diff options
author | Evan Cheng <evan.cheng@apple.com> | 2011-12-07 07:15:52 +0000 |
---|---|---|
committer | Evan Cheng <evan.cheng@apple.com> | 2011-12-07 07:15:52 +0000 |
commit | 5a96b3dad2f634c9081c8b2b6c2575441dc5a2bd (patch) | |
tree | 88fa5be8f6cf6e9a222e79c8806f29c8841925d1 /include/llvm/CodeGen/MachineInstr.h | |
parent | 5729c5848c74a2413cc1d32a5f3c746aff5d9ccc (diff) |
Add bundle aware API for querying instruction properties and switch the code
generator to it. For non-bundle instructions, these behave exactly the same
as the MC layer API.
For properties like mayLoad / mayStore, look into the bundle and if any of the
bundled instructions has the property it would return true.
For properties like isPredicable, only return true if *all* of the bundled
instructions have the property.
For properties like canFoldAsLoad, isCompare, conservatively return false for
bundles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146026 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include/llvm/CodeGen/MachineInstr.h')
-rw-r--r-- | include/llvm/CodeGen/MachineInstr.h | 257 |
1 files changed, 255 insertions, 2 deletions
diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h index 1558c4f957..00b41e74c2 100644 --- a/include/llvm/CodeGen/MachineInstr.h +++ b/include/llvm/CodeGen/MachineInstr.h @@ -274,14 +274,267 @@ public: return MemRefsEnd - MemRefs == 1; } - /// API for querying MachineInstr properties. These are bundle aware. + /// API for querying MachineInstr properties. They are the same as MCInstrDesc + /// queries but they are bundle aware. + + /// hasProperty - Return true if the instruction (or in the case of a bundle, + /// the instructions inside the bundle) has the specified property. + /// The first argument is the property being queried. + /// The second argument indicates whether the query should look inside + /// instruction bundles. + /// If the third argument is true, than the query can return true when *any* + /// of the bundled instructions has the queried property. If it's false, then + /// this can return true iff *all* of the instructions have the property. + bool hasProperty(unsigned Flag, + bool PeekInBundle = true, bool IsOr = true) const; + + /// isVariadic - Return true if this instruction can have a variable number of + /// operands. In this case, the variable operands will be after the normal + /// operands but before the implicit definitions and uses (if any are + /// present). + bool isVariadic() const { + return hasProperty(MCID::Variadic, false); + } + + /// hasOptionalDef - Set if this instruction has an optional definition, e.g. + /// ARM instructions which can set condition code if 's' bit is set. + bool hasOptionalDef() const { + return hasProperty(MCID::HasOptionalDef, false); + } + + /// isPseudo - Return true if this is a pseudo instruction that doesn't + /// correspond to a real machine instruction. /// - bool hasProperty(unsigned short Flag) const; + bool isPseudo() const { + return hasProperty(MCID::Pseudo, false); + } + + bool isReturn() const { + return hasProperty(MCID::Return); + } + + bool isCall() const { + return hasProperty(MCID::Call); + } + + /// isBarrier - Returns true if the specified instruction stops control flow + /// from executing the instruction immediately following it. Examples include + /// unconditional branches and return instructions. + bool isBarrier() const { + return hasProperty(MCID::Barrier); + } + /// isTerminator - Returns true if this instruction part of the terminator for + /// a basic block. Typically this is things like return and branch + /// instructions. + /// + /// Various passes use this to insert code into the bottom of a basic block, + /// but before control flow occurs. bool isTerminator() const { return hasProperty(MCID::Terminator); } + /// isBranch - Returns true if this is a conditional, unconditional, or + /// indirect branch. Predicates below can be used to discriminate between + /// these cases, and the TargetInstrInfo::AnalyzeBranch method can be used to + /// get more information. + bool isBranch() const { + return hasProperty(MCID::Branch); + } + + /// isIndirectBranch - Return true if this is an indirect branch, such as a + /// branch through a register. + bool isIndirectBranch() const { + return hasProperty(MCID::IndirectBranch); + } + + /// isConditionalBranch - Return true if this is a branch which may fall + /// through to the next instruction or may transfer control flow to some other + /// block. The TargetInstrInfo::AnalyzeBranch method can be used to get more + /// information about this branch. + bool isConditionalBranch() const { + return isBranch() & !isBarrier() & !isIndirectBranch(); + } + + /// isUnconditionalBranch - Return true if this is a branch which always + /// transfers control flow to some other block. The + /// TargetInstrInfo::AnalyzeBranch method can be used to get more information + /// about this branch. + bool isUnconditionalBranch() const { + return isBranch() & isBarrier() & !isIndirectBranch(); + } + + // isPredicable - Return true if this instruction has a predicate operand that + // controls execution. It may be set to 'always', or may be set to other + /// values. There are various methods in TargetInstrInfo that can be used to + /// control and modify the predicate in this instruction. + bool isPredicable() const { + // If it's a bundle than all bundled instructions must be predicable for this + // to return true. + return hasProperty(MCID::Predicable, true, false); + } + + /// isCompare - Return true if this instruction is a comparison. + bool isCompare() const { + return hasProperty(MCID::Compare, false); + } + + /// isMoveImmediate - Return true if this instruction is a move immediate + /// (including conditional moves) instruction. + bool isMoveImmediate() const { + return hasProperty(MCID::MoveImm, false); + } + + /// isBitcast - Return true if this instruction is a bitcast instruction. + /// + bool isBitcast() const { + return hasProperty(MCID::Bitcast, false); + } + + /// isNotDuplicable - Return true if this instruction cannot be safely + /// duplicated. For example, if the instruction has a unique labels attached + /// to it, duplicating it would cause multiple definition errors. + bool isNotDuplicable() const { + return hasProperty(MCID::NotDuplicable); + } + + /// hasDelaySlot - Returns true if the specified instruction has a delay slot + /// which must be filled by the code generator. + bool hasDelaySlot() const { + return hasProperty(MCID::DelaySlot); + } + + /// canFoldAsLoad - Return true for instructions that can be folded as + /// memory operands in other instructions. The most common use for this + /// is instructions that are simple loads from memory that don't modify + /// the loaded value in any way, but it can also be used for instructions + /// that can be expressed as constant-pool loads, such as V_SETALLONES + /// on x86, to allow them to be folded when it is beneficial. + /// This should only be set on instructions that return a value in their + /// only virtual register definition. + bool canFoldAsLoad() const { + return hasProperty(MCID::FoldableAsLoad, false); + } + + //===--------------------------------------------------------------------===// + // Side Effect Analysis + //===--------------------------------------------------------------------===// + + /// mayLoad - Return true if this instruction could possibly read memory. + /// Instructions with this flag set are not necessarily simple load + /// instructions, they may load a value and modify it, for example. + bool mayLoad() const { + return hasProperty(MCID::MayLoad); + } + + + /// mayStore - Return true if this instruction could possibly modify memory. + /// Instructions with this flag set are not necessarily simple store + /// instructions, they may store a modified value based on their operands, or + /// may not actually modify anything, for example. + bool mayStore() const { + return hasProperty(MCID::MayStore); + } + + //===--------------------------------------------------------------------===// + // Flags that indicate whether an instruction can be modified by a method. + //===--------------------------------------------------------------------===// + + /// isCommutable - Return true if this may be a 2- or 3-address + /// instruction (of the form "X = op Y, Z, ..."), which produces the same + /// result if Y and Z are exchanged. If this flag is set, then the + /// TargetInstrInfo::commuteInstruction method may be used to hack on the + /// instruction. + /// + /// Note that this flag may be set on instructions that are only commutable + /// sometimes. In these cases, the call to commuteInstruction will fail. + /// Also note that some instructions require non-trivial modification to + /// commute them. + bool isCommutable() const { + return hasProperty(MCID::Commutable, false); + } + + /// isConvertibleTo3Addr - Return true if this is a 2-address instruction + /// which can be changed into a 3-address instruction if needed. Doing this + /// transformation can be profitable in the register allocator, because it + /// means that the instruction can use a 2-address form if possible, but + /// degrade into a less efficient form if the source and dest register cannot + /// be assigned to the same register. For example, this allows the x86 + /// backend to turn a "shl reg, 3" instruction into an LEA instruction, which + /// is the same speed as the shift but has bigger code size. + /// + /// If this returns true, then the target must implement the + /// TargetInstrInfo::convertToThreeAddress method for this instruction, which + /// is allowed to fail if the transformation isn't valid for this specific + /// instruction (e.g. shl reg, 4 on x86). + /// + bool isConvertibleTo3Addr() const { + return hasProperty(MCID::ConvertibleTo3Addr, false); + } + + /// usesCustomInsertionHook - Return true if this instruction requires + /// custom insertion support when the DAG scheduler is inserting it into a + /// machine basic block. If this is true for the instruction, it basically + /// means that it is a pseudo instruction used at SelectionDAG time that is + /// expanded out into magic code by the target when MachineInstrs are formed. + /// + /// If this is true, the TargetLoweringInfo::InsertAtEndOfBasicBlock method + /// is used to insert this into the MachineBasicBlock. + bool usesCustomInsertionHook() const { + return hasProperty(MCID::UsesCustomInserter, false); + } + + /// hasPostISelHook - Return true if this instruction requires *adjustment* + /// after instruction selection by calling a target hook. For example, this + /// can be used to fill in ARM 's' optional operand depending on whether + /// the conditional flag register is used. + bool hasPostISelHook() const { + return hasProperty(MCID::HasPostISelHook, false); + } + + /// isRematerializable - Returns true if this instruction is a candidate for + /// remat. This flag is deprecated, please don't use it anymore. If this + /// flag is set, the isReallyTriviallyReMaterializable() method is called to + /// verify the instruction is really rematable. + bool isRematerializable() const { + // It's only possible to re-mat a bundle if all bundled instructions are + // re-materializable. + return hasProperty(MCID::Rematerializable, true, false); + } + + /// isAsCheapAsAMove - Returns true if this instruction has the same cost (or + /// less) than a move instruction. This is useful during certain types of + /// optimizations (e.g., remat during two-address conversion or machine licm) + /// where we would like to remat or hoist the instruction, but not if it costs + /// more than moving the instruction into the appropriate register. Note, we + /// are not marking copies from and to the same register class with this flag. + bool isAsCheapAsAMove() const { + // Only returns true for a bundle if all bundled instructions are cheap. + // FIXME: This probably requires a target hook. + return hasProperty(MCID::CheapAsAMove, true, true); + } + + /// hasExtraSrcRegAllocReq - Returns true if this instruction source operands + /// have special register allocation requirements that are not captured by the + /// operand register classes. e.g. ARM::STRD's two source registers must be an + /// even / odd pair, ARM::STM registers have to be in ascending order. + /// Post-register allocation passes should not attempt to change allocations + /// for sources of instructions with this flag. + bool hasExtraSrcRegAllocReq() const { + return hasProperty(MCID::ExtraSrcRegAllocReq); + } + + /// hasExtraDefRegAllocReq - Returns true if this instruction def operands + /// have special register allocation requirements that are not captured by the + /// operand register classes. e.g. ARM::LDRD's two def registers must be an + /// even / odd pair, ARM::LDM registers have to be in ascending order. + /// Post-register allocation passes should not attempt to change allocations + /// for definitions of instructions with this flag. + bool hasExtraDefRegAllocReq() const { + return hasProperty(MCID::ExtraDefRegAllocReq); + } + + enum MICheckType { CheckDefs, // Check all operands for equality CheckKillDead, // Check all operands including kill / dead markers |