[PATCH] StructurizeCFG: Add dependency on LowerSwitch pass

[Tom Stellard]

From: Tom Stellard <thomas.stellard at amd.com>

Switch instructions were crashing the StructurizeCFG pass, and it's
probably easier anyway if we don't need to handle them in this pass.
---
 lib/Transforms/Scalar/StructurizeCFG.cpp |  4 +++-
 test/Transforms/StructurizeCFG/switch.ll | 23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 test/Transforms/StructurizeCFG/switch.ll

diff --git a/lib/Transforms/Scalar/StructurizeCFG.cpp b/lib/Transforms/Scalar/StructurizeCFG.cpp
index bb6f163..72fea80 100644
--- a/lib/Transforms/Scalar/StructurizeCFG.cpp
+++ b/lib/Transforms/Scalar/StructurizeCFG.cpp
@@ -231,7 +231,7 @@ public:
 
   StructurizeCFG() :
     RegionPass(ID) {
-    initializeRegionInfoPass(*PassRegistry::getPassRegistry());
+    initializeStructurizeCFGPass(*PassRegistry::getPassRegistry());
   }
 
   using Pass::doInitialization;
@@ -244,6 +244,7 @@ public:
   }
 
   void getAnalysisUsage(AnalysisUsage &AU) const {
+    AU.addRequiredID(LowerSwitchID);
     AU.addRequired<DominatorTree>();
     AU.addPreserved<DominatorTree>();
     RegionPass::getAnalysisUsage(AU);
@@ -256,6 +257,7 @@ char StructurizeCFG::ID = 0;
 
 INITIALIZE_PASS_BEGIN(StructurizeCFG, "structurizecfg", "Structurize the CFG",
                       false, false)
+INITIALIZE_PASS_DEPENDENCY(LowerSwitch)
 INITIALIZE_PASS_DEPENDENCY(DominatorTree)
 INITIALIZE_PASS_DEPENDENCY(RegionInfo)
 INITIALIZE_PASS_END(StructurizeCFG, "structurizecfg", "Structurize the CFG",
diff --git a/test/Transforms/StructurizeCFG/switch.ll b/test/Transforms/StructurizeCFG/switch.ll
new file mode 100644
index 0000000..316df57
--- /dev/null
+++ b/test/Transforms/StructurizeCFG/switch.ll
@@ -0,0 +1,23 @@
+; RUN: opt -S -structurizecfg %s -o - | FileCheck %s
+
+; The structurizecfg pass cannot handle switch instructions, so we need to
+; make sure the lower switch pass is always run before structurizecfg.
+
+; CHECK-LABEL: @switch
+define void @switch(i32 addrspace(1)* %out, i32 %cond) nounwind {
+entry:
+; CHECK: icmp
+  switch i32 %cond, label %done [ i32 0, label %zero]
+
+; CHECK: zero:
+zero:
+; CHECK: store i32 7, i32 addrspace(1)* %out
+  store i32 7, i32 addrspace(1)* %out
+; CHECK: br label %done
+  br label %done
+
+; CHECK: done:
+done:
+; CHECK: ret void
+  ret void
+}
-- 
1.7.11.4