From: Michael D. Lowis <mike.lowis@gentex.com>
Date: Thu, 4 Mar 2021 21:56:36 +0000 (-0500)
Subject: tried finishing local and argument storing and fetching. Pretty sure those and/or... 
X-Git-Url: https://git.mdlowis.com/?a=commitdiff_plain;h=c8c918f5b59b2a34663ff84f24b0783fb9fce725;p=proto%2Falvm.git

tried finishing local and argument storing and fetching. Pretty sure those and/or the return primitive are busted
---

diff --git a/main.s b/main.s
index f93ae8a..d6514de 100644
--- a/main.s
+++ b/main.s
@@ -1,11 +1,11 @@
 //---------------------------------------------------------------------
 // Register Usage
 //---------------------------------------------------------------------
-//  %rsi    Program Counter
-//  %rsp    Stack Pointer
-//  %rbp    Frame Pointer
-//  %rax    Accumulator Register
-//  %rbx    Temporary Register
+.set PC, %rsi
+.set SP, %rsp
+.set FP, %rbp
+.set AC, %rax
+.set T1, %rbx
 
 //---------------------------------------------------------------------
 // Main Routine
@@ -14,7 +14,7 @@
 // Execute next instruction
 .macro NEXT
     lodsq
-    jmpq	*(%rax)
+    jmpq	*(AC)
 .endm
 
 // Macro to define a primitive
@@ -46,7 +46,7 @@ code_\name :
     .globl EXEC_FUN
     .p2align 4, 0x90
 EXEC_FUN:
-    pushq   %rsi
+    pushq   PC
     pushq   %rbp
     leaq    8(%rax), %rsi
     movq    %rsp, %rbp
@@ -61,12 +61,12 @@ defcode OP_halt
     popq    %rdi
     call    _exit
 
-// Exit a function, returning to the caller
+// Exit a function, returning to the caller                    BROKEN!!
 defcode OP_return
-    lodsq
     popq    %rbx
-    popq    %rbp
-    popq    %rsi
+    movq    8(%rbp), %rsi
+    movq    (%rbp), %rbp
+    lodsq
     leaq    (%rsp, %rax, 8), %rsp
     pushq   %rbx
     NEXT
@@ -98,12 +98,21 @@ defcode OP_localsn
 // Push the Nth argument onto the stack
 defcode OP_ldargn
     lodsq
-    addq    $16, %rax
+    addq    $2, %rax
     neg     %rax
     movq    (%rbp, %rax, 8), %rax
     pushq   %rax
     NEXT
 
+// Pop top of stack and store to the Nth argument slot
+defcode OP_stargn
+    popq %rbx
+    lodsq
+    addq    $2, %rax
+    neg     %rax
+    movq    %rbx, (%rbp, %rax, 8)
+    NEXT
+
 // Push the Nth local onto the stack
 defcode OP_ldlocn
     lodsq
@@ -111,12 +120,11 @@ defcode OP_ldlocn
     pushq   %rax
     NEXT
 
-// Pop top of stack and store to the Nth argument slot
-defcode OP_stargn
-    NEXT
-
 // Pop top of stack and store to the Nth local slot
 defcode OP_stlocn
+    popq %rbx
+    lodsq
+    movq    %rbx, (%rbp, %rax, 8)
     NEXT
 
 //---------------------------------------------------------------------
@@ -144,5 +152,10 @@ cold_start:
     .quad   OP_halt
 
 deffun dummy
-    .quad   OP_imm, 0x2A
+    .quad   OP_localsn, 2
+    .quad   OP_imm, 0x2B
+    .quad   OP_stlocn, 0
+    .quad   OP_ldlocn, 0
+    .quad   OP_stargn, 0
+    .quad   OP_ldargn, 0
     .quad   OP_return, -2