Do not share a single unknown val# for all the live ranges merged into a physical sub-register live interval. When coalescer is merging in clobbered virtaul register live interval into a physical register live interval, give each virtual register val# a separate val# in the physical register live interval. Otherwise, the coalescer would have lost track of the definitions information it needs to make correct coalescing decisions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70026 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 19 deletions

diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp
index 68d9ad4..39d6611 100644
--- a/lib/CodeGen/LiveInterval.cpp
+++ b/lib/CodeGen/LiveInterval.cpp
@@ -19,6 +19,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/LiveInterval.h"
+#include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Streams.h"
@@ -567,20 +568,6 @@ void LiveInterval::MergeValueInAsValue(const LiveInterval &RHS,
   }
 }
 
-VNInfo *LiveInterval::getUnknownValNo(BumpPtrAllocator &VNInfoAllocator) {
-  unsigned i = getNumValNums();
-  if (i) {
-    do {
-      --i;
-      VNInfo *VNI = getValNumInfo(i);
-      if (VNI->def == ~0U && !VNI->copy &&
-          !VNI->hasPHIKill && !VNI->redefByEC && VNI->kills.empty())
-        return VNI;
-    } while (i != 0);
-  }
-  return getNextValue(~0U, 0, VNInfoAllocator);
-}
-
 
 /// MergeInClobberRanges - For any live ranges that are not defined in the
 /// current interval, but are defined in the Clobbers interval, mark them
@@ -589,12 +576,19 @@ void LiveInterval::MergeInClobberRanges(const LiveInterval &Clobbers,
                                         BumpPtrAllocator &VNInfoAllocator) {
   if (Clobbers.empty()) return;
   
-  // Find a value # to use for the clobber ranges.  If there is already a value#
-  // for unknown values, use it.
-  VNInfo *ClobberValNo = getUnknownValNo(VNInfoAllocator);
-  
+  DenseMap<VNInfo*, VNInfo*> ValNoMaps;
   iterator IP = begin();
   for (const_iterator I = Clobbers.begin(), E = Clobbers.end(); I != E; ++I) {
+    // For every val# in the Clobbers interval, create a new "unknown" val#.
+    VNInfo *ClobberValNo = 0;
+    DenseMap<VNInfo*, VNInfo*>::iterator VI = ValNoMaps.find(I->valno);
+    if (VI != ValNoMaps.end())
+      ClobberValNo = VI->second;
+    else {
+      ClobberValNo = getNextValue(~0U, 0, VNInfoAllocator);
+      ValNoMaps.insert(std::make_pair(I->valno, ClobberValNo));
+    }
+
     bool Done = false;
     unsigned Start = I->start, End = I->end;
     // If a clobber range starts before an existing range and ends after
@@ -637,7 +631,7 @@ void LiveInterval::MergeInClobberRange(unsigned Start, unsigned End,
                                        BumpPtrAllocator &VNInfoAllocator) {
   // Find a value # to use for the clobber ranges.  If there is already a value#
   // for unknown values, use it.
-  VNInfo *ClobberValNo = getUnknownValNo(VNInfoAllocator);
+  VNInfo *ClobberValNo = getNextValue(~0U, 0, VNInfoAllocator);
   
   iterator IP = begin();
   IP = std::upper_bound(IP, end(), Start);