From: Chris Lattner <sabre@nondot.org>
Date: Thu, 8 May 2003 16:52:16 +0000 (+0000)
Subject: Add a pointersize/endianness safe load routine to match the store routine
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=f88b9a639770327196b2a00f365155b954dd1d30;p=oota-llvm.git

Add a pointersize/endianness safe load routine to match the store routine


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6042 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/ExecutionEngine/ExecutionEngine.h b/include/llvm/ExecutionEngine/ExecutionEngine.h
index 57eee953720..e833be78696 100644
--- a/include/llvm/ExecutionEngine/ExecutionEngine.h
+++ b/include/llvm/ExecutionEngine/ExecutionEngine.h
@@ -79,6 +79,7 @@ private:
 public:   // FIXME: protected:   // API shared among subclasses
   GenericValue getConstantValue(const Constant *C);
   void StoreValueToMemory(GenericValue Val, GenericValue *Ptr, const Type *Ty);
+  GenericValue LoadValueFromMemory(GenericValue *Ptr, const Type *Ty);
   void *CreateArgv(const std::vector<std::string> &InputArgv);
   void InitializeMemory(const Constant *Init, void *Addr);
 };
diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index dcfbde4985a..a3c3f47036f 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -152,6 +152,82 @@ void ExecutionEngine::StoreValueToMemory(GenericValue Val, GenericValue *Ptr,
   }
 }
 
+GenericValue ExecutionEngine::LoadValueFromMemory(GenericValue *Ptr,
+                                                  const Type *Ty) {
+  GenericValue Result;
+  if (getTargetData().isLittleEndian()) {
+    switch (Ty->getPrimitiveID()) {
+    case Type::BoolTyID:
+    case Type::UByteTyID:
+    case Type::SByteTyID:   Result.UByteVal = Ptr->Untyped[0]; break;
+    case Type::UShortTyID:
+    case Type::ShortTyID:   Result.UShortVal = (unsigned)Ptr->Untyped[0] |
+                                              ((unsigned)Ptr->Untyped[1] << 8);
+                            break;
+    Load4BytesLittleEndian:                            
+    case Type::FloatTyID:
+    case Type::UIntTyID:
+    case Type::IntTyID:     Result.UIntVal = (unsigned)Ptr->Untyped[0] |
+                                            ((unsigned)Ptr->Untyped[1] <<  8) |
+                                            ((unsigned)Ptr->Untyped[2] << 16) |
+                                            ((unsigned)Ptr->Untyped[3] << 24);
+                            break;
+    case Type::PointerTyID: if (getModule().has32BitPointers())
+                              goto Load4BytesLittleEndian;
+    case Type::DoubleTyID:
+    case Type::ULongTyID:
+    case Type::LongTyID:    Result.ULongVal = (uint64_t)Ptr->Untyped[0] |
+                                             ((uint64_t)Ptr->Untyped[1] <<  8) |
+                                             ((uint64_t)Ptr->Untyped[2] << 16) |
+                                             ((uint64_t)Ptr->Untyped[3] << 24) |
+                                             ((uint64_t)Ptr->Untyped[4] << 32) |
+                                             ((uint64_t)Ptr->Untyped[5] << 40) |
+                                             ((uint64_t)Ptr->Untyped[6] << 48) |
+                                             ((uint64_t)Ptr->Untyped[7] << 56);
+                            break;
+    default:
+      std::cout << "Cannot load value of type " << *Ty << "!\n";
+      abort();
+    }
+  } else {
+    switch (Ty->getPrimitiveID()) {
+    case Type::BoolTyID:
+    case Type::UByteTyID:
+    case Type::SByteTyID:   Result.UByteVal = Ptr->Untyped[0]; break;
+    case Type::UShortTyID:
+    case Type::ShortTyID:   Result.UShortVal = (unsigned)Ptr->Untyped[1] |
+                                              ((unsigned)Ptr->Untyped[0] << 8);
+                            break;
+    Load4BytesBigEndian:
+    case Type::FloatTyID:
+    case Type::UIntTyID:
+    case Type::IntTyID:     Result.UIntVal = (unsigned)Ptr->Untyped[3] |
+                                            ((unsigned)Ptr->Untyped[2] <<  8) |
+                                            ((unsigned)Ptr->Untyped[1] << 16) |
+                                            ((unsigned)Ptr->Untyped[0] << 24);
+                            break;
+    case Type::PointerTyID: if (getModule().has32BitPointers())
+                              goto Load4BytesBigEndian;
+    case Type::DoubleTyID:
+    case Type::ULongTyID:
+    case Type::LongTyID:    Result.ULongVal = (uint64_t)Ptr->Untyped[7] |
+                                             ((uint64_t)Ptr->Untyped[6] <<  8) |
+                                             ((uint64_t)Ptr->Untyped[5] << 16) |
+                                             ((uint64_t)Ptr->Untyped[4] << 24) |
+                                             ((uint64_t)Ptr->Untyped[3] << 32) |
+                                             ((uint64_t)Ptr->Untyped[2] << 40) |
+                                             ((uint64_t)Ptr->Untyped[1] << 48) |
+                                             ((uint64_t)Ptr->Untyped[0] << 56);
+                            break;
+    default:
+      std::cout << "Cannot load value of type " << *Ty << "!\n";
+      abort();
+    }
+  }
+  return Result;
+}
+
+
 // InitializeMemory - Recursive function to apply a Constant value into the
 // specified memory location...
 //