MachineSink: make shouldSink a TII target hook
Some targets may disagree on what they want sunk or not sunk,
so make this a target hook instead of hardcoded.
llvm-svn: 264799
diff --git a/llvm/lib/CodeGen/MachineSink.cpp b/llvm/lib/CodeGen/MachineSink.cpp
index 18aecda..07fbd3d 100644
--- a/llvm/lib/CodeGen/MachineSink.cpp
+++ b/llvm/lib/CodeGen/MachineSink.cpp
@@ -472,10 +472,6 @@
return true;
}
-static bool AvoidsSinking(MachineInstr *MI, MachineRegisterInfo *MRI) {
- return MI->isInsertSubreg() || MI->isSubregToReg() || MI->isRegSequence();
-}
-
/// collectDebgValues - Scan instructions following MI and collect any
/// matching DBG_VALUEs.
static void collectDebugValues(MachineInstr *MI,
@@ -724,9 +720,8 @@
/// instruction out of its current block into a successor.
bool MachineSinking::SinkInstruction(MachineInstr *MI, bool &SawStore,
AllSuccsCache &AllSuccessors) {
- // Don't sink insert_subreg, subreg_to_reg, reg_sequence. These are meant to
- // be close to the source to make it easier to coalesce.
- if (AvoidsSinking(MI, MRI))
+ // Don't sink instructions that the target prefers not to sink.
+ if (!TII->shouldSink(*MI))
return false;
// Check if it's safe to move the instruction.