From bf5d818f7e59ce33521ad81bbab68b1e7a09e0ba Mon Sep 17 00:00:00 2001 From: buzbee Date: Wed, 17 Sep 2014 13:23:58 -0700 Subject: [PATCH] ART: skip compilation of huge methods. Besides not being worthwhile to compile, it huge methods could cause overflow of some internal compiler structures. internal b/17524219 Change-Id: I0e47ff4757eec265809598830a2616ac367af77d --- compiler/dex/frontend.cc | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/compiler/dex/frontend.cc b/compiler/dex/frontend.cc index 2ba320f46..45fc19e66 100644 --- a/compiler/dex/frontend.cc +++ b/compiler/dex/frontend.cc @@ -623,11 +623,22 @@ static CompiledMethod* CompileMethod(CompilerDriver& driver, jobject class_loader, const DexFile& dex_file, void* llvm_compilation_unit) { VLOG(compiler) << "Compiling " << PrettyMethod(method_idx, dex_file) << "..."; - if (code_item->insns_size_in_code_units_ >= 0x10000) { - LOG(INFO) << "Method size exceeds compiler limits: " << code_item->insns_size_in_code_units_ + /* + * Skip compilation for pathologically large methods - either by instruction count or num vregs. + * Dalvik uses 16-bit uints for instruction and register counts. We'll limit to a quarter + * of that, which also guarantees we cannot overflow our 16-bit internal SSA name space. + */ + if (code_item->insns_size_in_code_units_ >= UINT16_MAX / 4) { + LOG(INFO) << "Method exceeds compiler instruction limit: " + << code_item->insns_size_in_code_units_ << " in " << PrettyMethod(method_idx, dex_file); return NULL; } + if (code_item->registers_size_ >= UINT16_MAX / 4) { + LOG(INFO) << "Method exceeds compiler virtual register limit: " + << code_item->registers_size_ << " in " << PrettyMethod(method_idx, dex_file); + return NULL; + } if (!driver.GetCompilerOptions().IsCompilationEnabled()) { return nullptr; -- 2.11.0