ART: Do not attempt to compile a method with too many registers
The mir_graph has a hard limit on how many ssa registers it can
handle, and will silently fail or fatal out in debug builds when
more SSA registers are necessary. This adds a check in the frontend
that tries to catch some of these cases, and makes the DCHECK a
CHECK to not silently fail.
Bug: 16018097
Change-Id: Iad82178945a8f8c34943cc7573fd73d2b4decade
diff --git a/compiler/dex/frontend.cc b/compiler/dex/frontend.cc
index d097500..51446f6 100644
--- a/compiler/dex/frontend.cc
+++ b/compiler/dex/frontend.cc
@@ -14,6 +14,8 @@
* limitations under the License.
*/
+#include <cstdint>
+
#include "compiler.h"
#include "compiler_internals.h"
#include "driver/compiler_driver.h"
@@ -470,6 +472,10 @@
COMPILE_ASSERT(sizeof(kUnsupportedOpcodesSize) == 8 * sizeof(size_t),
kUnsupportedOpcodesSize_unexp);
+// The maximum amount of Dalvik register in a method for which we will start compiling. Tries to
+// avoid an abort when we need to manage more SSA registers than we can.
+static constexpr size_t kMaxAllowedDalvikRegisters = INT16_MAX / 2;
+
CompilationUnit::CompilationUnit(ArenaPool* pool)
: compiler_driver(nullptr),
class_linker(nullptr),
@@ -548,6 +554,12 @@
// Skip the method that we do not support currently.
static bool CanCompileMethod(uint32_t method_idx, const DexFile& dex_file,
CompilationUnit& cu) {
+ // This is a limitation in mir_graph. See MirGraph::SetNumSSARegs.
+ if (cu.num_dalvik_registers > kMaxAllowedDalvikRegisters) {
+ VLOG(compiler) << "Too many dalvik registers : " << cu.num_dalvik_registers;
+ return false;
+ }
+
// Check whether we do have limitations at all.
if (kSupportedTypes[cu.instruction_set] == nullptr &&
kUnsupportedOpcodesSize[cu.instruction_set] == 0U) {
diff --git a/compiler/dex/mir_graph.h b/compiler/dex/mir_graph.h
index 1556a19..79b3edf 100644
--- a/compiler/dex/mir_graph.h
+++ b/compiler/dex/mir_graph.h
@@ -727,7 +727,7 @@
* would be filtered out with current settings. When orig_sreg field is removed
* from RegLocation, expand s_reg_low to handle all possible cases and remove DCHECK().
*/
- DCHECK_EQ(new_num, static_cast<int16_t>(new_num));
+ CHECK_EQ(new_num, static_cast<int16_t>(new_num));
num_ssa_regs_ = new_num;
}
