Rename TargetFrameInfo into TargetFrameLowering. Also, put couple of FIXMEs and fixes here and there.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123170 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Alpha/AlphaFrameLowering.cpp b/lib/Target/Alpha/AlphaFrameLowering.cpp
new file mode 100644
index 0000000..949bd4f
--- /dev/null
+++ b/lib/Target/Alpha/AlphaFrameLowering.cpp
@@ -0,0 +1,143 @@
+//=====- AlphaFrameLowering.cpp - Alpha Frame Information ------*- C++ -*-====//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the Alpha implementation of TargetFrameLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "AlphaFrameLowering.h"
+#include "AlphaInstrInfo.h"
+#include "AlphaMachineFunctionInfo.h"
+#include "llvm/Function.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/ADT/Twine.h"
+
+using namespace llvm;
+
+static long getUpper16(long l) {
+ long y = l / Alpha::IMM_MULT;
+ if (l % Alpha::IMM_MULT > Alpha::IMM_HIGH)
+ ++y;
+ return y;
+}
+
+static long getLower16(long l) {
+ long h = getUpper16(l);
+ return l - h * Alpha::IMM_MULT;
+}
+
+// hasFP - Return true if the specified function should have a dedicated frame
+// pointer register. This is true if the function has variable sized allocas or
+// if frame pointer elimination is disabled.
+//
+bool AlphaFrameLowering::hasFP(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ return MFI->hasVarSizedObjects();
+}
+
+void AlphaFrameLowering::emitPrologue(MachineFunction &MF) const {
+ MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
+ MachineBasicBlock::iterator MBBI = MBB.begin();
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+
+ DebugLoc dl = (MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc());
+ bool FP = hasFP(MF);
+
+ // Handle GOP offset
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::LDAHg), Alpha::R29)
+ .addGlobalAddress(MF.getFunction()).addReg(Alpha::R27).addImm(++curgpdist);
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::LDAg), Alpha::R29)
+ .addGlobalAddress(MF.getFunction()).addReg(Alpha::R29).addImm(curgpdist);
+
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::ALTENT))
+ .addGlobalAddress(MF.getFunction());
+
+ // Get the number of bytes to allocate from the FrameInfo
+ long NumBytes = MFI->getStackSize();
+
+ if (FP)
+ NumBytes += 8; //reserve space for the old FP
+
+ // Do we need to allocate space on the stack?
+ if (NumBytes == 0) return;
+
+ unsigned Align = getStackAlignment();
+ NumBytes = (NumBytes+Align-1)/Align*Align;
+
+ // Update frame info to pretend that this is part of the stack...
+ MFI->setStackSize(NumBytes);
+
+ // adjust stack pointer: r30 -= numbytes
+ NumBytes = -NumBytes;
+ if (NumBytes >= Alpha::IMM_LOW) {
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::LDA), Alpha::R30).addImm(NumBytes)
+ .addReg(Alpha::R30);
+ } else if (getUpper16(NumBytes) >= Alpha::IMM_LOW) {
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::LDAH), Alpha::R30)
+ .addImm(getUpper16(NumBytes)).addReg(Alpha::R30);
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::LDA), Alpha::R30)
+ .addImm(getLower16(NumBytes)).addReg(Alpha::R30);
+ } else {
+ report_fatal_error("Too big a stack frame at " + Twine(NumBytes));
+ }
+
+ // Now if we need to, save the old FP and set the new
+ if (FP) {
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::STQ))
+ .addReg(Alpha::R15).addImm(0).addReg(Alpha::R30);
+ // This must be the last instr in the prolog
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::BISr), Alpha::R15)
+ .addReg(Alpha::R30).addReg(Alpha::R30);
+ }
+
+}
+
+void AlphaFrameLowering::emitEpilogue(MachineFunction &MF,
+ MachineBasicBlock &MBB) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ MachineBasicBlock::iterator MBBI = prior(MBB.end());
+ const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+
+ assert((MBBI->getOpcode() == Alpha::RETDAG ||
+ MBBI->getOpcode() == Alpha::RETDAGp)
+ && "Can only insert epilog into returning blocks");
+ DebugLoc dl = MBBI->getDebugLoc();
+
+ bool FP = hasFP(MF);
+
+ // Get the number of bytes allocated from the FrameInfo...
+ long NumBytes = MFI->getStackSize();
+
+ //now if we need to, restore the old FP
+ if (FP) {
+ //copy the FP into the SP (discards allocas)
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::BISr), Alpha::R30).addReg(Alpha::R15)
+ .addReg(Alpha::R15);
+ //restore the FP
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::LDQ), Alpha::R15)
+ .addImm(0).addReg(Alpha::R15);
+ }
+
+ if (NumBytes != 0) {
+ if (NumBytes <= Alpha::IMM_HIGH) {
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::LDA), Alpha::R30).addImm(NumBytes)
+ .addReg(Alpha::R30);
+ } else if (getUpper16(NumBytes) <= Alpha::IMM_HIGH) {
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::LDAH), Alpha::R30)
+ .addImm(getUpper16(NumBytes)).addReg(Alpha::R30);
+ BuildMI(MBB, MBBI, dl, TII.get(Alpha::LDA), Alpha::R30)
+ .addImm(getLower16(NumBytes)).addReg(Alpha::R30);
+ } else {
+ report_fatal_error("Too big a stack frame at " + Twine(NumBytes));
+ }
+ }
+}