It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86InstrBuilder.h b/lib/Target/X86/X86InstrBuilder.h
new file mode 100644
index 0000000..c0fa58d
--- /dev/null
+++ b/lib/Target/X86/X86InstrBuilder.h
@@ -0,0 +1,125 @@
+//===-- X86InstrBuilder.h - Functions to aid building x86 insts -*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// 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.
+//
+// For reference, the order of operands for memory references is:
+// (Operand), Base, Scale, Index, Displacement.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef X86INSTRBUILDER_H
+#define X86INSTRBUILDER_H
+
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+
+namespace llvm {
+
+/// X86AddressMode - This struct holds a generalized full x86 address mode.
+/// The base register can be a frame index, which will eventually be replaced
+/// with BP or SP and Disp being offsetted accordingly. The displacement may
+/// also include the offset of a global value.
+struct X86AddressMode {
+ enum {
+ RegBase,
+ FrameIndexBase
+ } BaseType;
+
+ union {
+ unsigned Reg;
+ int FrameIndex;
+ } Base;
+
+ unsigned Scale;
+ unsigned IndexReg;
+ unsigned Disp;
+ GlobalValue *GV;
+
+ X86AddressMode() : BaseType(RegBase), Scale(1), IndexReg(0), Disp(0), GV(0) {
+ Base.Reg = 0;
+ }
+};
+
+/// addDirectMem - This function is used to add a direct memory reference to the
+/// current instruction -- that is, a dereference of an address in a register,
+/// with no scale, index or displacement. An example is: DWORD PTR [EAX].
+///
+inline const MachineInstrBuilder &addDirectMem(const MachineInstrBuilder &MIB,
+ unsigned Reg) {
+ // Because memory references are always represented with four
+ // values, this adds: Reg, [1, NoReg, 0] to the instruction.
+ return MIB.addReg(Reg).addImm(1).addReg(0).addImm(0);
+}
+
+
+/// addRegOffset - This function is used to add a memory reference of the form
+/// [Reg + Offset], i.e., one with no scale or index, but with a
+/// displacement. An example is: DWORD PTR [EAX + 4].
+///
+inline const MachineInstrBuilder &addRegOffset(const MachineInstrBuilder &MIB,
+ unsigned Reg, int Offset) {
+ return MIB.addReg(Reg).addImm(1).addReg(0).addImm(Offset);
+}
+
+/// addRegReg - This function is used to add a memory reference of the form:
+/// [Reg + Reg].
+inline const MachineInstrBuilder &addRegReg(const MachineInstrBuilder &MIB,
+ unsigned Reg1, unsigned Reg2) {
+ return MIB.addReg(Reg1).addImm(1).addReg(Reg2).addImm(0);
+}
+
+inline const MachineInstrBuilder &addFullAddress(const MachineInstrBuilder &MIB,
+ const X86AddressMode &AM) {
+ assert (AM.Scale == 1 || AM.Scale == 2 || AM.Scale == 4 || AM.Scale == 8);
+
+ if (AM.BaseType == X86AddressMode::RegBase)
+ MIB.addReg(AM.Base.Reg);
+ else if (AM.BaseType == X86AddressMode::FrameIndexBase)
+ MIB.addFrameIndex(AM.Base.FrameIndex);
+ else
+ assert (0);
+ MIB.addImm(AM.Scale).addReg(AM.IndexReg);
+ if (AM.GV)
+ return MIB.addGlobalAddress(AM.GV, AM.Disp);
+ else
+ return MIB.addImm(AM.Disp);
+}
+
+/// addFrameReference - This function is used to add a reference to the base of
+/// an abstract object on the stack frame of the current function. This
+/// reference has base register as the FrameIndex offset until it is resolved.
+/// This allows a constant offset to be specified as well...
+///
+inline const MachineInstrBuilder &
+addFrameReference(const MachineInstrBuilder &MIB, int FI, int Offset = 0) {
+ return MIB.addFrameIndex(FI).addImm(1).addReg(0).addImm(Offset);
+}
+
+/// addConstantPoolReference - This function is used to add a reference to the
+/// base of a constant value spilled to the per-function constant pool. The
+/// reference has base register ConstantPoolIndex offset which is retained until
+/// either machine code emission or assembly output. This allows an optional
+/// offset to be added as well.
+///
+inline const MachineInstrBuilder &
+addConstantPoolReference(const MachineInstrBuilder &MIB, unsigned CPI,
+ int Offset = 0) {
+ return MIB.addConstantPoolIndex(CPI).addImm(1).addReg(0).addImm(Offset);
+}
+
+} // End llvm namespace
+
+#endif