[clang] 4f61863 - [clang] Optimize SourceManager.getSpellingLocSlowCase and SourceManager.getFileLocSlowCase (#164269)

[via cfe-commits]

Author: SKill
Date: 2025-11-03T10:12:15-05:00
New Revision: 4f618636ddb4938bb91816b66250edc755cdc7d1

URL: https://github.com/llvm/llvm-project/commit/4f618636ddb4938bb91816b66250edc755cdc7d1
DIFF: https://github.com/llvm/llvm-project/commit/4f618636ddb4938bb91816b66250edc755cdc7d1.diff

LOG: [clang] Optimize SourceManager.getSpellingLocSlowCase and SourceManager.getFileLocSlowCase (#164269)

Optimize implementations of `getSpellingLocSlowCase` and
`getFileLocSlowCase` by inlining called methods to avoid repeated calls
to `getSLocEntry` and `getFileID`.

a performance improvement follow up for #160667

Added: 
    

Modified: 
    clang/lib/Basic/SourceManager.cpp

Removed: 
    


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diff  --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index 938c6485125ee..97aa0f2aa59b9 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/lib/Basic/SourceManager.cpp
@@ -907,19 +907,23 @@ getExpansionLocSlowCase(SourceLocation Loc) const {
 
 SourceLocation SourceManager::getSpellingLocSlowCase(SourceLocation Loc) const {
   do {
-    FileIDAndOffset LocInfo = getDecomposedLoc(Loc);
-    Loc = getSLocEntry(LocInfo.first).getExpansion().getSpellingLoc();
-    Loc = Loc.getLocWithOffset(LocInfo.second);
+    const SLocEntry &Entry = getSLocEntry(getFileID(Loc));
+    Loc = Entry.getExpansion().getSpellingLoc().getLocWithOffset(
+        Loc.getOffset() - Entry.getOffset());
   } while (!Loc.isFileID());
   return Loc;
 }
 
 SourceLocation SourceManager::getFileLocSlowCase(SourceLocation Loc) const {
   do {
-    if (isMacroArgExpansion(Loc))
-      Loc = getImmediateSpellingLoc(Loc);
-    else
-      Loc = getImmediateExpansionRange(Loc).getBegin();
+    const SLocEntry &Entry = getSLocEntry(getFileID(Loc));
+    const ExpansionInfo &ExpInfo = Entry.getExpansion();
+    if (ExpInfo.isMacroArgExpansion()) {
+      Loc = ExpInfo.getSpellingLoc().getLocWithOffset(Loc.getOffset() -
+                                                      Entry.getOffset());
+    } else {
+      Loc = ExpInfo.getExpansionLocStart();
+    }
   } while (!Loc.isFileID());
   return Loc;
 }