[llvm-commits] [llvm] r96175 - /llvm/trunk/lib/Target/PIC16/PIC16MemSelOpt.cpp
Sanjiv Gupta
sanjiv.gupta at microchip.com
Sun Feb 14 10:27:42 PST 2010
Author: sgupta
Date: Sun Feb 14 12:27:42 2010
New Revision: 96175
URL: http://llvm.org/viewvc/llvm-project?rev=96175&view=rev
Log:
fixes to pagesel/banksel inserter.
1. restore these across direct/indirect calls.
2. restore pagesel for any macros with gotos.
Modified:
llvm/trunk/lib/Target/PIC16/PIC16MemSelOpt.cpp
Modified: llvm/trunk/lib/Target/PIC16/PIC16MemSelOpt.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PIC16/PIC16MemSelOpt.cpp?rev=96175&r1=96174&r2=96175&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PIC16/PIC16MemSelOpt.cpp (original)
+++ llvm/trunk/lib/Target/PIC16/PIC16MemSelOpt.cpp Sun Feb 14 12:27:42 2010
@@ -59,6 +59,7 @@
const TargetInstrInfo *TII; // Machine instruction info.
MachineBasicBlock *MBB; // Current basic block
std::string CurBank;
+ int PageChanged;
};
char MemSelOpt::ID = 0;
@@ -93,10 +94,56 @@
// Let us assume that when entering a basic block now bank is selected.
// Ideally we should look at the predecessors for this information.
CurBank="";
+ PageChanged=0;
- for (MachineBasicBlock::iterator I = BB.begin(); I != BB.end(); ++I) {
+ MachineBasicBlock::iterator I;
+ for (I = BB.begin(); I != BB.end(); ++I) {
Changed |= processInstruction(I);
+
+ // if the page has changed insert a page sel before
+ // any instruction that needs one
+ if (PageChanged == 1)
+ {
+ // Restore the page if it was changed, before leaving the basic block,
+ // because it may be required by the goto terminator or the fall thru
+ // basic blcok.
+ // If the terminator is return, we don't need to restore since there
+ // is no goto or fall thru basic block.
+ if ((I->getOpcode() == PIC16::sublw_3) || //macro has goto
+ (I->getOpcode() == PIC16::sublw_6) || //macro has goto
+ (I->getOpcode() == PIC16::addlwc) || //macro has goto
+ (TII->get(I->getOpcode()).isBranch()))
+ {
+ DebugLoc dl = I->getDebugLoc();
+ BuildMI(*MBB, I, dl, TII->get(PIC16::pagesel)).addExternalSymbol("$");
+ Changed = true;
+ PageChanged = 0;
+ }
+ }
}
+
+ // The basic block is over, but if we did not find any goto yet,
+ // we haven't restored the page.
+ // Restore the page if it was changed, before leaving the basic block,
+ // because it may be required by fall thru basic blcok.
+ // If the terminator is return, we don't need to restore since there
+ // is fall thru basic block.
+ if (PageChanged == 1) {
+ // save the end pointer before we move back to last insn.
+ MachineBasicBlock::iterator J = I;
+ I--;
+ const TargetInstrDesc &TID = TII->get(I->getOpcode());
+ if (! TID.isReturn())
+ {
+ DebugLoc dl = I->getDebugLoc();
+ BuildMI(*MBB, J, dl,
+ TII->get(PIC16::pagesel)).addExternalSymbol("$");
+ Changed = true;
+ PageChanged = 0;
+ }
+ }
+
+
return Changed;
}
@@ -112,42 +159,74 @@
if (!(TID.isBranch() || TID.isCall() || TID.mayLoad() || TID.mayStore()))
return false;
+ // The first thing we should do is that record if banksel/pagesel are
+ // changed in an unknown way. This can happend via any type of call.
+ // We do it here first before scanning of MemOp / BBOp as the indirect
+ // call insns do not have any operands, but they still may change bank/page.
+ if (TID.isCall()) {
+ // Record that we have changed the page, so that we can restore it
+ // before basic block ends.
+ // We require to signal that a page anc bank change happened even for
+ // indirect calls.
+ PageChanged = 1;
+
+ // When a call is made, there may be banksel for variables in callee.
+ // Hence the banksel in caller needs to be reset.
+ CurBank = "";
+ }
+
// Scan for the memory address operand.
// FIXME: Should we use standard interfaces like memoperands_iterator,
// hasMemOperand() etc ?
int MemOpPos = -1;
+ int BBOpPos = -1;
for (unsigned i = 0; i < NumOperands; i++) {
MachineOperand Op = MI->getOperand(i);
if (Op.getType() == MachineOperand::MO_GlobalAddress ||
- Op.getType() == MachineOperand::MO_ExternalSymbol ||
- Op.getType() == MachineOperand::MO_MachineBasicBlock) {
+ Op.getType() == MachineOperand::MO_ExternalSymbol) {
// We found one mem operand. Next one may be BS.
MemOpPos = i;
- break;
+ }
+ if (Op.getType() == MachineOperand::MO_MachineBasicBlock) {
+ // We found one BB operand. Next one may be pagesel.
+ BBOpPos = i;
}
}
// If we did not find an insn accessing memory. Continue.
- if (MemOpPos == -1) return Changed;
+ if ((MemOpPos == -1) &&
+ (BBOpPos == -1))
+ return false;
+ assert ((BBOpPos != MemOpPos) && "operand can only be of one type");
- // Get the MemOp.
- MachineOperand &Op = MI->getOperand(MemOpPos);
// If this is a pagesel material, handle it first.
- if (MI->getOpcode() == PIC16::CALL ||
- MI->getOpcode() == PIC16::br_uncond) {
+ // CALL and br_ucond insns use MemOp (GA or ES) and not BBOp.
+ // Pagesel is required only for a direct call.
+ if ((MI->getOpcode() == PIC16::CALL)) {
+ // Get the BBOp.
+ MachineOperand &MemOp = MI->getOperand(MemOpPos);
DebugLoc dl = MI->getDebugLoc();
- BuildMI(*MBB, MI, dl, TII->get(PIC16::pagesel)).
- addOperand(Op);
- return true;
+ BuildMI(*MBB, MI, dl, TII->get(PIC16::pagesel)).addOperand(MemOp);
+
+ // CALL and br_ucond needs only pagesel. so we are done.
+ return true;
}
+ // Pagesel is handled. Now, add a Banksel if needed.
+ if (MemOpPos == -1) return Changed;
+ // Get the MemOp.
+ MachineOperand &Op = MI->getOperand(MemOpPos);
+
// Get the section name(NewBank) for MemOp.
// This assumes that the section names for globals are already set by
// AsmPrinter->doInitialization.
std::string NewBank = CurBank;
+ bool hasExternalLinkage = false;
if (Op.getType() == MachineOperand::MO_GlobalAddress &&
Op.getGlobal()->getType()->getAddressSpace() == PIC16ISD::RAM_SPACE) {
+ if (Op.getGlobal()->hasExternalLinkage())
+ hasExternalLinkage= true;
NewBank = Op.getGlobal()->getSection();
} else if (Op.getType() == MachineOperand::MO_ExternalSymbol) {
// External Symbol is generated for temp data and arguments. They are
@@ -162,7 +241,7 @@
// If the previous and new section names are same, we don't need to
// emit banksel.
- if (NewBank.compare(CurBank) != 0 ) {
+ if (NewBank.compare(CurBank) != 0 || hasExternalLinkage) {
DebugLoc dl = MI->getDebugLoc();
BuildMI(*MBB, MI, dl, TII->get(PIC16::banksel)).
addOperand(Op);
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