Target override to allow CodeGenPrepare to sink address operands to intrinsics in the same way it current does for loads and stores

llvm-svn: 152666

llvm/include/llvm/Target/TargetLowering.h

@@ -41,6 +41,7 @@ namespace llvm {
   class FastISel;
   class FunctionLoweringInfo;
   class ImmutableCallSite;
+  class IntrinsicInst;
   class MachineBasicBlock;
   class MachineFunction;
   class MachineInstr;
@@ -1539,6 +1540,17 @@ public:
     AddrMode() : BaseGV(0), BaseOffs(0), HasBaseReg(false), Scale(0) {}
   };
 
+  /// GetAddrModeArguments - CodeGenPrepare sinks address calculations into the
+  /// same BB as Load/Store instructions reading the address.  This allows as
+  /// much computation as possible to be done in the address mode for that
+  /// operand.  This hook lets targets also pass back when this should be done
+  /// on intrinsics which load/store.
+  virtual bool GetAddrModeArguments(IntrinsicInst *I,
+                                    SmallVectorImpl<Value*> &Ops,
+                                    Type *&AccessTy) const {
+    return false;
+  }
+
   /// isLegalAddressingMode - Return true if the addressing mode represented by
   /// AM is legal for this target, for a load/store of the specified type.
   /// The type may be VoidTy, in which case only return true if the addressing

llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp

@@ -579,6 +579,15 @@ bool CodeGenPrepare::OptimizeCallInst(CallInst *CI) {
     return true;
   }
 
+  if (II && TLI) {
+    SmallVector<Value*, 2> PtrOps;
+    Type *AccessTy;
+    if (TLI->GetAddrModeArguments(II, PtrOps, AccessTy))
+      while (!PtrOps.empty())
+        if (OptimizeMemoryInst(II, PtrOps.pop_back_val(), AccessTy))
+          return true;
+  }
+
   // From here on out we're working with named functions.
   if (CI->getCalledFunction() == 0) return false;