nudt csapp 2025 finished

Y86_as/input.txt

@@ -0,0 +1,40 @@
+# Execution begins at address 0
+.pos 0
+    irmovq stack, %rsp  # Set up stack pointer
+    call main           # Execute main program
+    halt                # Terminate program
+
+# Array of 4 elements
+.pos 0x18
+array:
+    .quad 0xd000d000d000d
+    .quad 0xc000c000c000c0
+    .quad 0xb000b000b000b
+    .quad 0xa000a000a000a
+
+main:
+    irmovq array, %rdi
+    irmovq $4, %rsi
+    call sum
+    ret
+
+# long sum(long *start, long count)
+# start in %rdi, count in %rsi
+sum:
+    irmovq $8,%r8
+    irmovq $1,%r9
+    xorq %rax,%rax
+    andq %rsi,%rsi
+    jmp test
+loop:
+    mrmovq (%rdi),%r10
+    addq %r10,%rax
+    addq %r8,%rdi      # start++
+    subq %r9,%rsi      # count--
+                       # Set CC
+test:
+    jne loop           # Stop when 0
+    ret                # Return
+
+.pos 0x200
+stack: