llvm-mirror/lib/MC/ConstantPools.cpp
Chandler Carruth ae65e281f3 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

116 lines
3.7 KiB
C++

//===- ConstantPools.cpp - ConstantPool class -----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements the ConstantPool and AssemblerConstantPools classes.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/ConstantPools.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDirectives.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/Casting.h"
using namespace llvm;
//
// ConstantPool implementation
//
// Emit the contents of the constant pool using the provided streamer.
void ConstantPool::emitEntries(MCStreamer &Streamer) {
if (Entries.empty())
return;
Streamer.EmitDataRegion(MCDR_DataRegion);
for (const ConstantPoolEntry &Entry : Entries) {
Streamer.EmitCodeAlignment(Entry.Size); // align naturally
Streamer.EmitLabel(Entry.Label);
Streamer.EmitValue(Entry.Value, Entry.Size, Entry.Loc);
}
Streamer.EmitDataRegion(MCDR_DataRegionEnd);
Entries.clear();
}
const MCExpr *ConstantPool::addEntry(const MCExpr *Value, MCContext &Context,
unsigned Size, SMLoc Loc) {
const MCConstantExpr *C = dyn_cast<MCConstantExpr>(Value);
// Check if there is existing entry for the same constant. If so, reuse it.
auto Itr = C ? CachedEntries.find(C->getValue()) : CachedEntries.end();
if (Itr != CachedEntries.end())
return Itr->second;
MCSymbol *CPEntryLabel = Context.createTempSymbol();
Entries.push_back(ConstantPoolEntry(CPEntryLabel, Value, Size, Loc));
const auto SymRef = MCSymbolRefExpr::create(CPEntryLabel, Context);
if (C)
CachedEntries[C->getValue()] = SymRef;
return SymRef;
}
bool ConstantPool::empty() { return Entries.empty(); }
void ConstantPool::clearCache() {
CachedEntries.clear();
}
//
// AssemblerConstantPools implementation
//
ConstantPool *AssemblerConstantPools::getConstantPool(MCSection *Section) {
ConstantPoolMapTy::iterator CP = ConstantPools.find(Section);
if (CP == ConstantPools.end())
return nullptr;
return &CP->second;
}
ConstantPool &
AssemblerConstantPools::getOrCreateConstantPool(MCSection *Section) {
return ConstantPools[Section];
}
static void emitConstantPool(MCStreamer &Streamer, MCSection *Section,
ConstantPool &CP) {
if (!CP.empty()) {
Streamer.SwitchSection(Section);
CP.emitEntries(Streamer);
}
}
void AssemblerConstantPools::emitAll(MCStreamer &Streamer) {
// Dump contents of assembler constant pools.
for (auto &CPI : ConstantPools) {
MCSection *Section = CPI.first;
ConstantPool &CP = CPI.second;
emitConstantPool(Streamer, Section, CP);
}
}
void AssemblerConstantPools::emitForCurrentSection(MCStreamer &Streamer) {
MCSection *Section = Streamer.getCurrentSectionOnly();
if (ConstantPool *CP = getConstantPool(Section))
emitConstantPool(Streamer, Section, *CP);
}
void AssemblerConstantPools::clearCacheForCurrentSection(MCStreamer &Streamer) {
MCSection *Section = Streamer.getCurrentSectionOnly();
if (ConstantPool *CP = getConstantPool(Section))
CP->clearCache();
}
const MCExpr *AssemblerConstantPools::addEntry(MCStreamer &Streamer,
const MCExpr *Expr,
unsigned Size, SMLoc Loc) {
MCSection *Section = Streamer.getCurrentSectionOnly();
return getOrCreateConstantPool(Section).addEntry(Expr, Streamer.getContext(),
Size, Loc);
}