XCore target: Refactor the loading of constants into a register

This common functionality will be used to lower FRAME_TO_ARGS_OFFSET.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198610 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 33 insertions, 0 deletions

diff --git a/lib/Target/XCore/XCoreInstrInfo.cpp b/lib/Target/XCore/XCoreInstrInfo.cpp
index 33c7f31be7..33b97fba8d 100644
--- a/lib/Target/XCore/XCoreInstrInfo.cpp
+++ b/lib/Target/XCore/XCoreInstrInfo.cpp
@@ -15,8 +15,11 @@
 #include "XCore.h"
 #include "XCoreMachineFunctionInfo.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Function.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -399,3 +402,33 @@ ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
   Cond[0].setImm(GetOppositeBranchCondition((XCore::CondCode)Cond[0].getImm()));
   return false;
 }
+
+static inline bool isImmU6(unsigned val) {
+  return val < (1 << 6);
+}
+
+static inline bool isImmU16(unsigned val) {
+  return val < (1 << 16);
+}
+
+MachineBasicBlock::iterator XCoreInstrInfo::loadImmediate(
+                                              MachineBasicBlock &MBB,
+                                              MachineBasicBlock::iterator MI,
+                                              unsigned Reg, uint64_t Value) const {
+  DebugLoc dl;
+  if (MI != MBB.end()) dl = MI->getDebugLoc();
+  if (isMask_32(Value)) {
+    int N = Log2_32(Value) + 1;
+    return BuildMI(MBB, MI, dl, get(XCore::MKMSK_rus), Reg).addImm(N);
+  }
+  if (isImmU16(Value)) {
+    int Opcode = isImmU6(Value) ? XCore::LDC_ru6 : XCore::LDC_lru6;
+    return BuildMI(MBB, MI, dl, get(Opcode), Reg).addImm(Value);
+  }
+  MachineConstantPool *ConstantPool = MBB.getParent()->getConstantPool();
+  const Constant *C = ConstantInt::get(
+        Type::getInt32Ty(MBB.getParent()->getFunction()->getContext()), Value);
+  unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4);
+  return BuildMI(MBB, MI, dl, get(XCore::LDWCP_lru6), Reg)
+            .addConstantPoolIndex(Idx);
+}