[llvm] r315826 - [TableGen] Avoid unnecessary std::string creations
Simon Pilgrim via llvm-commits
llvm-commits at lists.llvm.org
Sat Oct 14 23:13:49 PDT 2017
Hi Daniel,
I don’t have any tablegen changes planned right now, and will put up up for review anything that does arise.
My main concern is that those std::string creations are having a noticeable effect on windows debug tablegen performance. Please continue to keep StringRef wherever possible even if it means discrepancies in the API, and keep an eye out for build time regressions.
Cheers, Simon.
> On 15 Oct 2017, at 02:23, Daniel Sanders <daniel_l_sanders at apple.com> wrote:
>
> Hi Simon,
>
> We seem to be conflicting with each others commits at the moment. I'm currently trying to land several patches to GlobalISel emitter and some of them make a few of these (currently) unnecessary std::string creations necessary. I need to partially revert this patch so that getPredCode() returns a std::string. I'm also going to revert the getImmCode() change because I think getPredCode() and getImmCode() should have the same interface. The getImmType() and getImmTypeIdentifier() changes look ok to me.
>
> Do you have any other cleanups affecting GlobalISelEmitter.cpp planned? If so, we should probably discuss them to see if our patches conflict.
>
>> On 14 Oct 2017, at 14:27, Simon Pilgrim via llvm-commits <llvm-commits at lists.llvm.org> wrote:
>>
>> Author: rksimon
>> Date: Sat Oct 14 14:27:53 2017
>> New Revision: 315826
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=315826&view=rev
>> Log:
>> [TableGen] Avoid unnecessary std::string creations
>>
>> Avoid unnecessary std::string creations in the TreePredicateFn getters.
>>
>> Modified:
>> llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp
>> llvm/trunk/utils/TableGen/CodeGenDAGPatterns.h
>> llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp
>>
>> Modified: llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp?rev=315826&r1=315825&r2=315826&view=diff
>> ==============================================================================
>> --- llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp (original)
>> +++ llvm/trunk/utils/TableGen/CodeGenDAGPatterns.cpp Sat Oct 14 14:27:53 2017
>> @@ -854,11 +854,11 @@ TreePredicateFn::TreePredicateFn(TreePat
>> ".td file corrupt: can't have a node predicate *and* an imm predicate");
>> }
>>
>> -std::string TreePredicateFn::getPredCode() const {
>> +StringRef TreePredicateFn::getPredCode() const {
>> return PatFragRec->getRecord()->getValueAsString("PredicateCode");
>> }
>>
>> -std::string TreePredicateFn::getImmCode() const {
>> +StringRef TreePredicateFn::getImmCode() const {
>> return PatFragRec->getRecord()->getValueAsString("ImmediateCode");
>> }
>>
>> @@ -873,7 +873,7 @@ bool TreePredicateFn::immCodeUsesAPFloat
>> Unset);
>> }
>>
>> -std::string TreePredicateFn::getImmType() const {
>> +StringRef TreePredicateFn::getImmType() const {
>> if (immCodeUsesAPInt())
>> return "const APInt &";
>> if (immCodeUsesAPFloat())
>> @@ -881,7 +881,7 @@ std::string TreePredicateFn::getImmType(
>> return "int64_t";
>> }
>>
>> -std::string TreePredicateFn::getImmTypeIdentifier() const {
>> +StringRef TreePredicateFn::getImmTypeIdentifier() const {
>> if (immCodeUsesAPInt())
>> return "APInt";
>> else if (immCodeUsesAPFloat())
>> @@ -906,21 +906,21 @@ std::string TreePredicateFn::getFnName()
>> /// appropriate.
>> std::string TreePredicateFn::getCodeToRunOnSDNode() const {
>> // Handle immediate predicates first.
>> - std::string ImmCode = getImmCode();
>> + StringRef ImmCode = getImmCode();
>> if (!ImmCode.empty()) {
>> - std::string Result = " " + getImmType() + " Imm = ";
>> + std::string Result = " " + getImmType().str() + " Imm = ";
>> if (immCodeUsesAPFloat())
>> Result += "cast<ConstantFPSDNode>(Node)->getValueAPF();\n";
>> else if (immCodeUsesAPInt())
>> Result += "cast<ConstantSDNode>(Node)->getAPIntValue();\n";
>> else
>> Result += "cast<ConstantSDNode>(Node)->getSExtValue();\n";
>> - return Result + ImmCode;
>> + return Result + ImmCode.str();
>> }
>>
>> // Handle arbitrary node predicates.
>> assert(!getPredCode().empty() && "Don't have any predicate code!");
>> - std::string ClassName;
>> + StringRef ClassName;
>> if (PatFragRec->getOnlyTree()->isLeaf())
>> ClassName = "SDNode";
>> else {
>> @@ -931,9 +931,9 @@ std::string TreePredicateFn::getCodeToRu
>> if (ClassName == "SDNode")
>> Result = " SDNode *N = Node;\n";
>> else
>> - Result = " auto *N = cast<" + ClassName + ">(Node);\n";
>> + Result = " auto *N = cast<" + ClassName.str() + ">(Node);\n";
>>
>> - return Result + getPredCode();
>> + return Result + getPredCode().str();
>> }
>>
>> //===----------------------------------------------------------------------===//
>>
>> Modified: llvm/trunk/utils/TableGen/CodeGenDAGPatterns.h
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/CodeGenDAGPatterns.h?rev=315826&r1=315825&r2=315826&view=diff
>> ==============================================================================
>> --- llvm/trunk/utils/TableGen/CodeGenDAGPatterns.h (original)
>> +++ llvm/trunk/utils/TableGen/CodeGenDAGPatterns.h Sat Oct 14 14:27:53 2017
>> @@ -452,13 +452,12 @@ public:
>> /// getImmediatePredicateCode - Return the code that evaluates this pattern if
>> /// this is an immediate predicate. It is an error to call this on a
>> /// non-immediate pattern.
>> - std::string getImmediatePredicateCode() const {
>> - std::string Result = getImmCode();
>> + StringRef getImmediatePredicateCode() const {
>> + StringRef Result = getImmCode();
>> assert(!Result.empty() && "Isn't an immediate pattern!");
>> return Result;
>> }
>>
>> -
>> bool operator==(const TreePredicateFn &RHS) const {
>> return PatFragRec == RHS.PatFragRec;
>> }
>> @@ -476,15 +475,15 @@ public:
>> std::string getCodeToRunOnSDNode() const;
>>
>> /// Get the data type of the argument to getImmediatePredicateCode().
>> - std::string getImmType() const;
>> + StringRef getImmType() const;
>>
>> /// Get a string that describes the type returned by getImmType() but is
>> /// usable as part of an identifier.
>> - std::string getImmTypeIdentifier() const;
>> + StringRef getImmTypeIdentifier() const;
>>
>> private:
>> - std::string getPredCode() const;
>> - std::string getImmCode() const;
>> + StringRef getPredCode() const;
>> + StringRef getImmCode() const;
>> bool immCodeUsesAPInt() const;
>> bool immCodeUsesAPFloat() const;
>> };
>>
>> Modified: llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp?rev=315826&r1=315825&r2=315826&view=diff
>> ==============================================================================
>> --- llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp (original)
>> +++ llvm/trunk/utils/TableGen/GlobalISelEmitter.cpp Sat Oct 14 14:27:53 2017
>> @@ -68,13 +68,13 @@ namespace {
>>
>> /// Get the name of the enum value used to number the predicate function.
>> std::string getEnumNameForPredicate(const TreePredicateFn &Predicate) {
>> - return "GIPFP_" + Predicate.getImmTypeIdentifier() + "_" +
>> + return "GIPFP_" + Predicate.getImmTypeIdentifier().str() + "_" +
>> Predicate.getFnName();
>> }
>>
>> /// Get the opcode used to check this predicate.
>> std::string getMatchOpcodeForPredicate(const TreePredicateFn &Predicate) {
>> - return "GIM_Check" + Predicate.getImmTypeIdentifier() + "ImmPredicate";
>> + return "GIM_Check" + Predicate.getImmTypeIdentifier().str() + "ImmPredicate";
>> }
>>
>> /// This class stands in for LLT wherever we want to tablegen-erate an
>>
>>
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