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
This commit is contained in:
Duncan P. N. Exon Smith 2015-02-17 00:02:27 +00:00
parent ba51ae6864
commit ca3b3d5e2c
3 changed files with 8 additions and 16 deletions

View File

@ -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) {

View File

@ -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)

View File

@ -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) {