From b01fad6d19ac83f9c97eee16af438507383f36d8 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Mon, 12 Mar 2007 23:30:29 +0000
Subject: [PATCH] Updated TargetLowering LSR addressing mode hooks for ARM and
 Thumb.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35075 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/ARM/ARMISelLowering.cpp | 81 ++++++++++++++++++++++++++++--
 lib/Target/ARM/ARMISelLowering.h   | 15 ++++--
 2 files changed, 88 insertions(+), 8 deletions(-)

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 55f5c976ce7..2038a3e3aef 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -30,6 +30,7 @@
 #include "llvm/CodeGen/SSARegMap.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/ADT/VectorExtras.h"
+#include "llvm/Support/MathExtras.h"
 using namespace llvm;
 
 ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
@@ -1268,17 +1269,87 @@ ARMTargetLowering::InsertAtEndOfBasicBlock(MachineInstr *MI,
 //                           ARM Optimization Hooks
 //===----------------------------------------------------------------------===//
 
-/// isLegalAddressImmediate - Return true if the integer value or
-/// GlobalValue can be used as the offset of the target addressing mode.
-bool ARMTargetLowering::isLegalAddressImmediate(int64_t V) const {
-  // ARM allows a 12-bit immediate field.
-  return V == V & ((1LL << 12) - 1);
+/// isLegalAddressImmediate - Return true if the integer value can be used
+/// as the offset of the target addressing mode for load / store of the
+/// given type.
+bool ARMTargetLowering::isLegalAddressImmediate(int64_t V,const Type *Ty) const{
+  MVT::ValueType VT = getValueType(Ty);
+  if (Subtarget->isThumb()) {
+    if (V < 0)
+      return false;
+
+    unsigned Scale = 1;
+    switch (VT) {
+    default: return false;
+    case MVT::i1:
+    case MVT::i8:
+      // Scale == 1;
+      break;
+    case MVT::i16:
+      // Scale == 2;
+      Scale = 2;
+      break;
+    case MVT::i32:
+      // Scale == 4;
+      Scale = 4;
+      break;
+    }
+
+    if ((V & (Scale - 1)) != 0)
+      return false;
+    V /= Scale;
+    return V == V & ((1LL << 5) - 1);
+  }
+
+  if (V < 0)
+    V = - V;
+  switch (VT) {
+  default: return false;
+  case MVT::i1:
+  case MVT::i8:
+  case MVT::i32:
+    // +- imm12
+    return V == V & ((1LL << 12) - 1);
+  case MVT::i16:
+    // +- imm8
+    return V == V & ((1LL << 8) - 1);
+  case MVT::f32:
+  case MVT::f64:
+    if (!Subtarget->hasVFP2())
+      return false;
+    if ((V % 3) != 0)
+      return false;
+    V >>= 2;
+    return V == V & ((1LL << 8) - 1);
+  }
 }
 
 bool ARMTargetLowering::isLegalAddressImmediate(GlobalValue *GV) const {
   return false;
 }
 
+/// isLegalAddressScale - Return true if the integer value can be used as
+/// the scale of the target addressing mode for load / store of the given
+/// type.
+bool ARMTargetLowering::isLegalAddressScale(int64_t S, const Type *Ty) const {
+  if (Subtarget->isThumb())
+    return false;
+
+  MVT::ValueType VT = getValueType(Ty);
+  switch (VT) {
+  default: return false;
+  case MVT::i1:
+  case MVT::i8:
+  case MVT::i32:
+    // r + r
+    if (S == 2)
+      return true;
+    // r + r << imm
+    S &= ~1;
+    return isPowerOf2_32(S);
+  }
+}
+
 static bool getIndexedAddressParts(SDNode *Ptr, MVT::ValueType VT,
                                    bool isSEXTLoad, SDOperand &Base,
                                    SDOperand &Offset, bool &isInc,
diff --git a/lib/Target/ARM/ARMISelLowering.h b/lib/Target/ARM/ARMISelLowering.h
index 0dbc3d6b32a..7feb2c3ef7b 100644
--- a/lib/Target/ARM/ARMISelLowering.h
+++ b/lib/Target/ARM/ARMISelLowering.h
@@ -80,11 +80,20 @@ namespace llvm {
     virtual MachineBasicBlock *InsertAtEndOfBasicBlock(MachineInstr *MI,
                                                        MachineBasicBlock *MBB);
 
-    /// isLegalAddressImmediate - Return true if the integer value or
-    /// GlobalValue can be used as the offset of the target addressing mode.
-    virtual bool isLegalAddressImmediate(int64_t V) const;
+    /// isLegalAddressImmediate - Return true if the integer value can be used
+    /// as the offset of the target addressing mode for load / store of the
+    /// given type.
+    virtual bool isLegalAddressImmediate(int64_t V, const Type *Ty) const;
+
+    /// isLegalAddressImmediate - Return true if the GlobalValue can be used as
+    /// the offset of the target addressing mode.
     virtual bool isLegalAddressImmediate(GlobalValue *GV) const;
 
+    /// isLegalAddressScale - Return true if the integer value can be used as
+    /// the scale of the target addressing mode for load / store of the given
+    /// type.
+    virtual bool isLegalAddressScale(int64_t S, const Type *Ty) const;
+
     /// getPreIndexedAddressParts - returns true by value, base pointer and
     /// offset pointer and addressing mode by reference if the node's address
     /// can be legally represented as pre-indexed load / store address.