Make DataLayout Non-Optional in the Module

Summary:
DataLayout keeps the string used for its creation.

As a side effect it is no longer needed in the Module.
This is "almost" NFC, the string is no longer
canonicalized, you can't rely on two "equals" DataLayout
having the same string returned by getStringRepresentation().

Get rid of DataLayoutPass: the DataLayout is in the Module

The DataLayout is "per-module", let's enforce this by not
duplicating it more than necessary.
One more step toward non-optionality of the DataLayout in the
module.

Make DataLayout Non-Optional in the Module

Module->getDataLayout() will never returns nullptr anymore.

Reviewers: echristo

Subscribers: resistor, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D7992

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231270

1 files changed, 3 insertions, 90 deletions

diff --git a/llvm/lib/IR/DataLayout.cpp b/llvm/lib/IR/DataLayout.cpp
index 573e904f2ee..c70d7c68a91 100644
--- a/llvm/lib/IR/DataLayout.cpp
+++ b/llvm/lib/IR/DataLayout.cpp
@@ -33,11 +33,6 @@
 #include <cstdlib>
 using namespace llvm;
 
-// Handle the Pass registration stuff necessary to use DataLayout's.
-
-INITIALIZE_PASS(DataLayoutPass, "datalayout", "Data Layout", false, true)
-char DataLayoutPass::ID = 0;
-
 //===----------------------------------------------------------------------===//
 // Support for StructLayout
 //===----------------------------------------------------------------------===//
@@ -221,6 +216,7 @@ static unsigned inBytes(unsigned Bits) {
 }
 
 void DataLayout::parseSpecifier(StringRef Desc) {
+  StringRepresentation = Desc;
   while (!Desc.empty()) {
     // Split at '-'.
     std::pair<StringRef, StringRef> Split = split(Desc, '-');
@@ -378,13 +374,7 @@ DataLayout::DataLayout(const Module *M) : LayoutMap(nullptr) {
   init(M);
 }
 
-void DataLayout::init(const Module *M) {
-  const DataLayout *Other = M->getDataLayout();
-  if (Other)
-    *this = *Other;
-  else
-    reset("");
-}
+void DataLayout::init(const Module *M) { *this = M->getDataLayout(); }
 
 bool DataLayout::operator==(const DataLayout &Other) const {
   bool Ret = BigEndian == Other.BigEndian &&
@@ -392,7 +382,7 @@ bool DataLayout::operator==(const DataLayout &Other) const {
              ManglingMode == Other.ManglingMode &&
              LegalIntWidths == Other.LegalIntWidths &&
              Alignments == Other.Alignments && Pointers == Other.Pointers;
-  assert(Ret == (getStringRepresentation() == Other.getStringRepresentation()));
+  // Note: getStringRepresentation() might differs, it is not canonicalized
   return Ret;
 }
 
@@ -567,68 +557,6 @@ const StructLayout *DataLayout::getStructLayout(StructType *Ty) const {
   return L;
 }
 
-std::string DataLayout::getStringRepresentation() const {
-  std::string Result;
-  raw_string_ostream OS(Result);
-
-  OS << (BigEndian ? "E" : "e");
-
-  switch (ManglingMode) {
-  case MM_None:
-    break;
-  case MM_ELF:
-    OS << "-m:e";
-    break;
-  case MM_MachO:
-    OS << "-m:o";
-    break;
-  case MM_WINCOFF:
-    OS << "-m:w";
-    break;
-  case MM_Mips:
-    OS << "-m:m";
-    break;
-  }
-
-  for (const PointerAlignElem &PI : Pointers) {
-    // Skip default.
-    if (PI.AddressSpace == 0 && PI.ABIAlign == 8 && PI.PrefAlign == 8 &&
-        PI.TypeByteWidth == 8)
-      continue;
-
-    OS << "-p";
-    if (PI.AddressSpace) {
-      OS << PI.AddressSpace;
-    }
-    OS << ":" << PI.TypeByteWidth*8 << ':' << PI.ABIAlign*8;
-    if (PI.PrefAlign != PI.ABIAlign)
-      OS << ':' << PI.PrefAlign*8;
-  }
-
-  for (const LayoutAlignElem &AI : Alignments) {
-    if (std::find(std::begin(DefaultAlignments), std::end(DefaultAlignments),
-                  AI) != std::end(DefaultAlignments))
-      continue;
-    OS << '-' << (char)AI.AlignType;
-    if (AI.TypeBitWidth)
-      OS << AI.TypeBitWidth;
-    OS << ':' << AI.ABIAlign*8;
-    if (AI.ABIAlign != AI.PrefAlign)
-      OS << ':' << AI.PrefAlign*8;
-  }
-
-  if (!LegalIntWidths.empty()) {
-    OS << "-n" << (unsigned)LegalIntWidths[0];
-
-    for (unsigned i = 1, e = LegalIntWidths.size(); i != e; ++i)
-      OS << ':' << (unsigned)LegalIntWidths[i];
-  }
-
-  if (StackNaturalAlign)
-    OS << "-S" << StackNaturalAlign*8;
-
-  return OS.str();
-}
 
 unsigned DataLayout::getPointerABIAlignment(unsigned AS) const {
   PointersTy::const_iterator I = findPointerLowerBound(AS);
@@ -844,18 +772,3 @@ unsigned DataLayout::getPreferredAlignmentLog(const GlobalVariable *GV) const {
   return Log2_32(getPreferredAlignment(GV));
 }
 
-DataLayoutPass::DataLayoutPass() : ImmutablePass(ID), DL("") {
-  initializeDataLayoutPassPass(*PassRegistry::getPassRegistry());
-}
-
-DataLayoutPass::~DataLayoutPass() {}
-
-bool DataLayoutPass::doInitialization(Module &M) {
-  DL.init(&M);
-  return false;
-}
-
-bool DataLayoutPass::doFinalization(Module &M) {
-  DL.reset("");
-  return false;
-}