From 061f681c0dfa4d279dc656802bf81f3b9bfa3d34 Mon Sep 17 00:00:00 2001
From: Craig Topper <craig.topper@sifive.com>
Date: Sat, 16 Jan 2021 21:18:52 -0800
Subject: [PATCH] [RISCV] Remove an extra map lookup from
 RISCVCompressInstEmitter. NFC

When we looked up the map to see if the entry already existed,
this created the new entry for us. So save a reference to it so
we can use it to update the entry instead of looking it up again.

Also remove unnecessary StringRef constructors around string
literals on calls to this function.
---
 llvm/utils/TableGen/RISCVCompressInstEmitter.cpp | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/llvm/utils/TableGen/RISCVCompressInstEmitter.cpp b/llvm/utils/TableGen/RISCVCompressInstEmitter.cpp
index 8f781c9..beb9266 100644
--- a/llvm/utils/TableGen/RISCVCompressInstEmitter.cpp
+++ b/llvm/utils/TableGen/RISCVCompressInstEmitter.cpp
@@ -509,14 +509,13 @@ getReqFeatures(std::set<std::pair<bool, StringRef>> &FeaturesSet,
 static unsigned getPredicates(DenseMap<const Record *, unsigned> &PredicateMap,
                               std::vector<const Record *> &Predicates,
                               Record *Rec, StringRef Name) {
-  unsigned Entry = PredicateMap[Rec];
+  unsigned &Entry = PredicateMap[Rec];
   if (Entry)
     return Entry;
 
   if (!Rec->isValueUnset(Name)) {
     Predicates.push_back(Rec);
     Entry = Predicates.size();
-    PredicateMap[Rec] = Entry;
     return Entry;
   }
 
@@ -751,14 +750,16 @@ void RISCVCompressInstEmitter::emitCompressInstEmitter(raw_ostream &o,
         } else {
           // Handling immediate operands.
           if (CompressOrUncompress) {
-            unsigned Entry = getPredicates(MCOpPredicateMap, MCOpPredicates,
-              DestOperand.Rec, StringRef("MCOperandPredicate"));
+            unsigned Entry =
+                getPredicates(MCOpPredicateMap, MCOpPredicates, DestOperand.Rec,
+                              "MCOperandPredicate");
             CondStream.indent(6)
                 << Namespace << "ValidateMCOperand("
                 << "MI.getOperand(" << OpIdx << "), STI, " << Entry << ") &&\n";
           } else {
-            unsigned Entry = getPredicates(ImmLeafPredicateMap, ImmLeafPredicates,
-              DestOperand.Rec, StringRef("ImmediateCode"));
+            unsigned Entry =
+                getPredicates(ImmLeafPredicateMap, ImmLeafPredicates,
+                              DestOperand.Rec, "ImmediateCode");
             CondStream.indent(6)
                 << "MI.getOperand(" << OpIdx << ").isImm() &&\n";
             CondStream.indent(6) << Namespace << "ValidateMachineOperand("
@@ -774,14 +775,14 @@ void RISCVCompressInstEmitter::emitCompressInstEmitter(raw_ostream &o,
       case OpData::Imm: {
         if (CompressOrUncompress) {
           unsigned Entry = getPredicates(MCOpPredicateMap, MCOpPredicates,
-            DestOperand.Rec, StringRef("MCOperandPredicate"));
+                                         DestOperand.Rec, "MCOperandPredicate");
           CondStream.indent(6)
               << Namespace << "ValidateMCOperand("
               << "MCOperand::createImm(" << DestOperandMap[OpNo].Data.Imm
               << "), STI, " << Entry << ") &&\n";
         } else {
           unsigned Entry = getPredicates(ImmLeafPredicateMap, ImmLeafPredicates,
-            DestOperand.Rec, StringRef("ImmediateCode"));
+                                         DestOperand.Rec, "ImmediateCode");
           CondStream.indent(6)
               << Namespace
               << "ValidateMachineOperand(MachineOperand::CreateImm("
-- 
2.7.4