[ARM][HWLoops] Create hardware loops for sibling loops
Given a loop with two subloops, it should be possible for both to be
converted to hardware loops. That's what this patch does, simply enough.
It slightly alters the loop iterating order to try and convert all
subloops. If one (or more) succeeds, it stops as before.
Differential Revision: https://reviews.llvm.org/D78502
diff --git a/llvm/lib/CodeGen/HardwareLoops.cpp b/llvm/lib/CodeGen/HardwareLoops.cpp
index 3b97e7b..0ba7e92 100644
--- a/llvm/lib/CodeGen/HardwareLoops.cpp
+++ b/llvm/lib/CodeGen/HardwareLoops.cpp
@@ -245,14 +245,17 @@
// converted and the parent loop doesn't support containing a hardware loop.
bool HardwareLoops::TryConvertLoop(Loop *L) {
// Process nested loops first.
- for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I) {
- if (TryConvertLoop(*I)) {
- reportHWLoopFailure("nested hardware-loops not supported", "HWLoopNested",
- ORE, L);
- return true; // Stop search.
- }
+ bool AnyChanged = false;
+ for (Loop *SL : *L)
+ AnyChanged |= TryConvertLoop(SL);
+ if (AnyChanged) {
+ reportHWLoopFailure("nested hardware-loops not supported", "HWLoopNested",
+ ORE, L);
+ return true; // Stop search.
}
+ LLVM_DEBUG(dbgs() << "HWLoops: Loop " << L->getHeader()->getName() << "\n");
+
HardwareLoopInfo HWLoopInfo(L);
if (!HWLoopInfo.canAnalyze(*LI)) {
reportHWLoopFailure("cannot analyze loop, irreducible control flow",