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Add conditional and unconditional thumb-2 branch. Add thumb-2 jump table.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74543 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Goodwin
2009-06-30 18:04:13 +00:00
parent 72bf4473a6
commit 5e47a9a6e4
7 changed files with 112 additions and 33 deletions
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36
lib/Target/ARM/ARMConstantIslandPass.cpp
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@@ -124,6 +124,7 @@ namespace {
const TargetInstrInfo *TII;
ARMFunctionInfo *AFI;
bool isThumb;
bool isThumb2;
public:
static char ID;
ARMConstantIslands() : MachineFunctionPass(&ID) {}
@@ -213,6 +214,7 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &Fn) {
TII = Fn.getTarget().getInstrInfo();
AFI = Fn.getInfo<ARMFunctionInfo>();
isThumb = AFI->isThumbFunction();
isThumb2 = AFI->isThumb2Function();
HasFarJump = false;
@@ -376,6 +378,7 @@ void ARMConstantIslands::InitialFunctionScan(MachineFunction &Fn,
int UOpc = Opc;
switch (Opc) {
case ARM::tBR_JTr:
case ARM::t2BR_JTr:
// A Thumb table jump may involve padding; for the offsets to
// be right, functions containing these must be 4-byte aligned.
AFI->setAlign(2U);
@@ -402,6 +405,16 @@ void ARMConstantIslands::InitialFunctionScan(MachineFunction &Fn,
Bits = 11;
Scale = 2;
break;
case ARM::t2Bcc:
isCond = true;
UOpc = ARM::t2B;
Bits = 20;
Scale = 2;
break;
case ARM::t2B:
Bits = 24;
Scale = 2;
break;
}
// Record this immediate branch.
@@ -575,7 +588,7 @@ MachineBasicBlock *ARMConstantIslands::SplitBlockBeforeInstr(MachineInstr *MI) {
// There doesn't seem to be meaningful DebugInfo available; this doesn't
// correspond to anything in the source.
BuildMI(OrigBB, DebugLoc::getUnknownLoc(),
TII->get(isThumb ? ARM::tB : ARM::B)).addMBB(NewBB);
TII->get(isThumb ? ((isThumb2) ? ARM::t2B : ARM::tB) : ARM::B)).addMBB(NewBB);
NumSplit++;
// Update the CFG. All succs of OrigBB are now succs of NewBB.
@@ -719,7 +732,8 @@ static bool BBIsJumpedOver(MachineBasicBlock *MBB) {
MachineBasicBlock *Succ = *MBB->succ_begin();
MachineBasicBlock *Pred = *MBB->pred_begin();
MachineInstr *PredMI = &Pred->back();
if (PredMI->getOpcode() == ARM::B || PredMI->getOpcode() == ARM::tB)
if (PredMI->getOpcode() == ARM::B || PredMI->getOpcode() == ARM::tB
|| PredMI->getOpcode() == ARM::t2B)
return PredMI->getOperand(0).getMBB() == Succ;
return false;
}
@@ -751,7 +765,8 @@ void ARMConstantIslands::AdjustBBOffsetsAfter(MachineBasicBlock *BB,
// Thumb jump tables require padding. They should be at the end;
// following unconditional branches are removed by AnalyzeBranch.
MachineInstr *ThumbJTMI = NULL;
if (prior(MBB->end())->getOpcode() == ARM::tBR_JTr)
if ((prior(MBB->end())->getOpcode() == ARM::tBR_JTr)
|| (prior(MBB->end())->getOpcode() == ARM::t2BR_JTr))
ThumbJTMI = prior(MBB->end());
if (ThumbJTMI) {
unsigned newMIOffset = GetOffsetOf(ThumbJTMI);
@@ -842,7 +857,16 @@ int ARMConstantIslands::LookForExistingCPEntry(CPUser& U, unsigned UserOffset)
/// getUnconditionalBrDisp - Returns the maximum displacement that can fit in
/// the specific unconditional branch instruction.
static inline unsigned getUnconditionalBrDisp(int Opc) {
return (Opc == ARM::tB) ? ((1<<10)-1)*2 : ((1<<23)-1)*4;
switch (Opc) {
case ARM::tB:
return ((1<<10)-1)*2;
case ARM::t2B:
return ((1<<23)-1)*2;
default:
break;
}
return ((1<<23)-1)*4;
}
/// AcceptWater - Small amount of common code factored out of the following.
@@ -938,7 +962,7 @@ void ARMConstantIslands::CreateNewWater(unsigned CPUserIndex,
// range, but if the preceding conditional branch is out of range, the
// targets will be exchanged, and the altered branch may be out of
// range, so the machinery has to know about it.
int UncondBr = isThumb ? ARM::tB : ARM::B;
int UncondBr = isThumb ? ((isThumb2) ? ARM::t2B : ARM::tB) : ARM::B;
BuildMI(UserMBB, DebugLoc::getUnknownLoc(),
TII->get(UncondBr)).addMBB(*NewMBB);
unsigned MaxDisp = getUnconditionalBrDisp(UncondBr);
@@ -1168,7 +1192,7 @@ bool
ARMConstantIslands::FixUpUnconditionalBr(MachineFunction &Fn, ImmBranch &Br) {
MachineInstr *MI = Br.MI;
MachineBasicBlock *MBB = MI->getParent();
assert(isThumb && "Expected a Thumb function!");
assert(isThumb && !isThumb2 && "Expected a Thumb-1 function!");
// Use BL to implement far jump.
Br.MaxDisp = (1 << 21) * 2;