack.data[stack.len()-2], stack.data[stack.len()-1] mSize, mStart := stack.data[stack.len()-2], stack.data[stack.len()-1]
add := new(big.Int)
gas.Add(gas, params.LogGas) gas.Add(gas, params.LogGas)
gas.Add(gas, new(big.Int).Mul(big.NewInt(int64(n)), params.LogTopicGas)) gas.Add(gas, add.Mul(big.NewInt(int64(n)), params.LogTopicGas))
gas.Add(gas, new(big.Int).Mul(mSize, params.LogDataGas)) gas.Add(gas, add.Mul(mSize, params.LogDataGas))
newMemSize = calcMemSize(mStart, mSize) newMemSize = calcMemSize(mStart, mSize)
case EXP: case EXP:
@ -496,18 +497,20 @@ func jitCalculateGasAndSize(env Environment, context *Context, caller ContextRef
newMemSize.Mul(newMemSizeWords, u256(32)) newMemSize.Mul(newMemSizeWords, u256(32))
if newMemSize.Cmp(u256(int64(mem.Len()))) > 0 { if newMemSize.Cmp(u256(int64(mem.Len()))) > 0 {
// be careful reusing variables here when changing.
// The order has been optimised to reduce allocation
oldSize := toWordSize(big.NewInt(int64(mem.Len()))) oldSize := toWordSize(big.NewInt(int64(mem.Len())))
pow := new(big.Int).Exp(oldSize, common.Big2, Zero) pow := new(big.Int).Exp(oldSize, common.Big2, Zero)
linCoef := new(big.Int).Mul(oldSize, params.MemoryGas) linCoef := oldSize.Mul(oldSize, params.MemoryGas)
quadCoef := new(big.Int).Div(pow, params.QuadCoeffDiv) quadCoef := new(big.Int).Div(pow, params.QuadCoeffDiv)
oldTotalFee := new(big.Int).Add(linCoef, quadCoef) oldTotalFee := new(big.Int).Add(linCoef, quadCoef)
pow.Exp(newMemSizeWords, common.Big2, Zero) pow.Exp(newMemSizeWords, common.Big2, Zero)
linCoef = new(big.Int).Mul(newMemSizeWords, params.MemoryGas) linCoef = linCoef.Mul(newMemSizeWords, params.MemoryGas)
quadCoef = new(big.Int).Div(pow, params.QuadCoeffDiv) quadCoef = quadCoef.Div(pow, params.QuadCoeffDiv)
newTotalFee := new(big.Int).Add(linCoef, quadCoef) newTotalFee := linCoef.Add(linCoef, quadCoef)
fee := new(big.Int).Sub(newTotalFee, oldTotalFee) fee := newTotalFee.Sub(newTotalFee, oldTotalFee)
gas.Add(gas, fee) gas.Add(gas, fee)
} }
} }

11
core/vm/stack.go
View File

@ -21,14 +21,17 @@ import (
"math/big" "math/big"
) )
func newstack() *stack { // stack is an object for basic stack operations. Items popped to the stack are
return &stack{} // expected to be changed and modified. stack does not take care of adding newly
} // initialised objects.
type stack struct { type stack struct {
data []*big.Int data []*big.Int
} }
func newstack() *stack {
return &stack{}
}
func (st *stack) Data() []*big.Int { func (st *stack) Data() []*big.Int {
return st.data return st.data
} }

2
tests/vm_test.go
View File

@ -30,7 +30,7 @@ func BenchmarkVmAckermann32Tests(b *testing.B) {
func BenchmarkVmFibonacci16Tests(b *testing.B) { func BenchmarkVmFibonacci16Tests(b *testing.B) {
fn := filepath.Join(vmTestDir, "vmPerformanceTest.json") fn := filepath.Join(vmTestDir, "vmPerformanceTest.json")
if err := BenchVmTest(fn, bconf{"fibonacci16", true, true}, b); err != nil { if err := BenchVmTest(fn, bconf{"fibonacci16", true, false}, b); err != nil {
b.Error(err) b.Error(err)
} }
} }