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//===- SubtargetFeature.cpp - CPU characteristics Implementation ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Jim Laskey and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SubtargetFeature interface.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/SubtargetFeature.h"
#include <string>
#include <algorithm>
#include <vector>
#include <cassert>
#include <cctype>
using namespace llvm;
/// Splits a string of comma separated items in to a vector of strings.
void SubtargetFeatures::Split(std::vector<std::string> &V,
const std::string &S) {
// Start at beginning of string.
size_t Pos = 0;
while (true) {
// Find the next comma
size_t Comma = S.find(',', Pos);
// If no comma found then the the rest of the string is used
if (Comma == std::string::npos) {
// Add string to vector
V.push_back(S.substr(Pos));
break;
}
// Otherwise add substring to vector
V.push_back(S.substr(Pos, Comma - Pos));
// Advance to next item
Pos = Comma + 1;
}
}
/// Join a vector of strings to a string with a comma separating each element.
std::string SubtargetFeatures::Join(const std::vector<std::string> &V) {
// Start with empty string.
std::string Result;
// If the vector is not empty
if (!V.empty()) {
// Start with the CPU feature
Result = V[0];
// For each successive feature
for (size_t i = 1; i < V.size(); i++) {
// Add a comma
Result += ",";
// Add the feature
Result += V[i];
}
}
// Return the features string
return Result;
}
/// Convert a string to lowercase.
std::string SubtargetFeatures::toLower(const std::string &S) {
// Copy the string
std::string Result = S;
// For each character in string
for (size_t i = 0; i < Result.size(); i++) {
// Convert character to lowercase
Result[i] = std::tolower(Result[i]);
}
// Return the lowercased string
return Result;
}
/// Adding features.
void SubtargetFeatures::AddFeature(const std::string &String,
bool IsEnabled) {
// Don't add empty features
if (!String.empty()) {
// Convert to lowercase, prepend flag and add to vector
Features.push_back(PrependFlag(toLower(String), IsEnabled));
}
}
/// Find item in array using binary search.
const SubtargetFeatureKV *
SubtargetFeatures::Find(const std::string &S,
const SubtargetFeatureKV *A, size_t L) {
// Determine the end of the array
const SubtargetFeatureKV *Hi = A + L;
// Binary search the array
const SubtargetFeatureKV *F = std::lower_bound(A, Hi, S);
// If not found then return NULL
if (F == Hi || std::string(F->Key) != S) return NULL;
// Return the found array item
return F;
}
/// Display help for feature choices.
void SubtargetFeatures::Help(const char *Heading,
const SubtargetFeatureKV *Table, size_t TableSize) {
// Determine the length of the longest key
size_t MaxLen = 0;
for (size_t i = 0; i < TableSize; i++)
MaxLen = std::max(MaxLen, std::strlen(Table[i].Key));
// Print heading
std::cerr << "Help for " << Heading << " choices\n\n";
// For each feature
for (size_t i = 0; i < TableSize; i++) {
// Compute required padding
size_t Pad = MaxLen - std::strlen(Table[i].Key) + 1;
// Print details
std::cerr << Table[i].Key << std::string(Pad, ' ') << " - "
<< Table[i].Desc << "\n";
}
// Wrap it up
std::cerr << "\n\n";
// Leave tool
exit(1);
}
/// Parse feature string for quick usage.
uint32_t SubtargetFeatures::Parse(const std::string &String,
const std::string &DefaultCPU,
const SubtargetFeatureKV *CPUTable,
size_t CPUTableSize,
const SubtargetFeatureKV *FeatureTable,
size_t FeatureTableSize) {
assert(CPUTable && "missing CPU table");
assert(FeatureTable && "missing features table");
#ifndef NDEBUG
for (size_t i = 1; i < CPUTableSize; i++) {
assert(strcmp(CPUTable[i - 1].Key, CPUTable[i].Key) < 0 &&
"CPU table is not sorted");
}
for (size_t i = 1; i < FeatureTableSize; i++) {
assert(strcmp(FeatureTable[i - 1].Key, FeatureTable[i].Key) < 0 &&
"CPU features table is not sorted");
}
#endif
std::vector<std::string> Features; // Subtarget features as a vector
uint32_t Bits = 0; // Resulting bits
// Split up features
Split(Features, String);
// Check if default is needed
if (Features[0].empty()) Features[0] = DefaultCPU;
// Check for help
if (Features[0] == "help") Help("CPU", CPUTable, CPUTableSize);
// Find CPU entry
const SubtargetFeatureKV *CPUEntry =
Find(Features[0], CPUTable, CPUTableSize);
// If there is a match
if (CPUEntry) {
// Set base feature bits
Bits = CPUEntry->Value;
} else {
std::cerr << Features[0]
<< " is not a recognized processor for this target"
<< " (ignoring processor)"
<< "\n";
}
// Iterate through each feature
for (size_t i = 1; i < Features.size(); i++) {
// Get next feature
const std::string &Feature = Features[i];
// Check for help
if (Feature == "+help") Help("feature", FeatureTable, FeatureTableSize);
// Find feature in table.
const SubtargetFeatureKV *FeatureEntry =
Find(StripFlag(Feature), FeatureTable, FeatureTableSize);
// If there is a match
if (FeatureEntry) {
// Enable/disable feature in bits
if (isEnabled(Feature)) Bits |= FeatureEntry->Value;
else Bits &= ~FeatureEntry->Value;
} else {
std::cerr << Feature
<< " is not a recognized feature for this target"
<< " (ignoring feature)"
<< "\n";
}
}
return Bits;
}
/// Print feature string.
void SubtargetFeatures::print(std::ostream &OS) const {
for (size_t i = 0; i < Features.size(); i++) {
OS << Features[i] << " ";
}
OS << "\n";
}
/// Dump feature info.
void SubtargetFeatures::dump() const {
print(std::cerr);
}
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