From af4550f8265885bdf99b3b3f129f3e6fd24a41e5 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Thu, 2 Jul 2009 01:23:32 +0000
Subject: [PATCH] Factor out ARM indexed load matching code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74681 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMISelDAGToDAG.cpp | 103 ++++++++++++++++-------------
 1 file changed, 57 insertions(+), 46 deletions(-)

diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index 15136909bf9..da327e4b080 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -111,11 +111,13 @@ public:
 #include "ARMGenDAGISel.inc"
 
 private:
-    /// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
-    /// inline asm expressions.
-    virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op,
-                                              char ConstraintCode,
-                                              std::vector<SDValue> &OutOps);
+  SDNode *SelectARMIndexedLoad(SDValue Op);
+
+  /// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
+  /// inline asm expressions.
+  virtual bool SelectInlineAsmMemoryOperand(const SDValue &Op,
+                                            char ConstraintCode,
+                                            std::vector<SDValue> &OutOps);
 };
 }
 
@@ -713,6 +715,53 @@ static inline SDValue getAL(SelectionDAG *CurDAG) {
   return CurDAG->getTargetConstant((uint64_t)ARMCC::AL, MVT::i32);
 }
 
+SDNode *ARMDAGToDAGISel::SelectARMIndexedLoad(SDValue Op) {
+  LoadSDNode *LD = cast<LoadSDNode>(Op);
+  ISD::MemIndexedMode AM = LD->getAddressingMode();
+  if (AM == ISD::UNINDEXED)
+    return NULL;
+
+  MVT LoadedVT = LD->getMemoryVT();
+  SDValue Offset, AMOpc;
+  bool isPre = (AM == ISD::PRE_INC) || (AM == ISD::PRE_DEC);
+  unsigned Opcode = 0;
+  bool Match = false;
+  if (LoadedVT == MVT::i32 &&
+      SelectAddrMode2Offset(Op, LD->getOffset(), Offset, AMOpc)) {
+    Opcode = isPre ? ARM::LDR_PRE : ARM::LDR_POST;
+    Match = true;
+  } else if (LoadedVT == MVT::i16 &&
+             SelectAddrMode3Offset(Op, LD->getOffset(), Offset, AMOpc)) {
+    Match = true;
+    Opcode = (LD->getExtensionType() == ISD::SEXTLOAD)
+      ? (isPre ? ARM::LDRSH_PRE : ARM::LDRSH_POST)
+      : (isPre ? ARM::LDRH_PRE : ARM::LDRH_POST);
+  } else if (LoadedVT == MVT::i8 || LoadedVT == MVT::i1) {
+    if (LD->getExtensionType() == ISD::SEXTLOAD) {
+      if (SelectAddrMode3Offset(Op, LD->getOffset(), Offset, AMOpc)) {
+        Match = true;
+        Opcode = isPre ? ARM::LDRSB_PRE : ARM::LDRSB_POST;
+      }
+    } else {
+      if (SelectAddrMode2Offset(Op, LD->getOffset(), Offset, AMOpc)) {
+        Match = true;
+        Opcode = isPre ? ARM::LDRB_PRE : ARM::LDRB_POST;
+      }
+    }
+  }
+
+  if (Match) {
+    SDValue Chain = LD->getChain();
+    SDValue Base = LD->getBasePtr();
+    SDValue Ops[]= { Base, Offset, AMOpc, getAL(CurDAG),
+                     CurDAG->getRegister(0, MVT::i32), Chain };
+    return CurDAG->getTargetNode(Opcode, Op.getDebugLoc(), MVT::i32, MVT::i32,
+                                 MVT::Other, Ops, 6);
+  }
+
+  return NULL;
+}
+
 
 SDNode *ARMDAGToDAGISel::Select(SDValue Op) {
   SDNode *N = Op.getNode();
@@ -843,47 +892,9 @@ SDNode *ARMDAGToDAGISel::Select(SDValue Op) {
     return CurDAG->getTargetNode(ARM::SMULL, dl, MVT::i32, MVT::i32, Ops, 5);
   }
   case ISD::LOAD: {
-    LoadSDNode *LD = cast<LoadSDNode>(Op);
-    ISD::MemIndexedMode AM = LD->getAddressingMode();
-    MVT LoadedVT = LD->getMemoryVT();
-    if (AM != ISD::UNINDEXED) {
-      SDValue Offset, AMOpc;
-      bool isPre = (AM == ISD::PRE_INC) || (AM == ISD::PRE_DEC);
-      unsigned Opcode = 0;
-      bool Match = false;
-      if (LoadedVT == MVT::i32 &&
-          SelectAddrMode2Offset(Op, LD->getOffset(), Offset, AMOpc)) {
-        Opcode = isPre ? ARM::LDR_PRE : ARM::LDR_POST;
-        Match = true;
-      } else if (LoadedVT == MVT::i16 &&
-                 SelectAddrMode3Offset(Op, LD->getOffset(), Offset, AMOpc)) {
-        Match = true;
-        Opcode = (LD->getExtensionType() == ISD::SEXTLOAD)
-          ? (isPre ? ARM::LDRSH_PRE : ARM::LDRSH_POST)
-          : (isPre ? ARM::LDRH_PRE : ARM::LDRH_POST);
-      } else if (LoadedVT == MVT::i8 || LoadedVT == MVT::i1) {
-        if (LD->getExtensionType() == ISD::SEXTLOAD) {
-          if (SelectAddrMode3Offset(Op, LD->getOffset(), Offset, AMOpc)) {
-            Match = true;
-            Opcode = isPre ? ARM::LDRSB_PRE : ARM::LDRSB_POST;
-          }
-        } else {
-          if (SelectAddrMode2Offset(Op, LD->getOffset(), Offset, AMOpc)) {
-            Match = true;
-            Opcode = isPre ? ARM::LDRB_PRE : ARM::LDRB_POST;
-          }
-        }
-      }
-
-      if (Match) {
-        SDValue Chain = LD->getChain();
-        SDValue Base = LD->getBasePtr();
-        SDValue Ops[]= { Base, Offset, AMOpc, getAL(CurDAG),
-                           CurDAG->getRegister(0, MVT::i32), Chain };
-        return CurDAG->getTargetNode(Opcode, dl, MVT::i32, MVT::i32,
-                                     MVT::Other, Ops, 6);
-      }
-    }
+    SDNode *ResNode = SelectARMIndexedLoad(Op);
+    if (ResNode)
+      return ResNode;
     // Other cases are autogenerated.
     break;
   }