From: Anton Korobeynikov <asl@math.spbu.ru>
Date: Tue, 14 Jul 2009 09:53:14 +0000 (+0000)
Subject: Add extra sign extension to the same bit width before int sign
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=94ac0343cc866c632f230d069656c4358197ddf6;p=oota-llvm.git

Add extra sign extension to the same bit width before int sign
extension to another bit width. This is needed to get correct singed value.
Patch by Artur Pietrek!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75629 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/MSIL/MSILWriter.cpp b/lib/Target/MSIL/MSILWriter.cpp
index 61ec0283045..81e5cd4aec0 100644
--- a/lib/Target/MSIL/MSILWriter.cpp
+++ b/lib/Target/MSIL/MSILWriter.cpp
@@ -670,12 +670,18 @@ void MSILWriter::printIndirectSave(const Type* Ty) {
 
 
 void MSILWriter::printCastInstruction(unsigned int Op, const Value* V,
-                                      const Type* Ty) {
+                                      const Type* Ty, const Type* SrcTy) {
   std::string Tmp("");
   printValueLoad(V);
   switch (Op) {
   // Signed
   case Instruction::SExt:
+    // If sign extending int, convert first from unsigned to signed
+    // with the same bit size - because otherwise we will loose the sign.
+    if (SrcTy) {
+      Tmp = "conv."+getTypePostfix(SrcTy,false,true);
+      printSimpleInstruction(Tmp.c_str());
+    }
   case Instruction::SIToFP:
   case Instruction::FPToSI:
     Tmp = "conv."+getTypePostfix(Ty,false,true);
@@ -1152,9 +1158,13 @@ void MSILWriter::printInstruction(const Instruction* Inst) {
   case Instruction::Store:
     printIndirectSave(Inst->getOperand(1), Inst->getOperand(0));
     break;
+  case Instruction::SExt:
+    printCastInstruction(Inst->getOpcode(),Left,
+                         cast<CastInst>(Inst)->getDestTy(),
+                         cast<CastInst>(Inst)->getSrcTy());
+    break;
   case Instruction::Trunc:
   case Instruction::ZExt:
-  case Instruction::SExt:
   case Instruction::FPTrunc:
   case Instruction::FPExt:
   case Instruction::UIToFP:
diff --git a/lib/Target/MSIL/MSILWriter.h b/lib/Target/MSIL/MSILWriter.h
index 2ef8a85d2bc..ea0dfad0e46 100644
--- a/lib/Target/MSIL/MSILWriter.h
+++ b/lib/Target/MSIL/MSILWriter.h
@@ -187,7 +187,7 @@ namespace {
     void printIndirectSave(const Type* Ty);
 
     void printCastInstruction(unsigned int Op, const Value* V,
-                              const Type* Ty);
+                              const Type* Ty, const Type* SrcTy=0);
 
     void printGepInstruction(const Value* V, gep_type_iterator I,
                              gep_type_iterator E);