LLVM API Documentation
#include "llvm/Target/TargetLowering.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include <cctype>
Go to the source code of this file.
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static bool | ValueHasExactlyOneBitSet (SDValue Val, const SelectionDAG &DAG) |
static unsigned | getConstraintGenerality (TargetLowering::ConstraintType CT) |
static void | ChooseConstraint (TargetLowering::AsmOperandInfo &OpInfo, const TargetLowering &TLI, SDValue Op, SelectionDAG *DAG) |
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static |
ChooseConstraint - If there are multiple different constraints that we could pick for this operand (e.g. "imr") try to pick the 'best' one. This is somewhat tricky: constraints fall into four classes: Other -> immediates and magic values Register -> one specific register RegisterClass -> a group of regs Memory -> memory Ideally, we would pick the most specific constraint possible: if we have something that fits into a register, we would pick it. The problem here is that if we have something that could either be in a register or in memory that use of the register could cause selection of other operands to fail: they might only succeed if we pick memory. Because of this the heuristic we use is:
1) If there is an 'other' constraint, and if the operand is valid for that constraint, use it. This makes us take advantage of 'i' constraints when available. 2) Otherwise, pick the most general constraint present. This prefers 'm' over 'r', for example.
Definition at line 2426 of file TargetLowering.cpp.
References llvm::TargetLowering::C_Memory, llvm::TargetLowering::C_Other, llvm::TargetLowering::C_Unknown, llvm::InlineAsm::ConstraintInfo::Codes, llvm::TargetLowering::AsmOperandInfo::ConstraintCode, llvm::TargetLowering::AsmOperandInfo::ConstraintType, getConstraintGenerality(), llvm::TargetLowering::getConstraintType(), llvm::SDValue::getNode(), llvm::InlineAsm::ConstraintInfo::hasMatchingInput(), and llvm::TargetLowering::LowerAsmOperandForConstraint().
Referenced by llvm::TargetLowering::ComputeConstraintToUse().
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getConstraintGenerality - Return an integer indicating how general CT is.
Definition at line 2318 of file TargetLowering.cpp.
References llvm::TargetLowering::C_Memory, llvm::TargetLowering::C_Other, llvm::TargetLowering::C_Register, llvm::TargetLowering::C_RegisterClass, llvm::TargetLowering::C_Unknown, and llvm_unreachable.
Referenced by ChooseConstraint().
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ValueHasExactlyOneBitSet - Test if the given value is known to have exactly one bit set. This differs from ComputeMaskedBits in that it doesn't need to determine which bit is set.
Definition at line 1089 of file TargetLowering.cpp.
References llvm::CallingConv::C, llvm::SelectionDAG::ComputeMaskedBits(), llvm::APInt::countPopulation(), llvm::SDValue::getNode(), llvm::SDValue::getOpcode(), llvm::SDNode::getOperand(), llvm::EVT::getScalarType(), llvm::EVT::getSizeInBits(), llvm::SDValue::getValueType(), llvm::ISD::SHL, and llvm::ISD::SRL.
Referenced by llvm::TargetLowering::SimplifySetCC().