maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[NFC][ARM] Convert lambdas to static helpers 

Break up and convert some of the lambdas in ARMLowOverheadLoops into
static functions. 

llvm-svn: 365623
This commit is contained in:
Sam Parker 2019-07-10 12:29:43 +00:00
parent ef1aac3191
commit 775b2f598a
1 changed files with 73 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

130
llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
View File

@ -54,6 +54,12 @@ namespace {
bool ProcessLoop(MachineLoop *ML);
void RevertWhile(MachineInstr *MI) const;
void RevertLoopDec(MachineInstr *MI) const;
void RevertLoopEnd(MachineInstr *MI) const;
void Expand(MachineLoop *ML, MachineInstr *Start,
MachineInstr *Dec, MachineInstr *End, bool Revert);
@ -208,6 +214,68 @@ bool ARMLowOverheadLoops::ProcessLoop(MachineLoop *ML) {
return true;
}
// WhileLoopStart holds the exit block, so produce a cmp lr, 0 and then a
// beq that branches to the exit branch.
// FIXME: Need to check that we're not trashing the CPSR when generating the
// cmp. We could also try to generate a cbz if the value in LR is also in
// another low register.
void ARMLowOverheadLoops::RevertWhile(MachineInstr *MI) const {
LLVM_DEBUG(dbgs() << "ARM Loops: Reverting to cmp: " << *MI);
MachineBasicBlock *MBB = MI->getParent();
MachineInstrBuilder MIB = BuildMI(*MBB, MI, MI->getDebugLoc(),
TII->get(ARM::t2CMPri));
MIB.addReg(ARM::LR);
MIB.addImm(0);
MIB.addImm(ARMCC::AL);
MIB.addReg(ARM::CPSR);
// TODO: Try to use tBcc instead
MIB = BuildMI(*MBB, MI, MI->getDebugLoc(), TII->get(ARM::t2Bcc));
MIB.add(MI->getOperand(1)); // branch target
MIB.addImm(ARMCC::EQ); // condition code
MIB.addReg(ARM::CPSR);
MI->eraseFromParent();
}
// TODO: Check flags so that we can possibly generate a tSubs or tSub.
void ARMLowOverheadLoops::RevertLoopDec(MachineInstr *MI) const {
LLVM_DEBUG(dbgs() << "ARM Loops: Reverting to sub: " << *MI);
MachineBasicBlock *MBB = MI->getParent();
MachineInstrBuilder MIB = BuildMI(*MBB, MI, MI->getDebugLoc(),
TII->get(ARM::t2SUBri));
MIB.addDef(ARM::LR);
MIB.add(MI->getOperand(1));
MIB.add(MI->getOperand(2));
MIB.addImm(ARMCC::AL);
MIB.addReg(0);
MIB.addReg(0);
MI->eraseFromParent();
}
// Generate a subs, or sub and cmp, and a branch instead of an LE.
// FIXME: Need to check that we're not trashing the CPSR when generating
// the cmp.
void ARMLowOverheadLoops::RevertLoopEnd(MachineInstr *MI) const {
LLVM_DEBUG(dbgs() << "ARM Loops: Reverting to cmp, br: " << *MI);
// Create cmp
MachineBasicBlock *MBB = MI->getParent();
MachineInstrBuilder MIB = BuildMI(*MBB, MI, MI->getDebugLoc(),
TII->get(ARM::t2CMPri));
MIB.addReg(ARM::LR);
MIB.addImm(0);
MIB.addImm(ARMCC::AL);
MIB.addReg(ARM::CPSR);
// TODO Try to use tBcc instead.
// Create bne
MIB = BuildMI(*MBB, MI, MI->getDebugLoc(), TII->get(ARM::t2Bcc));
MIB.add(MI->getOperand(1)); // branch target
MIB.addImm(ARMCC::NE); // condition code
MIB.addReg(ARM::CPSR);
MI->eraseFromParent();
}
void ARMLowOverheadLoops::Expand(MachineLoop *ML, MachineInstr *Start,
MachineInstr *Dec, MachineInstr *End,
bool Revert) {
@ -269,60 +337,6 @@ void ARMLowOverheadLoops::Expand(MachineLoop *ML, MachineInstr *Start,
return &*MIB;
};
// Generate a subs, or sub and cmp, and a branch instead of an LE.
// TODO: Check flags so that we can possibly generate a subs.
// FIXME: Need to check that we're not trashing the CPSR when generating
// the cmp.
auto ExpandBranch = [this](MachineInstr *Dec, MachineInstr *End) {
LLVM_DEBUG(dbgs() << "ARM Loops: Reverting to sub, cmp, br.\n");
// Create sub
MachineBasicBlock *MBB = Dec->getParent();
MachineInstrBuilder MIB = BuildMI(*MBB, Dec, Dec->getDebugLoc(),
TII->get(ARM::t2SUBri));
MIB.addDef(ARM::LR);
MIB.add(Dec->getOperand(1));
MIB.add(Dec->getOperand(2));
MIB.addImm(ARMCC::AL);
MIB.addReg(0);
MIB.addReg(0);
// Create cmp
MBB = End->getParent();
MIB = BuildMI(*MBB, End, End->getDebugLoc(), TII->get(ARM::t2CMPri));
MIB.addReg(ARM::LR);
MIB.addImm(0);
MIB.addImm(ARMCC::AL);
MIB.addReg(ARM::CPSR);
// Create bne
MIB = BuildMI(*MBB, End, End->getDebugLoc(), TII->get(ARM::t2Bcc));
MIB.add(End->getOperand(1)); // branch target
MIB.addImm(ARMCC::NE); // condition code
MIB.addReg(ARM::CPSR);
End->eraseFromParent();
Dec->eraseFromParent();
};
// WhileLoopStart holds the exit block, so produce a cmp lr, 0 and then a
// beq that branches to the exit branch.
// FIXME: Need to check that we're not trashing the CPSR when generating the
// cmp. We could also try to generate a cbz if the value in LR is also in
// another low register.
auto ExpandStart = [this](MachineInstr *MI) {
MachineBasicBlock *MBB = MI->getParent();
MachineInstrBuilder MIB = BuildMI(*MBB, MI, MI->getDebugLoc(),
TII->get(ARM::t2CMPri));
MIB.addReg(ARM::LR);
MIB.addImm(0);
MIB.addImm(ARMCC::AL);
MIB.addReg(ARM::CPSR);
MIB = BuildMI(*MBB, MI, MI->getDebugLoc(), TII->get(ARM::t2Bcc));
MIB.add(MI->getOperand(1)); // branch target
MIB.addImm(ARMCC::EQ); // condition code
MIB.addReg(ARM::CPSR);
};
// TODO: We should be able to automatically remove these branches before we
// get here - probably by teaching analyzeBranch about the pseudo
// instructions.
@ -342,9 +356,11 @@ void ARMLowOverheadLoops::Expand(MachineLoop *ML, MachineInstr *Start,
if (Revert) {
if (Start->getOpcode() == ARM::t2WhileLoopStart)
ExpandStart(Start);
ExpandBranch(Dec, End);
Start->eraseFromParent();
RevertWhile(Start);
else
Start->eraseFromParent();
RevertLoopDec(Dec);
RevertLoopEnd(End);
} else {
Start = ExpandLoopStart(ML, Start);
RemoveDeadBranch(Start);