Factor out LiveIntervalAnalysis' code to determine whether an instruction

is trivially rematerializable and integrate it into
TargetInstrInfo::isTriviallyReMaterializable. This way, all places that
need to know whether an instruction is rematerializable will get the
same answer.

This enables the useful parts of the aggressive-remat option by
default -- using AliasAnalysis to determine whether a memory location
is invariant, and removes the questionable parts -- rematting operations
with virtual register inputs that may not be live everywhere.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83687 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index f50844f..44e9296 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -123,7 +123,7 @@ void ScheduleDAGInstrs::StartBlock(MachineBasicBlock *BB) {
     }
 }
 
-void ScheduleDAGInstrs::BuildSchedGraph() {
+void ScheduleDAGInstrs::BuildSchedGraph(AliasAnalysis *AA) {
   // We'll be allocating one SUnit for each instruction, plus one for
   // the region exit node.
   SUnits.reserve(BB->size());
@@ -375,7 +375,7 @@ void ScheduleDAGInstrs::BuildSchedGraph() {
         // Treat all other stores conservatively.
         goto new_chain;
     } else if (TID.mayLoad()) {
-      if (MI->isInvariantLoad()) {
+      if (MI->isInvariantLoad(AA)) {
         // Invariant load, no chain dependencies needed!
       } else if (const Value *V = getUnderlyingObjectForInstr(MI)) {
         // A load from a specific PseudoSourceValue. Add precise dependencies.