From 1f83e6567dc28b6a6d234a125b4945cf73b33bea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Felix=20Quei=C3=9Fner?= <git@mq32.de>
Date: Sat, 21 May 2016 21:36:34 +0200
Subject: [PATCH] Adds stack, base pointer manipulation.

---
 prototypes/supervm/supervm.md |  5 ++++-
 prototypes/supervm/vm.c       | 30 ++++++++++++++++++++++++++++++
 prototypes/supervm/vm.h       |  2 +-
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/prototypes/supervm/supervm.md b/prototypes/supervm/supervm.md
index e3ba165..d760011 100644
--- a/prototypes/supervm/supervm.md
+++ b/prototypes/supervm/supervm.md
@@ -80,7 +80,7 @@ An instruction is only executed when all conditions are met.
 |  4 | SET         | output = STACK[BP + input0] = input1 |
 |  5 | BPGET       | output = BP                          |
 |  6 | BPSET       | output = BP = input0                 |
-|  7 | RSTSTACK    | output = SP = BP                     |
+|  7 | CPGET       | output = CP + cmdinfo                |
 |  8 | MATH        | output = input0 OP[info] input1      |
 |  9 | SPGET       | output = SP + input0                 |
 | 10 | SPSET       | output = SP + input0 = input1        |
@@ -134,6 +134,9 @@ by the `cmdinfo`.
 | seti     |   no | pop  | pop  | set     | 0        | discard | no     |
 | bpget    |   no | zero | zero | bpget   | 0        | push    | no     |
 | bpset    |   no | pop  | zero | bpset   | 0        | discard | no     |
+| spget    |   no | zero | zero | spget   | 0        | push    | no     |
+| spset    |   no | pop  | zero | spset   | 0        | discard | no     |
+| cpget    |   no | zero | zero | cpget   | 1        | push    | no     |
 | add      |   no | pop  | pop  | math    | 0        | push    | no     |
 | sub      |   no | pop  | pop  | math    | 1        | push    | no     |
 | cmp      |   no | pop  | pop  | math    | 1        | discard | yes    |
diff --git a/prototypes/supervm/vm.c b/prototypes/supervm/vm.c
index 0323ef9..1026846 100644
--- a/prototypes/supervm/vm.c
+++ b/prototypes/supervm/vm.c
@@ -21,6 +21,31 @@ static void cmd_store(Process *p, CommandInfo *info)
 	info->output = info->input1;
 }
 
+static void cmd_spget(Process *p, CommandInfo *info)
+{
+	info->output = p->stackPointer;
+}
+
+static void cmd_spset(Process *p, CommandInfo *info)
+{
+	info->output = p->stackPointer = info->input0;
+}
+
+static void cmd_bpget(Process *p, CommandInfo *info)
+{
+	info->output = p->basePointer;
+}
+
+static void cmd_bpset(Process *p, CommandInfo *info)
+{
+	info->output = p->basePointer = info->input0;
+}
+
+static void cmd_cpget(Process *p, CommandInfo *info)
+{
+	info->output = p->codePointer + info->additional;
+}
+
 static void cmd_math(CommandInfo *info)
 {
 	switch(info->additional)
@@ -116,6 +141,11 @@ int vm_step_process(Process *process)
 			case VM_CMD_MATH: cmd_math(&info); break;
 			case VM_CMD_SYSCALL: vm_syscall(process, &info); break;
 			case VM_CMD_HWIO: vm_hwio(process, &info); break;
+			case VM_CMD_SPGET: cmd_spget(process, &info); break;
+			case VM_CMD_SPSET: cmd_spset(process, &info); break;
+			case VM_CMD_BPGET: cmd_bpget(process, &info); break;
+			case VM_CMD_BPSET: cmd_bpset(process, &info); break;
+			case VM_CMD_CPGET: cmd_cpget(process, &info); break;
 			default: vm_assert(0, "Invalid instruction: command undefined.");
 		}
 		
diff --git a/prototypes/supervm/vm.h b/prototypes/supervm/vm.h
index 71452d1..1208c38 100644
--- a/prototypes/supervm/vm.h
+++ b/prototypes/supervm/vm.h
@@ -28,7 +28,7 @@ extern "C" {
 #define VM_CMD_SET      4
 #define VM_CMD_BPGET    5
 #define VM_CMD_BPSET    6
-#define VM_CMD_RSTSTACK 7
+#define VM_CMD_CPGET    7
 #define VM_CMD_MATH     8
 #define VM_CMD_SPGET    9
 #define VM_CMD_SPSET    10