[X86] Cleanup convertIntLogicToFPLogic a little. NFCI

-Use early returns to reduce indentation
-Replace multipe ifs with a switch.
-Replace an assert with an llvm_unreachable default in the switch.
-Check that the FP type we're going to use for the
 X86ISD::FAND/FOR/FXOR is legal rather than checking that the
 integer type matches the width of a legal scalar fp type. This all
 runs after legalization so it shouldn't really matter, but making
 sure we're using a valid type in the X86ISD node is really
 whats important.

llvm-svn: 362565

1 files changed, 24 insertions, 23 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 6bdd448f5b8..64585c8de0a 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -37667,34 +37667,35 @@ static SDValue PromoteMaskArithmetic(SDNode *N, SelectionDAG &DAG,
 /// unnecessary moves from SSE to integer registers.
 static SDValue convertIntLogicToFPLogic(SDNode *N, SelectionDAG &DAG,
                                         const X86Subtarget &Subtarget) {
-  unsigned FPOpcode = ISD::DELETED_NODE;
-  if (N->getOpcode() == ISD::AND)
-    FPOpcode = X86ISD::FAND;
-  else if (N->getOpcode() == ISD::OR)
-    FPOpcode = X86ISD::FOR;
-  else if (N->getOpcode() == ISD::XOR)
-    FPOpcode = X86ISD::FXOR;
-
-  assert(FPOpcode != ISD::DELETED_NODE &&
-         "Unexpected input node for FP logic conversion");
-
   EVT VT = N->getValueType(0);
   SDValue N0 = N->getOperand(0);
   SDValue N1 = N->getOperand(1);
   SDLoc DL(N);
-  if (N0.getOpcode() == ISD::BITCAST && N1.getOpcode() == ISD::BITCAST &&
-      ((Subtarget.hasSSE1() && VT == MVT::i32) ||
-       (Subtarget.hasSSE2() && VT == MVT::i64))) {
-    SDValue N00 = N0.getOperand(0);
-    SDValue N10 = N1.getOperand(0);
-    EVT N00Type = N00.getValueType();
-    EVT N10Type = N10.getValueType();
-    if (N00Type.isFloatingPoint() && N10Type.isFloatingPoint()) {
-      SDValue FPLogic = DAG.getNode(FPOpcode, DL, N00Type, N00, N10);
-      return DAG.getBitcast(VT, FPLogic);
-    }
+
+  if (N0.getOpcode() != ISD::BITCAST || N1.getOpcode() != ISD::BITCAST)
+    return SDValue();
+
+  SDValue N00 = N0.getOperand(0);
+  SDValue N10 = N1.getOperand(0);
+  EVT N00Type = N00.getValueType();
+  EVT N10Type = N10.getValueType();
+
+  // Ensure that both types are the same and are legal scalar fp types.
+  if (N00Type != N10Type ||
+      !((Subtarget.hasSSE1() && N00Type == MVT::f32) ||
+        (Subtarget.hasSSE2() && N00Type == MVT::f64)))
+    return SDValue();
+
+  unsigned FPOpcode;
+  switch (N->getOpcode()) {
+  default: llvm_unreachable("Unexpected input node for FP logic conversion");
+  case ISD::AND: FPOpcode = X86ISD::FAND; break;
+  case ISD::OR:  FPOpcode = X86ISD::FOR;  break;
+  case ISD::XOR: FPOpcode = X86ISD::FXOR; break;
   }
-  return SDValue();
+
+  SDValue FPLogic = DAG.getNode(FPOpcode, DL, N00Type, N00, N10);
+  return DAG.getBitcast(VT, FPLogic);
 }
 
 /// If this is a zero/all-bits result that is bitwise-anded with a low bits