[Utils] Salvage debug info from all no-op casts
We already try to salvage debug values from no-op bitcasts and inttoptr
instructions: we should handle ptrtoint instructions as well.
This saves an additional 24,444 debug values in a stage2 build of clang,
and (according to llvm-dwarfdump --statistics) provides an additional
289 unique source variables.
llvm-svn: 324982
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 45962ca..e170b22 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1518,11 +1518,14 @@
doSalvage(DII, Ops);
};
- if (isa<BitCastInst>(&I) || isa<IntToPtrInst>(&I)) {
- // Bitcasts are entirely irrelevant for debug info. Rewrite dbg.value,
- // dbg.addr, and dbg.declare to use the cast's source.
+ if (auto *CI = dyn_cast<CastInst>(&I)) {
+ if (!CI->isNoopCast(M.getDataLayout()))
+ return;
+
+ // No-op casts are irrelevant for debug info.
+ MetadataAsValue *CastSrc = wrapMD(I.getOperand(0));
for (auto *DII : DbgUsers) {
- DII->setOperand(0, wrapMD(I.getOperand(0)));
+ DII->setOperand(0, CastSrc);
DEBUG(dbgs() << "SALVAGE: " << *DII << '\n');
}
} else if (auto *GEP = dyn_cast<GetElementPtrInst>(&I)) {