misched: DAG builder support for tracking register pressure within the current scheduling region.
The DAG builder is a convenient place to do it. Hopefully this is more
efficient than a separate traversal over the same region.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155456 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index 1b306d6..e2f33aa 100644
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -13,6 +13,7 @@
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "sched-instrs"
+#include "RegisterPressure.h"
#include "llvm/Operator.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/ValueTracking.h"
@@ -504,7 +505,11 @@
}
}
-void ScheduleDAGInstrs::buildSchedGraph(AliasAnalysis *AA) {
+/// If RegPressure is non null, compute register pressure as a side effect. The
+/// DAG builder is an efficient place to do it because it already visits
+/// operands.
+void ScheduleDAGInstrs::buildSchedGraph(AliasAnalysis *AA,
+ RegPressureTracker *RPTracker) {
// Create an SUnit for each real instruction.
initSUnits();
@@ -555,6 +560,10 @@
PrevMI = MI;
continue;
}
+ if (RPTracker) {
+ RPTracker->recede();
+ assert(RPTracker->getPos() == prior(MII) && "RPTracker can't find MI");
+ }
assert((!MI->isTerminator() || CanHandleTerminators) && !MI->isLabel() &&
"Cannot schedule terminators or labels!");