From: Owen Anderson <resistor@mac.com>
Date: Wed, 27 Aug 2008 22:30:02 +0000 (+0000)
Subject: Add a helper method that will be used to support EXTRACT_SUBREG for selecting trunc... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=8970f00deff00ffce1f35cf00883357e1582daa1;p=oota-llvm.git

Add a helper method that will be used to support EXTRACT_SUBREG for selecting trunc's in fast-isel.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55439 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/CodeGen/FastISel.h b/include/llvm/CodeGen/FastISel.h
index f28739448df..fcd970b8404 100644
--- a/include/llvm/CodeGen/FastISel.h
+++ b/include/llvm/CodeGen/FastISel.h
@@ -193,6 +193,11 @@ protected:
                           const TargetRegisterClass *RC,
                           uint64_t Imm);
 
+  /// FastEmitInst_extractsubreg - Emit a MachineInstr for an extract_subreg
+  /// from a specified index of a superregister.
+  unsigned FastEmitInst_extractsubreg(const TargetRegisterClass *RC,
+                                      unsigned Op0, uint32_t Idx);
+
 private:
   unsigned getRegForValue(Value *V,
                           DenseMap<const Value*, unsigned> &ValueMap);
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 82eee56cd2b..2dd228249b3 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -586,3 +586,14 @@ unsigned FastISel::FastEmitInst_i(unsigned MachineInstOpcode,
   BuildMI(MBB, II, ResultReg).addImm(Imm);
   return ResultReg;
 }
+
+unsigned FastISel::FastEmitInst_extractsubreg(const TargetRegisterClass *RC,
+                                              unsigned Op0, uint32_t Idx) {
+  const TargetRegisterClass* SRC = *(RC->subregclasses_begin()+Idx-1);
+  
+  unsigned ResultReg = createResultReg(SRC);
+  const TargetInstrDesc &II = TII.get(TargetInstrInfo::EXTRACT_SUBREG);
+  
+  BuildMI(MBB, II, ResultReg).addReg(Op0);
+  return ResultReg;
+}