[LVI] Check for @llvm.assume dominating the edge branch

[oota-llvm.git] / lib / Analysis / LazyValueInfo.cpp

diff --git a/lib/Analysis/LazyValueInfo.cpp b/lib/Analysis/LazyValueInfo.cpp
index 414aaab265a3c708e3e7c2d1b25220a4c26cb059..ec2c798e6c6e8cf5e83d0cab871329458a846891 100644 (file)
--- a/lib/Analysis/LazyValueInfo.cpp
+++ b/lib/Analysis/LazyValueInfo.cpp
@@ -27,7 +27,6 @@
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/PatternMatch.h"
 #include "llvm/IR/ValueHandle.h"
-#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetLibraryInfo.h"
@@ -38,20 +37,6 @@ using namespace PatternMatch;
 
 #define DEBUG_TYPE "lazy-value-info"
 
-// Experimentally derived threshold for the number of basic blocks lowered for
-// lattice value overdefined.
-static cl::opt<unsigned>
-OverdefinedBBThreshold("lvi-overdefined-BB-threshold",
-    cl::init(1500), cl::Hidden,
-    cl::desc("Threshold of the number of basic blocks lowered for lattice value"
-             "'overdefined'."));
-
-// Experimentally derived threshold for additional lowering lattice values
-// overdefined per block.
-static cl::opt<unsigned>
-OverdefinedThreshold("lvi-overdefined-threshold", cl::init(10), cl::Hidden,
-    cl::desc("Threshold of lowering lattice value 'overdefined'."));
-
 char LazyValueInfo::ID = 0;
 INITIALIZE_PASS_BEGIN(LazyValueInfo, "lazy-value-info",
                 "Lazy Value Information Analysis", false, true)
@@ -363,9 +348,6 @@ namespace {
     const DataLayout *DL;
     /// An optional DT pointer.
     DominatorTree *DT;
-    /// A counter to record how many times Overdefined has been tried to be
-    /// lowered.
-    DenseMap<BasicBlock *, unsigned> LoweringOverdefinedTimes;
     
     friend struct LVIValueHandle;
     
@@ -498,9 +480,6 @@ void LazyValueInfoCache::eraseBlock(BasicBlock *BB) {
 }
 
 void LazyValueInfoCache::solve() {
-  // Reset the counter of lowering overdefined value.
-  LoweringOverdefinedTimes.clear();
-
   while (!BlockValueStack.empty()) {
     std::pair<BasicBlock*, Value*> &e = BlockValueStack.top();
     if (solveBlockValue(e.second, e.first)) {
@@ -559,7 +538,6 @@ bool LazyValueInfoCache::solveBlockValue(Value *Val, BasicBlock *BB) {
   // lattice value to overdefined, so that cycles will terminate and be
   // conservatively correct.
   BBLV.markOverdefined();
-  ++LoweringOverdefinedTimes[BB];
   
   Instruction *BBI = dyn_cast<Instruction>(Val);
   if (!BBI || BBI->getParent() != BB) {
@@ -976,6 +954,7 @@ bool LazyValueInfoCache::getEdgeValue(Value *Val, BasicBlock *BBFrom,
 
     // Try to intersect ranges of the BB and the constraint on the edge.
     LVILatticeVal InBlock = getBlockValue(Val, BBFrom);
+    mergeAssumeBlockValueConstantRange(Val, InBlock, BBFrom->getTerminator());
     mergeAssumeBlockValueConstantRange(Val, InBlock, CxtI);
     if (!InBlock.isConstantRange())
       return true;
@@ -993,6 +972,7 @@ bool LazyValueInfoCache::getEdgeValue(Value *Val, BasicBlock *BBFrom,
 
   // if we couldn't compute the value on the edge, use the value from the BB
   Result = getBlockValue(Val, BBFrom);
+  mergeAssumeBlockValueConstantRange(Val, Result, BBFrom->getTerminator());
   mergeAssumeBlockValueConstantRange(Val, Result, CxtI);
   return true;
 }