From 188fcf68ed60ef7f229495280f5a92615074164b Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Wed, 11 Aug 2021 12:09:31 +0200
Subject: [PATCH 01/11] core/vm: more detailed benchmark for jumpdest analysis

---
 core/vm/analysis_test.go | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/core/vm/analysis_test.go b/core/vm/analysis_test.go
index fd2d744d87f4..29dd19a13f63 100644
--- a/core/vm/analysis_test.go
+++ b/core/vm/analysis_test.go
@@ -73,3 +73,22 @@ func BenchmarkJumpdestHashing_1200k(bench *testing.B) {
 	}
 	bench.StopTimer()
 }
+
+func BenchmarkJumpdestOpAnalysis(bench *testing.B) {
+	var op OpCode
+	bencher := func(b *testing.B) {
+		code := make([]byte, 32*b.N)
+		for i := range code {
+			code[i] = byte(op)
+		}
+		b.ResetTimer()
+		codeBitmap(code)
+	}
+	for op = PUSH1; op <= PUSH32; op++ {
+		bench.Run(op.String(), bencher)
+	}
+	op = JUMPDEST
+	bench.Run(op.String(), bencher)
+	op = STOP
+	bench.Run(op.String(), bencher)
+}

From c8c19a0c80eea4cd31831353374e2b743c10dae8 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Sun, 15 Aug 2021 20:43:37 +0200
Subject: [PATCH 02/11] core/vm: make jd analysis benchmark alloc free

---
 core/vm/analysis.go      | 7 +++++++
 core/vm/analysis_test.go | 3 ++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/core/vm/analysis.go b/core/vm/analysis.go
index 0ccf47b97903..2c813ecb240b 100644
--- a/core/vm/analysis.go
+++ b/core/vm/analysis.go
@@ -40,6 +40,13 @@ func codeBitmap(code []byte) bitvec {
 	// ends with a PUSH32, the algorithm will push zeroes onto the
 	// bitvector outside the bounds of the actual code.
 	bits := make(bitvec, len(code)/8+1+4)
+	return codeBitmapInternal(code, bits)
+}
+
+// codeBitmapInternal is the internal implementation of codeBitmap.
+// It exists for the purpose of being able to run benchmark tests
+// without dynamic allocations affecting the results.
+func codeBitmapInternal(code, bits bitvec) bitvec {
 	for pc := uint64(0); pc < uint64(len(code)); {
 		op := OpCode(code[pc])
 
diff --git a/core/vm/analysis_test.go b/core/vm/analysis_test.go
index 29dd19a13f63..61e508744275 100644
--- a/core/vm/analysis_test.go
+++ b/core/vm/analysis_test.go
@@ -81,8 +81,9 @@ func BenchmarkJumpdestOpAnalysis(bench *testing.B) {
 		for i := range code {
 			code[i] = byte(op)
 		}
+		bits := make(bitvec, len(code)/8+1+4)
 		b.ResetTimer()
-		codeBitmap(code)
+		codeBitmapInternal(code, bits)
 	}
 	for op = PUSH1; op <= PUSH32; op++ {
 		bench.Run(op.String(), bencher)

From 14e80e0be576a176b93c6d8e5903623bd51c3ff6 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Wed, 11 Aug 2021 13:46:34 +0200
Subject: [PATCH 03/11] core/vm: improve jumpdest analysis

---
 core/vm/analysis.go | 80 ++++++++++++++++++++++++++++++++++++---------
 1 file changed, 64 insertions(+), 16 deletions(-)

diff --git a/core/vm/analysis.go b/core/vm/analysis.go
index 2c813ecb240b..477c65a83f18 100644
--- a/core/vm/analysis.go
+++ b/core/vm/analysis.go
@@ -21,12 +21,48 @@ package vm
 // it's data (i.e. argument of PUSHxx).
 type bitvec []byte
 
+var lookup = [8]byte{
+	0x80, 0x40, 0x20, 0x10, 0x8, 0x4, 0x2, 0x1,
+}
+
 func (bits *bitvec) set(pos uint64) {
-	(*bits)[pos/8] |= 0x80 >> (pos % 8)
+	//(*bits)[pos/8] |= 0x80 >> (pos % 8)
+	(*bits)[pos/8] |= lookup[pos%8]
+}
+
+func (bits *bitvec) set2(pos uint64) {
+	(*bits)[pos/8+1] |= 0b1100_0000 << (8 - pos%8)
+	(*bits)[pos/8] |= 0b1100_0000 >> (pos % 8)
+}
+
+func (bits *bitvec) set3(pos uint64) {
+	(*bits)[pos/8+1] |= 0b1110_0000 << (8 - pos%8)
+	(*bits)[pos/8] |= 0b1110_0000 >> (pos % 8)
+}
+
+func (bits *bitvec) set4(pos uint64) {
+	(*bits)[pos/8+1] |= 0b1111_0000 << (8 - pos%8)
+	(*bits)[pos/8] |= 0b1111_0000 >> (pos % 8)
+}
+
+func (bits *bitvec) set5(pos uint64) {
+	(*bits)[pos/8+1] |= 0b1111_1000 << (8 - pos%8)
+	(*bits)[pos/8] |= 0b1111_1000 >> (pos % 8)
 }
+
+func (bits *bitvec) set6(pos uint64) {
+	(*bits)[pos/8+1] |= 0b1111_1100 << (8 - pos%8)
+	(*bits)[pos/8] |= 0b1111_1100 >> (pos % 8)
+}
+
+func (bits *bitvec) set7(pos uint64) {
+	(*bits)[pos/8+1] |= 0b1111_1110 << (8 - pos%8)
+	(*bits)[pos/8] |= 0b1111_1110 >> (pos % 8)
+}
+
 func (bits *bitvec) set8(pos uint64) {
-	(*bits)[pos/8] |= 0xFF >> (pos % 8)
 	(*bits)[pos/8+1] |= ^(0xFF >> (pos % 8))
+	(*bits)[pos/8] |= 0xFF >> (pos % 8)
 }
 
 // codeSegment checks if the position is in a code segment.
@@ -49,21 +85,33 @@ func codeBitmap(code []byte) bitvec {
 func codeBitmapInternal(code, bits bitvec) bitvec {
 	for pc := uint64(0); pc < uint64(len(code)); {
 		op := OpCode(code[pc])
-
-		if op >= PUSH1 && op <= PUSH32 {
-			numbits := op - PUSH1 + 1
-			pc++
-			for ; numbits >= 8; numbits -= 8 {
-				bits.set8(pc) // 8
-				pc += 8
-			}
-			for ; numbits > 0; numbits-- {
-				bits.set(pc)
-				pc++
-			}
-		} else {
-			pc++
+		pc++
+		if op < PUSH1 || op > PUSH32 {
+			continue
+		}
+		numbits := op - PUSH1 + 1
+		for ; numbits >= 8; numbits -= 8 {
+			bits.set8(pc) // 8
+			pc += 8
+		}
+		// numbits now max 7
+		switch numbits {
+		case 1:
+			bits.set(pc)
+		case 2:
+			bits.set2(pc)
+		case 3:
+			bits.set3(pc)
+		case 4:
+			bits.set4(pc)
+		case 5:
+			bits.set5(pc)
+		case 6:
+			bits.set6(pc)
+		case 7:
+			bits.set7(pc)
 		}
+		pc += uint64(numbits)
 	}
 	return bits
 }

From ee5b02609466550ed23940a68af87fe79da4d112 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Wed, 11 Aug 2021 14:23:18 +0200
Subject: [PATCH 04/11] core/vm: improve worst-case

---
 core/vm/analysis.go | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/core/vm/analysis.go b/core/vm/analysis.go
index 477c65a83f18..ae00d0569c35 100644
--- a/core/vm/analysis.go
+++ b/core/vm/analysis.go
@@ -89,6 +89,32 @@ func codeBitmapInternal(code, bits bitvec) bitvec {
 		if op < PUSH1 || op > PUSH32 {
 			continue
 		}
+		if op < PUSH8 {
+			switch op {
+			case PUSH1:
+				bits.set(pc)
+				pc += 1
+			case PUSH2:
+				bits.set2(pc)
+				pc += 2
+			case PUSH3:
+				bits.set3(pc)
+				pc += 3
+			case PUSH4:
+				bits.set4(pc)
+				pc += 4
+			case PUSH5:
+				bits.set5(pc)
+				pc += 5
+			case PUSH6:
+				bits.set6(pc)
+				pc += 6
+			case PUSH7:
+				bits.set7(pc)
+				pc += 7
+			}
+			continue
+		}
 		numbits := op - PUSH1 + 1
 		for ; numbits >= 8; numbits -= 8 {
 			bits.set8(pc) // 8

From 5c06f270b5a6d2d4b6f7ca5cc8655d7e02b3f690 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Sat, 14 Aug 2021 21:41:45 +0200
Subject: [PATCH 05/11] core/vm: further improvements in analysis

---
 core/vm/analysis.go      | 88 ++++++++++++++++++++--------------------
 core/vm/analysis_test.go |  4 +-
 2 files changed, 47 insertions(+), 45 deletions(-)

diff --git a/core/vm/analysis.go b/core/vm/analysis.go
index ae00d0569c35..f04352583fa7 100644
--- a/core/vm/analysis.go
+++ b/core/vm/analysis.go
@@ -31,38 +31,61 @@ func (bits *bitvec) set(pos uint64) {
 }
 
 func (bits *bitvec) set2(pos uint64) {
-	(*bits)[pos/8+1] |= 0b1100_0000 << (8 - pos%8)
-	(*bits)[pos/8] |= 0b1100_0000 >> (pos % 8)
+	a := uint16(0b1100_0000_0000_0000) >> (pos % 8)
+	(*bits)[pos/8] |= byte(a >> 8)
+	if b := byte(a); b != 0 {
+		//	If the bit-setting affects the neigbouring byte, we can assign - no need to OR it,
+		//	since it's the first write to that byte
+		(*bits)[pos/8+1] = b
+	}
 }
 
 func (bits *bitvec) set3(pos uint64) {
-	(*bits)[pos/8+1] |= 0b1110_0000 << (8 - pos%8)
-	(*bits)[pos/8] |= 0b1110_0000 >> (pos % 8)
+	a := uint16(0b1110_0000_0000_0000) >> (pos % 8)
+	(*bits)[pos/8] |= byte(a >> 8)
+	if b := byte(a); b != 0 {
+		(*bits)[pos/8+1] = b
+	}
 }
 
 func (bits *bitvec) set4(pos uint64) {
-	(*bits)[pos/8+1] |= 0b1111_0000 << (8 - pos%8)
-	(*bits)[pos/8] |= 0b1111_0000 >> (pos % 8)
+	a := uint16(0b1111_0000_0000_0000) >> (pos % 8)
+	(*bits)[pos/8] |= byte(a >> 8)
+	if b := byte(a); b != 0 {
+		(*bits)[pos/8+1] = b
+	}
 }
 
 func (bits *bitvec) set5(pos uint64) {
-	(*bits)[pos/8+1] |= 0b1111_1000 << (8 - pos%8)
-	(*bits)[pos/8] |= 0b1111_1000 >> (pos % 8)
+	a := uint16(0b1111_1000_0000_0000) >> (pos % 8)
+	(*bits)[pos/8] |= byte(a >> 8)
+	if b := byte(a); b != 0 {
+		(*bits)[pos/8+1] = b
+	}
 }
 
 func (bits *bitvec) set6(pos uint64) {
-	(*bits)[pos/8+1] |= 0b1111_1100 << (8 - pos%8)
-	(*bits)[pos/8] |= 0b1111_1100 >> (pos % 8)
+	a := uint16(0b1111_1100_0000_0000) >> (pos % 8)
+	(*bits)[pos/8] |= byte(a >> 8)
+	if b := byte(a); b != 0 {
+		(*bits)[pos/8+1] = b
+	}
 }
 
 func (bits *bitvec) set7(pos uint64) {
-	(*bits)[pos/8+1] |= 0b1111_1110 << (8 - pos%8)
-	(*bits)[pos/8] |= 0b1111_1110 >> (pos % 8)
+	a := uint16(0b1111_1110_0000_0000) >> (pos % 8)
+	(*bits)[pos/8] |= byte(a >> 8)
+	if b := byte(a); b != 0 {
+		(*bits)[pos/8+1] = b
+	}
 }
 
 func (bits *bitvec) set8(pos uint64) {
-	(*bits)[pos/8+1] |= ^(0xFF >> (pos % 8))
-	(*bits)[pos/8] |= 0xFF >> (pos % 8)
+	a := byte(0xFF >> (pos % 8))
+	(*bits)[pos/8] |= a
+	if ^a != 0{
+		(*bits)[pos/8+1] = ^a
+	}
 }
 
 // codeSegment checks if the position is in a code segment.
@@ -89,55 +112,34 @@ func codeBitmapInternal(code, bits bitvec) bitvec {
 		if op < PUSH1 || op > PUSH32 {
 			continue
 		}
-		if op < PUSH8 {
-			switch op {
-			case PUSH1:
-				bits.set(pc)
-				pc += 1
-			case PUSH2:
-				bits.set2(pc)
-				pc += 2
-			case PUSH3:
-				bits.set3(pc)
-				pc += 3
-			case PUSH4:
-				bits.set4(pc)
-				pc += 4
-			case PUSH5:
-				bits.set5(pc)
-				pc += 5
-			case PUSH6:
-				bits.set6(pc)
-				pc += 6
-			case PUSH7:
-				bits.set7(pc)
-				pc += 7
-			}
-			continue
-		}
 		numbits := op - PUSH1 + 1
 		for ; numbits >= 8; numbits -= 8 {
-			bits.set8(pc) // 8
+			bits.set8(pc)
 			pc += 8
 		}
-		// numbits now max 7
 		switch numbits {
 		case 1:
 			bits.set(pc)
+			pc += 1
 		case 2:
 			bits.set2(pc)
+			pc += 2
 		case 3:
 			bits.set3(pc)
+			pc += 3
 		case 4:
 			bits.set4(pc)
+			pc += 4
 		case 5:
 			bits.set5(pc)
+			pc += 5
 		case 6:
 			bits.set6(pc)
+			pc += 6
 		case 7:
 			bits.set7(pc)
+			pc += 7
 		}
-		pc += uint64(numbits)
 	}
 	return bits
 }
diff --git a/core/vm/analysis_test.go b/core/vm/analysis_test.go
index 61e508744275..585bb3097f44 100644
--- a/core/vm/analysis_test.go
+++ b/core/vm/analysis_test.go
@@ -47,10 +47,10 @@ func TestJumpDestAnalysis(t *testing.T) {
 		{[]byte{byte(PUSH32)}, 0xFF, 1},
 		{[]byte{byte(PUSH32)}, 0xFF, 2},
 	}
-	for _, test := range tests {
+	for i, test := range tests {
 		ret := codeBitmap(test.code)
 		if ret[test.which] != test.exp {
-			t.Fatalf("expected %x, got %02x", test.exp, ret[test.which])
+			t.Fatalf("test %d: expected %x, got %02x", i, test.exp, ret[test.which])
 		}
 	}
 }

From ac834652475d11480113816a4a4ee8efb7582879 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Sat, 14 Aug 2021 23:01:36 +0200
Subject: [PATCH 06/11] core/vm: improve jumpdest analysis >PUSH15

---
 core/vm/analysis.go | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/core/vm/analysis.go b/core/vm/analysis.go
index f04352583fa7..eb82904af26a 100644
--- a/core/vm/analysis.go
+++ b/core/vm/analysis.go
@@ -83,11 +83,20 @@ func (bits *bitvec) set7(pos uint64) {
 func (bits *bitvec) set8(pos uint64) {
 	a := byte(0xFF >> (pos % 8))
 	(*bits)[pos/8] |= a
-	if ^a != 0{
+	if ^a != 0 {
 		(*bits)[pos/8+1] = ^a
 	}
 }
 
+func (bits *bitvec) set16(pos uint64) {
+	a := byte(0xFF >> (pos % 8))
+	(*bits)[pos/8] |= a
+	(*bits)[pos/8+1] = 0xFF
+	if ^a != 0 {
+		(*bits)[pos/8+2] = ^a
+	}
+}
+
 // codeSegment checks if the position is in a code segment.
 func (bits *bitvec) codeSegment(pos uint64) bool {
 	return ((*bits)[pos/8] & (0x80 >> (pos % 8))) == 0
@@ -113,9 +122,15 @@ func codeBitmapInternal(code, bits bitvec) bitvec {
 			continue
 		}
 		numbits := op - PUSH1 + 1
-		for ; numbits >= 8; numbits -= 8 {
-			bits.set8(pc)
-			pc += 8
+		if numbits >= 8 {
+			for ; numbits >= 16; numbits -= 16 {
+				bits.set16(pc)
+				pc += 16
+			}
+			for ; numbits >= 8; numbits -= 8 {
+				bits.set8(pc)
+				pc += 8
+			}
 		}
 		switch numbits {
 		case 1:

From 3f60d8ba311a3b6a16bc582c06013eee09dbe66c Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Sun, 15 Aug 2021 20:44:28 +0200
Subject: [PATCH 07/11] core/vm: make jd analysis ref by value

---
 core/vm/analysis.go | 54 ++++++++++++++++++++++-----------------------
 1 file changed, 27 insertions(+), 27 deletions(-)

diff --git a/core/vm/analysis.go b/core/vm/analysis.go
index eb82904af26a..3ef085184865 100644
--- a/core/vm/analysis.go
+++ b/core/vm/analysis.go
@@ -25,75 +25,75 @@ var lookup = [8]byte{
 	0x80, 0x40, 0x20, 0x10, 0x8, 0x4, 0x2, 0x1,
 }
 
-func (bits *bitvec) set(pos uint64) {
+func (bits bitvec) set(pos uint64) {
 	//(*bits)[pos/8] |= 0x80 >> (pos % 8)
-	(*bits)[pos/8] |= lookup[pos%8]
+	bits[pos/8] |= lookup[pos%8]
 }
 
-func (bits *bitvec) set2(pos uint64) {
+func (bits bitvec) set2(pos uint64) {
 	a := uint16(0b1100_0000_0000_0000) >> (pos % 8)
-	(*bits)[pos/8] |= byte(a >> 8)
+	bits[pos/8] |= byte(a >> 8)
 	if b := byte(a); b != 0 {
 		//	If the bit-setting affects the neigbouring byte, we can assign - no need to OR it,
 		//	since it's the first write to that byte
-		(*bits)[pos/8+1] = b
+		bits[pos/8+1] = b
 	}
 }
 
-func (bits *bitvec) set3(pos uint64) {
+func (bits bitvec) set3(pos uint64) {
 	a := uint16(0b1110_0000_0000_0000) >> (pos % 8)
-	(*bits)[pos/8] |= byte(a >> 8)
+	bits[pos/8] |= byte(a >> 8)
 	if b := byte(a); b != 0 {
-		(*bits)[pos/8+1] = b
+		bits[pos/8+1] = b
 	}
 }
 
-func (bits *bitvec) set4(pos uint64) {
+func (bits bitvec) set4(pos uint64) {
 	a := uint16(0b1111_0000_0000_0000) >> (pos % 8)
-	(*bits)[pos/8] |= byte(a >> 8)
+	bits[pos/8] |= byte(a >> 8)
 	if b := byte(a); b != 0 {
-		(*bits)[pos/8+1] = b
+		bits[pos/8+1] = b
 	}
 }
 
-func (bits *bitvec) set5(pos uint64) {
+func (bits bitvec) set5(pos uint64) {
 	a := uint16(0b1111_1000_0000_0000) >> (pos % 8)
-	(*bits)[pos/8] |= byte(a >> 8)
+	bits[pos/8] |= byte(a >> 8)
 	if b := byte(a); b != 0 {
-		(*bits)[pos/8+1] = b
+		bits[pos/8+1] = b
 	}
 }
 
-func (bits *bitvec) set6(pos uint64) {
+func (bits bitvec) set6(pos uint64) {
 	a := uint16(0b1111_1100_0000_0000) >> (pos % 8)
-	(*bits)[pos/8] |= byte(a >> 8)
+	bits[pos/8] |= byte(a >> 8)
 	if b := byte(a); b != 0 {
-		(*bits)[pos/8+1] = b
+		bits[pos/8+1] = b
 	}
 }
 
-func (bits *bitvec) set7(pos uint64) {
+func (bits bitvec) set7(pos uint64) {
 	a := uint16(0b1111_1110_0000_0000) >> (pos % 8)
-	(*bits)[pos/8] |= byte(a >> 8)
+	bits[pos/8] |= byte(a >> 8)
 	if b := byte(a); b != 0 {
-		(*bits)[pos/8+1] = b
+		bits[pos/8+1] = b
 	}
 }
 
-func (bits *bitvec) set8(pos uint64) {
+func (bits bitvec) set8(pos uint64) {
 	a := byte(0xFF >> (pos % 8))
-	(*bits)[pos/8] |= a
+	bits[pos/8] |= a
 	if ^a != 0 {
-		(*bits)[pos/8+1] = ^a
+		bits[pos/8+1] = ^a
 	}
 }
 
-func (bits *bitvec) set16(pos uint64) {
+func (bits bitvec) set16(pos uint64) {
 	a := byte(0xFF >> (pos % 8))
-	(*bits)[pos/8] |= a
-	(*bits)[pos/8+1] = 0xFF
+	bits[pos/8] |= a
+	bits[pos/8+1] = 0xFF
 	if ^a != 0 {
-		(*bits)[pos/8+2] = ^a
+		bits[pos/8+2] = ^a
 	}
 }
 

From 0cb16d8521bae9785ca05ad069d39549357cf71d Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Mon, 16 Aug 2021 08:37:36 +0200
Subject: [PATCH 08/11] core/vm: fix misspell

---
 core/vm/analysis.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/vm/analysis.go b/core/vm/analysis.go
index 3ef085184865..812aa1e4833d 100644
--- a/core/vm/analysis.go
+++ b/core/vm/analysis.go
@@ -34,7 +34,7 @@ func (bits bitvec) set2(pos uint64) {
 	a := uint16(0b1100_0000_0000_0000) >> (pos % 8)
 	bits[pos/8] |= byte(a >> 8)
 	if b := byte(a); b != 0 {
-		//	If the bit-setting affects the neigbouring byte, we can assign - no need to OR it,
+		//	If the bit-setting affects the neighbouring byte, we can assign - no need to OR it,
 		//	since it's the first write to that byte
 		bits[pos/8+1] = b
 	}

From e3e0ce00e3cff868b578577686b10e956af89364 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Wed, 18 Aug 2021 13:38:49 +0200
Subject: [PATCH 09/11] core/vm: improve set8 and set16 a bit

---
 core/vm/analysis.go | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/core/vm/analysis.go b/core/vm/analysis.go
index 812aa1e4833d..0434e5092ee0 100644
--- a/core/vm/analysis.go
+++ b/core/vm/analysis.go
@@ -83,18 +83,14 @@ func (bits bitvec) set7(pos uint64) {
 func (bits bitvec) set8(pos uint64) {
 	a := byte(0xFF >> (pos % 8))
 	bits[pos/8] |= a
-	if ^a != 0 {
-		bits[pos/8+1] = ^a
-	}
+	bits[pos/8+1] = ^a
 }
 
 func (bits bitvec) set16(pos uint64) {
 	a := byte(0xFF >> (pos % 8))
 	bits[pos/8] |= a
 	bits[pos/8+1] = 0xFF
-	if ^a != 0 {
-		bits[pos/8+2] = ^a
-	}
+	bits[pos/8+2] = ^a
 }
 
 // codeSegment checks if the position is in a code segment.

From 8e05e089c189d3f1e7c585801e107d402972dff8 Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Wed, 18 Aug 2021 14:22:56 +0200
Subject: [PATCH 10/11] core/vm: reduce amount of code

---
 core/vm/analysis.go | 70 ++++++++++++---------------------------------
 1 file changed, 19 insertions(+), 51 deletions(-)

diff --git a/core/vm/analysis.go b/core/vm/analysis.go
index 0434e5092ee0..449cded2a896 100644
--- a/core/vm/analysis.go
+++ b/core/vm/analysis.go
@@ -16,6 +16,15 @@
 
 package vm
 
+const (
+	set2BitsMask = uint16(0b1100_0000_0000_0000)
+	set3BitsMask = uint16(0b1110_0000_0000_0000)
+	set4BitsMask = uint16(0b1111_0000_0000_0000)
+	set5BitsMask = uint16(0b1111_1000_0000_0000)
+	set6BitsMask = uint16(0b1111_1100_0000_0000)
+	set7BitsMask = uint16(0b1111_1110_0000_0000)
+)
+
 // bitvec is a bit vector which maps bytes in a program.
 // An unset bit means the byte is an opcode, a set bit means
 // it's data (i.e. argument of PUSHxx).
@@ -25,13 +34,12 @@ var lookup = [8]byte{
 	0x80, 0x40, 0x20, 0x10, 0x8, 0x4, 0x2, 0x1,
 }
 
-func (bits bitvec) set(pos uint64) {
-	//(*bits)[pos/8] |= 0x80 >> (pos % 8)
+func (bits bitvec) set1(pos uint64) {
 	bits[pos/8] |= lookup[pos%8]
 }
 
-func (bits bitvec) set2(pos uint64) {
-	a := uint16(0b1100_0000_0000_0000) >> (pos % 8)
+func (bits bitvec) setN(flag uint16, pos uint64) {
+	a := flag >> (pos % 8)
 	bits[pos/8] |= byte(a >> 8)
 	if b := byte(a); b != 0 {
 		//	If the bit-setting affects the neighbouring byte, we can assign - no need to OR it,
@@ -40,46 +48,6 @@ func (bits bitvec) set2(pos uint64) {
 	}
 }
 
-func (bits bitvec) set3(pos uint64) {
-	a := uint16(0b1110_0000_0000_0000) >> (pos % 8)
-	bits[pos/8] |= byte(a >> 8)
-	if b := byte(a); b != 0 {
-		bits[pos/8+1] = b
-	}
-}
-
-func (bits bitvec) set4(pos uint64) {
-	a := uint16(0b1111_0000_0000_0000) >> (pos % 8)
-	bits[pos/8] |= byte(a >> 8)
-	if b := byte(a); b != 0 {
-		bits[pos/8+1] = b
-	}
-}
-
-func (bits bitvec) set5(pos uint64) {
-	a := uint16(0b1111_1000_0000_0000) >> (pos % 8)
-	bits[pos/8] |= byte(a >> 8)
-	if b := byte(a); b != 0 {
-		bits[pos/8+1] = b
-	}
-}
-
-func (bits bitvec) set6(pos uint64) {
-	a := uint16(0b1111_1100_0000_0000) >> (pos % 8)
-	bits[pos/8] |= byte(a >> 8)
-	if b := byte(a); b != 0 {
-		bits[pos/8+1] = b
-	}
-}
-
-func (bits bitvec) set7(pos uint64) {
-	a := uint16(0b1111_1110_0000_0000) >> (pos % 8)
-	bits[pos/8] |= byte(a >> 8)
-	if b := byte(a); b != 0 {
-		bits[pos/8+1] = b
-	}
-}
-
 func (bits bitvec) set8(pos uint64) {
 	a := byte(0xFF >> (pos % 8))
 	bits[pos/8] |= a
@@ -130,25 +98,25 @@ func codeBitmapInternal(code, bits bitvec) bitvec {
 		}
 		switch numbits {
 		case 1:
-			bits.set(pc)
+			bits.set1(pc)
 			pc += 1
 		case 2:
-			bits.set2(pc)
+			bits.setN(set2BitsMask, pc)
 			pc += 2
 		case 3:
-			bits.set3(pc)
+			bits.setN(set3BitsMask, pc)
 			pc += 3
 		case 4:
-			bits.set4(pc)
+			bits.setN(set4BitsMask, pc)
 			pc += 4
 		case 5:
-			bits.set5(pc)
+			bits.setN(set5BitsMask, pc)
 			pc += 5
 		case 6:
-			bits.set6(pc)
+			bits.setN(set6BitsMask, pc)
 			pc += 6
 		case 7:
-			bits.set7(pc)
+			bits.setN(set7BitsMask, pc)
 			pc += 7
 		}
 	}

From 4d4879cafd1b3c906fc184a8c4a357137465128f Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Wed, 18 Aug 2021 13:34:52 +0200
Subject: [PATCH 11/11] core/vm: optimize byte copying

---
 core/vm/instructions.go | 4 ++++
 core/vm/interpreter.go  | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/core/vm/instructions.go b/core/vm/instructions.go
index f7ef2f900e20..6c8c6e6e6fa1 100644
--- a/core/vm/instructions.go
+++ b/core/vm/instructions.go
@@ -669,6 +669,7 @@ func opCall(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byt
 	}
 	stack.push(&temp)
 	if err == nil || err == ErrExecutionReverted {
+		ret = common.CopyBytes(ret)
 		scope.Memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
 	scope.Contract.Gas += returnGas
@@ -703,6 +704,7 @@ func opCallCode(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([
 	}
 	stack.push(&temp)
 	if err == nil || err == ErrExecutionReverted {
+		ret = common.CopyBytes(ret)
 		scope.Memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
 	scope.Contract.Gas += returnGas
@@ -730,6 +732,7 @@ func opDelegateCall(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext
 	}
 	stack.push(&temp)
 	if err == nil || err == ErrExecutionReverted {
+		ret = common.CopyBytes(ret)
 		scope.Memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
 	scope.Contract.Gas += returnGas
@@ -757,6 +760,7 @@ func opStaticCall(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext)
 	}
 	stack.push(&temp)
 	if err == nil || err == ErrExecutionReverted {
+		ret = common.CopyBytes(ret)
 		scope.Memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
 	scope.Contract.Gas += returnGas
diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go
index 9cf0c4e2c1e0..9fb83799c98c 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/interpreter.go
@@ -262,7 +262,7 @@ func (in *EVMInterpreter) Run(contract *Contract, input []byte, readOnly bool) (
 		// if the operation clears the return data (e.g. it has returning data)
 		// set the last return to the result of the operation.
 		if operation.returns {
-			in.returnData = common.CopyBytes(res)
+			in.returnData = res
 		}
 
 		switch {