-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/PseudoSourceValue.cpp b/lib/CodeGen/PseudoSourceValue.cpp
index 00c5d46..289a52b 100644
--- a/lib/CodeGen/PseudoSourceValue.cpp
+++ b/lib/CodeGen/PseudoSourceValue.cpp
@@ -63,6 +63,8 @@
virtual bool isConstant(const MachineFrameInfo *MFI) const;
+ virtual bool isAliased() const;
+
virtual void printCustom(raw_ostream &OS) const {
OS << "FixedStack" << FI;
}
@@ -89,6 +91,23 @@
return false;
}
+bool PseudoSourceValue::isAliased() const {
+ if (this == getStack() ||
+ this == getGOT() ||
+ this == getConstantPool() ||
+ this == getJumpTable())
+ return false;
+ llvm_unreachable("Unknown PseudoSourceValue!");
+ return true;
+}
+
bool FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const{
return MFI && MFI->isImmutableObjectIndex(FI);
}
+
+bool FixedStackPseudoSourceValue::isAliased() const{
+ // Negative frame indices are used for special things that don't
+ // appear in LLVM IR. Non-negative indices may be used for things
+ // like static allocas.
+ return FI >= 0;
+}