From 19aca3dfd1a2427bc16f90a926eed86704711c65 Mon Sep 17 00:00:00 2001
From: Joscha <joscha@plugh.de>
Date: Sun, 10 Nov 2019 18:17:32 +0000
Subject: [PATCH] Update example files

---
 examples/call_ret.mima         | Bin 36 -> 36 bytes
 examples/call_ret_stack.mima   | Bin 927 -> 927 bytes
 examples/call_ret_stack.mimasm |  12 +--
 examples/stack.mima            | Bin 1617 -> 1017 bytes
 examples/stack.mimasm          | 135 ++++++++++++++++++---------------
 5 files changed, 80 insertions(+), 67 deletions(-)

diff --git a/examples/call_ret.mima b/examples/call_ret.mima
index b18cb357af75163f2cd951cfef438dbc5d55e5e0..e775497a14d9198a19d8a4582fb190cc67d25183 100644
GIT binary patch
literal 36
ccmZR;02de-4=}J^U|{*cz;J=V=raQY05vWJPyhe`

literal 36
ccmZR;0KXU*4=}L)Vqp2e!0?N~=raQY06P{1&Hw-a

diff --git a/examples/call_ret_stack.mima b/examples/call_ret_stack.mima
index e50c406bce42ce48c47638ab96dfa09d5a7f4648..a64fbce31fb4652eddb6743a6d3bbf0205b37ba9 100644
GIT binary patch
delta 92
zcmbQwKA(Mq9V71r21W%2h64;I1Q-}DZ1!f9XEeOPz@osw@P&clHv_{r28R3p|9@v-
nIKZg$i-GYgSmXi&<97xIkOl@01qO!C69s?pfO!HS9s>ga-PRf2

delta 92
zcmbQwKA(Mq9V72A21W%2h64;I1Q-~8ZT4oAXEgl9z@osw@P&cl0RzJ~28Lh%|9@v-
mIKZfLfr0TWM1+CyI|Bnq0|SQw1H<Quf<Jh`JOL1ofdK#oOB%2M

diff --git a/examples/call_ret_stack.mimasm b/examples/call_ret_stack.mimasm
index 0a4800f..c0800ed 100644
--- a/examples/call_ret_stack.mimasm
+++ b/examples/call_ret_stack.mimasm
@@ -17,7 +17,7 @@ main:
   STV counter
   
   ; Since we're top-level, we don't need to (re-)store our RA when calling
-  CALL sub-a
+  CALL sub-1
 
   ; set counter bit 1
   LDV counter
@@ -27,7 +27,7 @@ main:
   HALT
 
 200:
-sub-a:
+sub-1:
   ; Set counter bit 2
   LDV counter
   ADC 0x04
@@ -36,18 +36,18 @@ sub-a:
   ;; Store the current RA on the stack
   ; Store the RA at current position of stack pointer
   LDRA
-  STVR 0
+  STRS 0
   ; Move stack pointer by 1 since the stack grew
   LDSP
   ADC -1
   STSP
   
   ; Call the subfunction
-  CALL sub-b
+  CALL sub-2
 
   ;; Pop and restore the RA from the stack
   ; Read RA from the top of the stack
-  LDVR 1
+  LDRS 1
   STRA
   ; Remove top element from stack
   LDSP
@@ -62,7 +62,7 @@ sub-a:
   RET
 
 300:
-sub-b:
+sub-2:
   ; Set counter bit 4
   LDV counter
   ADC 0x10
diff --git a/examples/stack.mima b/examples/stack.mima
index 6bec57d01ca73bd3e1cedcdfb78cb43ec3ab38dd..ea6cd3b933418073e11f40751d28170ccd987ad4 100644
GIT binary patch
literal 1017
zcmZQzNMQg2{{R2^|NjRwM+u@r-~hvk4@4;(RmAXvf#Ej;!#4(o`~UxcXJGir!0-iC
z1XBS61M6Q<$g%(Z|NjR_<Dc&g3<nr>{`~)^z`*e5|6c_L#vcp}7Z@17Gcf#NVEoCz
z@QZ=*E7%r@;AfEbp@%Vp;tvBW$jb~Y3Ji<_3=9SgjDH!J85kH87?>0om<1RZ3K*Cs
mFuDnVLg~K(1A_nqvjGF60t0gcqm2Lq^Irxgw1E1|zyJX8Q%@oQ

literal 1617
zcmZQzNMT@LU@)-c|No!=|9=pB6cZN$Ul<r3Ffe>$VEFa_|91w4AE?})AVXLmfJpZD
z|Nn!P{re784`Li({BnVTNr8dk0t2H01LF?{hF=Vf-$7i4pCFR)D?~9^PylSW00Sek
zQ6E5tkK)k~7!85Z5Fi`^m<7}Y23BzS!=k{zD8RsAz`*!`fti7UK><`QF$*v-6fiJN
kVB!-17jX&<3<3<y2B5-<xq*pAfPwh|0~1=Q^_hVI0I8Esj{pDw

diff --git a/examples/stack.mimasm b/examples/stack.mimasm
index 95ed0ac..f820b5e 100644
--- a/examples/stack.mimasm
+++ b/examples/stack.mimasm
@@ -12,8 +12,7 @@
 ; Functions take a fixed number of arguments. For this example, all
 ; values have a size of one word (24 bit).
 
-IAR = caller
-RA = 12345 ; to test whether the caller stores and restores the RA correctly
+IAR = main
 SP = 0xfffff
 FP = 0xfffff
 
@@ -29,78 +28,93 @@ tmp4: LIT 0
 tmp5: LIT 0
 
 100:
-caller:
-  ; 1. Push RA onto current stack frame
-  LDRA
-  STVR 0
-  LDSP
-  ADC -1
-  STSP ; SP offset: 1
+main:
+  CALL caller
+  HALT
 
-  ; 2. Create a new shared stack frame
+200:
+caller:
+  ;; 1. Initialisation
+
+  ; 1.1. Create own stack frame
   LDFP
-  STVR 0
+  STRS 0
   LDSP
   ADC -1
   STSP
   STFP
 
-  ; 3. Push function parameters onto shared stack frame
-  LDC 5
-  STVR 0
-  LDC 7
-  STVR -1
+  ; 2. Push RA onto current stack frame
+  LDRA
+  STRS 0
   LDSP
-  ADC -2
-  STSP ; SP offset: 2
+  ADC -1
+  STSP
+  
+  ; Do some work here
+  
+  ;; 2. Prepare call
 
-  ; 4. Create space for return values
+  ; 2.1. Create a new shared stack frame
+  LDFP
+  STRS 0
   LDSP
-  ADC -2
-  STSP; SP offset: 4
+  ADC -1
+  STSP
+  STFP
+
+  ; 2.2. Write function parameters onto shared stack frame and keep
+  ; space for return values
+  LDC 5
+  STRF 0
+  LDC 7
+  STRF -1
+  LDFP
+  ADC -4 ; 2 parameters and 2 return values
+  STSP
   
   ; Now, the shared stack frame looks like this:
-  ; 4: argument 1
-  ; 3: argument 2
-  ; 2: return value 1
-  ; 1: return value 2
+  ;
+  ; FP offset | Value
+  ;         0 | argument 1
+  ;        -1 | argument 2
+  ;        -2 | return value 1
+  ;        -3 | return value 2
 
-  ; 5. Call callee
+  ;; 3. Call callee
   CALL callee
   
-  ; 6. Copy resulting values from the shared stack frame, so we can
+  ;; 4. Cleanup after call
+  
+  ; 4.1. Copy resulting values from the shared stack frame, so we can
   ; restore our own stack frame
-  LDVR 2
+  LDRF -2
   STV tmp1
-  LDVR 1
+  LDRF -3
   STV tmp2
 
-  ; 7. Restore own stack frame
+  ; 4.2. Restore own stack frame
   LDFP
   ADC 1
   STSP
-  LDVR 0
+  LDRF 1
   STFP
   
-  ; 8. Pop and restore RA
-  LDVR 1
+  ; Now, we can use the results stored in tmp1 and tmp2.
+  ; Do some more work here
+
+  ;; 5. Cleanup before RET
+  
+  ; 5.1. Pop and restore RA
+  LDRS 1
   STRA
   LDSP
   ADC 1
-  STSP ; SP offset: 0
+  STSP
   
-  ; Now, we can use the results, or put them onto our own stack like so:
-  LDV tmp1
-  STVR 0
-  LDV tmp2
-  STVR -1
-  LDSP
-  ADC -2
-  STSP ; SP offset: 2
-  
-  HALT
+  RET
 
-500:
+300:
 callee:
   ; This callee doesn't really need its own stack since all
   ; calculations did fit into the temporary variables. I still created
@@ -109,34 +123,33 @@ callee:
 
   ; 1. Create own stack frame
   LDFP
-  STVR 0
+  STRS 0
   LDSP
   ADC -1
   STSP
   STFP
 
-  ; Now, the shared stack frame looks like this:
-  ; 5: argument 1
-  ; 4: argument 2
-  ; 3: return value 1
-  ; 2: return value 2
-  ; 1: previous FP
+  ; Since we've pushed the old FP to the shared stack frame (which now
+  ; has length 5) and moved the FP to after that, we've in effect
+  ; added 5 to the FP offset. This means that the shared stack frame
+  ; now looks like this:
   ;
-  ; The compiler needs to keep track of the offset of the SP within
-  ; the current stack frame, so that LDVR and STVR have the correct
-  ; offset when accessing variables inside it (or the previous, shared
-  ; stack frame).
+  ; FP offset | Value
+  ;         5 | argument 1
+  ;         4 | argument 2
+  ;         3 | return value 1
+  ;         2 | return value 2
 
   ; 2. Load arguments into temporary variables
-  LDVR 5
+  LDRF 5
   STV tmp1
-  LDVR 4
+  LDRF 4
   STV tmp2
   
   ; 3. Add arguments and put result into return value 1
   LDV tmp1
   ADD tmp2
-  STVR 3
+  STRF 3
   
   ; 4. Multiply arguments and put result into return value 2
   LDC 0
@@ -162,13 +175,13 @@ callee:
   callee-loop-end:
   ; Save the result in return value 2
   LDV tmp4
-  STVR 2
+  STRF 2
 
   ; 5. Restore shared stack frame
   LDFP
   ADC 1
   STSP
-  LDVR 0
+  LDRF 1
   STFP
   
   ; And this function is done :)