From e4c0a89889b08c6ce363014ee24a9c9406976ecf Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 19 May 2022 15:01:09 -0400
Subject: [PATCH] Just use the four-bit register number directly.
---
.../M68k/Implementation/ExecutorImplementation.hpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp b/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp
index d42e3dda8..7a8f17b52 100644
--- a/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp
+++ b/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp
@@ -205,8 +205,8 @@ uint32_t Executor<model, BusHandler>::State::index_8bitdisplacement() {
// also include the scale field even if not.
const auto extension = read_pc<uint16_t>();
const auto offset = int8_t(extension);
- const int register_index = (extension >> 12) & 7;
- const uint32_t displacement = registers[register_index + ((extension >> 12) & 0x08)].l;
+ const int register_index = (extension >> 12) & 15;
+ const uint32_t displacement = registers[register_index].l;
const uint32_t sized_displacement = (extension & 0x800) ? displacement : int16_t(displacement);
return offset + sized_displacement;
}