Add "hasSideEffects" method to MachineInstrInfo class.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45126 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2007-12-17 21:53:30 +00:00
parent ced09c47d9
commit 882d291487

View File

@ -314,6 +314,15 @@ public:
isReallyTriviallyReMaterializable(MI);
}
/// hasSideEffects - Returns true if the instruction has side effects that are
/// not captured by any operands of the instruction or other flags.
bool hasSideEffects(MachineInstr *MI) const {
const TargetInstrDescriptor *TID = MI->getInstrDescriptor();
if (!(TID->Flags & M_NEVER_HAS_SIDE_EFFECTS ||
TID->Flags & M_MAY_HAVE_SIDE_EFFECTS)) return true;
if (TID->Flags & M_NEVER_HAS_SIDE_EFFECTS) return false;
return !isReallySideEffectFree(MI); // May have side effects
}
protected:
/// isReallyTriviallyReMaterializable - For instructions with opcodes for
/// which the M_REMATERIALIZABLE flag is set, this function tests whether the
@ -329,7 +338,7 @@ protected:
/// isReallySideEffectFree - If the M_MAY_HAVE_SIDE_EFFECTS flag is set, this
/// method is called to determine if the specific instance of this
/// instructions has side effects. This is useful in cases of instructions,
/// instruction has side effects. This is useful in cases of instructions,
/// like loads, which generally always have side effects. A load from a
/// constant pool doesn't have side effects, though. So we need to
/// differentiate it from the general case.