refactor: use cached values in writer

Author: nnnkkk7

simd_scanner.go

@@ -23,9 +23,14 @@ var useAVX512 bool
 
 // Cached broadcast values for fixed characters (initialized in init()).
 var (
+	// AVX-512 (64-byte) cached values
 	cachedQuoteCmp archsimd.Int8x64
 	cachedCrCmp    archsimd.Int8x64
 	cachedNlCmp    archsimd.Int8x64
+	// AVX2 (32-byte) cached values
+	cachedQuoteCmp32 archsimd.Int8x32
+	cachedCrCmp32    archsimd.Int8x32
+	cachedNlCmp32    archsimd.Int8x32
 )
 
 // SIMD processing constants.
@@ -44,6 +49,10 @@ func init() {
 		cachedQuoteCmp = archsimd.BroadcastInt8x64('"')
 		cachedCrCmp = archsimd.BroadcastInt8x64('\r')
 		cachedNlCmp = archsimd.BroadcastInt8x64('\n')
+		// Pre-broadcast fixed characters for AVX2 (32-byte) operations
+		cachedQuoteCmp32 = archsimd.BroadcastInt8x32('"')
+		cachedCrCmp32 = archsimd.BroadcastInt8x32('\r')
+		cachedNlCmp32 = archsimd.BroadcastInt8x32('\n')
 	}
 }
 

writer.go

@@ -123,14 +123,16 @@ func (w *Writer) fieldNeedsQuotesScalar(field string) bool {
 }
 
 // fieldNeedsQuotesSIMD uses SIMD to detect special characters requiring quoting.
+// Uses cached broadcast values for fixed characters (quote, CR, NL) to avoid
+// repeated BroadcastInt8x32 calls.
 func (w *Writer) fieldNeedsQuotesSIMD(field string) bool {
 	data := unsafe.Slice(unsafe.StringData(field), len(field))
 	int8Data := bytesToInt8Slice(data)
 
 	commaCmp := archsimd.BroadcastInt8x32(int8(w.Comma))
-	newlineCmp := archsimd.BroadcastInt8x32('\n')
-	carriageReturnCmp := archsimd.BroadcastInt8x32('\r')
-	quoteCmp := archsimd.BroadcastInt8x32('"')
+	newlineCmp := cachedNlCmp32
+	carriageReturnCmp := cachedCrCmp32
+	quoteCmp := cachedQuoteCmp32
 
 	// Process 32-byte chunks
 	offset := 0
@@ -186,10 +188,11 @@ func (w *Writer) writeQuotedFieldScalar(field string) error {
 }
 
 // writeQuotedFieldSIMD escapes quotes using SIMD to find quote positions.
+// Uses cached broadcast value for quote character to avoid repeated BroadcastInt8x32 calls.
 func (w *Writer) writeQuotedFieldSIMD(field string) error {
 	data := unsafe.Slice(unsafe.StringData(field), len(field))
 	int8Data := bytesToInt8Slice(data)
-	quoteCmp := archsimd.BroadcastInt8x32('"')
+	quoteCmp := cachedQuoteCmp32
 
 	offset := 0
 	lastWritten := 0