From a9e4aaba0e67d5e6fa6fbd82139d9793c3332022 Mon Sep 17 00:00:00 2001
From: Erin <erin@erindesu.cz>
Date: Wed, 12 Jul 2023 12:45:50 +0200
Subject: [PATCH] =?UTF-8?q?JMP=20=E2=86=92=20JAL=20+=20spec=20fix?=
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---
 hbasm/src/lib.rs      |  4 ++--
 hbbytecode/src/lib.rs |  2 +-
 hbvm/src/validate.rs  |  4 ++--
 hbvm/src/vm/mod.rs    |  5 +++--
 spec.md               | 12 ++++++------
 5 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/hbasm/src/lib.rs b/hbasm/src/lib.rs
index 75a5731a..391b2514 100644
--- a/hbasm/src/lib.rs
+++ b/hbasm/src/lib.rs
@@ -21,11 +21,11 @@ macros::impl_both!(
         => [LD, ST],
     bbd(p0: R, p1: R, p2: I)
         => [ADDI, MULI, ANDI, ORI, XORI, SLI, SRI, SRSI, CMPI, CMPUI,
-            BMC, JEQ, JNE, JLT, JGT, JLTU, JGTU, ADDFI, MULFI],
+            BMC, JAL, JEQ, JNE, JLT, JGT, JLTU, JGTU, ADDFI, MULFI],
     bb(p0: R, p1: R)
         => [NEG, NOT, CP, SWA, NEGF, ITF, FTI],
     bd(p0: R, p1: I)
-        => [LI, JMP],
+        => [LI],
     n()
         => [NOP, ECALL],
 );
diff --git a/hbbytecode/src/lib.rs b/hbbytecode/src/lib.rs
index 19f46487..9b4f60bf 100644
--- a/hbbytecode/src/lib.rs
+++ b/hbbytecode/src/lib.rs
@@ -54,7 +54,7 @@ constmod!(pub opcode(u8) {
     BMC = 30, "BBD; [#0] ← [#1], imm #2 bytes";
     BRC = 31, "BBB; #0 ← #1, imm #2 registers";
 
-    JMP   = 32, "BD;  Unconditional jump [#0 + imm #1]";
+    JAL   = 32, "BD;  Copy PC to #0 and unconditional jump [#1 + imm #2]";
     JEQ   = 33, "BBD; if #0 = #1 → jump imm #2";
     JNE   = 34, "BBD; if #0 ≠ #1 → jump imm #2";
     JLT   = 35, "BBD; if #0 < #1 → jump imm #2";
diff --git a/hbvm/src/validate.rs b/hbvm/src/validate.rs
index 52f726ff..d75306bf 100644
--- a/hbvm/src/validate.rs
+++ b/hbvm/src/validate.rs
@@ -50,8 +50,8 @@ pub fn validate(mut program: &[u8]) -> Result<(), Error> {
             | [DIR | DIRF, _, _, _, _, rest @ ..]
             | [ADD..=CMPU | BRC | ADDF..=MULF, _, _, _, rest @ ..]
             | [NEG..=NOT | CP..=SWA | NEGF..=FTI, _, _, rest @ ..]
-            | [LI | JMP, _, _, _, _, _, _, _, _, _, rest @ ..]
-            | [ADDI..=CMPUI | BMC | JEQ..=JGTU | ADDFI..=MULFI, _, _, _, _, _, _, _, _, _, _, rest @ ..]
+            | [LI, _, _, _, _, _, _, _, _, _, rest @ ..]
+            | [ADDI..=CMPUI | BMC | JAL..=JGTU | ADDFI..=MULFI, _, _, _, _, _, _, _, _, _, _, rest @ ..]
             | [LD..=ST, _, _, _, _, _, _, _, _, _, _, _, _, rest @ ..] => rest,
             _ => {
                 return Err(Error {
diff --git a/hbvm/src/vm/mod.rs b/hbvm/src/vm/mod.rs
index 7c3a50f4..5e993607 100644
--- a/hbvm/src/vm/mod.rs
+++ b/hbvm/src/vm/mod.rs
@@ -259,8 +259,9 @@ impl<'a, PfHandler: HandlePageFault, const TIMER_QUOTIENT: usize>
                             usize::from(count * 8),
                         );
                     }
-                    JMP => {
-                        let ParamBD(reg, offset) = param!(self, ParamBD);
+                    JAL => {
+                        let ParamBBD(save, reg, offset) = param!(self, ParamBBD);
+                        self.write_reg(save, self.pc as u64);
                         self.pc = (self.read_reg(reg).as_u64() + offset) as usize;
                     }
                     JEQ => cond_jump!(self, int, Equal),
diff --git a/spec.md b/spec.md
index 4c64f267..55c3aaa4 100644
--- a/spec.md
+++ b/spec.md
@@ -153,7 +153,7 @@
 
 | Opcode | Name |              Action              |
 |:------:|:----:|:--------------------------------:|
-|   30   | BMC  | `[#0] ← [#1], copy imm #2 bytes` |
+|   30   | BMC  | `[#1] ← [#0], copy imm #2 bytes` |
 
 ### Register copy
 - Type BBB
@@ -161,16 +161,16 @@
 
 | Opcode | Name |              Action              |
 |:------:|:----:|:--------------------------------:|
-|   31   | BRC  | `#0 ← #1, copy imm #2 registers` |
+|   31   | BRC  | `#1 ← #0, copy imm #2 registers` |
 
 ## Control flow
 
 ### Unconditional jump
-- Type BD
+- Type BBD
 
-| Opcode | Name |        Action         |
-|:------:|:----:|:---------------------:|
-|   32   | JMP  | Jump at `#0 + imm #1` |
+| Opcode | Name |                      Action                       |
+|:------:|:----:|:-------------------------------------------------:|
+|   32   | JAL  | Save current PC to `#0` and jump at `#1 + imm #2` |
 
 ### Conditional jumps
 - Type BBD