From fbfaea2c886b4c2afc95712badb719deaf5fc67d Mon Sep 17 00:00:00 2001
From: Masaaki Goshima <goccy54@gmail.com>
Date: Mon, 22 Feb 2021 16:39:38 +0900
Subject: [PATCH] Refactor HeadInt operation

---
 encode_vm.go | 93 +++++++++++++++++++++++++---------------------------
 1 file changed, 45 insertions(+), 48 deletions(-)

diff --git a/encode_vm.go b/encode_vm.go
index faf1c73..46d44d1 100644
--- a/encode_vm.go
+++ b/encode_vm.go
@@ -596,67 +596,64 @@ func encodeRun(ctx *encodeRuntimeContext, b []byte, codeSet *opcodeSet, opt Enco
 				}
 			}
 		case opStructFieldPtrHeadInt:
-			store(ctxptr, code.idx, ptrToPtr(load(ctxptr, code.idx)))
+			p := ptrToPtr(load(ctxptr, code.idx))
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			store(ctxptr, code.idx, p)
 			fallthrough
 		case opStructFieldHeadInt:
-			ptr := load(ctxptr, code.idx)
-			if ptr == 0 {
+			p := load(ctxptr, code.idx) + code.offset
+			b = append(b, '{')
+			b = append(b, code.key...)
+			b = appendInt(b, ptrToUint64(p), code)
+			b = encodeComma(b)
+			code = code.next
+		case opStructFieldPtrHeadOmitEmptyInt:
+			p := ptrToPtr(load(ctxptr, code.idx))
+			if p == 0 {
 				b = encodeNull(b)
 				b = encodeComma(b)
 				code = code.end.next
-			} else {
-				b = append(b, '{')
-				b = append(b, code.key...)
-				b = appendInt(b, ptrToUint64(ptr+code.offset), code)
-				b = encodeComma(b)
-				code = code.next
-			}
-		case opStructFieldPtrHeadOmitEmptyInt:
-			ptr := load(ctxptr, code.idx)
-			if ptr != 0 {
-				store(ctxptr, code.idx, ptrToPtr(ptr))
+				break
 			}
+			store(ctxptr, code.idx, p)
 			fallthrough
 		case opStructFieldHeadOmitEmptyInt:
-			ptr := load(ctxptr, code.idx)
-			if ptr == 0 {
-				b = encodeNull(b)
-				b = encodeComma(b)
-				code = code.end.next
+			p := load(ctxptr, code.idx) + code.offset
+			b = append(b, '{')
+			u64 := ptrToUint64(p)
+			v := u64 & code.mask
+			if v == 0 {
+				code = code.nextField
 			} else {
-				b = append(b, '{')
-				u64 := ptrToUint64(ptr + code.offset)
-				v := u64 & code.mask
-				if v == 0 {
-					code = code.nextField
-				} else {
-					b = append(b, code.key...)
-					b = appendInt(b, u64, code)
-					b = encodeComma(b)
-					code = code.next
-				}
-			}
-		case opStructFieldPtrHeadStringTagInt:
-			ptr := load(ctxptr, code.idx)
-			if ptr != 0 {
-				store(ctxptr, code.idx, ptrToPtr(ptr))
-			}
-			fallthrough
-		case opStructFieldHeadStringTagInt:
-			ptr := load(ctxptr, code.idx)
-			if ptr == 0 {
-				b = encodeNull(b)
-				b = encodeComma(b)
-				code = code.end.next
-			} else {
-				b = append(b, '{')
 				b = append(b, code.key...)
-				b = append(b, '"')
-				b = appendInt(b, ptrToUint64(ptr+code.offset), code)
-				b = append(b, '"')
+				b = appendInt(b, u64, code)
 				b = encodeComma(b)
 				code = code.next
 			}
+		case opStructFieldPtrHeadStringTagInt:
+			p := ptrToPtr(load(ctxptr, code.idx))
+			if p == 0 {
+				b = encodeNull(b)
+				b = encodeComma(b)
+				code = code.end.next
+				break
+			}
+			store(ctxptr, code.idx, p)
+			fallthrough
+		case opStructFieldHeadStringTagInt:
+			p := load(ctxptr, code.idx) + code.offset
+			b = append(b, '{')
+			b = append(b, code.key...)
+			b = append(b, '"')
+			b = appendInt(b, ptrToUint64(p), code)
+			b = append(b, '"')
+			b = encodeComma(b)
+			code = code.next
 		case opStructFieldPtrHeadIntOnly, opStructFieldHeadIntOnly:
 			p := load(ctxptr, code.idx)
 			b = append(b, '{')