ARM: constrain Thumb LDRLIT pseudo-instructions to r0-r7.

[oota-llvm.git] / lib / Target / ARM / ARMTargetTransformInfo.cpp

diff --git a/lib/Target/ARM/ARMTargetTransformInfo.cpp b/lib/Target/ARM/ARMTargetTransformInfo.cpp
index 9dc1cd1feeb881499bdb5cb7d4062200b8f72c2d..2f2da73162cecf1c3ee824b9651ca9d53d649fbd 100644 (file)
--- a/lib/Target/ARM/ARMTargetTransformInfo.cpp
+++ b/lib/Target/ARM/ARMTargetTransformInfo.cpp
@@ -19,8 +19,8 @@
 #include "ARMTargetMachine.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/Support/Debug.h"
-#include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/CostTable.h"
+#include "llvm/Target/TargetLowering.h"
 using namespace llvm;
 
 // Declare the pass initialization routine locally as target-specific passes
@@ -129,6 +129,9 @@ public:
   unsigned getArithmeticInstrCost(unsigned Opcode, Type *Ty,
                                   OperandValueKind Op1Info = OK_AnyValue,
                                   OperandValueKind Op2Info = OK_AnyValue) const;
+
+  unsigned getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
+                           unsigned AddressSpace) const;
   /// @}
 };
 
@@ -523,8 +526,32 @@ unsigned ARMTTI::getArithmeticInstrCost(unsigned Opcode, Type *Ty, OperandValueK
   if (Idx != -1)
     return LT.first * CostTbl[Idx].Cost;
 
-
-  return TargetTransformInfo::getArithmeticInstrCost(Opcode, Ty, Op1Info,
-                                                     Op2Info);
+  unsigned Cost =
+      TargetTransformInfo::getArithmeticInstrCost(Opcode, Ty, Op1Info, Op2Info);
+
+  // This is somewhat of a hack. The problem that we are facing is that SROA
+  // creates a sequence of shift, and, or instructions to construct values.
+  // These sequences are recognized by the ISel and have zero-cost. Not so for
+  // the vectorized code. Because we have support for v2i64 but not i64 those
+  // sequences look particularily beneficial to vectorize.
+  // To work around this we increase the cost of v2i64 operations to make them
+  // seem less beneficial.
+  if (LT.second == MVT::v2i64 &&
+      Op2Info == TargetTransformInfo::OK_UniformConstantValue)
+    Cost += 4;
+
+  return Cost;
 }
 
+unsigned ARMTTI::getMemoryOpCost(unsigned Opcode, Type *Src, unsigned Alignment,
+                                 unsigned AddressSpace) const {
+  std::pair<unsigned, MVT> LT = TLI->getTypeLegalizationCost(Src);
+
+  if (Src->isVectorTy() && Alignment != 16 &&
+      Src->getVectorElementType()->isDoubleTy()) {
+    // Unaligned loads/stores are extremely inefficient.
+    // We need 4 uops for vst.1/vld.1 vs 1uop for vldr/vstr.
+    return LT.first * 4;
+  }
+  return LT.first;
+}