llvm-project/llvm/lib/Target/TargetRecip.cpp

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//===-------------------------- TargetRecip.cpp ---------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class is used to customize machine-specific reciprocal estimate code
// generation in a target-independent way.
// If a target does not support operations in this specification, then code
// generation will default to using supported operations.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetRecip.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
// These are the names of the individual reciprocal operations. These are
// the key strings for queries and command-line inputs.
// In addition, the command-line interface recognizes the global parameters
// "all", "none", and "default".
static const char *const RecipOps[] = {
"divd",
"divf",
"vec-divd",
"vec-divf",
"sqrtd",
"sqrtf",
"vec-sqrtd",
"vec-sqrtf",
};
// The uninitialized state is needed for the enabled settings and refinement
// steps because custom settings may arrive via the command-line before target
// defaults are set.
TargetRecip::TargetRecip() {
unsigned NumStrings = llvm::array_lengthof(RecipOps);
for (unsigned i = 0; i < NumStrings; ++i)
RecipMap.insert(std::make_pair(RecipOps[i], RecipParams()));
}
static bool parseRefinementStep(StringRef In, size_t &Position,
uint8_t &Value) {
const char RefStepToken = ':';
Position = In.find(RefStepToken);
if (Position == StringRef::npos)
return false;
StringRef RefStepString = In.substr(Position + 1);
// Allow exactly one numeric character for the additional refinement
// step parameter.
if (RefStepString.size() == 1) {
char RefStepChar = RefStepString[0];
if (RefStepChar >= '0' && RefStepChar <= '9') {
Value = RefStepChar - '0';
return true;
}
}
report_fatal_error("Invalid refinement step for -recip.");
}
bool TargetRecip::parseGlobalParams(const std::string &Arg) {
StringRef ArgSub = Arg;
// Look for an optional setting of the number of refinement steps needed
// for this type of reciprocal operation.
size_t RefPos;
uint8_t RefSteps;
StringRef RefStepString;
if (parseRefinementStep(ArgSub, RefPos, RefSteps)) {
// Split the string for further processing.
RefStepString = ArgSub.substr(RefPos + 1);
ArgSub = ArgSub.substr(0, RefPos);
}
bool Enable;
bool UseDefaults;
if (ArgSub == "all") {
UseDefaults = false;
Enable = true;
} else if (ArgSub == "none") {
UseDefaults = false;
Enable = false;
} else if (ArgSub == "default") {
UseDefaults = true;
} else {
// Any other string is invalid or an individual setting.
return false;
}
// All enable values will be initialized to target defaults if 'default' was
// specified.
if (!UseDefaults)
for (auto &KV : RecipMap)
KV.second.Enabled = Enable;
// Custom refinement count was specified with all, none, or default.
if (!RefStepString.empty())
for (auto &KV : RecipMap)
KV.second.RefinementSteps = RefSteps;
return true;
}
void TargetRecip::parseIndividualParams(const std::vector<std::string> &Args) {
static const char DisabledPrefix = '!';
unsigned NumArgs = Args.size();
for (unsigned i = 0; i != NumArgs; ++i) {
StringRef Val = Args[i];
bool IsDisabled = Val[0] == DisabledPrefix;
// Ignore the disablement token for string matching.
if (IsDisabled)
Val = Val.substr(1);
size_t RefPos;
uint8_t RefSteps;
StringRef RefStepString;
if (parseRefinementStep(Val, RefPos, RefSteps)) {
// Split the string for further processing.
RefStepString = Val.substr(RefPos + 1);
Val = Val.substr(0, RefPos);
}
RecipIter Iter = RecipMap.find(Val);
if (Iter == RecipMap.end()) {
// Try again specifying float suffix.
Iter = RecipMap.find(Val.str() + 'f');
if (Iter == RecipMap.end()) {
Iter = RecipMap.find(Val.str() + 'd');
assert(Iter == RecipMap.end() && "Float entry missing from map");
report_fatal_error("Invalid option for -recip.");
}
// The option was specified without a float or double suffix.
if (RecipMap[Val.str() + 'd'].Enabled != Uninitialized) {
// Make sure that the double entry was not already specified.
// The float entry will be checked below.
report_fatal_error("Duplicate option for -recip.");
}
}
if (Iter->second.Enabled != Uninitialized)
report_fatal_error("Duplicate option for -recip.");
// Mark the matched option as found. Do not allow duplicate specifiers.
Iter->second.Enabled = !IsDisabled;
if (!RefStepString.empty())
Iter->second.RefinementSteps = RefSteps;
// If the precision was not specified, the double entry is also initialized.
if (Val.back() != 'f' && Val.back() != 'd') {
RecipMap[Val.str() + 'd'].Enabled = !IsDisabled;
if (!RefStepString.empty())
RecipMap[Val.str() + 'd'].RefinementSteps = RefSteps;
}
}
}
TargetRecip::TargetRecip(const std::vector<std::string> &Args) :
TargetRecip() {
unsigned NumArgs = Args.size();
// Check if "all", "default", or "none" was specified.
if (NumArgs == 1 && parseGlobalParams(Args[0]))
return;
parseIndividualParams(Args);
}
bool TargetRecip::isEnabled(StringRef Key) const {
ConstRecipIter Iter = RecipMap.find(Key);
assert(Iter != RecipMap.end() && "Unknown name for reciprocal map");
assert(Iter->second.Enabled != Uninitialized &&
"Enablement setting was not initialized");
return Iter->second.Enabled;
}
unsigned TargetRecip::getRefinementSteps(StringRef Key) const {
ConstRecipIter Iter = RecipMap.find(Key);
assert(Iter != RecipMap.end() && "Unknown name for reciprocal map");
assert(Iter->second.RefinementSteps != Uninitialized &&
"Refinement step setting was not initialized");
return Iter->second.RefinementSteps;
}
/// Custom settings (previously initialized values) override target defaults.
void TargetRecip::setDefaults(StringRef Key, bool Enable,
unsigned RefSteps) {
if (Key == "all") {
for (auto &KV : RecipMap) {
RecipParams &RP = KV.second;
if (RP.Enabled == Uninitialized)
RP.Enabled = Enable;
if (RP.RefinementSteps == Uninitialized)
RP.RefinementSteps = RefSteps;
}
} else {
RecipParams &RP = RecipMap[Key];
if (RP.Enabled == Uninitialized)
RP.Enabled = Enable;
if (RP.RefinementSteps == Uninitialized)
RP.RefinementSteps = RefSteps;
}
}
bool TargetRecip::operator==(const TargetRecip &Other) const {
for (const auto &KV : RecipMap) {
StringRef Op = KV.first;
const RecipParams &RP = KV.second;
const RecipParams &OtherRP = Other.RecipMap.find(Op)->second;
if (RP.RefinementSteps != OtherRP.RefinementSteps)
return false;
if (RP.Enabled != OtherRP.Enabled)
return false;
}
return true;
}