[llvm-commits] [llvm] r52310 - in /llvm/trunk: include/llvm/CodeGen/ValueTypes.h lib/CodeGen/SelectionDAG/DAGCombiner.cpp

[Duncan Sands]

Author: baldrick
Date: Mon Jun 16 03:14:38 2008
New Revision: 52310

URL: http://llvm.org/viewvc/llvm-project?rev=52310&view=rev
Log:
Allow these transforms for types like i256 while
still excluding types like i1 (not byte sized)
and i120 (loading an i120 requires loading an i64,
an i32, an i16 and an i8, which is expensive). 

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

Modified: llvm/trunk/include/llvm/CodeGen/ValueTypes.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/ValueTypes.h?rev=52310&r1=52309&r2=52310&view=diff

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/ValueTypes.h (original)
+++ llvm/trunk/include/llvm/CodeGen/ValueTypes.h Mon Jun 16 03:14:38 2008
@@ -266,6 +266,12 @@
       return (getSizeInBits() & 7) == 0;
     }
 
+    /// isRound - Return true if the size is a power-of-two number of bytes.
+    inline bool isRound() const {
+      unsigned BitSize = getSizeInBits();
+      return BitSize >= 8 && !(BitSize & (BitSize - 1));
+    }
+
     /// bitsGT - Return true if this has more bits than VT.
     inline bool bitsGT(MVT VT) const {
       return getSizeInBits() > VT.getSizeInBits();

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=52310&r1=52309&r2=52310&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon Jun 16 03:14:38 2008
@@ -1787,10 +1787,9 @@
         EVT = MVT::getIntegerVT(ActiveBits);
 
       MVT LoadedVT = LN0->getMemoryVT();
-      // Do not generate loads of extended integer types since these can be
-      // expensive (and would be wrong if the type is not byte sized).
-      if (EVT != MVT::Other && LoadedVT.bitsGT(EVT) && EVT.isSimple() &&
-          EVT.isByteSized() && // Exclude MVT::i1, which is simple.
+      // Do not generate loads of non-round integer types since these can
+      // be expensive (and would be wrong if the type is not byte sized).
+      if (EVT != MVT::Other && LoadedVT.bitsGT(EVT) && EVT.isRound() &&
           (!AfterLegalize || TLI.isLoadXLegal(ISD::ZEXTLOAD, EVT))) {
         MVT PtrType = N0.getOperand(1).getValueType();
         // For big endian targets, we need to add an offset to the pointer to
@@ -3187,10 +3186,9 @@
     }
   }
 
-  // Do not generate loads of extended integer types since these can be
-  // expensive (and would be wrong if the type is not byte sized).
-  if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() && VT.isSimple() &&
-      VT.isByteSized() && // Exclude MVT::i1, which is simple.
+  // Do not generate loads of non-round integer types since these can
+  // be expensive (and would be wrong if the type is not byte sized).
+  if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() && VT.isRound() &&
       // Do not change the width of a volatile load.
       !cast<LoadSDNode>(N0)->isVolatile()) {
     assert(N0.getValueType().getSizeInBits() > EVTBits &&