From eea26d239321d37550cc2d1181e75ca45049a48c Mon Sep 17 00:00:00 2001
From: Michel Heily <michelheily@gmail.com>
Date: Mon, 22 Jul 2019 00:25:26 +0300
Subject: [PATCH] thumb: Change ordering when decoding thumb instruction.

This fixes a bug where "swi" instructions are decoded as conditional
branches.

The order really matters here, because Swi instructions are actually
conditional branch with illegal condition code.


Former-commit-id: 0024a8b53386a510dd321c157391c99a2af29223
---
 src/core/arm7tdmi/thumb/mod.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/core/arm7tdmi/thumb/mod.rs b/src/core/arm7tdmi/thumb/mod.rs
index 87ae10f..4f09d05 100644
--- a/src/core/arm7tdmi/thumb/mod.rs
+++ b/src/core/arm7tdmi/thumb/mod.rs
@@ -124,10 +124,10 @@ impl InstructionDecoder for ThumbInstruction {
             Ok(PushPop)
         } else if raw & 0xf000 == 0xc000 {
             Ok(LdmStm)
-        } else if raw & 0xf000 == 0xd000 {
-            Ok(BranchConditional)
         } else if raw & 0xff00 == 0xdf00 {
             Ok(Swi)
+        } else if raw & 0xf000 == 0xd000 {
+            Ok(BranchConditional)
         } else if raw & 0xf800 == 0xe000 {
             Ok(Branch)
         } else if raw & 0xf000 == 0xf000 {
@@ -323,7 +323,7 @@ impl ThumbInstruction {
     }
 
     pub fn cond(&self) -> ArmCond {
-        ArmCond::from_u8(self.raw.bit_range(8..12) as u8).unwrap()
+        ArmCond::from_u8(self.raw.bit_range(8..12) as u8).expect("bad condition")
     }
 
     pub fn flag(&self, bit: usize) -> bool {