aboutsummaryrefslogblamecommitdiff
path: root/core/vm/instructions.go
blob: ecdccbd8198ae264627ef82840cd6d4a98640edc (plain) (tree)
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009


















                                                                                  













































































































































































































































































































































































































                                                                                                                                    












































































































































































































































































































































































































































































































































































































                                                                                                                                                                                
// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package vm

import (
	"errors"
	"math/big"

	"github.com/ava-labs/coreth/core/types"
	"github.com/ava-labs/coreth/params"
	"github.com/ava-labs/go-ethereum/common"
	"github.com/ava-labs/go-ethereum/common/math"
	"golang.org/x/crypto/sha3"
)

var (
	bigZero                  = new(big.Int)
	tt255                    = math.BigPow(2, 255)
	errWriteProtection       = errors.New("evm: write protection")
	errReturnDataOutOfBounds = errors.New("evm: return data out of bounds")
	errExecutionReverted     = errors.New("evm: execution reverted")
	errMaxCodeSizeExceeded   = errors.New("evm: max code size exceeded")
	errInvalidJump           = errors.New("evm: invalid jump destination")
)

func opAdd(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()
	math.U256(y.Add(x, y))

	interpreter.intPool.put(x)
	return nil, nil
}

func opSub(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()
	math.U256(y.Sub(x, y))

	interpreter.intPool.put(x)
	return nil, nil
}

func opMul(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.pop()
	stack.push(math.U256(x.Mul(x, y)))

	interpreter.intPool.put(y)

	return nil, nil
}

func opDiv(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()
	if y.Sign() != 0 {
		math.U256(y.Div(x, y))
	} else {
		y.SetUint64(0)
	}
	interpreter.intPool.put(x)
	return nil, nil
}

func opSdiv(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := math.S256(stack.pop()), math.S256(stack.pop())
	res := interpreter.intPool.getZero()

	if y.Sign() == 0 || x.Sign() == 0 {
		stack.push(res)
	} else {
		if x.Sign() != y.Sign() {
			res.Div(x.Abs(x), y.Abs(y))
			res.Neg(res)
		} else {
			res.Div(x.Abs(x), y.Abs(y))
		}
		stack.push(math.U256(res))
	}
	interpreter.intPool.put(x, y)
	return nil, nil
}

func opMod(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.pop()
	if y.Sign() == 0 {
		stack.push(x.SetUint64(0))
	} else {
		stack.push(math.U256(x.Mod(x, y)))
	}
	interpreter.intPool.put(y)
	return nil, nil
}

func opSmod(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := math.S256(stack.pop()), math.S256(stack.pop())
	res := interpreter.intPool.getZero()

	if y.Sign() == 0 {
		stack.push(res)
	} else {
		if x.Sign() < 0 {
			res.Mod(x.Abs(x), y.Abs(y))
			res.Neg(res)
		} else {
			res.Mod(x.Abs(x), y.Abs(y))
		}
		stack.push(math.U256(res))
	}
	interpreter.intPool.put(x, y)
	return nil, nil
}

func opExp(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	base, exponent := stack.pop(), stack.pop()
	// some shortcuts
	cmpToOne := exponent.Cmp(big1)
	if cmpToOne < 0 { // Exponent is zero
		// x ^ 0 == 1
		stack.push(base.SetUint64(1))
	} else if base.Sign() == 0 {
		// 0 ^ y, if y != 0, == 0
		stack.push(base.SetUint64(0))
	} else if cmpToOne == 0 { // Exponent is one
		// x ^ 1 == x
		stack.push(base)
	} else {
		stack.push(math.Exp(base, exponent))
		interpreter.intPool.put(base)
	}
	interpreter.intPool.put(exponent)
	return nil, nil
}

func opSignExtend(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	back := stack.pop()
	if back.Cmp(big.NewInt(31)) < 0 {
		bit := uint(back.Uint64()*8 + 7)
		num := stack.pop()
		mask := back.Lsh(common.Big1, bit)
		mask.Sub(mask, common.Big1)
		if num.Bit(int(bit)) > 0 {
			num.Or(num, mask.Not(mask))
		} else {
			num.And(num, mask)
		}

		stack.push(math.U256(num))
	}

	interpreter.intPool.put(back)
	return nil, nil
}

func opNot(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x := stack.peek()
	math.U256(x.Not(x))
	return nil, nil
}

func opLt(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()
	if x.Cmp(y) < 0 {
		y.SetUint64(1)
	} else {
		y.SetUint64(0)
	}
	interpreter.intPool.put(x)
	return nil, nil
}

func opGt(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()
	if x.Cmp(y) > 0 {
		y.SetUint64(1)
	} else {
		y.SetUint64(0)
	}
	interpreter.intPool.put(x)
	return nil, nil
}

func opSlt(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()

	xSign := x.Cmp(tt255)
	ySign := y.Cmp(tt255)

	switch {
	case xSign >= 0 && ySign < 0:
		y.SetUint64(1)

	case xSign < 0 && ySign >= 0:
		y.SetUint64(0)

	default:
		if x.Cmp(y) < 0 {
			y.SetUint64(1)
		} else {
			y.SetUint64(0)
		}
	}
	interpreter.intPool.put(x)
	return nil, nil
}

func opSgt(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()

	xSign := x.Cmp(tt255)
	ySign := y.Cmp(tt255)

	switch {
	case xSign >= 0 && ySign < 0:
		y.SetUint64(0)

	case xSign < 0 && ySign >= 0:
		y.SetUint64(1)

	default:
		if x.Cmp(y) > 0 {
			y.SetUint64(1)
		} else {
			y.SetUint64(0)
		}
	}
	interpreter.intPool.put(x)
	return nil, nil
}

func opEq(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()
	if x.Cmp(y) == 0 {
		y.SetUint64(1)
	} else {
		y.SetUint64(0)
	}
	interpreter.intPool.put(x)
	return nil, nil
}

func opIszero(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x := stack.peek()
	if x.Sign() > 0 {
		x.SetUint64(0)
	} else {
		x.SetUint64(1)
	}
	return nil, nil
}

func opAnd(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.pop()
	stack.push(x.And(x, y))

	interpreter.intPool.put(y)
	return nil, nil
}

func opOr(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()
	y.Or(x, y)

	interpreter.intPool.put(x)
	return nil, nil
}

func opXor(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y := stack.pop(), stack.peek()
	y.Xor(x, y)

	interpreter.intPool.put(x)
	return nil, nil
}

func opByte(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	th, val := stack.pop(), stack.peek()
	if th.Cmp(common.Big32) < 0 {
		b := math.Byte(val, 32, int(th.Int64()))
		val.SetUint64(uint64(b))
	} else {
		val.SetUint64(0)
	}
	interpreter.intPool.put(th)
	return nil, nil
}

func opAddmod(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y, z := stack.pop(), stack.pop(), stack.pop()
	if z.Cmp(bigZero) > 0 {
		x.Add(x, y)
		x.Mod(x, z)
		stack.push(math.U256(x))
	} else {
		stack.push(x.SetUint64(0))
	}
	interpreter.intPool.put(y, z)
	return nil, nil
}

func opMulmod(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	x, y, z := stack.pop(), stack.pop(), stack.pop()
	if z.Cmp(bigZero) > 0 {
		x.Mul(x, y)
		x.Mod(x, z)
		stack.push(math.U256(x))
	} else {
		stack.push(x.SetUint64(0))
	}
	interpreter.intPool.put(y, z)
	return nil, nil
}

// opSHL implements Shift Left
// The SHL instruction (shift left) pops 2 values from the stack, first arg1 and then arg2,
// and pushes on the stack arg2 shifted to the left by arg1 number of bits.
func opSHL(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	// Note, second operand is left in the stack; accumulate result into it, and no need to push it afterwards
	shift, value := math.U256(stack.pop()), math.U256(stack.peek())
	defer interpreter.intPool.put(shift) // First operand back into the pool

	if shift.Cmp(common.Big256) >= 0 {
		value.SetUint64(0)
		return nil, nil
	}
	n := uint(shift.Uint64())
	math.U256(value.Lsh(value, n))

	return nil, nil
}

// opSHR implements Logical Shift Right
// The SHR instruction (logical shift right) pops 2 values from the stack, first arg1 and then arg2,
// and pushes on the stack arg2 shifted to the right by arg1 number of bits with zero fill.
func opSHR(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	// Note, second operand is left in the stack; accumulate result into it, and no need to push it afterwards
	shift, value := math.U256(stack.pop()), math.U256(stack.peek())
	defer interpreter.intPool.put(shift) // First operand back into the pool

	if shift.Cmp(common.Big256) >= 0 {
		value.SetUint64(0)
		return nil, nil
	}
	n := uint(shift.Uint64())
	math.U256(value.Rsh(value, n))

	return nil, nil
}

// opSAR implements Arithmetic Shift Right
// The SAR instruction (arithmetic shift right) pops 2 values from the stack, first arg1 and then arg2,
// and pushes on the stack arg2 shifted to the right by arg1 number of bits with sign extension.
func opSAR(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	// Note, S256 returns (potentially) a new bigint, so we're popping, not peeking this one
	shift, value := math.U256(stack.pop()), math.S256(stack.pop())
	defer interpreter.intPool.put(shift) // First operand back into the pool

	if shift.Cmp(common.Big256) >= 0 {
		if value.Sign() >= 0 {
			value.SetUint64(0)
		} else {
			value.SetInt64(-1)
		}
		stack.push(math.U256(value))
		return nil, nil
	}
	n := uint(shift.Uint64())
	value.Rsh(value, n)
	stack.push(math.U256(value))

	return nil, nil
}

func opSha3(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	offset, size := stack.pop(), stack.pop()
	data := memory.Get(offset.Int64(), size.Int64())

	if interpreter.hasher == nil {
		interpreter.hasher = sha3.NewLegacyKeccak256().(keccakState)
	} else {
		interpreter.hasher.Reset()
	}
	interpreter.hasher.Write(data)
	interpreter.hasher.Read(interpreter.hasherBuf[:])

	evm := interpreter.evm
	if evm.vmConfig.EnablePreimageRecording {
		evm.StateDB.AddPreimage(interpreter.hasherBuf, data)
	}
	stack.push(interpreter.intPool.get().SetBytes(interpreter.hasherBuf[:]))

	interpreter.intPool.put(offset, size)
	return nil, nil
}

func opAddress(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetBytes(contract.Address().Bytes()))
	return nil, nil
}

func opBalance(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	slot := stack.peek()
	slot.Set(interpreter.evm.StateDB.GetBalance(common.BigToAddress(slot)))
	return nil, nil
}

func opBalanceMultiCoin(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	addr, cid := stack.pop(), stack.pop()
	stack.push(interpreter.evm.StateDB.GetBalanceMultiCoin(common.BigToAddress(addr), common.BigToHash(cid)))
	return nil, nil
}

func opOrigin(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetBytes(interpreter.evm.Origin.Bytes()))
	return nil, nil
}

func opCaller(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetBytes(contract.Caller().Bytes()))
	return nil, nil
}

func opCallValue(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().Set(contract.value))
	return nil, nil
}

func opCallDataLoad(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetBytes(getDataBig(contract.Input, stack.pop(), big32)))
	return nil, nil
}

func opCallDataSize(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetInt64(int64(len(contract.Input))))
	return nil, nil
}

func opCallDataCopy(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	var (
		memOffset  = stack.pop()
		dataOffset = stack.pop()
		length     = stack.pop()
	)
	memory.Set(memOffset.Uint64(), length.Uint64(), getDataBig(contract.Input, dataOffset, length))

	interpreter.intPool.put(memOffset, dataOffset, length)
	return nil, nil
}

func opReturnDataSize(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetUint64(uint64(len(interpreter.returnData))))
	return nil, nil
}

func opReturnDataCopy(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	var (
		memOffset  = stack.pop()
		dataOffset = stack.pop()
		length     = stack.pop()

		end = interpreter.intPool.get().Add(dataOffset, length)
	)
	defer interpreter.intPool.put(memOffset, dataOffset, length, end)

	if !end.IsUint64() || uint64(len(interpreter.returnData)) < end.Uint64() {
		return nil, errReturnDataOutOfBounds
	}
	memory.Set(memOffset.Uint64(), length.Uint64(), interpreter.returnData[dataOffset.Uint64():end.Uint64()])

	return nil, nil
}

func opExtCodeSize(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	slot := stack.peek()
	slot.SetUint64(uint64(interpreter.evm.StateDB.GetCodeSize(common.BigToAddress(slot))))

	return nil, nil
}

func opCodeSize(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	l := interpreter.intPool.get().SetInt64(int64(len(contract.Code)))
	stack.push(l)

	return nil, nil
}

func opCodeCopy(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	var (
		memOffset  = stack.pop()
		codeOffset = stack.pop()
		length     = stack.pop()
	)
	codeCopy := getDataBig(contract.Code, codeOffset, length)
	memory.Set(memOffset.Uint64(), length.Uint64(), codeCopy)

	interpreter.intPool.put(memOffset, codeOffset, length)
	return nil, nil
}

func opExtCodeCopy(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	var (
		addr       = common.BigToAddress(stack.pop())
		memOffset  = stack.pop()
		codeOffset = stack.pop()
		length     = stack.pop()
	)
	codeCopy := getDataBig(interpreter.evm.StateDB.GetCode(addr), codeOffset, length)
	memory.Set(memOffset.Uint64(), length.Uint64(), codeCopy)

	interpreter.intPool.put(memOffset, codeOffset, length)
	return nil, nil
}

// opExtCodeHash returns the code hash of a specified account.
// There are several cases when the function is called, while we can relay everything
// to `state.GetCodeHash` function to ensure the correctness.
//   (1) Caller tries to get the code hash of a normal contract account, state
// should return the relative code hash and set it as the result.
//
//   (2) Caller tries to get the code hash of a non-existent account, state should
// return common.Hash{} and zero will be set as the result.
//
//   (3) Caller tries to get the code hash for an account without contract code,
// state should return emptyCodeHash(0xc5d246...) as the result.
//
//   (4) Caller tries to get the code hash of a precompiled account, the result
// should be zero or emptyCodeHash.
//
// It is worth noting that in order to avoid unnecessary create and clean,
// all precompile accounts on mainnet have been transferred 1 wei, so the return
// here should be emptyCodeHash.
// If the precompile account is not transferred any amount on a private or
// customized chain, the return value will be zero.
//
//   (5) Caller tries to get the code hash for an account which is marked as suicided
// in the current transaction, the code hash of this account should be returned.
//
//   (6) Caller tries to get the code hash for an account which is marked as deleted,
// this account should be regarded as a non-existent account and zero should be returned.
func opExtCodeHash(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	slot := stack.peek()
	address := common.BigToAddress(slot)
	if interpreter.evm.StateDB.Empty(address) {
		slot.SetUint64(0)
	} else {
		slot.SetBytes(interpreter.evm.StateDB.GetCodeHash(address).Bytes())
	}
	return nil, nil
}

func opGasprice(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().Set(interpreter.evm.GasPrice))
	return nil, nil
}

func opBlockhash(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	num := stack.pop()

	n := interpreter.intPool.get().Sub(interpreter.evm.BlockNumber, common.Big257)
	if num.Cmp(n) > 0 && num.Cmp(interpreter.evm.BlockNumber) < 0 {
		stack.push(interpreter.evm.GetHash(num.Uint64()).Big())
	} else {
		stack.push(interpreter.intPool.getZero())
	}
	interpreter.intPool.put(num, n)
	return nil, nil
}

func opCoinbase(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetBytes(interpreter.evm.Coinbase.Bytes()))
	return nil, nil
}

func opTimestamp(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(math.U256(interpreter.intPool.get().Set(interpreter.evm.Time)))
	return nil, nil
}

func opNumber(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(math.U256(interpreter.intPool.get().Set(interpreter.evm.BlockNumber)))
	return nil, nil
}

func opDifficulty(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(math.U256(interpreter.intPool.get().Set(interpreter.evm.Difficulty)))
	return nil, nil
}

func opGasLimit(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(math.U256(interpreter.intPool.get().SetUint64(interpreter.evm.GasLimit)))
	return nil, nil
}

func opPop(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	interpreter.intPool.put(stack.pop())
	return nil, nil
}

func opMload(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	offset := stack.pop()
	val := interpreter.intPool.get().SetBytes(memory.Get(offset.Int64(), 32))
	stack.push(val)

	interpreter.intPool.put(offset)
	return nil, nil
}

func opMstore(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	// pop value of the stack
	mStart, val := stack.pop(), stack.pop()
	memory.Set32(mStart.Uint64(), val)

	interpreter.intPool.put(mStart, val)
	return nil, nil
}

func opMstore8(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	off, val := stack.pop().Int64(), stack.pop().Int64()
	memory.store[off] = byte(val & 0xff)

	return nil, nil
}

func opSload(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	loc := stack.peek()
	val := interpreter.evm.StateDB.GetState(contract.Address(), common.BigToHash(loc))
	loc.SetBytes(val.Bytes())
	return nil, nil
}

func opSstore(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	loc := common.BigToHash(stack.pop())
	val := stack.pop()
	if err := interpreter.evm.StateDB.SetState(contract.Address(), loc, common.BigToHash(val)); err != nil {
		return nil, err
	}
	interpreter.intPool.put(val)
	return nil, nil
}

func opJump(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	pos := stack.pop()
	if !contract.validJumpdest(pos) {
		return nil, errInvalidJump
	}
	*pc = pos.Uint64()

	interpreter.intPool.put(pos)
	return nil, nil
}

func opJumpi(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	pos, cond := stack.pop(), stack.pop()
	if cond.Sign() != 0 {
		if !contract.validJumpdest(pos) {
			return nil, errInvalidJump
		}
		*pc = pos.Uint64()
	} else {
		*pc++
	}

	interpreter.intPool.put(pos, cond)
	return nil, nil
}

func opJumpdest(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	return nil, nil
}

func opPc(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetUint64(*pc))
	return nil, nil
}

func opMsize(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetInt64(int64(memory.Len())))
	return nil, nil
}

func opGas(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	stack.push(interpreter.intPool.get().SetUint64(contract.Gas))
	return nil, nil
}

func opCreate(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	var (
		value        = stack.pop()
		offset, size = stack.pop(), stack.pop()
		input        = memory.Get(offset.Int64(), size.Int64())
		gas          = contract.Gas
	)
	if interpreter.evm.chainRules.IsEIP150 {
		gas -= gas / 64
	}

	contract.UseGas(gas)
	res, addr, returnGas, suberr := interpreter.evm.Create(contract, input, gas, value)
	// Push item on the stack based on the returned error. If the ruleset is
	// homestead we must check for CodeStoreOutOfGasError (homestead only
	// rule) and treat as an error, if the ruleset is frontier we must
	// ignore this error and pretend the operation was successful.
	if interpreter.evm.chainRules.IsHomestead && suberr == ErrCodeStoreOutOfGas {
		stack.push(interpreter.intPool.getZero())
	} else if suberr != nil && suberr != ErrCodeStoreOutOfGas {
		stack.push(interpreter.intPool.getZero())
	} else {
		stack.push(interpreter.intPool.get().SetBytes(addr.Bytes()))
	}
	contract.Gas += returnGas
	interpreter.intPool.put(value, offset, size)

	if suberr == errExecutionReverted {
		return res, nil
	}
	return nil, nil
}

func opCreate2(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	var (
		endowment    = stack.pop()
		offset, size = stack.pop(), stack.pop()
		salt         = stack.pop()
		input        = memory.Get(offset.Int64(), size.Int64())
		gas          = contract.Gas
	)

	// Apply EIP150
	gas -= gas / 64
	contract.UseGas(gas)
	res, addr, returnGas, suberr := interpreter.evm.Create2(contract, input, gas, endowment, salt)
	// Push item on the stack based on the returned error.
	if suberr != nil {
		stack.push(interpreter.intPool.getZero())
	} else {
		stack.push(interpreter.intPool.get().SetBytes(addr.Bytes()))
	}
	contract.Gas += returnGas
	interpreter.intPool.put(endowment, offset, size, salt)

	if suberr == errExecutionReverted {
		return res, nil
	}
	return nil, nil
}

func opCall(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	// Pop gas. The actual gas in interpreter.evm.callGasTemp.
	interpreter.intPool.put(stack.pop())
	gas := interpreter.evm.callGasTemp
	// Pop other call parameters.
	addr, value, inOffset, inSize, retOffset, retSize := stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop()
	toAddr := common.BigToAddress(addr)
	value = math.U256(value)
	// Get the arguments from the memory.
	args := memory.Get(inOffset.Int64(), inSize.Int64())

	if value.Sign() != 0 {
		gas += params.CallStipend
	}
	ret, returnGas, err := interpreter.evm.Call(contract, toAddr, args, gas, value)
	if err != nil {
		stack.push(interpreter.intPool.getZero())
	} else {
		stack.push(interpreter.intPool.get().SetUint64(1))
	}
	if err == nil || err == errExecutionReverted {
		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
	}
	contract.Gas += returnGas

	interpreter.intPool.put(addr, value, inOffset, inSize, retOffset, retSize)
	return ret, nil
}

func opCallExpert(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	// Pop gas. The actual gas in interpreter.evm.callGasTemp.
	interpreter.intPool.put(stack.pop())
	gas := interpreter.evm.callGasTemp
	// Pop other call parameters.
	addr, value, cid, value2, inOffset, inSize, retOffset, retSize := stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop()
	toAddr := common.BigToAddress(addr)
	coinID := common.BigToHash(cid)
	value = math.U256(value)
	value2 = math.U256(value2)
	// Get the arguments from the memory.
	args := memory.Get(inOffset.Int64(), inSize.Int64())

	if value.Sign() != 0 {
		gas += params.CallStipend
	}
	ret, returnGas, err := interpreter.evm.CallExpert(contract, toAddr, args, gas, value, &coinID, value2)
	if err != nil {
		stack.push(interpreter.intPool.getZero())
	} else {
		stack.push(interpreter.intPool.get().SetUint64(1))
	}
	if err == nil || err == errExecutionReverted {
		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
	}
	contract.Gas += returnGas

	interpreter.intPool.put(addr, value, inOffset, inSize, retOffset, retSize)
	return ret, nil
}

func opCallCode(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	// Pop gas. The actual gas is in interpreter.evm.callGasTemp.
	interpreter.intPool.put(stack.pop())
	gas := interpreter.evm.callGasTemp
	// Pop other call parameters.
	addr, value, inOffset, inSize, retOffset, retSize := stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop()
	toAddr := common.BigToAddress(addr)
	value = math.U256(value)
	// Get arguments from the memory.
	args := memory.Get(inOffset.Int64(), inSize.Int64())

	if value.Sign() != 0 {
		gas += params.CallStipend
	}
	ret, returnGas, err := interpreter.evm.CallCode(contract, toAddr, args, gas, value)
	if err != nil {
		stack.push(interpreter.intPool.getZero())
	} else {
		stack.push(interpreter.intPool.get().SetUint64(1))
	}
	if err == nil || err == errExecutionReverted {
		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
	}
	contract.Gas += returnGas

	interpreter.intPool.put(addr, value, inOffset, inSize, retOffset, retSize)
	return ret, nil
}

func opDelegateCall(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	// Pop gas. The actual gas is in interpreter.evm.callGasTemp.
	interpreter.intPool.put(stack.pop())
	gas := interpreter.evm.callGasTemp
	// Pop other call parameters.
	addr, inOffset, inSize, retOffset, retSize := stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop()
	toAddr := common.BigToAddress(addr)
	// Get arguments from the memory.
	args := memory.Get(inOffset.Int64(), inSize.Int64())

	ret, returnGas, err := interpreter.evm.DelegateCall(contract, toAddr, args, gas)
	if err != nil {
		stack.push(interpreter.intPool.getZero())
	} else {
		stack.push(interpreter.intPool.get().SetUint64(1))
	}
	if err == nil || err == errExecutionReverted {
		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
	}
	contract.Gas += returnGas

	interpreter.intPool.put(addr, inOffset, inSize, retOffset, retSize)
	return ret, nil
}

func opStaticCall(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	// Pop gas. The actual gas is in interpreter.evm.callGasTemp.
	interpreter.intPool.put(stack.pop())
	gas := interpreter.evm.callGasTemp
	// Pop other call parameters.
	addr, inOffset, inSize, retOffset, retSize := stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop()
	toAddr := common.BigToAddress(addr)
	// Get arguments from the memory.
	args := memory.Get(inOffset.Int64(), inSize.Int64())

	ret, returnGas, err := interpreter.evm.StaticCall(contract, toAddr, args, gas)
	if err != nil {
		stack.push(interpreter.intPool.getZero())
	} else {
		stack.push(interpreter.intPool.get().SetUint64(1))
	}
	if err == nil || err == errExecutionReverted {
		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
	}
	contract.Gas += returnGas

	interpreter.intPool.put(addr, inOffset, inSize, retOffset, retSize)
	return ret, nil
}

func opReturn(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	offset, size := stack.pop(), stack.pop()
	ret := memory.GetPtr(offset.Int64(), size.Int64())

	interpreter.intPool.put(offset, size)
	return ret, nil
}

func opRevert(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	offset, size := stack.pop(), stack.pop()
	ret := memory.GetPtr(offset.Int64(), size.Int64())

	interpreter.intPool.put(offset, size)
	return ret, nil
}

func opStop(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	return nil, nil
}

func opSuicide(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	balance := interpreter.evm.StateDB.GetBalance(contract.Address())
	interpreter.evm.StateDB.AddBalance(common.BigToAddress(stack.pop()), balance)

	interpreter.evm.StateDB.Suicide(contract.Address())
	return nil, nil
}

func opEMC(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	return nil, interpreter.evm.StateDB.EnableMultiCoin(contract.Address())
}

// following functions are used by the instruction jump  table

// make log instruction function
func makeLog(size int) executionFunc {
	return func(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
		topics := make([]common.Hash, size)
		mStart, mSize := stack.pop(), stack.pop()
		for i := 0; i < size; i++ {
			topics[i] = common.BigToHash(stack.pop())
		}

		d := memory.Get(mStart.Int64(), mSize.Int64())
		interpreter.evm.StateDB.AddLog(&types.Log{
			Address: contract.Address(),
			Topics:  topics,
			Data:    d,
			// This is a non-consensus field, but assigned here because
			// core/state doesn't know the current block number.
			BlockNumber: interpreter.evm.BlockNumber.Uint64(),
		})

		interpreter.intPool.put(mStart, mSize)
		return nil, nil
	}
}

// opPush1 is a specialized version of pushN
func opPush1(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
	var (
		codeLen = uint64(len(contract.Code))
		integer = interpreter.intPool.get()
	)
	*pc += 1
	if *pc < codeLen {
		stack.push(integer.SetUint64(uint64(contract.Code[*pc])))
	} else {
		stack.push(integer.SetUint64(0))
	}
	return nil, nil
}

// make push instruction function
func makePush(size uint64, pushByteSize int) executionFunc {
	return func(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
		codeLen := len(contract.Code)

		startMin := codeLen
		if int(*pc+1) < startMin {
			startMin = int(*pc + 1)
		}

		endMin := codeLen
		if startMin+pushByteSize < endMin {
			endMin = startMin + pushByteSize
		}

		integer := interpreter.intPool.get()
		stack.push(integer.SetBytes(common.RightPadBytes(contract.Code[startMin:endMin], pushByteSize)))

		*pc += size
		return nil, nil
	}
}

// make dup instruction function
func makeDup(size int64) executionFunc {
	return func(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
		stack.dup(interpreter.intPool, int(size))
		return nil, nil
	}
}

// make swap instruction function
func makeSwap(size int64) executionFunc {
	// switch n + 1 otherwise n would be swapped with n
	size++
	return func(pc *uint64, interpreter *EVMInterpreter, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
		stack.swap(int(size))
		return nil, nil
	}
}