[llvm] r186330 - Teaching llvm-tblgen to not emit a switch statement when there are no case statements.
Aaron Ballman
aaron at aaronballman.com
Mon Jul 15 09:53:33 PDT 2013
Author: aaronballman
Date: Mon Jul 15 11:53:32 2013
New Revision: 186330
URL: http://llvm.org/viewvc/llvm-project?rev=186330&view=rev
Log:
Teaching llvm-tblgen to not emit a switch statement when there are no case statements.
Modified:
llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp
llvm/trunk/utils/TableGen/FixedLenDecoderEmitter.cpp
llvm/trunk/utils/TableGen/InstrInfoEmitter.cpp
Modified: llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp?rev=186330&r1=186329&r2=186330&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp (original)
+++ llvm/trunk/utils/TableGen/AsmMatcherEmitter.cpp Mon Jul 15 11:53:32 2013
@@ -114,6 +114,7 @@
#include <cassert>
#include <map>
#include <set>
+#include <sstream>
using namespace llvm;
static cl::opt<std::string>
@@ -2066,9 +2067,11 @@ static void emitIsSubclass(CodeGenTarget
OS << " if (A == B)\n";
OS << " return true;\n\n";
- OS << " switch (A) {\n";
- OS << " default:\n";
- OS << " return false;\n";
+ std::stringstream SS;
+ unsigned Count = 0;
+ SS << " switch (A) {\n";
+ SS << " default:\n";
+ SS << " return false;\n";
for (std::vector<ClassInfo*>::iterator it = Infos.begin(),
ie = Infos.end(); it != ie; ++it) {
ClassInfo &A = **it;
@@ -2084,21 +2087,35 @@ static void emitIsSubclass(CodeGenTarget
if (SuperClasses.empty())
continue;
+ ++Count;
- OS << "\n case " << A.Name << ":\n";
+ SS << "\n case " << A.Name << ":\n";
if (SuperClasses.size() == 1) {
- OS << " return B == " << SuperClasses.back() << ";\n";
+ SS << " return B == " << SuperClasses.back().str() << ";\n";
continue;
}
- OS << " switch (B) {\n";
- OS << " default: return false;\n";
- for (unsigned i = 0, e = SuperClasses.size(); i != e; ++i)
- OS << " case " << SuperClasses[i] << ": return true;\n";
- OS << " }\n";
+ if (!SuperClasses.empty()) {
+ SS << " switch (B) {\n";
+ SS << " default: return false;\n";
+ for (unsigned i = 0, e = SuperClasses.size(); i != e; ++i)
+ SS << " case " << SuperClasses[i].str() << ": return true;\n";
+ SS << " }\n";
+ } else {
+ // No case statement to emit
+ SS << " return false;\n";
+ }
}
- OS << " }\n";
+ SS << " }\n";
+
+ // If there were case statements emitted into the string stream, write them
+ // to the output stream, otherwise write the default.
+ if (Count)
+ OS << SS.str();
+ else
+ OS << " return false;\n";
+
OS << "}\n\n";
}
@@ -2194,18 +2211,24 @@ static void emitOperandDiagnosticTypes(A
static void emitGetSubtargetFeatureName(AsmMatcherInfo &Info, raw_ostream &OS) {
OS << "// User-level names for subtarget features that participate in\n"
<< "// instruction matching.\n"
- << "static const char *getSubtargetFeatureName(unsigned Val) {\n"
- << " switch(Val) {\n";
- for (std::map<Record*, SubtargetFeatureInfo*>::const_iterator
- it = Info.SubtargetFeatures.begin(),
- ie = Info.SubtargetFeatures.end(); it != ie; ++it) {
- SubtargetFeatureInfo &SFI = *it->second;
- // FIXME: Totally just a placeholder name to get the algorithm working.
- OS << " case " << SFI.getEnumName() << ": return \""
- << SFI.TheDef->getValueAsString("PredicateName") << "\";\n";
+ << "static const char *getSubtargetFeatureName(unsigned Val) {\n";
+ if (!Info.SubtargetFeatures.empty()) {
+ OS << " switch(Val) {\n";
+ for (std::map<Record*, SubtargetFeatureInfo*>::const_iterator
+ it = Info.SubtargetFeatures.begin(),
+ ie = Info.SubtargetFeatures.end(); it != ie; ++it) {
+ SubtargetFeatureInfo &SFI = *it->second;
+ // FIXME: Totally just a placeholder name to get the algorithm working.
+ OS << " case " << SFI.getEnumName() << ": return \""
+ << SFI.TheDef->getValueAsString("PredicateName") << "\";\n";
+ }
+ OS << " default: return \"(unknown)\";\n";
+ OS << " }\n";
+ } else {
+ // Nothing to emit, so skip the switch
+ OS << " return \"(unknown)\";\n";
}
- OS << " default: return \"(unknown)\";\n";
- OS << " }\n}\n\n";
+ OS << "}\n\n";
}
/// emitComputeAvailableFeatures - Emit the function to compute the list of
Modified: llvm/trunk/utils/TableGen/FixedLenDecoderEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/FixedLenDecoderEmitter.cpp?rev=186330&r1=186329&r2=186330&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/FixedLenDecoderEmitter.cpp (original)
+++ llvm/trunk/utils/TableGen/FixedLenDecoderEmitter.cpp Mon Jul 15 11:53:32 2013
@@ -879,15 +879,20 @@ emitPredicateFunction(formatted_raw_ostr
OS.indent(Indentation) << "static bool checkDecoderPredicate(unsigned Idx, "
<< "uint64_t Bits) {\n";
Indentation += 2;
- OS.indent(Indentation) << "switch (Idx) {\n";
- OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n";
- unsigned Index = 0;
- for (PredicateSet::const_iterator I = Predicates.begin(), E = Predicates.end();
- I != E; ++I, ++Index) {
- OS.indent(Indentation) << "case " << Index << ":\n";
- OS.indent(Indentation+2) << "return (" << *I << ");\n";
+ if (!Predicates.empty()) {
+ OS.indent(Indentation) << "switch (Idx) {\n";
+ OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n";
+ unsigned Index = 0;
+ for (PredicateSet::const_iterator I = Predicates.begin(), E = Predicates.end();
+ I != E; ++I, ++Index) {
+ OS.indent(Indentation) << "case " << Index << ":\n";
+ OS.indent(Indentation+2) << "return (" << *I << ");\n";
+ }
+ OS.indent(Indentation) << "}\n";
+ } else {
+ // No case statement to emit
+ OS.indent(Indentation) << "llvm_unreachable(\"Invalid index!\");\n";
}
- OS.indent(Indentation) << "}\n";
Indentation -= 2;
OS.indent(Indentation) << "}\n\n";
}
Modified: llvm/trunk/utils/TableGen/InstrInfoEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/InstrInfoEmitter.cpp?rev=186330&r1=186329&r2=186330&view=diff
==============================================================================
--- llvm/trunk/utils/TableGen/InstrInfoEmitter.cpp (original)
+++ llvm/trunk/utils/TableGen/InstrInfoEmitter.cpp Mon Jul 15 11:53:32 2013
@@ -270,33 +270,40 @@ void InstrInfoEmitter::emitOperandNameMa
OS << "namespace llvm {";
OS << "namespace " << Namespace << " {\n";
OS << "int16_t getNamedOperandIdx(uint16_t Opcode, uint16_t NamedIdx) {\n";
- OS << " static const int16_t OperandMap []["<< Operands.size() << "] = {\n";
- for (OpNameMapTy::iterator i = OperandMap.begin(), e = OperandMap.end();
- i != e; ++i) {
- const std::map<unsigned, unsigned> &OpList = i->first;
- OS << "{";
+ if (!Operands.empty()) {
+ OS << " static const int16_t OperandMap [][" << Operands.size()
+ << "] = {\n";
+ for (OpNameMapTy::iterator i = OperandMap.begin(), e = OperandMap.end();
+ i != e; ++i) {
+ const std::map<unsigned, unsigned> &OpList = i->first;
+ OS << "{";
- // Emit a row of the OperandMap table
- for (unsigned ii = 0, ie = Operands.size(); ii != ie; ++ii)
- OS << (OpList.count(ii) == 0 ? -1 : (int)OpList.find(ii)->second) << ", ";
+ // Emit a row of the OperandMap table
+ for (unsigned ii = 0, ie = Operands.size(); ii != ie; ++ii)
+ OS << (OpList.count(ii) == 0 ? -1 : (int)OpList.find(ii)->second)
+ << ", ";
- OS << "},\n";
- }
- OS << "};\n";
+ OS << "},\n";
+ }
+ OS << "};\n";
- OS << " switch(Opcode) {\n";
- unsigned TableIndex = 0;
- for (OpNameMapTy::iterator i = OperandMap.begin(), e = OperandMap.end();
- i != e; ++i) {
- std::vector<std::string> &OpcodeList = i->second;
+ OS << " switch(Opcode) {\n";
+ unsigned TableIndex = 0;
+ for (OpNameMapTy::iterator i = OperandMap.begin(), e = OperandMap.end();
+ i != e; ++i) {
+ std::vector<std::string> &OpcodeList = i->second;
- for (unsigned ii = 0, ie = OpcodeList.size(); ii != ie; ++ii)
- OS << " case " << OpcodeList[ii] << ":\n";
+ for (unsigned ii = 0, ie = OpcodeList.size(); ii != ie; ++ii)
+ OS << " case " << OpcodeList[ii] << ":\n";
- OS << " return OperandMap[" << TableIndex++ << "][NamedIdx];\n";
+ OS << " return OperandMap[" << TableIndex++ << "][NamedIdx];\n";
+ }
+ OS << " default: return -1;\n";
+ OS << " }\n";
+ } else {
+ // There are no operands, so no need to emit anything
+ OS << " return -1;\n";
}
- OS << " default: return -1;\n";
- OS << " }\n";
OS << "}\n";
OS << "} // End namespace " << Namespace << "\n";
OS << "} // End namespace llvm\n";
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