diff --git a/internal/cmd/generator/Dockerfile.simd b/internal/cmd/generator/Dockerfile.simd
index d50be5a..6f9cc7f 100644
--- a/internal/cmd/generator/Dockerfile.simd
+++ b/internal/cmd/generator/Dockerfile.simd
@@ -11,7 +11,6 @@ RUN go install \
     github.com/minio/c2goasm \
     github.com/klauspost/asmfmt/cmd/asmfmt
 
-COPY ./simd/string.h ./string.h
 COPY ./simd/string.c ./string.c
 
 RUN clang -S \
diff --git a/internal/cmd/generator/Makefile b/internal/cmd/generator/Makefile
index fc9e967..f1e0c86 100644
--- a/internal/cmd/generator/Makefile
+++ b/internal/cmd/generator/Makefile
@@ -5,4 +5,4 @@ asm:
 .PHONY: generate
 generate:
 	docker build -f Dockerfile.simd -t go-json-simd .
-	docker run --rm -v "$(CURDIR):/tmp" go-json-simd bash -c "cp /work/string_avx.s /tmp/string_avx.s"
+	docker run --rm -v "$(CURDIR)/simd:/tmp" go-json-simd bash -c "cp /work/string_avx.s /tmp/string_avx.s"
diff --git a/internal/cmd/generator/simd/string.c b/internal/cmd/generator/simd/string.c
index 0351095..5d59f92 100644
--- a/internal/cmd/generator/simd/string.c
+++ b/internal/cmd/generator/simd/string.c
@@ -1,6 +1,34 @@
-#include "string.h"
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
 #include <immintrin.h>
 
+uint64_t findEscapeIndex64(char *buf, int len) {
+  static const uint64_t lsb = 0x0101010101010101;
+  static const uint64_t msb = 0x8080808080808080;
+
+  static const uint64_t space  = lsb * 0x20;
+  static const uint64_t quote  = lsb * '"';
+  static const uint64_t escape = lsb * '\\';
+  static const uint64_t lt     = lsb * '<';
+  static const uint64_t gt     = lsb * '>';
+  static const uint64_t amp    = lsb * '&';
+
+  char *sp = buf;
+  size_t chunkLen = len / 8;
+  int chunkIdx = 0;
+  for (; chunkIdx < chunkLen; chunkIdx++) {
+    uint64_t n    = *(uint64_t *)sp;
+    uint64_t mask = n | (n - space) | ((n ^ quote) - lsb) | ((n ^ escape) - lsb) | ((n ^ lt) - lsb) | ((n ^ gt) - lsb) | ((n ^ amp) - lsb);
+    uint64_t masked = mask & msb;
+    if (masked != 0) {
+      return __builtin_ctz(masked);
+    }
+    sp += 8;
+  }
+  return 8 * chunkLen;
+}
+
 uint64_t findEscapeIndex128(char *buf, int len) {
   static const uint64_t lsb = 0x0101010101010101;
   static const uint64_t msb = 0x8080808080808080;
@@ -41,7 +69,11 @@ uint64_t findEscapeIndex128(char *buf, int len) {
     }
     sp += 16;
   }
-  return 16 * chunkLen;
+  int idx = 16 * chunkLen;
+  if (len - idx >= 8) {
+    return findEscapeIndex64(sp, len - idx);
+  }
+  return idx;
 }
 
 uint64_t findEscapeIndex256(char *buf, int len) {
@@ -84,5 +116,12 @@ uint64_t findEscapeIndex256(char *buf, int len) {
     }
     sp += 32;
   }
-  return 32 * chunkLen;
+  int idx = 32 * chunkLen;
+  int remainLen = len - idx;
+  if (remainLen >= 16) {
+    return findEscapeIndex128(sp, remainLen);
+  } else if (remainLen >= 8) {
+    return findEscapeIndex64(sp, remainLen);
+  }
+  return idx;
 }
diff --git a/internal/cmd/generator/simd/string.h b/internal/cmd/generator/simd/string.h
deleted file mode 100644
index e7fda34..0000000
--- a/internal/cmd/generator/simd/string.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#include <stdio.h>
-#include <stdint.h>
-#include <string.h>
-
-typedef struct GoString {
-  char *buf;
-  size_t len;
-} GoString;
diff --git a/internal/cmd/generator/simd/string_avx.go b/internal/cmd/generator/simd/string_avx.go
index ece014f..75ce996 100644
--- a/internal/cmd/generator/simd/string_avx.go
+++ b/internal/cmd/generator/simd/string_avx.go
@@ -2,6 +2,10 @@ package encoder
 
 import "unsafe"
 
+//go:nosplit
+//go:noescape
+func _findEscapeIndex64(buf unsafe.Pointer, len int) (ret int)
+
 //go:nosplit
 //go:noescape
 func _findEscapeIndex128(buf unsafe.Pointer, len int) (ret int)
diff --git a/internal/encoder/string.go b/internal/encoder/string.go
index e8e57d4..c146b06 100644
--- a/internal/encoder/string.go
+++ b/internal/encoder/string.go
@@ -374,36 +374,12 @@ func AppendString(ctx *RuntimeContext, buf []byte, s string) []byte {
 	switch valLen {
 	case 1, 2, 3, 4, 5, 6, 7:
 	case 8, 9, 10, 11, 12, 13, 14, 15:
-		chunks := stringToUint64Slice(s)
-		for _, n := range chunks {
-			// combine masks before checking for the MSB of each byte. We include
-			// `n` in the mask to check whether any of the *input* byte MSBs were
-			// set (i.e. the byte was outside the ASCII range).
-			mask := n | (n - (lsb * 0x20)) |
-				((n ^ (lsb * '"')) - lsb) |
-				((n ^ (lsb * '\\')) - lsb) |
-				((n ^ (lsb * '<')) - lsb) |
-				((n ^ (lsb * '>')) - lsb) |
-				((n ^ (lsb * '&')) - lsb)
-			if (mask & msb) != 0 {
-				j = bits.TrailingZeros64(mask&msb) / 8
-				goto ESCAPE_END
-			}
-		}
-		for i := len(chunks) * 8; i < valLen; i++ {
-			if needEscapeWithHTML[s[i]] {
-				j = i
-				goto ESCAPE_END
-			}
-		}
-		// no found any escape characters.
-		return append(append(buf, s...), '"')
+		j = _findEscapeIndex64((*runtime.SliceHeader)(unsafe.Pointer(&s)).Data, len(s))
 	case 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31:
 		j = _findEscapeIndex128((*runtime.SliceHeader)(unsafe.Pointer(&s)).Data, len(s))
 	default:
 		j = _findEscapeIndex256((*runtime.SliceHeader)(unsafe.Pointer(&s)).Data, len(s))
 	}
-ESCAPE_END:
 	for j < valLen {
 		c := s[j]
 
diff --git a/internal/encoder/string_avx.go b/internal/encoder/string_avx.go
index ece014f..75ce996 100644
--- a/internal/encoder/string_avx.go
+++ b/internal/encoder/string_avx.go
@@ -2,6 +2,10 @@ package encoder
 
 import "unsafe"
 
+//go:nosplit
+//go:noescape
+func _findEscapeIndex64(buf unsafe.Pointer, len int) (ret int)
+
 //go:nosplit
 //go:noescape
 func _findEscapeIndex128(buf unsafe.Pointer, len int) (ret int)
diff --git a/internal/encoder/string_avx.s b/internal/encoder/string_avx.s
index 99b4829..d365c3b 100644
--- a/internal/encoder/string_avx.s
+++ b/internal/encoder/string_avx.s
@@ -1,6 +1,70 @@
 //+build !noasm !appengine
 // AUTO-GENERATED BY C2GOASM -- DO NOT EDIT
 
+TEXT ·_findEscapeIndex64(SB), $0-24
+
+	MOVQ buf+0(FP), DI
+	MOVQ len+8(FP), SI
+
+	WORD $0xf089                           // mov    eax, esi
+	WORD $0xf8c1; BYTE $0x1f               // sar    eax, 31
+	WORD $0xe8c1; BYTE $0x1d               // shr    eax, 29
+	WORD $0xf001                           // add    eax, esi
+	WORD $0xf8c1; BYTE $0x03               // sar    eax, 3
+	WORD $0x9848                           // cdqe
+	WORD $0xc683; BYTE $0x07               // add    esi, 7
+	WORD $0xfe83; BYTE $0x0f               // cmp    esi, 15
+	JB   LBB0_5
+	QUAD $0xfefefefefeffbd49; WORD $0xfefe // mov    r13, -72340172838076673
+	WORD $0xd231                           // xor    edx, edx
+	QUAD $0x222222222222b949; WORD $0x2222 // mov    r9, 2459565876494606882
+	QUAD $0x5c5c5c5c5c5cba49; WORD $0x5c5c // mov    r10, 6655295901103053916
+	QUAD $0x3c3c3c3c3c3cbb49; WORD $0x3c3c // mov    r11, 4340410370284600380
+	QUAD $0x3e3e3e3e3e3ebe49; WORD $0x3e3e // mov    r14, 4485090715960753726
+	QUAD $0x262626262626bf49; WORD $0x2626 // mov    r15, 2748926567846913574
+	QUAD $0x808080808080bc49; WORD $0x8080 // mov    r12, -9187201950435737472
+
+LBB0_2:
+	LONG $0xd71c8b48                       // mov    rbx, qword [rdi + 8*rdx]
+	QUAD $0xdfdfdfdfdfe0b948; WORD $0xdfdf // mov    rcx, -2314885530818453536
+	LONG $0x0b348d48                       // lea    rsi, [rbx + rcx]
+	WORD $0x0948; BYTE $0xde               // or    rsi, rbx
+	WORD $0x8948; BYTE $0xd9               // mov    rcx, rbx
+	WORD $0x314c; BYTE $0xc9               // xor    rcx, r9
+	WORD $0x014c; BYTE $0xe9               // add    rcx, r13
+	WORD $0x0948; BYTE $0xf1               // or    rcx, rsi
+	WORD $0x8948; BYTE $0xde               // mov    rsi, rbx
+	WORD $0x314c; BYTE $0xd6               // xor    rsi, r10
+	WORD $0x014c; BYTE $0xee               // add    rsi, r13
+	WORD $0x8949; BYTE $0xd8               // mov    r8, rbx
+	WORD $0x314d; BYTE $0xd8               // xor    r8, r11
+	WORD $0x014d; BYTE $0xe8               // add    r8, r13
+	WORD $0x0949; BYTE $0xf0               // or    r8, rsi
+	WORD $0x0949; BYTE $0xc8               // or    r8, rcx
+	WORD $0x8948; BYTE $0xd9               // mov    rcx, rbx
+	WORD $0x314c; BYTE $0xf1               // xor    rcx, r14
+	WORD $0x014c; BYTE $0xe9               // add    rcx, r13
+	WORD $0x314c; BYTE $0xfb               // xor    rbx, r15
+	WORD $0x014c; BYTE $0xeb               // add    rbx, r13
+	WORD $0x0948; BYTE $0xcb               // or    rbx, rcx
+	WORD $0x094c; BYTE $0xc3               // or    rbx, r8
+	WORD $0x214c; BYTE $0xe3               // and    rbx, r12
+	JNE  LBB0_3
+	LONG $0x01c28348                       // add    rdx, 1
+	WORD $0x3948; BYTE $0xc2               // cmp    rdx, rax
+	JB   LBB0_2
+
+LBB0_5:
+	LONG $0x03e0c148 // shl    rax, 3
+	JMP  LBB0_6
+
+LBB0_3:
+	WORD $0xbc0f; BYTE $0xc3 // bsf    eax, ebx
+
+LBB0_6:
+	MOVQ AX, ret+16(FP)
+	RET
+
 DATA LCDATA1<>+0x000(SB)/8, $0xdfdfdfdfdfdfdfe0
 DATA LCDATA1<>+0x008(SB)/8, $0xdfdfdfdfdfdfdfe0
 DATA LCDATA1<>+0x010(SB)/8, $0x2222222222222222
@@ -30,21 +94,21 @@ TEXT ·_findEscapeIndex128(SB), $0-24
 	WORD $0xe8c1; BYTE $0x1c     // shr    eax, 28
 	WORD $0xf001                 // add    eax, esi
 	WORD $0xf8c1; BYTE $0x04     // sar    eax, 4
-	WORD $0x9848                 // cdqe
-	WORD $0xc683; BYTE $0x0f     // add    esi, 15
-	WORD $0xfe83; BYTE $0x1f     // cmp    esi, 31
-	JB   LBB0_5
-	WORD $0xc931                 // xor    ecx, ecx
-	LONG $0x456f79c5; BYTE $0x00 // vmovdqa    xmm8, oword 0[rbp] /* [rip + .LCPI0_0] */
-	LONG $0x4d6f79c5; BYTE $0x10 // vmovdqa    xmm9, oword 16[rbp] /* [rip + .LCPI0_1] */
-	LONG $0x556ff9c5; BYTE $0x20 // vmovdqa    xmm2, oword 32[rbp] /* [rip + .LCPI0_2] */
-	LONG $0x556f79c5; BYTE $0x30 // vmovdqa    xmm10, oword 48[rbp] /* [rip + .LCPI0_3] */
-	LONG $0x5d6f79c5; BYTE $0x40 // vmovdqa    xmm11, oword 64[rbp] /* [rip + .LCPI0_4] */
-	LONG $0x656f79c5; BYTE $0x50 // vmovdqa    xmm12, oword 80[rbp] /* [rip + .LCPI0_5] */
-	LONG $0x6d6f79c5; BYTE $0x60 // vmovdqa    xmm13, oword 96[rbp] /* [rip + .LCPI0_6] */
-	LONG $0x7d6ff9c5; BYTE $0x70 // vmovdqa    xmm7, oword 112[rbp] /* [rip + .LCPI0_7] */
+	WORD $0x4e8d; BYTE $0x0f     // lea    ecx, [rsi + 15]
+	WORD $0xf983; BYTE $0x1f     // cmp    ecx, 31
+	JB   LBB1_5
+	WORD $0x6348; BYTE $0xc8     // movsxd    rcx, eax
+	WORD $0xd231                 // xor    edx, edx
+	LONG $0x456f79c5; BYTE $0x00 // vmovdqa    xmm8, oword 0[rbp] /* [rip + .LCPI1_0] */
+	LONG $0x4d6f79c5; BYTE $0x10 // vmovdqa    xmm9, oword 16[rbp] /* [rip + .LCPI1_1] */
+	LONG $0x556ff9c5; BYTE $0x20 // vmovdqa    xmm2, oword 32[rbp] /* [rip + .LCPI1_2] */
+	LONG $0x556f79c5; BYTE $0x30 // vmovdqa    xmm10, oword 48[rbp] /* [rip + .LCPI1_3] */
+	LONG $0x5d6f79c5; BYTE $0x40 // vmovdqa    xmm11, oword 64[rbp] /* [rip + .LCPI1_4] */
+	LONG $0x656f79c5; BYTE $0x50 // vmovdqa    xmm12, oword 80[rbp] /* [rip + .LCPI1_5] */
+	LONG $0x6d6f79c5; BYTE $0x60 // vmovdqa    xmm13, oword 96[rbp] /* [rip + .LCPI1_6] */
+	LONG $0x7d6ff9c5; BYTE $0x70 // vmovdqa    xmm7, oword 112[rbp] /* [rip + .LCPI1_7] */
 
-LBB0_2:
+LBB1_2:
 	LONG $0x076ffac5             // vmovdqu    xmm0, oword [rdi]
 	LONG $0xd479c1c4; BYTE $0xc8 // vpaddq    xmm1, xmm0, xmm8
 	LONG $0xef79c1c4; BYTE $0xd9 // vpxor    xmm3, xmm0, xmm9
@@ -64,22 +128,75 @@ LBB0_2:
 	LONG $0xc4ebf9c5             // vpor    xmm0, xmm0, xmm4
 	LONG $0xc5ebf9c5             // vpor    xmm0, xmm0, xmm5
 	LONG $0xc7dbf9c5             // vpand    xmm0, xmm0, xmm7
-	LONG $0xd0d7f9c5             // vpmovmskb    edx, xmm0
-	WORD $0xd285                 // test    edx, edx
-	JNE  LBB0_3
+	LONG $0xd8d7f9c5             // vpmovmskb    ebx, xmm0
+	WORD $0xdb85                 // test    ebx, ebx
+	JNE  LBB1_3
 	LONG $0x10c78348             // add    rdi, 16
-	LONG $0x01c18348             // add    rcx, 1
-	WORD $0x3948; BYTE $0xc1     // cmp    rcx, rax
-	JB   LBB0_2
+	LONG $0x01c28348             // add    rdx, 1
+	WORD $0x3948; BYTE $0xca     // cmp    rdx, rcx
+	JB   LBB1_2
 
-LBB0_5:
-	LONG $0x04e0c148 // shl    rax, 4
-	JMP  LBB0_6
+LBB1_5:
+	WORD $0xe0c1; BYTE $0x04               // shl    eax, 4
+	WORD $0xc629                           // sub    esi, eax
+	WORD $0xfe83; BYTE $0x08               // cmp    esi, 8
+	JL   LBB1_11
+	QUAD $0xfefefefefeffba49; WORD $0xfefe // mov    r10, -72340172838076673
+	WORD $0x8941; BYTE $0xf5               // mov    r13d, esi
+	LONG $0x03edc141                       // shr    r13d, 3
+	WORD $0xd231                           // xor    edx, edx
+	QUAD $0x3c3c3c3c3c3cbb49; WORD $0x3c3c // mov    r11, 4340410370284600380
+	QUAD $0x3e3e3e3e3e3ebe49; WORD $0x3e3e // mov    r14, 4485090715960753726
+	QUAD $0x262626262626bf49; WORD $0x2626 // mov    r15, 2748926567846913574
+	QUAD $0x808080808080bc49; WORD $0x8080 // mov    r12, -9187201950435737472
 
-LBB0_3:
-	WORD $0xbc0f; BYTE $0xc2 // bsf    eax, edx
+LBB1_7:
+	LONG $0xd71c8b48                       // mov    rbx, qword [rdi + 8*rdx]
+	QUAD $0xdfdfdfdfdfe0b948; WORD $0xdfdf // mov    rcx, -2314885530818453536
+	LONG $0x0b0c8d48                       // lea    rcx, [rbx + rcx]
+	WORD $0x0948; BYTE $0xd9               // or    rcx, rbx
+	WORD $0x8949; BYTE $0xd8               // mov    r8, rbx
+	QUAD $0x222222222222b848; WORD $0x2222 // mov    rax, 2459565876494606882
+	WORD $0x3149; BYTE $0xc0               // xor    r8, rax
+	WORD $0x014d; BYTE $0xd0               // add    r8, r10
+	WORD $0x0949; BYTE $0xc8               // or    r8, rcx
+	WORD $0x8948; BYTE $0xd9               // mov    rcx, rbx
+	QUAD $0x5c5c5c5c5c5cb848; WORD $0x5c5c // mov    rax, 6655295901103053916
+	WORD $0x3148; BYTE $0xc1               // xor    rcx, rax
+	WORD $0x014c; BYTE $0xd1               // add    rcx, r10
+	WORD $0x8949; BYTE $0xd9               // mov    r9, rbx
+	WORD $0x314d; BYTE $0xd9               // xor    r9, r11
+	WORD $0x014d; BYTE $0xd1               // add    r9, r10
+	WORD $0x0949; BYTE $0xc9               // or    r9, rcx
+	WORD $0x094d; BYTE $0xc1               // or    r9, r8
+	WORD $0x8948; BYTE $0xd9               // mov    rcx, rbx
+	WORD $0x314c; BYTE $0xf1               // xor    rcx, r14
+	WORD $0x014c; BYTE $0xd1               // add    rcx, r10
+	WORD $0x314c; BYTE $0xfb               // xor    rbx, r15
+	WORD $0x014c; BYTE $0xd3               // add    rbx, r10
+	WORD $0x0948; BYTE $0xcb               // or    rbx, rcx
+	WORD $0x094c; BYTE $0xcb               // or    rbx, r9
+	WORD $0x214c; BYTE $0xe3               // and    rbx, r12
+	JNE  LBB1_8
+	LONG $0x01c28348                       // add    rdx, 1
+	WORD $0x394c; BYTE $0xea               // cmp    rdx, r13
+	JB   LBB1_7
+	WORD $0xe683; BYTE $0xf8               // and    esi, -8
+	JMP  LBB1_12
 
-LBB0_6:
+LBB1_11:
+	WORD $0x6348; BYTE $0xf0 // movsxd    rsi, eax
+	JMP  LBB1_12
+
+LBB1_3:
+	WORD $0xbc0f; BYTE $0xf3 // bsf    esi, ebx
+	JMP  LBB1_12
+
+LBB1_8:
+	WORD $0xbc0f; BYTE $0xf3 // bsf    esi, ebx
+
+LBB1_12:
+	WORD $0x8948; BYTE $0xf0 // mov    rax, rsi
 	MOVQ AX, ret+16(FP)
 	RET
 
@@ -95,7 +212,23 @@ DATA LCDATA2<>+0x040(SB)/8, $0x8080808080808080
 DATA LCDATA2<>+0x048(SB)/8, $0x8080808080808080
 DATA LCDATA2<>+0x050(SB)/8, $0x8080808080808080
 DATA LCDATA2<>+0x058(SB)/8, $0x8080808080808080
-GLOBL LCDATA2<>(SB), 8, $96
+DATA LCDATA2<>+0x060(SB)/8, $0xdfdfdfdfdfdfdfe0
+DATA LCDATA2<>+0x068(SB)/8, $0xdfdfdfdfdfdfdfe0
+DATA LCDATA2<>+0x070(SB)/8, $0x2222222222222222
+DATA LCDATA2<>+0x078(SB)/8, $0x2222222222222222
+DATA LCDATA2<>+0x080(SB)/8, $0xfefefefefefefeff
+DATA LCDATA2<>+0x088(SB)/8, $0xfefefefefefefeff
+DATA LCDATA2<>+0x090(SB)/8, $0x5c5c5c5c5c5c5c5c
+DATA LCDATA2<>+0x098(SB)/8, $0x5c5c5c5c5c5c5c5c
+DATA LCDATA2<>+0x0a0(SB)/8, $0x3c3c3c3c3c3c3c3c
+DATA LCDATA2<>+0x0a8(SB)/8, $0x3c3c3c3c3c3c3c3c
+DATA LCDATA2<>+0x0b0(SB)/8, $0x3e3e3e3e3e3e3e3e
+DATA LCDATA2<>+0x0b8(SB)/8, $0x3e3e3e3e3e3e3e3e
+DATA LCDATA2<>+0x0c0(SB)/8, $0x2626262626262626
+DATA LCDATA2<>+0x0c8(SB)/8, $0x2626262626262626
+DATA LCDATA2<>+0x0d0(SB)/8, $0x8080808080808080
+DATA LCDATA2<>+0x0d8(SB)/8, $0x8080808080808080
+GLOBL LCDATA2<>(SB), 8, $224
 
 TEXT ·_findEscapeIndex256(SB), $0-24
 
@@ -108,21 +241,21 @@ TEXT ·_findEscapeIndex256(SB), $0-24
 	WORD $0xe8c1; BYTE $0x1b       // shr    eax, 27
 	WORD $0xf001                   // add    eax, esi
 	WORD $0xf8c1; BYTE $0x05       // sar    eax, 5
-	WORD $0x9848                   // cdqe
-	WORD $0xc683; BYTE $0x1f       // add    esi, 31
-	WORD $0xfe83; BYTE $0x3f       // cmp    esi, 63
-	JB   LBB1_5
-	LONG $0x597de2c4; WORD $0x0045 // vpbroadcastq    ymm0, qword 0[rbp] /* [rip + .LCPI1_0] */
-	LONG $0x597de2c4; WORD $0x084d // vpbroadcastq    ymm1, qword 8[rbp] /* [rip + .LCPI1_1] */
-	LONG $0x597de2c4; WORD $0x1055 // vpbroadcastq    ymm2, qword 16[rbp] /* [rip + .LCPI1_2] */
-	LONG $0x597de2c4; WORD $0x185d // vpbroadcastq    ymm3, qword 24[rbp] /* [rip + .LCPI1_3] */
-	LONG $0x597de2c4; WORD $0x2065 // vpbroadcastq    ymm4, qword 32[rbp] /* [rip + .LCPI1_4] */
-	LONG $0x597de2c4; WORD $0x286d // vpbroadcastq    ymm5, qword 40[rbp] /* [rip + .LCPI1_5] */
-	WORD $0xc931                   // xor    ecx, ecx
-	LONG $0x597de2c4; WORD $0x3075 // vpbroadcastq    ymm6, qword 48[rbp] /* [rip + .LCPI1_6] */
-	LONG $0x7d6ffdc5; BYTE $0x40   // vmovdqa    ymm7, yword 64[rbp] /* [rip + .LCPI1_7] */
+	WORD $0x4e8d; BYTE $0x1f       // lea    ecx, [rsi + 31]
+	WORD $0xf983; BYTE $0x3f       // cmp    ecx, 63
+	JB   LBB2_4
+	WORD $0x6348; BYTE $0xc8       // movsxd    rcx, eax
+	LONG $0x597de2c4; WORD $0x0045 // vpbroadcastq    ymm0, qword 0[rbp] /* [rip + .LCPI2_0] */
+	LONG $0x597de2c4; WORD $0x084d // vpbroadcastq    ymm1, qword 8[rbp] /* [rip + .LCPI2_1] */
+	LONG $0x597de2c4; WORD $0x1055 // vpbroadcastq    ymm2, qword 16[rbp] /* [rip + .LCPI2_2] */
+	LONG $0x597de2c4; WORD $0x185d // vpbroadcastq    ymm3, qword 24[rbp] /* [rip + .LCPI2_3] */
+	LONG $0x597de2c4; WORD $0x2065 // vpbroadcastq    ymm4, qword 32[rbp] /* [rip + .LCPI2_4] */
+	LONG $0x597de2c4; WORD $0x286d // vpbroadcastq    ymm5, qword 40[rbp] /* [rip + .LCPI2_5] */
+	WORD $0xd231                   // xor    edx, edx
+	LONG $0x597de2c4; WORD $0x3075 // vpbroadcastq    ymm6, qword 48[rbp] /* [rip + .LCPI2_6] */
+	LONG $0x7d6ffdc5; BYTE $0x40   // vmovdqa    ymm7, yword 64[rbp] /* [rip + .LCPI2_7] */
 
-LBB1_2:
+LBB2_2:
 	LONG $0x076f7ec5             // vmovdqu    ymm8, yword [rdi]
 	LONG $0xc8d43dc5             // vpaddq    ymm9, ymm8, ymm0
 	LONG $0xd1ef3dc5             // vpxor    ymm10, ymm8, ymm1
@@ -142,22 +275,169 @@ LBB1_2:
 	LONG $0xeb3d41c4; BYTE $0xc3 // vpor    ymm8, ymm8, ymm11
 	LONG $0xeb3d41c4; BYTE $0xc4 // vpor    ymm8, ymm8, ymm12
 	LONG $0xc7db3dc5             // vpand    ymm8, ymm8, ymm7
-	LONG $0xd77dc1c4; BYTE $0xd0 // vpmovmskb    edx, ymm8
-	WORD $0xd285                 // test    edx, edx
-	JNE  LBB1_3
+	LONG $0xd77dc1c4; BYTE $0xd8 // vpmovmskb    ebx, ymm8
+	WORD $0xdb85                 // test    ebx, ebx
+	JNE  LBB2_19
 	LONG $0x20c78348             // add    rdi, 32
-	LONG $0x01c18348             // add    rcx, 1
-	WORD $0x3948; BYTE $0xc1     // cmp    rcx, rax
-	JB   LBB1_2
+	LONG $0x01c28348             // add    rdx, 1
+	WORD $0x3948; BYTE $0xca     // cmp    rdx, rcx
+	JB   LBB2_2
 
-LBB1_5:
-	LONG $0x05e0c148 // shl    rax, 5
-	JMP  LBB1_6
+LBB2_4:
+	WORD $0xe0c1; BYTE $0x05     // shl    eax, 5
+	WORD $0xc629                 // sub    esi, eax
+	WORD $0xfe83; BYTE $0x10     // cmp    esi, 16
+	JL   LBB2_13
+	WORD $0xf089                 // mov    eax, esi
+	WORD $0xe8c1; BYTE $0x04     // shr    eax, 4
+	WORD $0xc931                 // xor    ecx, ecx
+	LONG $0x456f79c5; BYTE $0x60 // vmovdqa    xmm8, oword 96[rbp] /* [rip + .LCPI2_8] */
+	LONG $0x4d6f79c5; BYTE $0x70 // vmovdqa    xmm9, oword 112[rbp] /* [rip + .LCPI2_9] */
+	QUAD $0x00000080956ff9c5     // vmovdqa    xmm2, oword 128[rbp] /* [rip + .LCPI2_10] */
+	QUAD $0x00000090956f79c5     // vmovdqa    xmm10, oword 144[rbp] /* [rip + .LCPI2_11] */
+	QUAD $0x000000a09d6f79c5     // vmovdqa    xmm11, oword 160[rbp] /* [rip + .LCPI2_12] */
+	QUAD $0x000000b0a56f79c5     // vmovdqa    xmm12, oword 176[rbp] /* [rip + .LCPI2_13] */
+	QUAD $0x000000c0ad6f79c5     // vmovdqa    xmm13, oword 192[rbp] /* [rip + .LCPI2_14] */
+	QUAD $0x000000d0bd6ff9c5     // vmovdqa    xmm7, oword 208[rbp] /* [rip + .LCPI2_15] */
 
-LBB1_3:
-	WORD $0xbc0f; BYTE $0xc2 // bsf    eax, edx
+LBB2_6:
+	LONG $0x076ffac5                       // vmovdqu    xmm0, oword [rdi]
+	LONG $0xd479c1c4; BYTE $0xc8           // vpaddq    xmm1, xmm0, xmm8
+	LONG $0xef79c1c4; BYTE $0xd9           // vpxor    xmm3, xmm0, xmm9
+	LONG $0xdad4e1c5                       // vpaddq    xmm3, xmm3, xmm2
+	LONG $0xef79c1c4; BYTE $0xe2           // vpxor    xmm4, xmm0, xmm10
+	LONG $0xe2d4d9c5                       // vpaddq    xmm4, xmm4, xmm2
+	LONG $0xef79c1c4; BYTE $0xeb           // vpxor    xmm5, xmm0, xmm11
+	LONG $0xead4d1c5                       // vpaddq    xmm5, xmm5, xmm2
+	LONG $0xe5ebd9c5                       // vpor    xmm4, xmm4, xmm5
+	LONG $0xef79c1c4; BYTE $0xec           // vpxor    xmm5, xmm0, xmm12
+	LONG $0xead4d1c5                       // vpaddq    xmm5, xmm5, xmm2
+	LONG $0xef79c1c4; BYTE $0xf5           // vpxor    xmm6, xmm0, xmm13
+	LONG $0xf2d4c9c5                       // vpaddq    xmm6, xmm6, xmm2
+	LONG $0xeeebd1c5                       // vpor    xmm5, xmm5, xmm6
+	LONG $0xc0ebf1c5                       // vpor    xmm0, xmm1, xmm0
+	LONG $0xc3ebf9c5                       // vpor    xmm0, xmm0, xmm3
+	LONG $0xc4ebf9c5                       // vpor    xmm0, xmm0, xmm4
+	LONG $0xc5ebf9c5                       // vpor    xmm0, xmm0, xmm5
+	LONG $0xc7dbf9c5                       // vpand    xmm0, xmm0, xmm7
+	LONG $0xd0d7f9c5                       // vpmovmskb    edx, xmm0
+	WORD $0xd285                           // test    edx, edx
+	JNE  LBB2_20
+	LONG $0x10c78348                       // add    rdi, 16
+	LONG $0x01c18348                       // add    rcx, 1
+	WORD $0x3948; BYTE $0xc1               // cmp    rcx, rax
+	JB   LBB2_6
+	WORD $0xf089                           // mov    eax, esi
+	WORD $0xe083; BYTE $0xf0               // and    eax, -16
+	WORD $0xc629                           // sub    esi, eax
+	WORD $0xfe83; BYTE $0x08               // cmp    esi, 8
+	JL   LBB2_18
+	QUAD $0xfefefefefeffb848; WORD $0xfefe // mov    rax, -72340172838076673
+	QUAD $0x5c5c5c5c5c5cba49; WORD $0x5c5c // mov    r10, 6655295901103053916
+	QUAD $0x3e3e3e3e3e3ebb49; WORD $0x3e3e // mov    r11, 4485090715960753726
+	QUAD $0x3c3c3c3c3c3cbe49; WORD $0x3c3c // mov    r14, 4340410370284600380
+	QUAD $0x262626262626bf49; WORD $0x2626 // mov    r15, 2748926567846913574
+	QUAD $0x222222222222bc49; WORD $0x2222 // mov    r12, 2459565876494606882
+	WORD $0x8941; BYTE $0xf5               // mov    r13d, esi
+	LONG $0x03edc141                       // shr    r13d, 3
+	WORD $0xdb31                           // xor    ebx, ebx
 
-LBB1_6:
+LBB2_10:
+	LONG $0xdf148b48                       // mov    rdx, qword [rdi + 8*rbx]
+	QUAD $0xdfdfdfdfdfe0b948; WORD $0xdfdf // mov    rcx, -2314885530818453536
+	LONG $0x0a0c8d48                       // lea    rcx, [rdx + rcx]
+	WORD $0x0948; BYTE $0xd1               // or    rcx, rdx
+	WORD $0x8949; BYTE $0xd0               // mov    r8, rdx
+	WORD $0x314d; BYTE $0xe0               // xor    r8, r12
+	WORD $0x0149; BYTE $0xc0               // add    r8, rax
+	WORD $0x0949; BYTE $0xc8               // or    r8, rcx
+	WORD $0x8948; BYTE $0xd1               // mov    rcx, rdx
+	WORD $0x314c; BYTE $0xd1               // xor    rcx, r10
+	WORD $0x0148; BYTE $0xc1               // add    rcx, rax
+	WORD $0x8949; BYTE $0xd1               // mov    r9, rdx
+	WORD $0x314d; BYTE $0xf1               // xor    r9, r14
+	WORD $0x0149; BYTE $0xc1               // add    r9, rax
+	WORD $0x0949; BYTE $0xc9               // or    r9, rcx
+	WORD $0x094d; BYTE $0xc1               // or    r9, r8
+	WORD $0x8948; BYTE $0xd1               // mov    rcx, rdx
+	WORD $0x314c; BYTE $0xd9               // xor    rcx, r11
+	WORD $0x0148; BYTE $0xc1               // add    rcx, rax
+	WORD $0x314c; BYTE $0xfa               // xor    rdx, r15
+	WORD $0x0148; BYTE $0xc2               // add    rdx, rax
+	WORD $0x0948; BYTE $0xca               // or    rdx, rcx
+	WORD $0x094c; BYTE $0xca               // or    rdx, r9
+	QUAD $0x808080808080b948; WORD $0x8080 // mov    rcx, -9187201950435737472
+	WORD $0x2148; BYTE $0xca               // and    rdx, rcx
+	JNE  LBB2_22
+	LONG $0x01c38348                       // add    rbx, 1
+	WORD $0x394c; BYTE $0xeb               // cmp    rbx, r13
+	JB   LBB2_10
+	WORD $0xe683; BYTE $0xf8               // and    esi, -8
+	JMP  LBB2_23
+
+LBB2_13:
+	WORD $0xfe83; BYTE $0x08               // cmp    esi, 8
+	JL   LBB2_18
+	QUAD $0xfefefefefeffbd49; WORD $0xfefe // mov    r13, -72340172838076673
+	QUAD $0x808080808080b949; WORD $0x8080 // mov    r9, -9187201950435737472
+	QUAD $0x5c5c5c5c5c5cba49; WORD $0x5c5c // mov    r10, 6655295901103053916
+	QUAD $0x3e3e3e3e3e3ebb49; WORD $0x3e3e // mov    r11, 4485090715960753726
+	QUAD $0x3c3c3c3c3c3cbe49; WORD $0x3c3c // mov    r14, 4340410370284600380
+	QUAD $0x262626262626bf49; WORD $0x2626 // mov    r15, 2748926567846913574
+	QUAD $0x222222222222bc49; WORD $0x2222 // mov    r12, 2459565876494606882
+	WORD $0xeec1; BYTE $0x03               // shr    esi, 3
+	WORD $0xe683; BYTE $0x1f               // and    esi, 31
+	WORD $0xc931                           // xor    ecx, ecx
+
+LBB2_15:
+	LONG $0xcf148b48                       // mov    rdx, qword [rdi + 8*rcx]
+	QUAD $0xdfdfdfdfdfe0b848; WORD $0xdfdf // mov    rax, -2314885530818453536
+	LONG $0x021c8d48                       // lea    rbx, [rdx + rax]
+	WORD $0x0948; BYTE $0xd3               // or    rbx, rdx
+	WORD $0x8948; BYTE $0xd0               // mov    rax, rdx
+	WORD $0x314c; BYTE $0xe0               // xor    rax, r12
+	WORD $0x014c; BYTE $0xe8               // add    rax, r13
+	WORD $0x0948; BYTE $0xd8               // or    rax, rbx
+	WORD $0x8948; BYTE $0xd3               // mov    rbx, rdx
+	WORD $0x314c; BYTE $0xd3               // xor    rbx, r10
+	WORD $0x014c; BYTE $0xeb               // add    rbx, r13
+	WORD $0x8949; BYTE $0xd0               // mov    r8, rdx
+	WORD $0x314d; BYTE $0xf0               // xor    r8, r14
+	WORD $0x014d; BYTE $0xe8               // add    r8, r13
+	WORD $0x0949; BYTE $0xd8               // or    r8, rbx
+	WORD $0x0949; BYTE $0xc0               // or    r8, rax
+	WORD $0x8948; BYTE $0xd0               // mov    rax, rdx
+	WORD $0x314c; BYTE $0xd8               // xor    rax, r11
+	WORD $0x014c; BYTE $0xe8               // add    rax, r13
+	WORD $0x314c; BYTE $0xfa               // xor    rdx, r15
+	WORD $0x014c; BYTE $0xea               // add    rdx, r13
+	WORD $0x0948; BYTE $0xc2               // or    rdx, rax
+	WORD $0x094c; BYTE $0xc2               // or    rdx, r8
+	WORD $0x214c; BYTE $0xca               // and    rdx, r9
+	JNE  LBB2_22
+	LONG $0x01c18348                       // add    rcx, 1
+	WORD $0x3948; BYTE $0xf1               // cmp    rcx, rsi
+	JB   LBB2_15
+	WORD $0xe6c1; BYTE $0x03               // shl    esi, 3
+	JMP  LBB2_23
+
+LBB2_18:
+	WORD $0x6348; BYTE $0xf0 // movsxd    rsi, eax
+	JMP  LBB2_23
+
+LBB2_19:
+	WORD $0xbc0f; BYTE $0xf3 // bsf    esi, ebx
+	JMP  LBB2_23
+
+LBB2_20:
+	WORD $0xbc0f; BYTE $0xf2 // bsf    esi, edx
+	JMP  LBB2_23
+
+LBB2_22:
+	WORD $0xbc0f; BYTE $0xf2 // bsf    esi, edx
+
+LBB2_23:
+	WORD $0x8948; BYTE $0xf0 // mov    rax, rsi
 	VZEROUPPER
 	MOVQ AX, ret+16(FP)
 	RET