Add codegen support for FP16 on ARM

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98502 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 54 insertions, 12 deletions

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 3dd0313f4b..d37a36eb7b 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -426,12 +426,20 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
   setOperationAction(ISD::FPOW,      MVT::f64, Expand);
   setOperationAction(ISD::FPOW,      MVT::f32, Expand);
 
-  // int <-> fp are custom expanded into bit_convert + ARMISD ops.
-  if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only()) {
-    setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
-    setOperationAction(ISD::UINT_TO_FP, MVT::i32, Custom);
-    setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
-    setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
+  // Various VFP goodness
+  if (!UseSoftFloat && !Subtarget->isThumb1Only()) {
+    // int <-> fp are custom expanded into bit_convert + ARMISD ops.
+    if (Subtarget->hasVFP2()) {
+      setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
+      setOperationAction(ISD::UINT_TO_FP, MVT::i32, Custom);
+      setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
+      setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
+    }
+    // Special handling for half-precision FP.
+    if (Subtarget->hasVFP3()) {
+      setOperationAction(ISD::FP16_TO_FP32, MVT::f32, Custom);
+      setOperationAction(ISD::FP32_TO_FP16, MVT::i32, Custom);
+    }
   }
 
   // We have target-specific dag combine patterns for the following nodes:
@@ -491,6 +499,8 @@ const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
   case ARMISD::FTOUI:         return "ARMISD::FTOUI";
   case ARMISD::SITOF:         return "ARMISD::SITOF";
   case ARMISD::UITOF:         return "ARMISD::UITOF";
+  case ARMISD::F16_TO_F32:    return "ARMISD::F16_TO_F32";
+  case ARMISD::F32_TO_F16:    return "ARMISD::F32_TO_F16";
 
   case ARMISD::SRL_FLAG:      return "ARMISD::SRL_FLAG";
   case ARMISD::SRA_FLAG:      return "ARMISD::SRA_FLAG";
@@ -1972,8 +1982,21 @@ SDValue ARMTargetLowering::LowerBR_JT(SDValue Op, SelectionDAG &DAG) {
 
 static SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
   DebugLoc dl = Op.getDebugLoc();
-  unsigned Opc =
-    Op.getOpcode() == ISD::FP_TO_SINT ? ARMISD::FTOSI : ARMISD::FTOUI;
+  unsigned Opc;
+
+  switch (Op.getOpcode()) {
+  default:
+    assert(0 && "Invalid opcode!");
+  case ISD::FP32_TO_FP16:
+    Opc = ARMISD::F32_TO_F16;
+    break;
+  case ISD::FP_TO_SINT:
+    Opc = ARMISD::FTOSI;
+    break;
+  case ISD::FP_TO_UINT:
+    Opc = ARMISD::FTOUI;
+    break;
+  }
   Op = DAG.getNode(Opc, dl, MVT::f32, Op.getOperand(0));
   return DAG.getNode(ISD::BIT_CONVERT, dl, MVT::i32, Op);
 }
@@ -1981,8 +2004,21 @@ static SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
 static SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
   EVT VT = Op.getValueType();
   DebugLoc dl = Op.getDebugLoc();
-  unsigned Opc =
-    Op.getOpcode() == ISD::SINT_TO_FP ? ARMISD::SITOF : ARMISD::UITOF;
+  unsigned Opc;
+
+  switch (Op.getOpcode()) {
+  default:
+    assert(0 && "Invalid opcode!");
+  case ISD::FP16_TO_FP32:
+    Opc = ARMISD::F16_TO_F32;
+    break;
+  case ISD::SINT_TO_FP:
+    Opc = ARMISD::SITOF;
+    break;
+  case ISD::UINT_TO_FP:
+    Opc = ARMISD::UITOF;
+    break;
+  }
 
   Op = DAG.getNode(ISD::BIT_CONVERT, dl, MVT::f32, Op.getOperand(0));
   return DAG.getNode(Opc, dl, VT, Op);
@@ -3042,8 +3078,10 @@ SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
   case ISD::VASTART:       return LowerVASTART(Op, DAG, VarArgsFrameIndex);
   case ISD::MEMBARRIER:    return LowerMEMBARRIER(Op, DAG, Subtarget);
+  case ISD::FP16_TO_FP32:
   case ISD::SINT_TO_FP:
   case ISD::UINT_TO_FP:    return LowerINT_TO_FP(Op, DAG);
+  case ISD::FP32_TO_FP16:
   case ISD::FP_TO_SINT:
   case ISD::FP_TO_UINT:    return LowerFP_TO_INT(Op, DAG);
   case ISD::FCOPYSIGN:     return LowerFCOPYSIGN(Op, DAG);
diff --git a/lib/Target/ARM/ARMISelLowering.h b/lib/Target/ARM/ARMISelLowering.h
index f8f8adc70a..d7b2ba3b5c 100644
--- a/lib/Target/ARM/ARMISelLowering.h
+++ b/lib/Target/ARM/ARMISelLowering.h
@@ -59,6 +59,8 @@ namespace llvm {
       FTOUI,        // FP to uint within a FP register.
       SITOF,        // sint to FP within a FP register.
       UITOF,        // uint to FP within a FP register.
+      F16_TO_F32,   // Half FP to single FP within a FP register.
+      F32_TO_F16,   // Single FP to half FP within a FP register.
 
       SRL_FLAG,     // V,Flag = srl_flag X -> srl X, 1 + save carry out.
       SRA_FLAG,     // V,Flag = sra_flag X -> sra X, 1 + save carry out.
diff --git a/lib/Target/ARM/ARMInstrVFP.td b/lib/Target/ARM/ARMInstrVFP.td
index 44c02b4e4f..4d1d48a113 100644
--- a/lib/Target/ARM/ARMInstrVFP.td
+++ b/lib/Target/ARM/ARMInstrVFP.td
@@ -25,6 +25,8 @@ def arm_ftoui  : SDNode<"ARMISD::FTOUI",  SDT_FTOI>;
 def arm_ftosi  : SDNode<"ARMISD::FTOSI",  SDT_FTOI>;
 def arm_sitof  : SDNode<"ARMISD::SITOF",  SDT_ITOF>;
 def arm_uitof  : SDNode<"ARMISD::UITOF",  SDT_ITOF>;
+def arm_f16tof32 : SDNode<"ARMISD::F16_TO_F32", SDT_ITOF>;
+def arm_f32tof16 : SDNode<"ARMISD::F32_TO_F16", SDT_FTOI>;
 def arm_fmstat : SDNode<"ARMISD::FMSTAT", SDTNone, [SDNPInFlag,SDNPOutFlag]>;
 def arm_cmpfp  : SDNode<"ARMISD::CMPFP",  SDT_ARMCmp, [SDNPOutFlag]>;
 def arm_cmpfp0 : SDNode<"ARMISD::CMPFPw0",SDT_CMPFP0, [SDNPOutFlag]>;
@@ -257,11 +259,11 @@ def VCVTSD : VFPAI<(outs SPR:$dst), (ins DPR:$a), VFPUnaryFrm,
 
 def VCVTBSH : ASuI<0b11101, 0b11, 0b0010, 0b01, 0, (outs SPR:$dst), (ins SPR:$a),
                  /* FIXME */ IIC_fpCVTDS, "vcvtb", ".f32.f16\t$dst, $a",
-                 [/* For disassembly only; pattern left blank */]>;
+                 [(set SPR:$dst, (f32 (arm_f32tof16 SPR:$a)))]>;
 
 def VCVTBHS : ASuI<0b11101, 0b11, 0b0011, 0b01, 0, (outs SPR:$dst), (ins SPR:$a),
                  /* FIXME */ IIC_fpCVTDS, "vcvtb", ".f16.f32\t$dst, $a",
-                 [/* For disassembly only; pattern left blank */]>;
+                 [(set SPR:$dst, (arm_f16tof32 SPR:$a))]>;
 
 def VCVTTSH : ASuI<0b11101, 0b11, 0b0010, 0b11, 0, (outs SPR:$dst), (ins SPR:$a),
                  /* FIXME */ IIC_fpCVTDS, "vcvtt", ".f32.f16\t$dst, $a",