[llvm-commits] CVS: llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp

[Chris Lattner]

Changes in directory llvm-poolalloc/lib/PoolAllocate:

PointerCompress.cpp updated: 1.23 -> 1.24
---
Log message:

'load null' does not really make any sense, but we have to support it 
correctly.  Particularly since bugpoint is fond of producing these when
reducing testcases.


---
Diffs of the changes:  (+9 -1)

 PointerCompress.cpp |   10 +++++++++-
 1 files changed, 9 insertions(+), 1 deletion(-)


Index: llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp
diff -u llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp:1.23 llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp:1.24
--- llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp:1.23	Thu Feb 24 13:22:32 2005
+++ llvm-poolalloc/lib/PoolAllocate/PointerCompress.cpp	Thu Feb 24 13:35:56 2005
@@ -353,6 +353,8 @@
     Value *getTransformedValue(Value *V) {
       if (isa<ConstantPointerNull>(V))                // null -> uint 0
         return Constant::getNullValue(SCALARUINTTYPE);
+      if (isa<UndefValue>(V))                // undef -> uint undef
+        return UndefValue::get(SCALARUINTTYPE);
 
       assert(getNodeIfCompressed(V) && "Value is not compressed!");
       Value *&RV = OldToNewValueMap[V];
@@ -582,7 +584,13 @@
 }
 
 void InstructionRewriter::visitLoadInst(LoadInst &LI) {
-  if (isa<ConstantPointerNull>(LI.getOperand(0))) return; // load null ??
+  if (isa<ConstantPointerNull>(LI.getOperand(0))) { // load null ??
+    // Load null doesn't make any sense, but if the result is a pointer into a
+    // compressed pool, we have to transform it.
+    if (isa<PointerType>(LI.getType()) && getPoolInfo(&LI))
+      setTransformedValue(LI, UndefValue::get(SCALARUINTTYPE));
+    return;
+  }
 
   const CompressedPoolInfo *SrcPI = getPoolInfo(LI.getOperand(0));
   if (SrcPI == 0) {