Clean up uses of switch instructions so they are not dependent on the operand ordering. Patch by Stepan Dyatkovskiy.

llvm-svn: 140803

2 files changed, 21 insertions, 11 deletions

diff --git a/llvm/lib/Target/CBackend/CBackend.cpp b/llvm/lib/Target/CBackend/CBackend.cpp
index e3524e4c38d..020b80102eb 100644
--- a/llvm/lib/Target/CBackend/CBackend.cpp
+++ b/llvm/lib/Target/CBackend/CBackend.cpp
@@ -2383,22 +2383,29 @@ void CWriter::visitReturnInst(ReturnInst &I) {
 
 void CWriter::visitSwitchInst(SwitchInst &SI) {
 
+  Value* Cond = SI.getCondition();
+
   Out << "  switch (";
-  writeOperand(SI.getOperand(0));
+  writeOperand(Cond);
   Out << ") {\n  default:\n";
   printPHICopiesForSuccessor (SI.getParent(), SI.getDefaultDest(), 2);
   printBranchToBlock(SI.getParent(), SI.getDefaultDest(), 2);
   Out << ";\n";
-  for (unsigned i = 2, e = SI.getNumOperands(); i != e; i += 2) {
+
+  unsigned NumCases = SI.getNumCases();
+  // Skip the first item since that's the default case.
+  for (unsigned i = 1; i < NumCases; ++i) {
+    ConstantInt* CaseVal = SI.getCaseValue(i);
+    BasicBlock* Succ = SI.getSuccessor(i);
     Out << "  case ";
-    writeOperand(SI.getOperand(i));
+    writeOperand(CaseVal);
     Out << ":\n";
-    BasicBlock *Succ = cast<BasicBlock>(SI.getOperand(i+1));
     printPHICopiesForSuccessor (SI.getParent(), Succ, 2);
     printBranchToBlock(SI.getParent(), Succ, 2);
     if (Function::iterator(Succ) == llvm::next(Function::iterator(SI.getParent())))
       Out << "    break;\n";
   }
+
   Out << "  }\n";
 }
 
diff --git a/llvm/lib/Target/CppBackend/CPPBackend.cpp b/llvm/lib/Target/CppBackend/CPPBackend.cpp
index 8d6eda12046..16401a8f98b 100644
--- a/llvm/lib/Target/CppBackend/CPPBackend.cpp
+++ b/llvm/lib/Target/CppBackend/CPPBackend.cpp
@@ -154,7 +154,7 @@ namespace {
     void printFunctionHead(const Function *F);
     void printFunctionBody(const Function *F);
     void printInstruction(const Instruction *I, const std::string& bbname);
-    std::string getOpName(Value*);
+    std::string getOpName(const Value*);
 
     void printModuleBody();
   };
@@ -979,7 +979,7 @@ void CppWriter::printVariableBody(const GlobalVariable *GV) {
   }
 }
 
-std::string CppWriter::getOpName(Value* V) {
+std::string CppWriter::getOpName(const Value* V) {
   if (!isa<Instruction>(V) || DefinedValues.find(V) != DefinedValues.end())
     return getCppName(V);
 
@@ -1044,14 +1044,17 @@ void CppWriter::printInstruction(const Instruction *I,
   case Instruction::Switch: {
     const SwitchInst *SI = cast<SwitchInst>(I);
     Out << "SwitchInst* " << iName << " = SwitchInst::Create("
-        << opNames[0] << ", "
-        << opNames[1] << ", "
+        << getOpName(SI->getCondition()) << ", "
+        << getOpName(SI->getDefaultDest()) << ", "
         << SI->getNumCases() << ", " << bbname << ");";
     nl(Out);
-    for (unsigned i = 2; i != SI->getNumOperands(); i += 2) {
+    unsigned NumCases = SI->getNumCases();
+    for (unsigned i = 1; i < NumCases; ++i) {
+      const ConstantInt* CaseVal = SI->getCaseValue(i);
+      const BasicBlock* BB = SI->getSuccessor(i);
       Out << iName << "->addCase("
-          << opNames[i] << ", "
-          << opNames[i+1] << ");";
+          << getOpName(CaseVal) << ", "
+          << getOpName(BB) << ");";
       nl(Out);
     }
     break;