DataLayout is mandatory, update the API to reflect it with references.

Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index db4174d..f6e43f2 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -78,7 +78,6 @@
   /// revectored to the false side of the second if.
   ///
   class JumpThreading : public FunctionPass {
-    const DataLayout *DL;
     TargetLibraryInfo *TLI;
     LazyValueInfo *LVI;
 #ifdef NDEBUG
@@ -159,7 +158,6 @@
     return false;
 
   DEBUG(dbgs() << "Jump threading on function '" << F.getName() << "'\n");
-  DL = &F.getParent()->getDataLayout();
   TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
   LVI = &getAnalysis<LazyValueInfo>();
 
@@ -504,6 +502,7 @@
     assert(Preference == WantInteger && "Compares only produce integers");
     PHINode *PN = dyn_cast<PHINode>(Cmp->getOperand(0));
     if (PN && PN->getParent() == BB) {
+      const DataLayout &DL = PN->getModule()->getDataLayout();
       // We can do this simplification if any comparisons fold to true or false.
       // See if any do.
       for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
@@ -708,7 +707,8 @@
   // Run constant folding to see if we can reduce the condition to a simple
   // constant.
   if (Instruction *I = dyn_cast<Instruction>(Condition)) {
-    Value *SimpleVal = ConstantFoldInstruction(I, DL, TLI);
+    Value *SimpleVal =
+        ConstantFoldInstruction(I, BB->getModule()->getDataLayout(), TLI);
     if (SimpleVal) {
       I->replaceAllUsesWith(SimpleVal);
       I->eraseFromParent();
@@ -1520,7 +1520,7 @@
   // At this point, the IR is fully up to date and consistent.  Do a quick scan
   // over the new instructions and zap any that are constants or dead.  This
   // frequently happens because of phi translation.
-  SimplifyInstructionsInBlock(NewBB, DL, TLI);
+  SimplifyInstructionsInBlock(NewBB, TLI);
 
   // Threaded an edge!
   ++NumThreads;
@@ -1585,7 +1585,6 @@
   BasicBlock::iterator BI = BB->begin();
   for (; PHINode *PN = dyn_cast<PHINode>(BI); ++BI)
     ValueMapping[PN] = PN->getIncomingValueForBlock(PredBB);
-
   // Clone the non-phi instructions of BB into PredBB, keeping track of the
   // mapping and using it to remap operands in the cloned instructions.
   for (; BI != BB->end(); ++BI) {
@@ -1602,7 +1601,8 @@
     // If this instruction can be simplified after the operands are updated,
     // just use the simplified value instead.  This frequently happens due to
     // phi translation.
-    if (Value *IV = SimplifyInstruction(New, DL)) {
+    if (Value *IV =
+            SimplifyInstruction(New, BB->getModule()->getDataLayout())) {
       delete New;
       ValueMapping[BI] = IV;
     } else {