Add functions to buld X86 specific constructs

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4714 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86InstrBuilder.h b/lib/Target/X86/X86InstrBuilder.h
new file mode 100644 (file)
index 0000000..1d9d6b9
--- /dev/null
+++ b/lib/Target/X86/X86InstrBuilder.h
@@ -0,0 +1,28 @@
+//===-- X86InstrBuilder.h - Functions to aid building x86 insts -*- C++ -*-===//
+//
+// This file exposes functions that may be used with BuildMI from the
+// MachineInstrBuilder.h file to handle X86'isms in a clean way.
+//
+// The BuildMem function may be used with the BuildMI function to add entire
+// memory references in a single, typed, function call.  X86 memory references
+// can be very complex expressions (described in the README), so wrapping them
+// up behind an easier to use interface makes sense.  Descriptions of the
+// functions are included below.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef X86INSTRBUILDER_H
+#define X86INSTRBUILDER_H
+
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+
+/// addDirectMem - This function is used to add a direct memory reference to the
+/// current instruction.  Because memory references are always represented with
+/// four values, this adds: Reg, [1, NoReg, 0] to the instruction
+///
+inline const MachineInstrBuilder &addDirectMem(const MachineInstrBuilder &MIB,
+                                               unsigned Reg) {
+  return MIB.addReg(Reg).addZImm(1).addMReg(0).addSImm(0);
+}
+
+#endif