Allow TargetLowering::getRegClassFor() to be called on illegal types. Also

allow target to override it in order to map register classes to illegal
but synthesizable types. e.g. v4i64, v8i64 for ARM / NEON.

llvm-svn: 103854

1 files changed, 13 insertions, 7 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 529f7115f5b..9db641172d7 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -266,13 +266,6 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
     addQRTypeForNEON(MVT::v4i32);
     addQRTypeForNEON(MVT::v2i64);
 
-    // Map v4i64 to QQ registers but do not make the type legal for any
-    // operations. Similarly map v8i64 to QQQQ registers. v4i64 and v8i64 are
-    // only used for REG_SEQUENCE to load / store 4 to 8 consecutive
-    // D registers.
-    addRegisterClass(MVT::v4i64, ARM::QQPRRegisterClass);
-    addRegisterClass(MVT::v8i64, ARM::QQQQPRRegisterClass);
-
     // v2f64 is legal so that QR subregs can be extracted as f64 elements, but
     // neither Neon nor VFP support any arithmetic operations on it.
     setOperationAction(ISD::FADD, MVT::v2f64, Expand);
@@ -586,6 +579,19 @@ const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
   }
 }
 
+/// getRegClassFor - Return the register class that should be used for the
+/// specified value type.
+TargetRegisterClass *ARMTargetLowering::getRegClassFor(EVT VT) const {
+  // Map v4i64 to QQ registers but do not make the type legal. Similarly map
+  // v8i64 to QQQQ registers. v4i64 and v8i64 are only used for REG_SEQUENCE to
+  // load / store 4 to 8 consecutive D registers.
+  if (VT == MVT::v4i64)
+    return ARM::QQPRRegisterClass;
+  else if (VT == MVT::v8i64)
+    return ARM::QQQQPRRegisterClass;
+  return TargetLowering::getRegClassFor(VT);
+}
+
 /// getFunctionAlignment - Return the Log2 alignment of this function.
 unsigned ARMTargetLowering::getFunctionAlignment(const Function *F) const {
   return getTargetMachine().getSubtarget<ARMSubtarget>().isThumb() ? 0 : 1;