AsmPrinter: Stop creating DebugLocs

While looking at a heap profile of a clang LTO bootstrap with -g, I
noticed that 2.2% of memory in an `llvm-lto` of clang is from calling
`DebugLoc::get()` in `collectVariableInfo()` (accounting for ~40% of
memory used for `MDLocation`s).

I suspect this was introduced by r226736, whose goal was to prevent
uniquing of `DebugLoc`s (goal achieved, if so).

There's no reason we need a `DebugLoc` here at all -- it was just being
used for (in)convenient API -- so the fix is to pass the scope and
inlined-at directly to `LexicalScopes::findInlinedScope()`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229459 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/CodeGen/LexicalScopes.h b/include/llvm/CodeGen/LexicalScopes.h
index 11a360a..b3a8405 100644 (file)
--- a/include/llvm/CodeGen/LexicalScopes.h
+++ b/include/llvm/CodeGen/LexicalScopes.h
@@ -180,9 +180,11 @@ public:
     return I != AbstractScopeMap.end() ? &I->second : nullptr;
   }
 
-  /// findInlinedScope - Find an inlined scope for the given DebugLoc or return
-  /// NULL.
-  LexicalScope *findInlinedScope(DebugLoc DL);
+  /// findInlinedScope - Find an inlined scope for the given scope/inlined-at.
+  LexicalScope *findInlinedScope(const MDNode *N, const MDNode *IA) {
+    auto I = InlinedLexicalScopeMap.find(std::make_pair(N, IA));
+    return I != InlinedLexicalScopeMap.end() ? &I->second : nullptr;
+  }
 
   /// findLexicalScope - Find regular lexical scope or return null.
   LexicalScope *findLexicalScope(const MDNode *N) {

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 3b6f461..79e6e46 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -949,11 +949,9 @@ DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU, DISubprogram SP,
       continue;
 
     LexicalScope *Scope = nullptr;
-    if (MDNode *IA = DV.getInlinedAt()) {
-      DebugLoc DL = DebugLoc::getFromDILocation(IA);
-      Scope = LScopes.findInlinedScope(DebugLoc::get(
-          DL.getLine(), DL.getCol(), DV.getContext(), IA));
-    } else
+    if (MDNode *IA = DV.getInlinedAt())
+      Scope = LScopes.findInlinedScope(DV.getContext(), IA);
+    else
       Scope = LScopes.findLexicalScope(DV.getContext());
     // If variable scope is not found then skip this variable.
     if (!Scope)

diff --git a/lib/CodeGen/LexicalScopes.cpp b/lib/CodeGen/LexicalScopes.cpp
index d71b0af..9eaf7da 100644 (file)
--- a/lib/CodeGen/LexicalScopes.cpp
+++ b/lib/CodeGen/LexicalScopes.cpp
@@ -104,14 +104,6 @@ void LexicalScopes::extractLexicalScopes(
   }
 }
 
-LexicalScope *LexicalScopes::findInlinedScope(DebugLoc DL) {
-  MDNode *Scope = nullptr;
-  MDNode *IA = nullptr;
-  DL.getScopeAndInlinedAt(Scope, IA, MF->getFunction()->getContext());
-  auto I = InlinedLexicalScopeMap.find(std::make_pair(Scope, IA));
-  return I != InlinedLexicalScopeMap.end() ? &I->second : nullptr;
-}
-
 /// findLexicalScope - Find lexical scope, either regular or inlined, for the
 /// given DebugLoc. Return NULL if not found.
 LexicalScope *LexicalScopes::findLexicalScope(DebugLoc DL) {