Second attempt:

Massive check in. This changes the "-fast" flag to "-O#" in llc. If you want to
use the old behavior, the flag is -O0. This change allows for finer-grained
control over which optimizations are run at different -O levels.

Most of this work was pretty mechanical. The majority of the fixes came from
verifying that a "fast" variable wasn't used anymore. The JIT still uses a
"Fast" flag. I'll change the JIT with a follow-up patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70343 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index bd724af..8a41423 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -57,9 +57,9 @@
     SelectionDAG &DAG;
     const TargetLowering &TLI;
     CombineLevel Level;
+    unsigned OptLevel;
     bool LegalOperations;
     bool LegalTypes;
-    bool Fast;
 
     // Worklist of all of the nodes that need to be simplified.
     std::vector<SDNode*> WorkList;
@@ -254,13 +254,13 @@
     }
 
 public:
-    DAGCombiner(SelectionDAG &D, AliasAnalysis &A, bool fast)
+    DAGCombiner(SelectionDAG &D, AliasAnalysis &A, unsigned OL)
       : DAG(D),
         TLI(D.getTargetLoweringInfo()),
         Level(Unrestricted),
+        OptLevel(OL),
         LegalOperations(false),
         LegalTypes(false),
-        Fast(fast),
         AA(A) {}
 
     /// Run - runs the dag combiner on all nodes in the work list
@@ -4784,7 +4784,7 @@
   SDValue Ptr   = LD->getBasePtr();
 
   // Try to infer better alignment information than the load already has.
-  if (!Fast && LD->isUnindexed()) {
+  if (OptLevel != 0 && LD->isUnindexed()) {
     if (unsigned Align = InferAlignment(Ptr, DAG)) {
       if (Align > LD->getAlignment())
         return DAG.getExtLoad(LD->getExtensionType(), N->getDebugLoc(),
@@ -4904,7 +4904,7 @@
   SDValue Ptr   = ST->getBasePtr();
 
   // Try to infer better alignment information than the store already has.
-  if (!Fast && ST->isUnindexed()) {
+  if (OptLevel != 0 && ST->isUnindexed()) {
     if (unsigned Align = InferAlignment(Ptr, DAG)) {
       if (Align > ST->getAlignment())
         return DAG.getTruncStore(Chain, N->getDebugLoc(), Value,
@@ -6084,8 +6084,9 @@
 
 // SelectionDAG::Combine - This is the entry point for the file.
 //
-void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA, bool Fast) {
+void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis &AA,
+                           unsigned OptLevel) {
   /// run - This is the main entry point to this class.
   ///
-  DAGCombiner(*this, AA, Fast).Run(Level);
+  DAGCombiner(*this, AA, OptLevel).Run(Level);
 }