Extend a trace with a backward branch into a loop.
When seeing a trace that ends with a backward branch, exhaust all code
blocks reachable from that trace and try to identify if there exists a
non-nested loop. If the derived loop is found to be too complex or only
acyclic code is seen, revert to the original compilation mechanism to
translate a simple trace.
This CL uses the whole-method parser/dataflow analysis framework to
identify such loops. No optimization/codegen are performed yet.
Bug: 4086718
Change-Id: I19ed3ee53ea1cbda33940c533de8e9220e647156
diff --git a/vm/compiler/Compiler.h b/vm/compiler/Compiler.h
index 2a0eef4..5d5036f 100644
--- a/vm/compiler/Compiler.h
+++ b/vm/compiler/Compiler.h
@@ -232,6 +232,7 @@
DataFlowAnalysisMode dfaMode,
bool isIterative);
void dvmCompilerMethodSSATransformation(struct CompilationUnit *cUnit);
+bool dvmCompilerBuildLoop(struct CompilationUnit *cUnit);
void dvmCompilerStateRefresh(void);
JitTraceDescription *dvmCopyTraceDescriptor(const u2 *pc,
const struct JitEntry *desc);