Fix usage of registers in assembler demo

1 files changed, 7 insertions, 3 deletions

diff --git a/demo/asm/add_answer.asm b/demo/asm/add_answer.asm
index 2864c3c..3bcda83 100644
--- a/demo/asm/add_answer.asm
+++ b/demo/asm/add_answer.asm
@@ -19,12 +19,16 @@ add_answer:
     push    rcx

     push    rdx

     push    rsi

-; Handle Win64 calling convention

+; "Handle" Win64 calling convention

 ;    push    rdi ; used by System V

     push    rcx ; used by Win64

     push    1

     mov     rdi, rsp

 

+    ; Make sure that we commit the stack space we are going to use with the

+    ; registers

+    sub rsp, 24

+

     mov [rdi - 8], byte 42

 

     mov r8, [rdi + 8]

@@ -33,9 +37,9 @@ add_answer:
     mov rcx, r8

     add rcx, r9

 

-    mov [rdi + 16], rcx

+    mov [rdi - 16], rcx

 

-    mov eax, [rdi + 16]

+    mov eax, [rdi - 16]

     mov rsp, r15

     pop r15

     pop rbp