[llvm-commits] [llvm] r43934 - in /llvm/trunk: include/llvm/CodeGen/ValueTypes.h lib/CodeGen/SelectionDAG/DAGCombiner.cpp lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp

[Duncan Sands]

Author: baldrick
Date: Fri Nov  9 02:57:19 2007
New Revision: 43934

URL: http://llvm.org/viewvc/llvm-project?rev=43934&view=rev
Log:
Fix some load/store logic that would be wrong for
apints on big-endian machines if the bitwidth is
not a multiple of 8.  Introduce a new helper,
MVT::getStoreSizeInBits, and use it.

Modified:
    llvm/trunk/include/llvm/CodeGen/ValueTypes.h
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp

Modified: llvm/trunk/include/llvm/CodeGen/ValueTypes.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/ValueTypes.h?rev=43934&r1=43933&r2=43934&view=diff

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/ValueTypes.h (original)
+++ llvm/trunk/include/llvm/CodeGen/ValueTypes.h Fri Nov  9 02:57:19 2007
@@ -243,6 +243,13 @@
     }
   }
 
+  /// MVT::getStoreSizeInBits - Return the number of bits overwritten by a
+  /// store of the specified value type.
+  ///
+  static inline unsigned getStoreSizeInBits(ValueType VT) {
+    return (getSizeInBits(VT) + 7)/8*8;
+  }
+
   /// MVT::getIntegerType - Returns the ValueType that represents an integer
   /// with the given number of bits.
   ///

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=43934&r1=43933&r2=43934&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Fri Nov  9 02:57:19 2007
@@ -1713,8 +1713,9 @@
         // For big endian targets, we need to add an offset to the pointer to
         // load the correct bytes.  For little endian systems, we merely need to
         // read fewer bytes from the same pointer.
-        unsigned PtrOff =
-          (MVT::getSizeInBits(LoadedVT) - MVT::getSizeInBits(EVT)) / 8;
+        unsigned LVTStoreBytes = MVT::getStoreSizeInBits(LoadedVT)/8;
+        unsigned EVTStoreBytes = MVT::getStoreSizeInBits(EVT)/8;
+        unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
         unsigned Alignment = LN0->getAlignment();
         SDOperand NewPtr = LN0->getBasePtr();
         if (!TLI.isLittleEndian()) {
@@ -2991,8 +2992,11 @@
     MVT::ValueType PtrType = N0.getOperand(1).getValueType();
     // For big endian targets, we need to adjust the offset to the pointer to
     // load the correct bytes.
-    if (!TLI.isLittleEndian())
-      ShAmt = MVT::getSizeInBits(N0.getValueType()) - ShAmt - EVTBits;
+    if (!TLI.isLittleEndian()) {
+      unsigned LVTStoreBits = MVT::getStoreSizeInBits(N0.getValueType());
+      unsigned EVTStoreBits = MVT::getStoreSizeInBits(EVT);
+      ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
+    }
     uint64_t PtrOff =  ShAmt / 8;
     unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
     SDOperand NewPtr = DAG.getNode(ISD::ADD, PtrType, LN0->getBasePtr(),

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp?rev=43934&r1=43933&r2=43934&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAGTypes.cpp Fri Nov  9 02:57:19 2007
@@ -1036,7 +1036,7 @@
     // Big-endian - high bits are at low addresses.  Favor aligned loads at
     // the cost of some bit-fiddling.
     MVT::ValueType EVT = N->getLoadedVT();
-    unsigned EBytes = (MVT::getSizeInBits(EVT) + 7)/8;
+    unsigned EBytes = MVT::getStoreSizeInBits(EVT)/8;
     unsigned IncrementSize = MVT::getSizeInBits(NVT)/8;
     unsigned ExcessBits = (EBytes - IncrementSize)*8;
 
@@ -2069,7 +2069,7 @@
     GetExpandedOp(N->getValue(), Lo, Hi);
 
     MVT::ValueType EVT = N->getStoredVT();
-    unsigned EBytes = (MVT::getSizeInBits(EVT) + 7)/8;
+    unsigned EBytes = MVT::getStoreSizeInBits(EVT)/8;
     unsigned IncrementSize = MVT::getSizeInBits(NVT)/8;
     unsigned ExcessBits = (EBytes - IncrementSize)*8;
     MVT::ValueType HiVT =