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src/compilation/CLI/Runtime/nub_string.s

@@ -0,0 +1,32 @@
+.intel_syntax noprefix
+
+.text
+.globl nub_string_length
+# func nub_string_length(string: string): u64
+nub_string_length:
+    mov rsi, [rdi]  # Length of string in bytes
+    
+    add rdi, 8      # Start of bytes
+    xor rax, rax    # Character count
+    xor rdx, rdx    # Current byte position
+    
+    test rsi, rsi
+    jz _done
+    
+_count_loop:
+    cmp rdx, rsi
+    jge _done
+    
+    mov dl, [rdi + rdx]
+    and dl, 0b11000000
+    cmp dl, 0b10000000
+    je _skip_byte
+    
+    inc rax
+    
+_skip_byte:
+    inc rdx
+    jmp _count_loop
+    
+_done:
+    ret