VFABIDemangler.cpp | Explore in Territory

//===- VFABIDemangler.cpp - Vector Function ABI demangler -----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "llvm/IR/VFABIDemangler.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <limits>

usingnamespacellvm;

#define DEBUG_TYPE …

namespace {
/// Utilities for the Vector Function ABI name parser.

/// Return types for the parser functions.
enum class ParseRet { … };

/// Extracts the `<isa>` information from the mangled string, and
/// sets the `ISA` accordingly. If successful, the <isa> token is removed
/// from the input string `MangledName`.
static ParseRet tryParseISA(StringRef &MangledName, VFISAKind &ISA) { … }

/// Extracts the `<mask>` information from the mangled string, and
/// sets `IsMasked` accordingly. If successful, the <mask> token is removed
/// from the input string `MangledName`.
static ParseRet tryParseMask(StringRef &MangledName, bool &IsMasked) { … }

/// Extract the `<vlen>` information from the mangled string, and
/// sets `ParsedVF` accordingly. A `<vlen> == "x"` token is interpreted as a
/// scalable vector length and the boolean is set to true, otherwise a nonzero
/// unsigned integer will be directly used as a VF. On success, the `<vlen>`
/// token is removed from the input string `ParseString`.
static ParseRet tryParseVLEN(StringRef &ParseString, VFISAKind ISA,
                             std::pair<unsigned, bool> &ParsedVF) { … }

/// The function looks for the following strings at the beginning of
/// the input string `ParseString`:
///
///  <token> <number>
///
/// On success, it removes the parsed parameter from `ParseString`,
/// sets `PKind` to the correspondent enum value, sets `Pos` to
/// <number>, and return success.  On a syntax error, it return a
/// parsing error. If nothing is parsed, it returns std::nullopt.
///
/// The function expects <token> to be one of "ls", "Rs", "Us" or
/// "Ls".
static ParseRet tryParseLinearTokenWithRuntimeStep(StringRef &ParseString,
                                                   VFParamKind &PKind, int &Pos,
                                                   const StringRef Token) { … }

/// The function looks for the following string at the beginning of
/// the input string `ParseString`:
///
///  <token> <number>
///
/// <token> is one of "ls", "Rs", "Us" or "Ls".
///
/// On success, it removes the parsed parameter from `ParseString`,
/// sets `PKind` to the correspondent enum value, sets `StepOrPos` to
/// <number>, and return success.  On a syntax error, it return a
/// parsing error. If nothing is parsed, it returns std::nullopt.
static ParseRet tryParseLinearWithRuntimeStep(StringRef &ParseString,
                                              VFParamKind &PKind,
                                              int &StepOrPos) { … }

/// The function looks for the following strings at the beginning of
/// the input string `ParseString`:
///
///  <token> {"n"} <number>
///
/// On success, it removes the parsed parameter from `ParseString`,
/// sets `PKind` to the correspondent enum value, sets `LinearStep` to
/// <number>, and return success.  On a syntax error, it return a
/// parsing error. If nothing is parsed, it returns std::nullopt.
///
/// The function expects <token> to be one of "l", "R", "U" or
/// "L".
static ParseRet tryParseCompileTimeLinearToken(StringRef &ParseString,
                                               VFParamKind &PKind,
                                               int &LinearStep,
                                               const StringRef Token) { … }

/// The function looks for the following strings at the beginning of
/// the input string `ParseString`:
///
/// ["l" | "R" | "U" | "L"] {"n"} <number>
///
/// On success, it removes the parsed parameter from `ParseString`,
/// sets `PKind` to the correspondent enum value, sets `LinearStep` to
/// <number>, and return success.  On a syntax error, it return a
/// parsing error. If nothing is parsed, it returns std::nullopt.
static ParseRet tryParseLinearWithCompileTimeStep(StringRef &ParseString,
                                                  VFParamKind &PKind,
                                                  int &StepOrPos) { … }

/// Looks into the <parameters> part of the mangled name in search
/// for valid paramaters at the beginning of the string
/// `ParseString`.
///
/// On success, it removes the parsed parameter from `ParseString`,
/// sets `PKind` to the correspondent enum value, sets `StepOrPos`
/// accordingly, and return success.  On a syntax error, it return a
/// parsing error. If nothing is parsed, it returns std::nullopt.
static ParseRet tryParseParameter(StringRef &ParseString, VFParamKind &PKind,
                                  int &StepOrPos) { … }

/// Looks into the <parameters> part of the mangled name in search
/// of a valid 'aligned' clause. The function should be invoked
/// after parsing a parameter via `tryParseParameter`.
///
/// On success, it removes the parsed parameter from `ParseString`,
/// sets `PKind` to the correspondent enum value, sets `StepOrPos`
/// accordingly, and return success.  On a syntax error, it return a
/// parsing error. If nothing is parsed, it returns std::nullopt.
static ParseRet tryParseAlign(StringRef &ParseString, Align &Alignment) { … }

// Returns the 'natural' VF for a given scalar element type, based on the
// current architecture.
//
// For SVE (currently the only scalable architecture with a defined name
// mangling), we assume a minimum vector size of 128b and return a VF based on
// the number of elements of the given type which would fit in such a vector.
static std::optional<ElementCount> getElementCountForTy(const VFISAKind ISA,
                                                        const Type *Ty) { … }

// Extract the VectorizationFactor from a given function signature, based
// on the widest scalar element types that will become vector parameters.
static std::optional<ElementCount>
getScalableECFromSignature(const FunctionType *Signature, const VFISAKind ISA,
                           const SmallVectorImpl<VFParameter> &Params) { … }
} // namespace

// Format of the ABI name:
// _ZGV<isa><mask><vlen><parameters>_<scalarname>[(<redirection>)]
std::optional<VFInfo> VFABI::tryDemangleForVFABI(StringRef MangledName,
                                                 const FunctionType *FTy) { … }

VFParamKind VFABI::getVFParamKindFromString(const StringRef Token) { … }

void VFABI::getVectorVariantNames(
    const CallInst &CI, SmallVectorImpl<std::string> &VariantMappings) { … }

FunctionType *VFABI::createFunctionType(const VFInfo &Info,
                                        const FunctionType *ScalarFTy) { … }

void VFABI::setVectorVariantNames(CallInst *CI,
                                  ArrayRef<std::string> VariantMappings) { … }

bool VFShape::hasValidParameterList() const { … }
llvm/llvm/lib/IR/VFABIDemangler.cpp
