ARM64: Combine shifts and uses from different basic block to bit-extract instruction

[oota-llvm.git] / lib / Target / ARM64 / ARM64ISelLowering.cpp

diff --git a/lib/Target/ARM64/ARM64ISelLowering.cpp b/lib/Target/ARM64/ARM64ISelLowering.cpp
index efd979b5e2e8a269639e213663baa74f3ec251eb..ee498e65c71c5991903e9bd10c0ccedb7a2c8747 100644 (file)
--- a/lib/Target/ARM64/ARM64ISelLowering.cpp
+++ b/lib/Target/ARM64/ARM64ISelLowering.cpp
@@ -435,7 +435,11 @@ ARM64TargetLowering::ARM64TargetLowering(ARM64TargetMachine &TM)
 
   setMinFunctionAlignment(2);
 
+  setDivIsWellDefined(true);
+
   RequireStrictAlign = StrictAlign;
+
+  setHasExtractBitsInsn(true);
 }
 
 void ARM64TargetLowering::addTypeForNEON(EVT VT, EVT PromotedBitwiseVT) {
@@ -1313,10 +1317,16 @@ static SDValue LowerVectorFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
   if (VT.getSizeInBits() == InVT.getSizeInBits())
     return Op;
 
-  if (InVT == MVT::v2f64) {
+  if (InVT == MVT::v2f64 || InVT == MVT::v4f32) {
     SDLoc dl(Op);
-    SDValue Cv = DAG.getNode(Op.getOpcode(), dl, MVT::v2i64, Op.getOperand(0));
+    SDValue Cv =
+        DAG.getNode(Op.getOpcode(), dl, InVT.changeVectorElementTypeToInteger(),
+                    Op.getOperand(0));
     return DAG.getNode(ISD::TRUNCATE, dl, VT, Cv);
+  } else if (InVT == MVT::v2f32) {
+    SDLoc dl(Op);
+    SDValue Ext = DAG.getNode(ISD::FP_EXTEND, dl, MVT::v2f64, Op.getOperand(0));
+    return DAG.getNode(Op.getOpcode(), dl, VT, Ext);
   }
 
   // Type changing conversions are illegal.
@@ -3945,11 +3955,13 @@ static bool isEXTMask(ArrayRef<int> M, EVT VT, bool &ReverseEXT,
   unsigned NumElts = VT.getVectorNumElements();
   ReverseEXT = false;
 
-  // Assume that the first shuffle index is not UNDEF.  Fail if it is.
-  if (M[0] < 0)
-    return false;
-
-  Imm = M[0];
+  // Look for the first non-undef choice and count backwards from
+  // that. E.g. <-1, -1, 3, ...> means that an EXT must start at 3 - 2 = 1. This
+  // guarantees that at least one index is correct.
+  const int *FirstRealElt =
+      std::find_if(M.begin(), M.end(), [](int Elt) { return Elt >= 0; });
+  assert(FirstRealElt != M.end() && "Completely UNDEF shuffle? Why bother?");
+  Imm = *FirstRealElt - (FirstRealElt - M.begin());
 
   // If this is a VEXT shuffle, the immediate value is the index of the first
   // element.  The other shuffle indices must be the successive elements after