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_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 58feb67..9a1f2b8 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -5980,8 +5980,16 @@
HInvokeStaticOrDirect::DispatchInfo CodeGeneratorARM::GetSupportedInvokeStaticOrDirectDispatch(
const HInvokeStaticOrDirect::DispatchInfo& desired_dispatch_info,
MethodReference target_method) {
- if (desired_dispatch_info.code_ptr_location ==
- HInvokeStaticOrDirect::CodePtrLocation::kCallPCRelative) {
+ 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;
+ }
+
+ if (dispatch_info.code_ptr_location == HInvokeStaticOrDirect::CodePtrLocation::kCallPCRelative) {
const DexFile& outer_dex_file = GetGraph()->GetDexFile();
if (&outer_dex_file != target_method.dex_file) {
// Calls across dex files are more likely to exceed the available BL range,
@@ -5992,14 +6000,14 @@
? HInvokeStaticOrDirect::CodePtrLocation::kCallDirectWithFixup
: HInvokeStaticOrDirect::CodePtrLocation::kCallArtMethod;
return HInvokeStaticOrDirect::DispatchInfo {
- desired_dispatch_info.method_load_kind,
+ dispatch_info.method_load_kind,
code_ptr_location,
- desired_dispatch_info.method_load_data,
+ dispatch_info.method_load_data,
0u
};
}
}
- return desired_dispatch_info;
+ return dispatch_info;
}
Register CodeGeneratorARM::GetInvokeStaticOrDirectExtraParameter(HInvokeStaticOrDirect* invoke,