commit e2eb3a53006741ebeae2b0116b94ef03555d0132
author Duncan P. N. Exon Smith <dexonsmith@apple.com> Sat May 16 00:03:06 2015 +0000
committer Duncan P. N. Exon Smith <dexonsmith@apple.com> Sat May 16 00:03:06 2015 +0000
tree 87bbe1974670e8596a1448c024468b3bbbd0dca8
parent a75696f77eaba6216980a45f766fddc57c3d33a3

MC: Merge MCSymbol and MCSymbolData

Turn `MCSymbolData` into a field inside of `MCSymbol`.  Keep all the old
API alive for now, so that consumers can be updated in a later commit.
This means we still temporarily need the back pointer from
`MCSymbolData` to `MCSymbol`, but I'll remove it in a follow-up.

This optimizes for object emission over assembly emission.  By removing
the `DenseMap` in `MCAssembler`, llc memory usage drops from around 1040
MB to 1001 MB (3.8%).

(I'm looking at `llc` memory usage on `verify-uselistorder.lto.opt.bc`;
see r236629 for details.)

llvm-svn: 237490

llvm/lib/MC/MCAssembler.cpp

diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index b4b9a47..ff230dfd 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -360,10 +360,18 @@
 
 MCSymbolData::MCSymbolData() : Symbol(nullptr) {}
 
-MCSymbolData::MCSymbolData(const MCSymbol &Symbol, MCFragment *Fragment,
-                           uint64_t Offset)
-    : Symbol(&Symbol), Fragment(Fragment), Offset(Offset), SymbolSize(nullptr),
-      CommonAlign(-1U), Flags(0), Index(0) {}
+void MCSymbolData::initialize(const MCSymbol &Symbol, MCFragment *Fragment,
+                              uint64_t Offset) {
+  assert(!isInitialized() && "Expected uninitialized symbol");
+
+  this->Symbol = &Symbol;
+  this->Fragment.setPointer(Fragment);
+  this->Offset = Offset;
+  this->SymbolSize = nullptr;
+  this->CommonAlign = -1U;
+  this->Flags = 0;
+  this->Index = 0;
+}
 
 /* *** */
 
@@ -383,7 +391,6 @@
   Sections.clear();
   Symbols.clear();
   SectionMap.clear();
-  SymbolMap.clear();
   IndirectSymbols.clear();
   DataRegions.clear();
   LinkerOptions.clear();