Add "mayHaveSideEffects" and "neverHasSideEffects" flags to some instructions. I
based what flag to set on whether it was already marked as
"isRematerializable". If there was a further check to determine if it's "really"
rematerializable, then I marked it as "mayHaveSideEffects" and created a check
in the X86 back-end similar to the remat one.
llvm-svn: 45132
diff --git a/llvm/lib/Target/X86/X86InstrInfo.h b/llvm/lib/Target/X86/X86InstrInfo.h
index 2694481..02d25c7 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.h
+++ b/llvm/lib/Target/X86/X86InstrInfo.h
@@ -240,7 +240,8 @@
unsigned isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const;
unsigned isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const;
bool isReallyTriviallyReMaterializable(MachineInstr *MI) const;
-
+ bool isReallySideEffectFree(MachineInstr *MI) const;
+
/// convertToThreeAddress - This method must be implemented by targets that
/// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target
/// may be able to convert a two-address instruction into a true