From 3b7660dea62f2940c8ade2cbc26792d341284dfe Mon Sep 17 00:00:00 2001 From: Serguei Katkov Date: Tue, 14 Jul 2015 19:04:48 +0600 Subject: ART: DCE should know that array-length can throw NPE array-length can throw NPE so it should be taking into account. Bug: 22521944 Signed-off-by: Serguei Katkov (cherry picked from commit b016c6dd3c30b04104a0a43dc294ce93e5f63874) Change-Id: I6232430a02f9e6d156ad2aae0eb5a630118c0e79 --- compiler/dex/gvn_dead_code_elimination.cc | 8 +++++++- compiler/dex/gvn_dead_code_elimination_test.cc | 27 ++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 1 deletion(-) (limited to 'compiler') diff --git a/compiler/dex/gvn_dead_code_elimination.cc b/compiler/dex/gvn_dead_code_elimination.cc index b1f5d870d..044989e2a 100644 --- a/compiler/dex/gvn_dead_code_elimination.cc +++ b/compiler/dex/gvn_dead_code_elimination.cc @@ -1192,7 +1192,6 @@ bool GvnDeadCodeElimination::RecordMIR(MIR* mir) { case Instruction::CONST_WIDE_32: case Instruction::CONST_WIDE: case Instruction::CONST_WIDE_HIGH16: - case Instruction::ARRAY_LENGTH: case Instruction::CMPL_FLOAT: case Instruction::CMPG_FLOAT: case Instruction::CMPL_DOUBLE: @@ -1316,6 +1315,13 @@ bool GvnDeadCodeElimination::RecordMIR(MIR* mir) { } break; + case Instruction::ARRAY_LENGTH: + if ((mir->optimization_flags & MIR_IGNORE_NULL_CHECK) == 0) { + must_keep = true; + uses_all_vregs = true; + } + break; + case Instruction::AGET_OBJECT: case Instruction::AGET: case Instruction::AGET_WIDE: diff --git a/compiler/dex/gvn_dead_code_elimination_test.cc b/compiler/dex/gvn_dead_code_elimination_test.cc index 461c844a6..6ba91b64b 100644 --- a/compiler/dex/gvn_dead_code_elimination_test.cc +++ b/compiler/dex/gvn_dead_code_elimination_test.cc @@ -2066,4 +2066,31 @@ TEST_F(GvnDeadCodeEliminationTestSimple, UnusedRegs2) { } } +TEST_F(GvnDeadCodeEliminationTestSimple, ArrayLengthThrows) { + static const MIRDef mirs[] = { + DEF_CONST(3, Instruction::CONST, 0u, 0), // null + DEF_UNOP(3, Instruction::ARRAY_LENGTH, 1u, 0u), // null.length + DEF_CONST(3, Instruction::CONST, 2u, 1000u), // Overwrite the array-length dest. + }; + + static const int32_t sreg_to_vreg_map[] = { 0, 1, 1 }; + PrepareSRegToVRegMap(sreg_to_vreg_map); + + PrepareMIRs(mirs); + PerformGVN_DCE(); + + ASSERT_EQ(arraysize(mirs), value_names_.size()); + static const size_t diff_indexes[] = { 0, 1, 2 }; + ExpectValueNamesNE(diff_indexes); + + static const bool eliminated[] = { + false, false, false, + }; + static_assert(arraysize(eliminated) == arraysize(mirs), "array size mismatch"); + for (size_t i = 0; i != arraysize(eliminated); ++i) { + bool actually_eliminated = (static_cast(mirs_[i].dalvikInsn.opcode) == kMirOpNop); + EXPECT_EQ(eliminated[i], actually_eliminated) << i; + } +} + } // namespace art -- cgit v1.2.3