From ce07b5458d87d5f5ad306a1d86785537e9a3ce0c Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@apple.com>
Date: Thu, 9 Sep 2010 20:26:31 +0000
Subject: [PATCH] Add FPTrunc, fix some bugs where I forgot to update the value
 map.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113533 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMFastISel.cpp | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index 7af9fc5291c..c7673ecc60b 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -115,6 +115,7 @@ class ARMFastISel : public FastISel {
     virtual bool ARMSelectBranch(const Instruction *I);
     virtual bool ARMSelectCmp(const Instruction *I);
     virtual bool ARMSelectFPExt(const Instruction *I);
+    virtual bool ARMSelectFPTrunc(const Instruction *I);
     virtual bool ARMSelectBinaryOp(const Instruction *I, unsigned ISDOpcode);
     virtual bool ARMSelectSIToFP(const Instruction *I);
     virtual bool ARMSelectFPToSI(const Instruction *I);
@@ -545,7 +546,6 @@ bool ARMFastISel::ARMEmitLoad(EVT VT, unsigned &ResultReg,
     AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
                             TII.get(Opc), ResultReg)
                     .addReg(Reg).addReg(0).addImm(Offset));
-
   return true;
 }
 
@@ -630,7 +630,6 @@ bool ARMFastISel::ARMSelectStore(const Instruction *I) {
   if (!ARMEmitStore(VT, SrcReg, Reg, Offset /* 0 */)) return false;
 
   return false;
-
 }
 
 bool ARMFastISel::ARMSelectLoad(const Instruction *I) {
@@ -720,6 +719,8 @@ bool ARMFastISel::ARMSelectCmp(const Instruction *I) {
   if (isFloat)
     AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
                             TII.get(ARM::FMSTAT)));
+
+  // TODO: How to update the value map when there's no result reg?
   return true;
 }
 
@@ -736,6 +737,26 @@ bool ARMFastISel::ARMSelectFPExt(const Instruction *I) {
 
   unsigned Result = createResultReg(ARM::DPRRegisterClass);
 
+  AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
+                          TII.get(ARM::VCVTSD), Result)
+                  .addReg(Op));
+  UpdateValueMap(I, Result);
+  return true;
+}
+
+bool ARMFastISel::ARMSelectFPTrunc(const Instruction *I) {
+  // Make sure we have VFP and that we're truncating double to float.
+  if (!Subtarget->hasVFP2()) return false;
+
+  Value *V = I->getOperand(0);
+  if (!I->getType()->isFloatTy() ||
+      !V->getType()->isDoubleTy()) return false;
+
+  unsigned Op = getRegForValue(V);
+  if (Op == 0) return false;
+
+  unsigned Result = createResultReg(ARM::SPRRegisterClass);
+
   AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
                           TII.get(ARM::VCVTDS), Result)
                   .addReg(Op));
@@ -764,6 +785,7 @@ bool ARMFastISel::ARMSelectSIToFP(const Instruction *I) {
   AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc),
                           ResultReg)
                   .addReg(Op));
+  UpdateValueMap(I, ResultReg);
   return true;
 }
 
@@ -789,6 +811,7 @@ bool ARMFastISel::ARMSelectFPToSI(const Instruction *I) {
   AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc),
                           ResultReg)
                   .addReg(Op));
+  UpdateValueMap(I, ResultReg);
   return true;
 }
 
@@ -829,6 +852,7 @@ bool ARMFastISel::ARMSelectBinaryOp(const Instruction *I, unsigned ISDOpcode) {
   AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
                           TII.get(Opc), ResultReg)
                   .addReg(Op1).addReg(Op2));
+  UpdateValueMap(I, ResultReg);
   return true;
 }
 
@@ -849,6 +873,8 @@ bool ARMFastISel::TargetSelectInstruction(const Instruction *I) {
       return ARMSelectCmp(I);
     case Instruction::FPExt:
       return ARMSelectFPExt(I);
+    case Instruction::FPTrunc:
+      return ARMSelectFPTrunc(I);
     case Instruction::SIToFP:
       return ARMSelectSIToFP(I);
     case Instruction::FPToSI: