feat(asm): assemble static symbols and the whole go-flac AVX2 kernel byte-identically

Assisted-by: Qwen 3.8 Max Preview

cmd/gasm/main.go

@@ -26,7 +26,7 @@ import (
 
 // version is the release version, stamped at build time via
 // -ldflags "-X main.version=…" (defaulting to the current release).
-var version = "0.3.0"
+var version = "0.4.0"
 
 func main() {
 	if len(os.Args) < 2 {
@@ -238,20 +238,18 @@ func cmdAsm(args []string) int {
 		return 1
 	}
 
-	var all []byte
-	functions := 0
-	for _, d := range f.Decls {
-		txt, ok := d.(*ast.Text)
-		if !ok {
-			continue
-		}
-		code, _, err := asm.Assemble(txt)
-		if err != nil {
-			fmt.Fprintf(os.Stderr, "%s: %s: %v\n", path, txt.Name.Name, err)
-			return 1
-		}
-		functions++
-		fmt.Printf("%s: %d bytes\n", txt.Name.Name, len(code))
+	img, err := asm.AssembleFile(f)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%s: %v\n", path, err)
+		return 1
+	}
+	if len(img.Funcs) == 0 {
+		fmt.Fprintln(os.Stderr, "gasm asm: no assemblable TEXT functions found")
+		return 1
+	}
+	for _, fn := range img.Funcs {
+		code := img.Code[fn.Offset : fn.Offset+fn.Size]
+		fmt.Printf("%s: %d bytes\n", fn.Name, fn.Size)
 		for i := 0; i < len(code); i += 16 {
 			end := i + 16
 			if end > len(code) {
@@ -263,13 +261,34 @@ func cmdAsm(args []string) int {
 			}
 			fmt.Println()
 		}
-		all = append(all, code...)
 	}
-	if functions == 0 {
-		fmt.Fprintln(os.Stderr, "gasm asm: no assemblable TEXT functions found")
-		return 1
+	if len(img.Data) > 0 {
+		fmt.Printf("data: %d bytes at 0x%x\n", len(img.Data), len(img.Code))
+		for _, d := range f.Decls {
+			g, ok := d.(*ast.Globl)
+			if !ok || g.Name == nil || g.Name.Pseudo != "SB" {
+				continue
+			}
+			size := 0
+			if g.Size != nil && g.Size.Imm.HasVal {
+				size = int(g.Size.Imm.Val)
+			}
+			fmt.Printf("  %s: %d bytes at 0x%x\n", g.Name.Name, size, img.Symbols[g.Name.Name])
+		}
+		for i := 0; i < len(img.Data); i += 16 {
+			end := i + 16
+			if end > len(img.Data) {
+				end = len(img.Data)
+			}
+			fmt.Printf("  %04x:", len(img.Code)+i)
+			for _, b := range img.Data[i:end] {
+				fmt.Printf(" %02x", b)
+			}
+			fmt.Println()
+		}
 	}
 	if *out != "" {
+		all := img.Bytes()
 		if err := os.WriteFile(*out, all, 0o644); err != nil {
 			fmt.Fprintln(os.Stderr, "gasm asm:", err)
 			return 1