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Emit the LLVM<->DWARF register mapping as a sorted table and use binary search to do the lookup. 

This also avoids emitting the information twice, which led to code bloat. On i386-linux-Release+Asserts
with all targets built this change shaves a whopping 1.3 MB off clang. The number is probably exaggerated
by recent inliner changes but the methods were already enormous with the old inline cost computation.

The DWARF reg -> LLVM reg mapping doesn't seem to have holes in it, so it could be a simple lookup table.
I didn't implement that optimization yet to avoid potentially changing functionality.

There is still some duplication both in tablegen and the generated code that should be cleaned up eventually.

llvm-svn: 153837
This commit is contained in:
Benjamin Kramer 2012-04-01 14:23:58 +00:00
parent 45ae88f5fc
commit 12af4285d1
3 changed files with 201 additions and 72 deletions
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78
llvm/include/llvm/MC/MCRegisterInfo.h
View File

@ -127,6 +127,16 @@ struct MCRegisterDesc {
class MCRegisterInfo {
public:
typedef const MCRegisterClass *regclass_iterator;
/// DwarfLLVMRegPair - Emitted by tablegen so Dwarf<->LLVM reg mappings can be
/// performed with a binary search.
struct DwarfLLVMRegPair {
unsigned FromReg;
unsigned ToReg;
bool operator==(unsigned Reg) const { return FromReg == Reg; }
bool operator<(unsigned Reg) const { return FromReg < Reg; }
};
private:
const MCRegisterDesc *Desc; // Pointer to the descriptor array
unsigned NumRegs; // Number of entries in the array
@ -137,10 +147,15 @@ private:
const uint16_t *SubRegIndices; // Pointer to the subreg lookup
// array.
unsigned NumSubRegIndices; // Number of subreg indices.
DenseMap<unsigned, int> L2DwarfRegs; // LLVM to Dwarf regs mapping
DenseMap<unsigned, int> EHL2DwarfRegs; // LLVM to Dwarf regs mapping EH
DenseMap<unsigned, unsigned> Dwarf2LRegs; // Dwarf to LLVM regs mapping
DenseMap<unsigned, unsigned> EHDwarf2LRegs; // Dwarf to LLVM regs mapping EH
unsigned L2DwarfRegsSize;
unsigned EHL2DwarfRegsSize;
unsigned Dwarf2LRegsSize;
unsigned EHDwarf2LRegsSize;
const DwarfLLVMRegPair *L2DwarfRegs; // LLVM to Dwarf regs mapping
const DwarfLLVMRegPair *EHL2DwarfRegs; // LLVM to Dwarf regs mapping EH
const DwarfLLVMRegPair *Dwarf2LRegs; // Dwarf to LLVM regs mapping
const DwarfLLVMRegPair *EHDwarf2LRegs; // Dwarf to LLVM regs mapping EH
DenseMap<unsigned, int> L2SEHRegs; // LLVM to SEH regs mapping
public:
@ -161,24 +176,32 @@ public:
NumSubRegIndices = NumIndices;
}
/// mapLLVMRegToDwarfReg - Used to initialize LLVM register to Dwarf
/// mapLLVMRegsToDwarfRegs - Used to initialize LLVM register to Dwarf
/// register number mapping. Called by TableGen auto-generated routines.
/// *DO NOT USE*.
void mapLLVMRegToDwarfReg(unsigned LLVMReg, int DwarfReg, bool isEH) {
if (isEH)
EHL2DwarfRegs[LLVMReg] = DwarfReg;
else
L2DwarfRegs[LLVMReg] = DwarfReg;
void mapLLVMRegsToDwarfRegs(const DwarfLLVMRegPair *Map, unsigned Size,
bool isEH) {
if (isEH) {
EHL2DwarfRegs = Map;
EHL2DwarfRegsSize = Size;
} else {
L2DwarfRegs = Map;
L2DwarfRegsSize = Size;
}
}
/// mapDwarfRegToLLVMReg - Used to initialize Dwarf register to LLVM
/// mapDwarfRegsToLLVMRegs - Used to initialize Dwarf register to LLVM
/// register number mapping. Called by TableGen auto-generated routines.
/// *DO NOT USE*.
void mapDwarfRegToLLVMReg(unsigned DwarfReg, unsigned LLVMReg, bool isEH) {
if (isEH)
EHDwarf2LRegs[DwarfReg] = LLVMReg;
else
Dwarf2LRegs[DwarfReg] = LLVMReg;
void mapDwarfRegsToLLVMRegs(const DwarfLLVMRegPair *Map, unsigned Size,
bool isEH) {
if (isEH) {
EHDwarf2LRegs = Map;
EHDwarf2LRegsSize = Size;
} else {
Dwarf2LRegs = Map;
Dwarf2LRegsSize = Size;
}
}
/// mapLLVMRegToSEHReg - Used to initialize LLVM register to SEH register
@ -289,21 +312,24 @@ public:
/// parameter allows targets to use different numberings for EH info and
/// debugging info.
int getDwarfRegNum(unsigned RegNum, bool isEH) const {
const DenseMap<unsigned, int> &M = isEH ? EHL2DwarfRegs : L2DwarfRegs;
const DenseMap<unsigned, int>::const_iterator I = M.find(RegNum);
if (I == M.end()) return -1;
return I->second;
const DwarfLLVMRegPair *M = isEH ? EHL2DwarfRegs : L2DwarfRegs;
unsigned Size = isEH ? EHL2DwarfRegsSize : L2DwarfRegsSize;
const DwarfLLVMRegPair *I = std::lower_bound(M, M+Size, RegNum);
if (I == M+Size || I->FromReg != RegNum)
return -1;
return I->ToReg;
}
/// getLLVMRegNum - Map a dwarf register back to a target register.
///
int getLLVMRegNum(unsigned RegNum, bool isEH) const {
const DenseMap<unsigned, unsigned> &M = isEH ? EHDwarf2LRegs : Dwarf2LRegs;
const DenseMap<unsigned, unsigned>::const_iterator I = M.find(RegNum);
if (I == M.end()) {
llvm_unreachable("Invalid RegNum");
}
return I->second;
const DwarfLLVMRegPair *M = isEH ? EHDwarf2LRegs : Dwarf2LRegs;
unsigned Size = isEH ? EHDwarf2LRegsSize : Dwarf2LRegsSize;
const DwarfLLVMRegPair *I = std::lower_bound(M, M+Size, RegNum);
assert(I != M+Size && I->FromReg == RegNum && "Invalid RegNum");
return I->ToReg;
}
/// getSEHRegNum - Map a target register to an equivalent SEH register

192
llvm/utils/TableGen/RegisterInfoEmitter.cpp
View File

@ -118,11 +118,11 @@ RegisterInfoEmitter::runEnums(raw_ostream &OS,
OS << "#endif // GET_REGINFO_ENUM\n\n";
}
void
RegisterInfoEmitter::EmitRegMapping(raw_ostream &OS,
const std::vector<CodeGenRegister*> &Regs,
bool isCtor) {
void
RegisterInfoEmitter::EmitRegMappingTables(raw_ostream &OS,
const std::vector<CodeGenRegister*> &Regs,
bool isCtor) {
// Collect all information about dwarf register numbers
typedef std::map<Record*, std::vector<int64_t>, LessRecord> DwarfRegNumsMapTy;
DwarfRegNumsMapTy DwarfRegNums;
@ -148,38 +148,52 @@ RegisterInfoEmitter::EmitRegMapping(raw_ostream &OS,
for (unsigned i = I->second.size(), e = maxLength; i != e; ++i)
I->second.push_back(-1);
std::string Namespace = Regs[0]->TheDef->getValueAsString("Namespace");
OS << "// " << Namespace << " Dwarf<->LLVM register mappings.\n";
// Emit reverse information about the dwarf register numbers.
for (unsigned j = 0; j < 2; ++j) {
OS << " switch (";
if (j == 0)
OS << "DwarfFlavour";
else
OS << "EHFlavour";
OS << ") {\n"
<< " default:\n"
<< " llvm_unreachable(\"Unknown DWARF flavour\");\n";
for (unsigned i = 0, e = maxLength; i != e; ++i) {
OS << " case " << i << ":\n";
for (DwarfRegNumsMapTy::iterator
I = DwarfRegNums.begin(), E = DwarfRegNums.end(); I != E; ++I) {
int DwarfRegNo = I->second[i];
if (DwarfRegNo < 0)
continue;
OS << " ";
if (!isCtor)
OS << "RI->";
OS << "mapDwarfRegToLLVMReg(" << DwarfRegNo << ", "
<< getQualifiedName(I->first) << ", ";
if (j == 0)
OS << "false";
else
OS << "true";
OS << " );\n";
OS << "extern const MCRegisterInfo::DwarfLLVMRegPair " << Namespace;
OS << (j == 0 ? "DwarfFlavour" : "EHFlavour");
OS << i << "Dwarf2L[]";
if (!isCtor) {
OS << " = {\n";
// Store the mapping sorted by the LLVM reg num so lookup can be done
// with a binary search.
std::map<uint64_t, Record*> Dwarf2LMap;
for (DwarfRegNumsMapTy::iterator
I = DwarfRegNums.begin(), E = DwarfRegNums.end(); I != E; ++I) {
int DwarfRegNo = I->second[i];
if (DwarfRegNo < 0)
continue;
Dwarf2LMap[DwarfRegNo] = I->first;
}
for (std::map<uint64_t, Record*>::iterator
I = Dwarf2LMap.begin(), E = Dwarf2LMap.end(); I != E; ++I)
OS << " { " << I->first << "U, " << getQualifiedName(I->second)
<< " },\n";
OS << "};\n";
} else {
OS << ";\n";
}
OS << " break;\n";
// We have to store the size in a const global, it's used in multiple
// places.
OS << "extern const unsigned " << Namespace
<< (j == 0 ? "DwarfFlavour" : "EHFlavour") << i << "Dwarf2LSize";
if (!isCtor)
OS << " = sizeof(" << Namespace
<< (j == 0 ? "DwarfFlavour" : "EHFlavour") << i
<< "Dwarf2L)/sizeof(MCRegisterInfo::DwarfLLVMRegPair);\n\n";
else
OS << ";\n\n";
}
OS << " }\n";
}
for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
@ -193,6 +207,93 @@ RegisterInfoEmitter::EmitRegMapping(raw_ostream &OS,
DwarfRegNums[Reg] = DwarfRegNums[Alias];
}
// Emit information about the dwarf register numbers.
for (unsigned j = 0; j < 2; ++j) {
for (unsigned i = 0, e = maxLength; i != e; ++i) {
OS << "extern const MCRegisterInfo::DwarfLLVMRegPair " << Namespace;
OS << (j == 0 ? "DwarfFlavour" : "EHFlavour");
OS << i << "L2Dwarf[]";
if (!isCtor) {
OS << " = {\n";
// Store the mapping sorted by the Dwarf reg num so lookup can be done
// with a binary search.
for (DwarfRegNumsMapTy::iterator
I = DwarfRegNums.begin(), E = DwarfRegNums.end(); I != E; ++I) {
int RegNo = I->second[i];
if (RegNo == -1) // -1 is the default value, don't emit a mapping.
continue;
OS << " { " << getQualifiedName(I->first) << ", " << RegNo
<< "U },\n";
}
OS << "};\n";
} else {
OS << ";\n";
}
// We have to store the size in a const global, it's used in multiple
// places.
OS << "extern const unsigned " << Namespace
<< (j == 0 ? "DwarfFlavour" : "EHFlavour") << i << "L2DwarfSize";
if (!isCtor)
OS << " = sizeof(" << Namespace
<< (j == 0 ? "DwarfFlavour" : "EHFlavour") << i
<< "L2Dwarf)/sizeof(MCRegisterInfo::DwarfLLVMRegPair);\n\n";
else
OS << ";\n\n";
}
}
}
void
RegisterInfoEmitter::EmitRegMapping(raw_ostream &OS,
const std::vector<CodeGenRegister*> &Regs,
bool isCtor) {
// Emit the initializer so the tables from EmitRegMappingTables get wired up
// to the MCRegisterInfo object.
unsigned maxLength = 0;
for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
Record *Reg = Regs[i]->TheDef;
maxLength = std::max((size_t)maxLength,
Reg->getValueAsListOfInts("DwarfNumbers").size());
}
if (!maxLength)
return;
std::string Namespace = Regs[0]->TheDef->getValueAsString("Namespace");
// Emit reverse information about the dwarf register numbers.
for (unsigned j = 0; j < 2; ++j) {
OS << " switch (";
if (j == 0)
OS << "DwarfFlavour";
else
OS << "EHFlavour";
OS << ") {\n"
<< " default:\n"
<< " llvm_unreachable(\"Unknown DWARF flavour\");\n";
for (unsigned i = 0, e = maxLength; i != e; ++i) {
OS << " case " << i << ":\n";
OS << " ";
if (!isCtor)
OS << "RI->";
std::string Tmp;
raw_string_ostream(Tmp) << Namespace
<< (j == 0 ? "DwarfFlavour" : "EHFlavour") << i
<< "Dwarf2L";
OS << "mapDwarfRegsToLLVMRegs(" << Tmp << ", " << Tmp << "Size, ";
if (j == 0)
OS << "false";
else
OS << "true";
OS << ");\n";
OS << " break;\n";
}
OS << " }\n";
}
// Emit information about the dwarf register numbers.
for (unsigned j = 0; j < 2; ++j) {
OS << " switch (";
@ -206,24 +307,19 @@ RegisterInfoEmitter::EmitRegMapping(raw_ostream &OS,
for (unsigned i = 0, e = maxLength; i != e; ++i) {
OS << " case " << i << ":\n";
// Sort by name to get a stable order.
for (DwarfRegNumsMapTy::iterator
I = DwarfRegNums.begin(), E = DwarfRegNums.end(); I != E; ++I) {
int RegNo = I->second[i];
if (RegNo == -1) // -1 is the default value, don't emit a mapping.
continue;
OS << " ";
if (!isCtor)
OS << "RI->";
OS << "mapLLVMRegToDwarfReg(" << getQualifiedName(I->first) << ", "
<< RegNo << ", ";
if (j == 0)
OS << " ";
if (!isCtor)
OS << "RI->";
std::string Tmp;
raw_string_ostream(Tmp) << Namespace
<< (j == 0 ? "DwarfFlavour" : "EHFlavour") << i
<< "L2Dwarf";
OS << "mapLLVMRegsToDwarfRegs(" << Tmp << ", " << Tmp << "Size, ";
if (j == 0)
OS << "false";
else
OS << "true";
OS << " );\n";
}
OS << ");\n";
OS << " break;\n";
}
OS << " }\n";
@ -448,6 +544,8 @@ RegisterInfoEmitter::runMCDesc(raw_ostream &OS, CodeGenTarget &Target,
<< "SubRegTable;\n}\n\n";
}
EmitRegMappingTables(OS, Regs, false);
// MCRegisterInfo initialization routine.
OS << "static inline void Init" << TargetName
<< "MCRegisterInfo(MCRegisterInfo *RI, unsigned RA, "
@ -872,6 +970,8 @@ RegisterInfoEmitter::runTargetDesc(raw_ostream &OS, CodeGenTarget &Target,
OS << "extern const uint16_t *get" << TargetName
<< "SubRegTable();\n";
EmitRegMappingTables(OS, Regs, true);
OS << ClassName << "::\n" << ClassName
<< "(unsigned RA, unsigned DwarfFlavour, unsigned EHFlavour)\n"
<< " : TargetRegisterInfo(" << TargetName << "RegInfoDesc"

3
llvm/utils/TableGen/RegisterInfoEmitter.h
View File

@ -50,6 +50,9 @@ public:
private:
void EmitRegMapping(raw_ostream &o,
const std::vector<CodeGenRegister*> &Regs, bool isCtor);
void EmitRegMappingTables(raw_ostream &o,
const std::vector<CodeGenRegister*> &Regs,
bool isCtor);
void EmitRegClasses(raw_ostream &OS, CodeGenTarget &Target);
};