[llvm-commits] [llvm] r128084 - in /llvm/trunk: lib/Target/PTX/PTXInstrInfo.cpp lib/Target/PTX/PTXInstrInfo.h lib/Target/PTX/PTXInstrInfo.td test/CodeGen/PTX/bra.ll
Che-Liang Chiou
clchiou at gmail.com
Tue Mar 22 07:12:00 PDT 2011
Author: clchiou
Date: Tue Mar 22 09:12:00 2011
New Revision: 128084
URL: http://llvm.org/viewvc/llvm-project?rev=128084&view=rev
Log:
ptx: add analyze/insert/remove branch
Modified:
llvm/trunk/lib/Target/PTX/PTXInstrInfo.cpp
llvm/trunk/lib/Target/PTX/PTXInstrInfo.h
llvm/trunk/lib/Target/PTX/PTXInstrInfo.td
llvm/trunk/test/CodeGen/PTX/bra.ll
Modified: llvm/trunk/lib/Target/PTX/PTXInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PTX/PTXInstrInfo.cpp?rev=128084&r1=128083&r2=128084&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PTX/PTXInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/PTX/PTXInstrInfo.cpp Tue Mar 22 09:12:00 2011
@@ -11,11 +11,15 @@
//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "ptx-instrinfo"
+
#include "PTX.h"
#include "PTXInstrInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
using namespace llvm;
@@ -132,7 +136,6 @@
return false;
}
-
bool PTXInstrInfo::
DefinesPredicate(MachineInstr *MI,
std::vector<MachineOperand> &Pred) const {
@@ -165,6 +168,127 @@
}
}
+// branch support
+
+bool PTXInstrInfo::
+AnalyzeBranch(MachineBasicBlock &MBB,
+ MachineBasicBlock *&TBB,
+ MachineBasicBlock *&FBB,
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
+ // TODO implement cases when AllowModify is true
+
+ if (MBB.empty())
+ return true;
+
+ MachineBasicBlock::const_iterator iter = MBB.end();
+ const MachineInstr& instLast1 = *--iter;
+ const TargetInstrDesc &desc1 = instLast1.getDesc();
+ // for special case that MBB has only 1 instruction
+ const bool IsSizeOne = MBB.size() == 1;
+ // if IsSizeOne is true, *--iter and instLast2 are invalid
+ // we put a dummy value in instLast2 and desc2 since they are used
+ const MachineInstr& instLast2 = IsSizeOne ? instLast1 : *--iter;
+ const TargetInstrDesc &desc2 = IsSizeOne ? desc1 : instLast2.getDesc();
+
+ DEBUG(dbgs() << "\n");
+ DEBUG(dbgs() << "AnalyzeBranch: opcode: " << instLast1.getOpcode() << "\n");
+ DEBUG(dbgs() << "AnalyzeBranch: MBB: " << MBB.getName().str() << "\n");
+ DEBUG(dbgs() << "AnalyzeBranch: TBB: " << TBB << "\n");
+ DEBUG(dbgs() << "AnalyzeBranch: FBB: " << FBB << "\n");
+
+ // this block ends with no branches
+ if (!IsAnyKindOfBranch(instLast1)) {
+ DEBUG(dbgs() << "AnalyzeBranch: ends with no branch\n");
+ return false;
+ }
+
+ // this block ends with only an unconditional branch
+ if (desc1.isUnconditionalBranch() &&
+ // when IsSizeOne is true, it "absorbs" the evaluation of instLast2
+ (IsSizeOne || !IsAnyKindOfBranch(instLast2))) {
+ DEBUG(dbgs() << "AnalyzeBranch: ends with only uncond branch\n");
+ TBB = GetBranchTarget(instLast1);
+ return false;
+ }
+
+ // this block ends with a conditional branch and
+ // it falls through to a successor block
+ if (desc1.isConditionalBranch() &&
+ IsAnySuccessorAlsoLayoutSuccessor(MBB)) {
+ DEBUG(dbgs() << "AnalyzeBranch: ends with cond branch and fall through\n");
+ TBB = GetBranchTarget(instLast1);
+ int i = instLast1.findFirstPredOperandIdx();
+ Cond.push_back(instLast1.getOperand(i));
+ Cond.push_back(instLast1.getOperand(i+1));
+ return false;
+ }
+
+ // when IsSizeOne is true, we are done
+ if (IsSizeOne)
+ return true;
+
+ // this block ends with a conditional branch
+ // followed by an unconditional branch
+ if (desc2.isConditionalBranch() &&
+ desc1.isUnconditionalBranch()) {
+ DEBUG(dbgs() << "AnalyzeBranch: ends with cond and uncond branch\n");
+ TBB = GetBranchTarget(instLast2);
+ FBB = GetBranchTarget(instLast1);
+ int i = instLast2.findFirstPredOperandIdx();
+ Cond.push_back(instLast2.getOperand(i));
+ Cond.push_back(instLast2.getOperand(i+1));
+ return false;
+ }
+
+ // branch cannot be understood
+ DEBUG(dbgs() << "AnalyzeBranch: cannot be understood\n");
+ return true;
+}
+
+unsigned PTXInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
+ unsigned count;
+ for (count = 0; IsAnyKindOfBranch(MBB.back()); ++count)
+ MBB.pop_back();
+ DEBUG(dbgs() << "RemoveBranch: MBB: " << MBB.getName().str() << "\n");
+ DEBUG(dbgs() << "RemoveBranch: count: " << count << "\n");
+ return count;
+}
+
+unsigned PTXInstrInfo::
+InsertBranch(MachineBasicBlock &MBB,
+ MachineBasicBlock *TBB,
+ MachineBasicBlock *FBB,
+ const SmallVectorImpl<MachineOperand> &Cond,
+ DebugLoc DL) const {
+ DEBUG(dbgs() << "InsertBranch: MBB: " << MBB.getName().str() << "\n");
+ DEBUG(if (TBB) dbgs() << "InsertBranch: TBB: "
+ << TBB->getName().str() << "\n";
+ else dbgs() << "InsertBranch: TBB: (NULL)\n");
+ DEBUG(if (FBB) dbgs() << "InsertBranch: FBB: "
+ << FBB->getName().str() << "\n";
+ else dbgs() << "InsertBranch: FBB: (NULL)\n");
+ DEBUG(dbgs() << "InsertBranch: Cond size: " << Cond.size() << "\n");
+
+ assert(TBB && "TBB is NULL");
+
+ if (FBB) {
+ BuildMI(&MBB, DL, get(PTX::BRAdp))
+ .addMBB(TBB).addReg(Cond[0].getReg()).addImm(Cond[1].getImm());
+ BuildMI(&MBB, DL, get(PTX::BRAd))
+ .addMBB(FBB).addReg(PTX::NoRegister).addImm(PTX::PRED_NORMAL);
+ return 2;
+ } else if (Cond.size()) {
+ BuildMI(&MBB, DL, get(PTX::BRAdp))
+ .addMBB(TBB).addReg(Cond[0].getReg()).addImm(Cond[1].getImm());
+ return 1;
+ } else {
+ BuildMI(&MBB, DL, get(PTX::BRAd))
+ .addMBB(TBB).addReg(PTX::NoRegister).addImm(PTX::PRED_NORMAL);
+ return 1;
+ }
+}
+
// static helper routines
MachineSDNode *PTXInstrInfo::
@@ -187,7 +311,28 @@
void PTXInstrInfo::AddDefaultPredicate(MachineInstr *MI) {
if (MI->findFirstPredOperandIdx() == -1) {
- MI->addOperand(MachineOperand::CreateReg(0, /*IsDef=*/false));
+ MI->addOperand(MachineOperand::CreateReg(PTX::NoRegister, /*IsDef=*/false));
MI->addOperand(MachineOperand::CreateImm(PTX::PRED_NORMAL));
}
}
+
+bool PTXInstrInfo::IsAnyKindOfBranch(const MachineInstr& inst) {
+ const TargetInstrDesc &desc = inst.getDesc();
+ return desc.isTerminator() || desc.isBranch() || desc.isIndirectBranch();
+}
+
+bool PTXInstrInfo::
+IsAnySuccessorAlsoLayoutSuccessor(const MachineBasicBlock& MBB) {
+ for (MachineBasicBlock::const_succ_iterator
+ i = MBB.succ_begin(), e = MBB.succ_end(); i != e; ++i)
+ if (MBB.isLayoutSuccessor((const MachineBasicBlock*) &*i))
+ return true;
+ return false;
+}
+
+MachineBasicBlock *PTXInstrInfo::GetBranchTarget(const MachineInstr& inst) {
+ // FIXME So far all branch instructions put destination in 1st operand
+ const MachineOperand& target = inst.getOperand(0);
+ assert(target.isMBB() && "FIXME: detect branch target operand");
+ return target.getMBB();
+}
Modified: llvm/trunk/lib/Target/PTX/PTXInstrInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PTX/PTXInstrInfo.h?rev=128084&r1=128083&r2=128084&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PTX/PTXInstrInfo.h (original)
+++ llvm/trunk/lib/Target/PTX/PTXInstrInfo.h Tue Mar 22 09:12:00 2011
@@ -70,6 +70,20 @@
// PTX is fully-predicable
virtual bool isPredicable(MachineInstr *MI) const { return true; }
+ // branch support
+
+ 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,
+ DebugLoc DL) const;
+
// static helper routines
static MachineSDNode *GetPTXMachineNode(SelectionDAG *DAG, unsigned Opcode,
@@ -81,6 +95,12 @@
SDValue Op1, SDValue Op2);
static void AddDefaultPredicate(MachineInstr *MI);
+
+ static bool IsAnyKindOfBranch(const MachineInstr& inst);
+
+ static bool IsAnySuccessorAlsoLayoutSuccessor(const MachineBasicBlock& MBB);
+
+ static MachineBasicBlock *GetBranchTarget(const MachineInstr& inst);
}; // class PTXInstrInfo
} // namespace llvm
Modified: llvm/trunk/lib/Target/PTX/PTXInstrInfo.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PTX/PTXInstrInfo.td?rev=128084&r1=128083&r2=128084&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PTX/PTXInstrInfo.td (original)
+++ llvm/trunk/lib/Target/PTX/PTXInstrInfo.td Tue Mar 22 09:12:00 2011
@@ -575,10 +575,12 @@
///===- Control Flow Instructions -----------------------------------------===//
-let isBranch = 1, isTerminator = 1 in {
+let isBranch = 1, isTerminator = 1, isBarrier = 1 in {
def BRAd
: InstPTX<(outs), (ins brtarget:$d), "bra\t$d", [(br bb:$d)]>;
+}
+let isBranch = 1, isTerminator = 1 in {
// FIXME: should be able to write a pattern for brcond, but can't use
// a two-value operand where a dag node expects two operands. :(
// NOTE: ARM & PowerPC backend also report the same problem
Modified: llvm/trunk/test/CodeGen/PTX/bra.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PTX/bra.ll?rev=128084&r1=128083&r2=128084&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/PTX/bra.ll (original)
+++ llvm/trunk/test/CodeGen/PTX/bra.ll Tue Mar 22 09:12:00 2011
@@ -10,7 +10,10 @@
define ptx_device i32 @test_bra_cond_direct(i32 %x, i32 %y) {
entry:
+; CHECK: setp.le.u32 p0, r1, r2
%p = icmp ugt i32 %x, %y
+; CHECK-NEXT: @p0 bra
+; CHECK-NOT: bra
br i1 %p, label %clause.if, label %clause.else
clause.if:
; CHECK: mov.u32 r0, r1
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