From ca016033888ce10df246ce6a8ec6235913210416 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Bylica?= <pawel.bylica@imapp.pl>
Date: Tue, 21 Oct 2014 15:55:29 +0200
Subject: [PATCH] Remove unreachable basic blocks before "linking"

---
 libevmjit/Compiler.cpp | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/libevmjit/Compiler.cpp b/libevmjit/Compiler.cpp
index ab98b27d0..fe720b811 100644
--- a/libevmjit/Compiler.cpp
+++ b/libevmjit/Compiler.cpp
@@ -911,7 +911,26 @@ void Compiler::linkBasicBlocks()
 		}
 	};
 
-	
+	// Remove dead basic blocks
+	auto sthErased = false;
+	do
+	{
+		sthErased = false;
+		for (auto it = basicBlocks.begin(); it != basicBlocks.end();)
+		{
+			auto llvmBB = it->second.llvm();
+			if (llvm::pred_begin(llvmBB) == llvm::pred_end(llvmBB))
+			{
+				llvmBB->eraseFromParent();
+				basicBlocks.erase(it++);
+				sthErased = true;
+			}
+			else
+				++it;
+		}
+	}
+	while (sthErased);
+
 	// TODO: It is crappy visiting of basic blocks.
 	llvm::SmallPtrSet<llvm::BasicBlock*, 32> visitSet;
 	for (auto&& bb : basicBlocks) // TODO: External loop is to visit unreable blocks that can also have phi nodes