Implement irreducible loop support in optimizing.
So we don't fallback to the interpreter in the presence of
irreducible loops.
Implications:
- A loop pre-header does not necessarily dominate a loop header.
- Non-constant redundant phis will be kept in loop headers, to
satisfy our linear scan register allocation algorithm.
- while-graph optimizations, such as gvn, licm, lse, and dce
need to know when they are dealing with irreducible loops.
Change-Id: I2cea8934ce0b40162d215353497c7f77d6c9137e
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index a808c27..86327fb 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -4185,19 +4185,28 @@
HInvokeStaticOrDirect::DispatchInfo CodeGeneratorX86::GetSupportedInvokeStaticOrDirectDispatch(
const HInvokeStaticOrDirect::DispatchInfo& desired_dispatch_info,
MethodReference target_method ATTRIBUTE_UNUSED) {
- switch (desired_dispatch_info.code_ptr_location) {
+ HInvokeStaticOrDirect::DispatchInfo dispatch_info = desired_dispatch_info;
+
+ // We disable pc-relative load when there is an irreducible loop, as the optimization
+ // is incompatible with it.
+ if (GetGraph()->HasIrreducibleLoops() &&
+ (dispatch_info.method_load_kind ==
+ HInvokeStaticOrDirect::MethodLoadKind::kDexCachePcRelative)) {
+ dispatch_info.method_load_kind = HInvokeStaticOrDirect::MethodLoadKind::kDexCacheViaMethod;
+ }
+ switch (dispatch_info.code_ptr_location) {
case HInvokeStaticOrDirect::CodePtrLocation::kCallDirectWithFixup:
case HInvokeStaticOrDirect::CodePtrLocation::kCallDirect:
// For direct code, we actually prefer to call via the code pointer from ArtMethod*.
// (Though the direct CALL ptr16:32 is available for consideration).
return HInvokeStaticOrDirect::DispatchInfo {
- desired_dispatch_info.method_load_kind,
+ dispatch_info.method_load_kind,
HInvokeStaticOrDirect::CodePtrLocation::kCallArtMethod,
- desired_dispatch_info.method_load_data,
+ dispatch_info.method_load_data,
0u
};
default:
- return desired_dispatch_info;
+ return dispatch_info;
}
}