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authorJeffrey Wilcke <geffobscura@gmail.com>2015-08-07 05:06:47 +0800
committerJeffrey Wilcke <geffobscura@gmail.com>2015-08-07 18:52:23 +0800
commitac697326a6045eaa760b159e4bda37c57be61cbf (patch)
tree9f26ac6308b7ae0b9d0a6daab772aae796ee7a54
parent184e9ae9a81df2db6381e18d3daa035d913ae341 (diff)
downloaddexon-ac697326a6045eaa760b159e4bda37c57be61cbf.tar.gz
dexon-ac697326a6045eaa760b159e4bda37c57be61cbf.tar.zst
dexon-ac697326a6045eaa760b159e4bda37c57be61cbf.zip
core/vm: reduced big int allocations
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.
-rw-r--r--core/vm/instructions.go171
-rw-r--r--core/vm/jit.go17
-rw-r--r--core/vm/stack.go11
-rw-r--r--tests/vm_test.go2
4 files changed, 78 insertions, 123 deletions
diff --git a/core/vm/instructions.go b/core/vm/instructions.go
index d7605e5a2..6b7b41220 100644
--- a/core/vm/instructions.go
+++ b/core/vm/instructions.go
@@ -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) {
x, y := stack.pop(), stack.pop()
-
- stack.push(U256(new(big.Int).Add(x, y)))
+ stack.push(U256(x.Add(x, y)))
}
func opSub(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop()
-
- stack.push(U256(new(big.Int).Sub(x, y)))
+ stack.push(U256(x.Sub(x, y)))
}
func opMul(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop()
-
- stack.push(U256(new(big.Int).Mul(x, y)))
+ stack.push(U256(x.Mul(x, y)))
}
func opDiv(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
- base := new(big.Int)
x, y := stack.pop(), stack.pop()
-
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) {
- base := new(big.Int)
x, y := S256(stack.pop()), S256(stack.pop())
-
if y.Cmp(common.Big0) == 0 {
- base.Set(common.Big0)
+ stack.push(new(big.Int))
+ return
} else {
n := new(big.Int)
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)
}
- 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) {
- base := new(big.Int)
x, y := stack.pop(), stack.pop()
-
if y.Cmp(common.Big0) == 0 {
- base.Set(common.Big0)
+ stack.push(new(big.Int))
} 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) {
- base := new(big.Int)
x, y := S256(stack.pop()), S256(stack.pop())
if y.Cmp(common.Big0) == 0 {
- base.Set(common.Big0)
+ stack.push(new(big.Int))
} else {
n := new(big.Int)
if x.Cmp(common.Big0) < 0 {
@@ -125,23 +110,16 @@ func opSmod(instr instruction, env Environment, context *Context, memory *Memory
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) {
- base := new(big.Int)
x, y := stack.pop(), stack.pop()
-
- base.Exp(x, y, Pow256)
-
- U256(base)
-
- stack.push(base)
+ stack.push(U256(x.Exp(x, y, Pow256)))
}
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 {
bit := uint(back.Uint64()*8 + 7)
num := stack.pop()
- mask := new(big.Int).Lsh(common.Big1, bit)
+ mask := back.Lsh(common.Big1, bit)
mask.Sub(mask, common.Big1)
if common.BitTest(num, int(bit)) {
num.Or(num, mask.Not(mask))
@@ -157,145 +135,116 @@ func opSignExtend(instr instruction, env Environment, context *Context, memory *
num.And(num, mask)
}
- num = U256(num)
-
- stack.push(num)
+ stack.push(U256(num))
}
}
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) {
x, y := stack.pop(), stack.pop()
-
- // x < y
if x.Cmp(y) < 0 {
- stack.push(common.BigTrue)
+ stack.push(big.NewInt(1))
} else {
- stack.push(common.BigFalse)
+ stack.push(new(big.Int))
}
}
func opGt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop()
-
- // x > y
if x.Cmp(y) > 0 {
- stack.push(common.BigTrue)
+ stack.push(big.NewInt(1))
} else {
- stack.push(common.BigFalse)
+ stack.push(new(big.Int))
}
}
func opSlt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := S256(stack.pop()), S256(stack.pop())
-
- // x < y
if x.Cmp(S256(y)) < 0 {
- stack.push(common.BigTrue)
+ stack.push(big.NewInt(1))
} else {
- stack.push(common.BigFalse)
+ stack.push(new(big.Int))
}
}
func opSgt(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := S256(stack.pop()), S256(stack.pop())
-
- // x > y
if x.Cmp(y) > 0 {
- stack.push(common.BigTrue)
+ stack.push(big.NewInt(1))
} else {
- stack.push(common.BigFalse)
+ stack.push(new(big.Int))
}
}
func opEq(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop()
-
- // x == y
if x.Cmp(y) == 0 {
- stack.push(common.BigTrue)
+ stack.push(big.NewInt(1))
} else {
- stack.push(common.BigFalse)
+ stack.push(new(big.Int))
}
}
func opIszero(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x := stack.pop()
- if x.Cmp(common.BigFalse) > 0 {
- stack.push(common.BigFalse)
+ if x.Cmp(common.Big0) > 0 {
+ stack.push(new(big.Int))
} else {
- stack.push(common.BigTrue)
+ stack.push(big.NewInt(1))
}
}
func opAnd(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop()
-
- stack.push(new(big.Int).And(x, y))
+ stack.push(x.And(x, y))
}
func opOr(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop()
-
- stack.push(new(big.Int).Or(x, y))
+ stack.push(x.Or(x, y))
}
func opXor(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
x, y := stack.pop(), stack.pop()
-
- stack.push(new(big.Int).Xor(x, y))
+ stack.push(x.Xor(x, y))
}
func opByte(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
- base := new(big.Int)
th, val := stack.pop(), stack.pop()
-
if th.Cmp(big.NewInt(32)) < 0 {
- byt := big.NewInt(int64(common.LeftPadBytes(val.Bytes(), 32)[th.Int64()]))
-
- base.Set(byt)
+ byte := big.NewInt(int64(common.LeftPadBytes(val.Bytes(), 32)[th.Int64()]))
+ stack.push(byte)
} 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) {
- base := new(big.Int)
- x := stack.pop()
- y := stack.pop()
- z := stack.pop()
-
+ x, y, z := stack.pop(), stack.pop(), stack.pop()
if z.Cmp(Zero) > 0 {
- add := new(big.Int).Add(x, y)
- base.Mod(add, z)
-
- base = U256(base)
+ add := x.Add(x, y)
+ add.Mod(add, z)
+ stack.push(U256(add))
+ } else {
+ stack.push(new(big.Int))
}
-
- stack.push(base)
}
func opMulmod(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
- base := new(big.Int)
- x := stack.pop()
- y := stack.pop()
- z := stack.pop()
-
+ x, y, z := stack.pop(), stack.pop(), stack.pop()
if z.Cmp(Zero) > 0 {
- mul := new(big.Int).Mul(x, y)
- base.Mod(mul, z)
-
- U256(base)
+ mul := x.Mul(x, y)
+ mul.Mod(mul, z)
+ stack.push(U256(mul))
+ } else {
+ stack.push(new(big.Int))
}
-
- stack.push(base)
}
func opSha3(instr instruction, env Environment, context *Context, memory *Memory, stack *stack) {
offset, size := stack.pop(), stack.pop()
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) {
@@ -383,7 +332,7 @@ func opBlockhash(instr instruction, env Environment, context *Context, memory *M
if num.Cmp(n) > 0 && num.Cmp(env.BlockNumber()) < 0 {
stack.push(env.GetHash(num.Uint64()).Big())
} 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)
ret, suberr, ref := env.Create(context, input, gas, context.Price, value)
if suberr != nil {
- stack.push(common.BigFalse)
+ stack.push(new(big.Int))
} else {
// 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)
if err != nil {
- stack.push(common.BigFalse)
+ stack.push(new(big.Int))
} else {
- stack.push(common.BigTrue)
+ stack.push(big.NewInt(1))
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)
if err != nil {
- stack.push(common.BigFalse)
+ stack.push(new(big.Int))
} else {
- stack.push(common.BigTrue)
+ stack.push(big.NewInt(1))
memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
}
diff --git a/core/vm/jit.go b/core/vm/jit.go
index c66630ae8..d5c2d7830 100644
--- a/core/vm/jit.go
+++ b/core/vm/jit.go
@@ -404,9 +404,10 @@ func jitCalculateGasAndSize(env Environment, context *Context, caller ContextRef
mSize, mStart := stack.data[stack.len()-2], stack.data[stack.len()-1]
+ add := new(big.Int)
gas.Add(gas, params.LogGas)
- gas.Add(gas, new(big.Int).Mul(big.NewInt(int64(n)), params.LogTopicGas))
- gas.Add(gas, new(big.Int).Mul(mSize, params.LogDataGas))
+ gas.Add(gas, add.Mul(big.NewInt(int64(n)), params.LogTopicGas))
+ gas.Add(gas, add.Mul(mSize, params.LogDataGas))
newMemSize = calcMemSize(mStart, mSize)
case EXP:
@@ -496,18 +497,20 @@ func jitCalculateGasAndSize(env Environment, context *Context, caller ContextRef
newMemSize.Mul(newMemSizeWords, u256(32))
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())))
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)
oldTotalFee := new(big.Int).Add(linCoef, quadCoef)
pow.Exp(newMemSizeWords, common.Big2, Zero)
- linCoef = new(big.Int).Mul(newMemSizeWords, params.MemoryGas)
- quadCoef = new(big.Int).Div(pow, params.QuadCoeffDiv)
- newTotalFee := new(big.Int).Add(linCoef, quadCoef)
+ linCoef = linCoef.Mul(newMemSizeWords, params.MemoryGas)
+ quadCoef = quadCoef.Div(pow, params.QuadCoeffDiv)
+ newTotalFee := linCoef.Add(linCoef, quadCoef)
- fee := new(big.Int).Sub(newTotalFee, oldTotalFee)
+ fee := newTotalFee.Sub(newTotalFee, oldTotalFee)
gas.Add(gas, fee)
}
}
diff --git a/core/vm/stack.go b/core/vm/stack.go
index 23c109455..009ac9e1b 100644
--- a/core/vm/stack.go
+++ b/core/vm/stack.go
@@ -21,14 +21,17 @@ import (
"math/big"
)
-func newstack() *stack {
- return &stack{}
-}
-
+// stack is an object for basic stack operations. Items popped to the stack are
+// expected to be changed and modified. stack does not take care of adding newly
+// initialised objects.
type stack struct {
data []*big.Int
}
+func newstack() *stack {
+ return &stack{}
+}
+
func (st *stack) Data() []*big.Int {
return st.data
}
diff --git a/tests/vm_test.go b/tests/vm_test.go
index 6b6b179fd..afa1424d5 100644
--- a/tests/vm_test.go
+++ b/tests/vm_test.go
@@ -30,7 +30,7 @@ func BenchmarkVmAckermann32Tests(b *testing.B) {
func BenchmarkVmFibonacci16Tests(b *testing.B) {
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)
}
}