-Revert parts of 84326 and 84411. Distinquishing between fixed and non-fixed
stack slots and giving them different PseudoSourceValue's did not fix the
problem of post-alloc scheduling miscompiling llvm itself.
- Apply Dan's conservative workaround by assuming any non fixed stack slots can
alias other memory locations. This means a load from spill slot #1 cannot
move above a store of spill slot #2.
- Enable post-alloc scheduling for x86 at optimization leverl Default and above.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84424 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index 44e9296..768ca16 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -106,10 +106,19 @@
return 0;
V = getUnderlyingObject(V);
- if (!isa<PseudoSourceValue>(V) && !isIdentifiedObject(V))
- return 0;
+ if (const PseudoSourceValue *PSV = dyn_cast<PseudoSourceValue>(V)) {
+ // For now, ignore PseudoSourceValues which may alias LLVM IR values
+ // because the code that uses this function has no way to cope with
+ // such aliases.
+ if (PSV->isAliased())
+ return 0;
+ return V;
+ }
- return V;
+ if (isIdentifiedObject(V))
+ return V;
+
+ return 0;
}
void ScheduleDAGInstrs::StartBlock(MachineBasicBlock *BB) {