From c940b116a75fe61494e9be41b0fa967ac421d42e Mon Sep 17 00:00:00 2001
From: Pietro Fezzardi <pietrofezzardi@gmail.com>
Date: Fri, 16 Feb 2018 10:31:48 +0100
Subject: [PATCH] Use `getTypeAllocSize()` instead of `getTypeSizeInBits()`

The function `getTypeSizeInBits()` was wrongly used in many places when
reasoning about memory allocation, memory accesses, and memory offsets,
The result was often divided by 8 (possibly losing spare bits) or even
multiplied by 8, which makes no sense.
These uses were error prone, even if they didn't cause problems yet.
The `getTypeAllocSize()` is better suited for these uses, because it
returns the number of bytes necessary to allocate an object of the given
Type.
---
 generatedcodebasicinfo.cpp | 2 +-
 memoryaccess.h             | 4 ++--
 variablemanager.cpp        | 7 +++----
 3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/generatedcodebasicinfo.cpp b/generatedcodebasicinfo.cpp
index bfba628d8..f53287866 100644
--- a/generatedcodebasicinfo.cpp
+++ b/generatedcodebasicinfo.cpp
@@ -41,7 +41,7 @@ bool GeneratedCodeBasicInfo::runOnFunction(llvm::Function &F) {
   SP = M->getGlobalVariable(QMD.extract<StringRef>(Tuple, 3), true);
 
   Type *PCType = PC->getType()->getPointerElementType();
-  PCRegSize = M->getDataLayout().getTypeSizeInBits(PCType) / 8;
+  PCRegSize = M->getDataLayout().getTypeAllocSize(PCType);
 
   for (BasicBlock &BB : F) {
     if (!BB.empty()) {
diff --git a/memoryaccess.h b/memoryaccess.h
index 6e752eaf6..2cd6b39ab 100644
--- a/memoryaccess.h
+++ b/memoryaccess.h
@@ -27,7 +27,7 @@ public:
     if (CacheIt != Cache.end()) {
       return CacheIt->second;
     } else {
-      auto Result = DL.getTypeSizeInBits(T) * 8;
+      auto Result = DL.getTypeAllocSize(T);
       Cache[T] = Result;
       return Result;
     }
@@ -161,7 +161,7 @@ private:
                   llvm::Value *PointeeValue,
                   const llvm::DataLayout &DL) {
     // Set the size
-    Size = DL.getTypeSizeInBits(PointeeValue->getType()) * 8;
+    Size = DL.getTypeAllocSize(PointeeValue->getType());
     initialize(Pointer);
   }
 
diff --git a/variablemanager.cpp b/variablemanager.cpp
index e1b4d7ae2..1574aa398 100644
--- a/variablemanager.cpp
+++ b/variablemanager.cpp
@@ -139,7 +139,7 @@ bool CorrectCPUStateUsagePass::runOnModule(Module& TheModule) {
 
           bool Success = false;
           if (Load != nullptr) {
-            unsigned Size = DL.getTypeSizeInBits(TheUser->getType()) / 8;
+            unsigned Size = DL.getTypeAllocSize(TheUser->getType());
             assert(Size != 0);
 
             unsigned CurrentEnvOffset = CurrentOffset - EnvOffset;
@@ -151,7 +151,7 @@ bool CorrectCPUStateUsagePass::runOnModule(Module& TheModule) {
               TheUser->replaceAllUsesWith(Loaded);
           } else {
             Value *ToStore = Store->getValueOperand();
-            unsigned Size = DL.getTypeSizeInBits(ToStore->getType()) / 8;
+            unsigned Size = DL.getTypeAllocSize(ToStore->getType());
             assert(Size != 0);
 
             unsigned CurrentEnvOffset = CurrentOffset - EnvOffset;
@@ -262,7 +262,7 @@ bool CorrectCPUStateUsagePass::runOnModule(Module& TheModule) {
               }
 
               Type *PointeeTy = Var->getType()->getPointerElementType();
-              uint64_t Size = DL.getTypeSizeInBits(PointeeTy) / 8;
+              uint64_t Size = DL.getTypeAllocSize(PointeeTy);
 
               Value *Address = Builder.CreateAdd(Builder.getInt64(Offset),
                                                  BasePtr);
@@ -561,7 +561,6 @@ VariableManager::VariableManager(Module& TheModule,
     if (startsWith(HelperFunction.getName(), HelperPrefix)
         && HelperFunction.getFunctionType()->getNumParams() > 1) {
 
-
       for (Type *Candidate : HelperType->params()) {
         Structs.insert(dyn_cast<StructType>(Candidate));
         if (Candidate->isPointerTy()) {