[ARM] FP16 VSEL codegen

This is a follow up of rL327695 to instruction select more variants of VSELGT
and VSELGE, for which it is necessary to custom lower SELECT.

More work is required in this area, which will be addressed soon:
- more variants need to be regression tested, but this depends on the next point.
- first LowerConstantFP need to be adjusted for fp16 values.

Differential Revision: https://reviews.llvm.org/D45205

llvm-svn: 329788

1 files changed, 10 insertions, 4 deletions

diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index b5f72de1135..7f0222019f2 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -1047,16 +1047,19 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
     setLibcallName(RTLIB::UNWIND_RESUME, "_Unwind_SjLj_Resume");
 
   setOperationAction(ISD::SETCC,     MVT::i32, Expand);
-  setOperationAction(ISD::SETCC,     MVT::f16, Expand);
   setOperationAction(ISD::SETCC,     MVT::f32, Expand);
   setOperationAction(ISD::SETCC,     MVT::f64, Expand);
   setOperationAction(ISD::SELECT,    MVT::i32, Custom);
   setOperationAction(ISD::SELECT,    MVT::f32, Custom);
   setOperationAction(ISD::SELECT,    MVT::f64, Custom);
-  setOperationAction(ISD::SELECT_CC, MVT::f16, Custom);
   setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
   setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
   setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
+  if (Subtarget->hasFullFP16()) {
+    setOperationAction(ISD::SETCC,     MVT::f16, Expand);
+    setOperationAction(ISD::SELECT,    MVT::f16, Custom);
+    setOperationAction(ISD::SELECT_CC, MVT::f16, Custom);
+  }
 
   // Thumb-1 cannot currently select ARMISD::SUBE.
   if (!Subtarget->isThumb1Only())
@@ -1064,7 +1067,8 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
 
   setOperationAction(ISD::BRCOND,    MVT::Other, Custom);
   setOperationAction(ISD::BR_CC,     MVT::i32,   Custom);
-  setOperationAction(ISD::BR_CC,     MVT::f16,   Custom);
+  if (Subtarget->hasFullFP16())
+      setOperationAction(ISD::BR_CC, MVT::f16,   Custom);
   setOperationAction(ISD::BR_CC,     MVT::f32,   Custom);
   setOperationAction(ISD::BR_CC,     MVT::f64,   Custom);
   setOperationAction(ISD::BR_JT,     MVT::Other, Custom);
@@ -4522,7 +4526,9 @@ SDValue ARMTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const {
   // Normalize the fp compare. If RHS is zero we keep it there so we match
   // CMPFPw0 instead of CMPFP.
   if (Subtarget->hasFPARMv8() && !isFloatingPointZero(RHS) &&
-    (TrueVal.getValueType() == MVT::f32 || TrueVal.getValueType() == MVT::f64)) {
+     (TrueVal.getValueType() == MVT::f16 ||
+      TrueVal.getValueType() == MVT::f32 ||
+      TrueVal.getValueType() == MVT::f64)) {
     bool swpCmpOps = false;
     bool swpVselOps = false;
     checkVSELConstraints(CC, CondCode, swpCmpOps, swpVselOps);