From 078186809262ca9e5bf696934ff0c61f924bde11 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Wed, 15 Jul 2020 01:37:16 +0200
Subject: [PATCH] UserspaceEmulator: Implement IDIV_RM32

---
 DevTools/UserspaceEmulator/SoftCPU.cpp | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/DevTools/UserspaceEmulator/SoftCPU.cpp b/DevTools/UserspaceEmulator/SoftCPU.cpp
index 9670aa8274..e20a2bbcef 100644
--- a/DevTools/UserspaceEmulator/SoftCPU.cpp
+++ b/DevTools/UserspaceEmulator/SoftCPU.cpp
@@ -908,7 +908,25 @@ void SoftCPU::ENTER32(const X86::Instruction&) { TODO(); }
 void SoftCPU::ESCAPE(const X86::Instruction&) { TODO(); }
 void SoftCPU::HLT(const X86::Instruction&) { TODO(); }
 void SoftCPU::IDIV_RM16(const X86::Instruction&) { TODO(); }
-void SoftCPU::IDIV_RM32(const X86::Instruction&) { TODO(); }
+
+void SoftCPU::IDIV_RM32(const X86::Instruction& insn)
+{
+    auto divisor = insn.modrm().read32(*this, insn);
+    if (divisor == 0) {
+        warn() << "Divide by zero";
+        TODO();
+    }
+    i64 dividend = ((i64)edx() << 32) | eax();
+    auto result = dividend / divisor;
+    if (result > NumericLimits<i32>::max()) {
+        warn() << "Divide overflow";
+        TODO();
+    }
+
+    set_eax(result);
+    set_edx(dividend % divisor);
+}
+
 void SoftCPU::IDIV_RM8(const X86::Instruction&) { TODO(); }
 void SoftCPU::IMUL_RM16(const X86::Instruction&) { TODO(); }
 void SoftCPU::IMUL_RM32(const X86::Instruction&) { TODO(); }