use MVN to handle small negative constants

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32459 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 39 insertions, 7 deletions

diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index 08864a7b6d..48d918c1d6 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -781,6 +781,8 @@ public:
   virtual void InstructionSelectBasicBlock(SelectionDAG &DAG);
   bool SelectAddrMode1(SDOperand Op, SDOperand N, SDOperand &Arg,
                        SDOperand &Shift, SDOperand &ShiftType);
+  bool SelectAddrMode1a(SDOperand Op, SDOperand N, SDOperand &Arg,
+			SDOperand &Shift, SDOperand &ShiftType);
   bool SelectAddrMode2(SDOperand Op, SDOperand N, SDOperand &Arg,
                        SDOperand &Offset);
   bool SelectAddrMode5(SDOperand Op, SDOperand N, SDOperand &Arg,
@@ -883,6 +885,25 @@ bool ARMDAGToDAGISel::SelectAddrMode1(SDOperand Op,
   return true;
 }
 
+bool ARMDAGToDAGISel::SelectAddrMode1a(SDOperand Op,
+				       SDOperand N,
+				       SDOperand &Arg,
+				       SDOperand &Shift,
+				       SDOperand &ShiftType) {
+  if (N.getOpcode() != ISD::Constant)
+    return false;
+
+  uint32_t val = ~cast<ConstantSDNode>(N)->getValue();
+  if(!isRotInt8Immediate(val))
+    return false;
+
+  Arg       = CurDAG->getTargetConstant(val,    MVT::i32);
+  Shift     = CurDAG->getTargetConstant(0,             MVT::i32);
+  ShiftType = CurDAG->getTargetConstant(ARMShift::LSL, MVT::i32);
+
+  return true;
+}
+
 bool ARMDAGToDAGISel::SelectAddrMode2(SDOperand Op, SDOperand N,
                                       SDOperand &Arg, SDOperand &Offset) {
   //TODO: complete and cleanup!
diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index 4be2b74a5e..2d1bfc0e55 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -18,6 +18,11 @@ def op_addr_mode1 : Operand<iPTR> {
   let MIOperandInfo = (ops ptr_rc, ptr_rc, i32imm);
 }
 
+def op_addr_mode1a : Operand<iPTR> {
+  let PrintMethod = "printAddrMode1";
+  let MIOperandInfo = (ops ptr_rc, ptr_rc, i32imm);
+}
+
 def op_addr_mode2 : Operand<iPTR> {
   let PrintMethod = "printAddrMode2";
   let MIOperandInfo = (ops ptr_rc, i32imm);
@@ -33,6 +38,9 @@ def op_addr_mode5 : Operand<iPTR> {
 def addr_mode1 : ComplexPattern<iPTR, 3, "SelectAddrMode1", [imm, sra, shl, srl],
                                 []>;
 
+//Addressing Mode 1a: MVN hack
+def addr_mode1a : ComplexPattern<iPTR, 3, "SelectAddrMode1a", [imm], []>;
+
 //Addressing Mode 2: Load and Store Word or Unsigned Byte
 def addr_mode2 : ComplexPattern<iPTR, 2, "SelectAddrMode2", [], []>;
 
@@ -193,6 +201,9 @@ def MOV   : InstARM<(ops IntRegs:$dst, op_addr_mode1:$src),
 def MVN     : InstARM<(ops IntRegs:$dst, op_addr_mode1:$src),
                        "mvn $dst, $src", [(set IntRegs:$dst, (not addr_mode1:$src))]>;
 
+def MVN2    : InstARM<(ops IntRegs:$dst, op_addr_mode1:$src),
+                       "mvn $dst, $src", [(set IntRegs:$dst, addr_mode1a:$src)]>;
+
 def ADD     : Addr1BinOp<"add",  add>;
 def ADCS    : Addr1BinOp<"adcs", adde>;
 def ADDS    : Addr1BinOp<"adds", addc>;
diff --git a/test/CodeGen/ARM/long.ll b/test/CodeGen/ARM/long.ll
index 33e9b31bd0..f067c517fc 100644
--- a/test/CodeGen/ARM/long.ll
+++ b/test/CodeGen/ARM/long.ll
@@ -1,9 +1,9 @@
 ; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm &&
 ; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep "mov r1, #0" | wc -l | grep 4 &&
 ; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep "mov r0, #1" | wc -l | grep 1 &&
-; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep ".word.*2147483647" | wc -l | grep 2 &&
+; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep "mvn r0, #-2147483648" | wc -l | grep 1 &&
 ; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep "mov r0, #-2147483648" | wc -l | grep 1 &&
-; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep ".word.*4294967295" | wc -l | grep 1 &&
+; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep "mvn r1, #-2147483648" | wc -l | grep 1 &&
 ; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep "adds" | wc -l | grep 1 &&
 ; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep "adcs" | wc -l | grep 1 &&
 ; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep "subs" | wc -l | grep 1 &&
diff --git a/test/CodeGen/ARM/mvn.ll b/test/CodeGen/ARM/mvn.ll
index fc788b80fd..d425498ea7 100644
--- a/test/CodeGen/ARM/mvn.ll
+++ b/test/CodeGen/ARM/mvn.ll
@@ -1,10 +1,10 @@
 ; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm &&
-; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep mvn | wc -l | grep 4
+; RUN: llvm-upgrade < %s | llvm-as | llc -march=arm | grep mvn | wc -l | grep 5
 
-;int %f1() {
-;entry:
-;	ret int -1
-;}
+int %f1() {
+entry:
+	ret int -1
+}
 
 int %f2(int %a) {
 entry: