From 04695957e2b52e58a534bc0f823672be8ecca509 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 12 Jul 2020 15:33:29 +0200
Subject: [PATCH] UserspaceEmulator: Implement the MOVSX instruction

---
 DevTools/UserspaceEmulator/SoftCPU.cpp | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/DevTools/UserspaceEmulator/SoftCPU.cpp b/DevTools/UserspaceEmulator/SoftCPU.cpp
index 44581cc517..57f4677bd9 100644
--- a/DevTools/UserspaceEmulator/SoftCPU.cpp
+++ b/DevTools/UserspaceEmulator/SoftCPU.cpp
@@ -1055,9 +1055,20 @@ void SoftCPU::MOVSW(const X86::Instruction& insn)
         });
     }
 }
-void SoftCPU::MOVSX_reg16_RM8(const X86::Instruction&) { TODO(); }
-void SoftCPU::MOVSX_reg32_RM16(const X86::Instruction&) { TODO(); }
-void SoftCPU::MOVSX_reg32_RM8(const X86::Instruction&) { TODO(); }
+void SoftCPU::MOVSX_reg16_RM8(const X86::Instruction& insn)
+{
+    gpr16(insn.reg16()) = sign_extended_to<u16>(insn.modrm().read8(*this, insn));
+}
+
+void SoftCPU::MOVSX_reg32_RM16(const X86::Instruction& insn)
+{
+    gpr32(insn.reg32()) = sign_extended_to<u32>(insn.modrm().read16(*this, insn));
+}
+
+void SoftCPU::MOVSX_reg32_RM8(const X86::Instruction& insn)
+{
+    gpr32(insn.reg32()) = sign_extended_to<u32>(insn.modrm().read8(*this, insn));
+}
 
 void SoftCPU::MOVZX_reg16_RM8(const X86::Instruction& insn)
 {