diff options
| -rw-r--r-- | compiler/optimizing/instruction_simplifier.cc | 13 | ||||
| -rw-r--r-- | test/475-simplify-mul-zero/expected.txt | 1 | ||||
| -rw-r--r-- | test/475-simplify-mul-zero/info.txt | 2 | ||||
| -rw-r--r-- | test/475-simplify-mul-zero/src/Main.java | 28 |
4 files changed, 41 insertions, 3 deletions
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc index 98c0eedeb2..225af77a19 100644 --- a/compiler/optimizing/instruction_simplifier.cc +++ b/compiler/optimizing/instruction_simplifier.cc @@ -427,9 +427,16 @@ void InstructionSimplifierVisitor::VisitMul(HMul* instruction) { if (Primitive::IsIntOrLongType(type)) { int64_t factor = Int64FromConstant(input_cst); - // We expect the `0` case to have been handled in the constant folding pass. - DCHECK_NE(factor, 0); - if (IsPowerOfTwo(factor)) { + // Even though constant propagation also takes care of the zero case, other + // optimizations can lead to having a zero multiplication. + if (factor == 0) { + // Replace code looking like + // MUL dst, src, 0 + // with + // 0 + instruction->ReplaceWith(input_cst); + instruction->GetBlock()->RemoveInstruction(instruction); + } else if (IsPowerOfTwo(factor)) { // Replace code looking like // MUL dst, src, pow_of_2 // with diff --git a/test/475-simplify-mul-zero/expected.txt b/test/475-simplify-mul-zero/expected.txt new file mode 100644 index 0000000000..7ed6ff82de --- /dev/null +++ b/test/475-simplify-mul-zero/expected.txt @@ -0,0 +1 @@ +5 diff --git a/test/475-simplify-mul-zero/info.txt b/test/475-simplify-mul-zero/info.txt new file mode 100644 index 0000000000..0db11f2823 --- /dev/null +++ b/test/475-simplify-mul-zero/info.txt @@ -0,0 +1,2 @@ +Regression check for optimizing simplify instruction pass. +Mul should expect zero constant as input.
\ No newline at end of file diff --git a/test/475-simplify-mul-zero/src/Main.java b/test/475-simplify-mul-zero/src/Main.java new file mode 100644 index 0000000000..57adcff01e --- /dev/null +++ b/test/475-simplify-mul-zero/src/Main.java @@ -0,0 +1,28 @@ +/* + * Copyright (C) 2015 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +public class Main { + public static void main(String[] args) { + long l3 = 2207693990L; + int i12 = 5; + + for (int i = 1; i < 2; ++i) { + i12 ^= (int)(-((-(-(l3 - l3))) * i)); + } + + System.out.println(i12); + } +} |