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Implement AnalyzeBranch in Sparc Backend.

llvm-svn: 123561
This commit is contained in:
Venkatraman Govindaraju 2011-01-16 03:15:11 +00:00
parent 24ea7f696e
commit fe346f6cba
3 changed files with 206 additions and 14 deletions

View File

@ -66,15 +66,200 @@ unsigned SparcInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
return 0;
}
static bool IsIntegerCC(unsigned CC)
{
return (CC <= SPCC::ICC_VC);
}
static SPCC::CondCodes GetOppositeBranchCondition(SPCC::CondCodes CC)
{
switch(CC) {
default: llvm_unreachable("Unknown condition code");
case SPCC::ICC_NE: return SPCC::ICC_E;
case SPCC::ICC_E: return SPCC::ICC_NE;
case SPCC::ICC_G: return SPCC::ICC_LE;
case SPCC::ICC_LE: return SPCC::ICC_G;
case SPCC::ICC_GE: return SPCC::ICC_L;
case SPCC::ICC_L: return SPCC::ICC_GE;
case SPCC::ICC_GU: return SPCC::ICC_LEU;
case SPCC::ICC_LEU: return SPCC::ICC_GU;
case SPCC::ICC_CC: return SPCC::ICC_CS;
case SPCC::ICC_CS: return SPCC::ICC_CC;
case SPCC::ICC_POS: return SPCC::ICC_NEG;
case SPCC::ICC_NEG: return SPCC::ICC_POS;
case SPCC::ICC_VC: return SPCC::ICC_VS;
case SPCC::ICC_VS: return SPCC::ICC_VC;
case SPCC::FCC_U: return SPCC::FCC_O;
case SPCC::FCC_O: return SPCC::FCC_U;
case SPCC::FCC_G: return SPCC::FCC_LE;
case SPCC::FCC_LE: return SPCC::FCC_G;
case SPCC::FCC_UG: return SPCC::FCC_ULE;
case SPCC::FCC_ULE: return SPCC::FCC_UG;
case SPCC::FCC_L: return SPCC::FCC_GE;
case SPCC::FCC_GE: return SPCC::FCC_L;
case SPCC::FCC_UL: return SPCC::FCC_UGE;
case SPCC::FCC_UGE: return SPCC::FCC_UL;
case SPCC::FCC_LG: return SPCC::FCC_UE;
case SPCC::FCC_UE: return SPCC::FCC_LG;
case SPCC::FCC_NE: return SPCC::FCC_E;
case SPCC::FCC_E: return SPCC::FCC_NE;
}
}
bool SparcInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const
{
MachineBasicBlock::iterator I = MBB.end();
MachineBasicBlock::iterator UnCondBrIter = MBB.end();
while (I != MBB.begin()) {
--I;
if (I->isDebugValue())
continue;
//When we see a non-terminator, we are done
if (!isUnpredicatedTerminator(I))
break;
//Terminator is not a branch
if (!I->getDesc().isBranch())
return true;
//Handle Unconditional branches
if (I->getOpcode() == SP::BA) {
UnCondBrIter = I;
if (!AllowModify) {
TBB = I->getOperand(0).getMBB();
continue;
}
while (llvm::next(I) != MBB.end())
llvm::next(I)->eraseFromParent();
Cond.clear();
FBB = 0;
if (MBB.isLayoutSuccessor(I->getOperand(0).getMBB())) {
TBB = 0;
I->eraseFromParent();
I = MBB.end();
UnCondBrIter = MBB.end();
continue;
}
TBB = I->getOperand(0).getMBB();
continue;
}
unsigned Opcode = I->getOpcode();
if (Opcode != SP::BCOND && Opcode != SP::FBCOND)
return true; //Unknown Opcode
SPCC::CondCodes BranchCode = (SPCC::CondCodes)I->getOperand(1).getImm();
if (Cond.empty()) {
MachineBasicBlock *TargetBB = I->getOperand(0).getMBB();
if (AllowModify && UnCondBrIter != MBB.end() &&
MBB.isLayoutSuccessor(TargetBB)) {
//Transform the code
//
// brCC L1
// ba L2
// L1:
// ..
// L2:
//
// into
//
// brnCC L2
// L1:
// ...
// L2:
//
BranchCode = GetOppositeBranchCondition(BranchCode);
MachineBasicBlock::iterator OldInst = I;
BuildMI(MBB, UnCondBrIter, MBB.findDebugLoc(I), get(Opcode))
.addMBB(UnCondBrIter->getOperand(0).getMBB()).addImm(BranchCode);
BuildMI(MBB, UnCondBrIter, MBB.findDebugLoc(I), get(SP::BA))
.addMBB(TargetBB);
MBB.addSuccessor(TargetBB);
OldInst->eraseFromParent();
UnCondBrIter->eraseFromParent();
UnCondBrIter = MBB.end();
I = MBB.end();
continue;
}
FBB = TBB;
TBB = I->getOperand(0).getMBB();
Cond.push_back(MachineOperand::CreateImm(BranchCode));
continue;
}
//FIXME: Handle subsequent conditional branches
//For now, we can't handle multiple conditional branches
return true;
}
return false;
}
unsigned
SparcInstrInfo::InsertBranch(MachineBasicBlock &MBB,MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond,
DebugLoc DL)const{
// Can only insert uncond branches so far.
assert(Cond.empty() && !FBB && TBB && "Can only handle uncond branches!");
BuildMI(&MBB, DL, get(SP::BA)).addMBB(TBB);
return 1;
DebugLoc DL) const {
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 1 || Cond.size() == 0) &&
"Sparc branch conditions should have one component!");
if (Cond.empty()) {
assert(!FBB && "Unconditional branch with multiple successors!");
BuildMI(&MBB, DL, get(SP::BA)).addMBB(TBB);
return 1;
}
//Conditional branch
unsigned CC = Cond[0].getImm();
if (IsIntegerCC(CC))
BuildMI(&MBB, DL, get(SP::BCOND)).addMBB(TBB).addImm(CC);
else
BuildMI(&MBB, DL, get(SP::FBCOND)).addMBB(TBB).addImm(CC);
if (!FBB)
return 1;
BuildMI(&MBB, DL, get(SP::BA)).addMBB(FBB);
return 2;
}
unsigned SparcInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const
{
MachineBasicBlock::iterator I = MBB.end();
unsigned Count = 0;
while (I != MBB.begin()) {
--I;
if (I->isDebugValue())
continue;
if (I->getOpcode() != SP::BA
&& I->getOpcode() != SP::BCOND
&& I->getOpcode() != SP::FBCOND)
break; // Not a branch
I->eraseFromParent();
I = MBB.end();
++Count;
}
return Count;
}
void SparcInstrInfo::copyPhysReg(MachineBasicBlock &MBB,

View File

@ -58,8 +58,15 @@ public:
/// any side effects other than storing to the stack slot.
virtual unsigned isStoreToStackSlot(const MachineInstr *MI,
int &FrameIndex) const;
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify = false) const ;
virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond,

View File

@ -17,7 +17,7 @@ define i32 @test_select_int_icc(i32 %a, i32 %b, i32 %c) nounwind readnone noinli
entry:
; CHECK: test_select_int_icc
; CHECK: subcc
; CHECK: be
; CHECK: {{be|bne}}
%0 = icmp eq i32 %a, 0
%1 = select i1 %0, i32 %b, i32 %c
ret i32 %1
@ -28,7 +28,7 @@ define float @test_select_fp_icc(i32 %a, float %f1, float %f2) nounwind readnone
entry:
; CHECK: test_select_fp_icc
; CHECK: subcc
; CHECK: be
; CHECK: {{be|bne}}
%0 = icmp eq i32 %a, 0
%1 = select i1 %0, float %f1, float %f2
ret float %1
@ -36,9 +36,9 @@ entry:
define double @test_select_dfp_icc(i32 %a, double %f1, double %f2) nounwind readnone noinline {
entry:
; CHECK: test_select_fp_icc
; CHECK: test_select_dfp_icc
; CHECK: subcc
; CHECK: be
; CHECK: {{be|bne}}
%0 = icmp eq i32 %a, 0
%1 = select i1 %0, double %f1, double %f2
ret double %1
@ -48,7 +48,7 @@ define i32 @test_select_int_fcc(float %f, i32 %a, i32 %b) nounwind readnone noin
entry:
;CHECK: test_select_int_fcc
;CHECK: fcmps
;CHECK: fbne
;CHECK: {{fbe|fbne}}
%0 = fcmp une float %f, 0.000000e+00
%a.b = select i1 %0, i32 %a, i32 %b
ret i32 %a.b
@ -59,7 +59,7 @@ define float @test_select_fp_fcc(float %f, float %f1, float %f2) nounwind readno
entry:
;CHECK: test_select_fp_fcc
;CHECK: fcmps
;CHECK: fbne
;CHECK: {{fbe|fbne}}
%0 = fcmp une float %f, 0.000000e+00
%1 = select i1 %0, float %f1, float %f2
ret float %1
@ -69,7 +69,7 @@ define double @test_select_dfp_fcc(double %f, double %f1, double %f2) nounwind r
entry:
;CHECK: test_select_dfp_fcc
;CHECK: fcmpd
;CHECK: fbne
;CHECK: {{fbne|fbe}}
%0 = fcmp une double %f, 0.000000e+00
%1 = select i1 %0, double %f1, double %f2
ret double %1