[lld] r302708 - Use a DenseMap in LinkerScript::getCmd.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Wed May 10 14:13:38 2017
New Revision: 302708

URL: http://llvm.org/viewvc/llvm-project?rev=302708&view=rev
Log:
Use a DenseMap in LinkerScript::getCmd.

This improves many-sections.s with a linker script from 22s to 0.9s.

Modified:
    lld/trunk/ELF/LinkerScript.cpp
    lld/trunk/ELF/LinkerScript.h
    lld/trunk/test/ELF/many-sections.s

Modified: lld/trunk/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.cpp?rev=302708&r1=302707&r2=302708&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.cpp (original)
+++ lld/trunk/ELF/LinkerScript.cpp Wed May 10 14:13:38 2017
@@ -415,6 +415,7 @@ void LinkerScript::processCommands(Outpu
       if (OutputSection *Sec = Cmd->Sec) {
         assert(Sec->SectionIndex == INT_MAX);
         Sec->SectionIndex = I;
+        SecToCommand[Sec] = Cmd;
       }
     }
   }
@@ -444,6 +445,7 @@ void LinkerScript::fabricateDefaultComma
 
     auto *OSCmd = make<OutputSectionCommand>(Sec->Name);
     OSCmd->Sec = Sec;
+    SecToCommand[Sec] = OSCmd;
 
     // Prefer user supplied address over additional alignment constraint
     auto I = Config->SectionStartMap.find(Sec->Name);
@@ -488,6 +490,7 @@ void LinkerScript::addOrphanSections(Out
       auto *Cmd = cast<OutputSectionCommand>(*I);
       Factory.addInputSec(S, Name, Cmd->Sec);
       if (OutputSection *Sec = Cmd->Sec) {
+        SecToCommand[Sec] = Cmd;
         unsigned Index = std::distance(Opt.Commands.begin(), I);
         assert(Sec->SectionIndex == INT_MAX || Sec->SectionIndex == Index);
         Sec->SectionIndex = Index;
@@ -703,6 +706,7 @@ void LinkerScript::adjustSectionsBeforeS
     OutSec->SectionIndex = I;
     OutputSections->push_back(OutSec);
     Cmd->Sec = OutSec;
+    SecToCommand[OutSec] = Cmd;
   }
 }
 
@@ -833,6 +837,7 @@ void LinkerScript::placeOrphanSections()
       ++CmdIndex;
 
       Cmd->Sec = Sec;
+      SecToCommand[Sec] = Cmd;
       auto *ISD = make<InputSectionDescription>("");
       for (InputSection *IS : Sec->Sections)
         ISD->Sections.push_back(IS);
@@ -1025,12 +1030,11 @@ bool LinkerScript::ignoreInterpSection()
   return true;
 }
 
-OutputSectionCommand *LinkerScript::getCmd(OutputSection *Sec) {
-  for (BaseCommand *Base : Opt.Commands)
-    if (auto *Cmd = dyn_cast<OutputSectionCommand>(Base))
-      if (Cmd->Sec == Sec)
-        return Cmd;
-  return nullptr;
+OutputSectionCommand *LinkerScript::getCmd(OutputSection *Sec) const {
+  auto I = SecToCommand.find(Sec);
+  if (I == SecToCommand.end())
+    return nullptr;
+  return I->second;
 }
 
 Optional<uint32_t> LinkerScript::getFiller(OutputSection *Sec) {

Modified: lld/trunk/ELF/LinkerScript.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LinkerScript.h?rev=302708&r1=302707&r2=302708&view=diff
==============================================================================
--- lld/trunk/ELF/LinkerScript.h (original)
+++ lld/trunk/ELF/LinkerScript.h Wed May 10 14:13:38 2017
@@ -212,7 +212,8 @@ struct ScriptConfiguration {
 };
 
 class LinkerScript final {
-  OutputSectionCommand *getCmd(OutputSection *Sec);
+  llvm::DenseMap<OutputSection *, OutputSectionCommand *> SecToCommand;
+  OutputSectionCommand *getCmd(OutputSection *Sec) const;
   void assignSymbol(SymbolAssignment *Cmd, bool InSec);
   void setDot(Expr E, const Twine &Loc, bool InSec);
 

Modified: lld/trunk/test/ELF/many-sections.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/many-sections.s?rev=302708&r1=302707&r2=302708&view=diff
==============================================================================
--- lld/trunk/test/ELF/many-sections.s (original)
+++ lld/trunk/test/ELF/many-sections.s Wed May 10 14:13:38 2017
@@ -14,6 +14,11 @@
 // RUN: ld.lld %t -o %t2
 // RUN: llvm-readobj -t %t2 | FileCheck --check-prefix=LINKED %s
 
+// Test also with a linker script.
+// RUN: echo "SECTIONS { . = SIZEOF_HEADERS; .text : { *(.text) } }" > %t.script
+// RUN: ld.lld -T %t.script %t -o %t2
+// RUN: llvm-readobj -t %t2 | FileCheck --check-prefix=LINKED %s
+
 // Test that _start is in the correct section.
 // LINKED:      Name: _start
 // LINKED-NEXT: Value: 0x0