From ac697326a6045eaa760b159e4bda37c57be61cbf Mon Sep 17 00:00:00 2001 From: Jeffrey Wilcke Date: Thu, 6 Aug 2015 23:06:47 +0200 Subject: [PATCH] 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. --- core/vm/instructions.go | 171 ++++++++++++++-------------------------- core/vm/jit.go | 17 ++-- core/vm/stack.go | 11 ++- tests/vm_test.go | 2 +- 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) } }