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/*
* Copyright (C) 2022 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) throws Exception {
assertEquals(2, $noinline$testDivideOverTen(20));
assertEquals(-2, $noinline$testDivideOverTen(-20));
assertEquals(0, $noinline$testSimpleDivisionInLoop(0));
assertEquals(1, $noinline$testSimpleDivisionInLoop(81));
assertEquals(10, $noinline$testOptimizeSeparateBranches(60, true));
assertEquals(10, $noinline$testOptimizeSeparateBranches(80, false));
assertEquals(1, $noinline$testDoNotOptimizeOneBranchThrows(81, false));
assertEquals(-1000, $noinline$testDoNotOptimizeOneBranchThrows(81, true));
assertEquals(1, $noinline$testOptimizeAfterOneBranchDisappears(81, false));
assertEquals(10, $noinline$testRemoveTryBoundaryNested(60));
assertEquals(-2000, $noinline$testRemoveTryBoundaryNestedButNotCatch(60, true));
assertEquals(30, $noinline$testRemoveTryBoundaryNestedButNotCatch(60, false));
assertEquals(30, $noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(60, false));
}
public static void assertEquals(int expected, int result) {
if (expected != result) {
throw new Error("Expected: " + expected + ", found: " + result);
}
}
// Check that this version cannot remove the TryBoundary instructions since we may throw.
/// CHECK-START: int Main.$inline$division(int, int) register (after)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$inline$division(int, int) register (after)
/// CHECK: flags "catch_block"
private static int $inline$division(int a, int b) {
try {
return a / b;
} catch (Error unexpected) {
return -1000;
}
}
// Check that we can remove the TryBoundary afer inlining since we know we can't throw.
/// CHECK-START: int Main.$noinline$testDivideOverTen(int) inliner (after)
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testDivideOverTen(int) inliner (after)
/// CHECK-NOT: flags "catch_block"
private static int $noinline$testDivideOverTen(int a) {
return $inline$division(a, 10);
}
/// CHECK-START: int Main.$noinline$testSimpleDivisionInLoop(int) dead_code_elimination$initial (before)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testSimpleDivisionInLoop(int) dead_code_elimination$initial (before)
/// CHECK: flags "catch_block"
/// CHECK-START: int Main.$noinline$testSimpleDivisionInLoop(int) dead_code_elimination$initial (after)
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testSimpleDivisionInLoop(int) dead_code_elimination$initial (after)
/// CHECK-NOT: flags "catch_block"
private static int $noinline$testSimpleDivisionInLoop(int a) {
try {
for (int i = 0; i < 4; i++) {
a /= 3;
}
} catch (Error unexpected) {
return -1000;
}
return a;
}
// Even though the `TryBoundary`s are split, we can remove them as nothing in the try can throw.
/// CHECK-START: int Main.$noinline$testOptimizeSeparateBranches(int, boolean) dead_code_elimination$initial (before)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testOptimizeSeparateBranches(int, boolean) dead_code_elimination$initial (before)
/// CHECK: flags "catch_block"
/// CHECK-NOT: flags "catch_block"
/// CHECK-START: int Main.$noinline$testOptimizeSeparateBranches(int, boolean) dead_code_elimination$initial (after)
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testOptimizeSeparateBranches(int, boolean) dead_code_elimination$initial (after)
/// CHECK-NOT: flags "catch_block"
private static int $noinline$testOptimizeSeparateBranches(int a, boolean val) {
try {
if (val) {
// TryBoundary kind:entry
a /= 3;
} else {
// TryBoundary kind:entry
a /= 4;
}
a /= 2;
// TryBoundary kind:exit
} catch (Error unexpected) {
return -1000;
}
return a;
}
// Even though the `a /= 3;` can't throw, we don't eliminate any `TryBoundary` instructions. This
// is because we have the `throw new Error();` in the try as well. We could potentially support
// removing some `TryBoundary` instructions and not all in the try, but this would complicate the
// code and wouldn't bring code size reductions since we would be unable to remove the catch
// block.
/// CHECK-START: int Main.$noinline$testDoNotOptimizeOneBranchThrows(int, boolean) register (after)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testDoNotOptimizeOneBranchThrows(int, boolean) register (after)
/// CHECK: flags "catch_block"
public static int $noinline$testDoNotOptimizeOneBranchThrows(int a, boolean val) {
try {
for (int i = 0; i < 4; i++) {
// TryBoundary kind:entry
a /= 3;
// TryBoundary kind:exit
}
if (val) {
// TryBoundary kind:entry
throw new Error();
// TryBoundary kind:exit
}
} catch (Error e) {
return -1000;
}
return a;
}
// The throw gets eliminated by `SimplifyIfs` in DCE, so we can detect that nothing can throw in
// the graph and eliminate the `TryBoundary` instructions.
/// CHECK-START: int Main.$noinline$testOptimizeAfterOneBranchDisappears(int, boolean) dead_code_elimination$initial (before)
/// CHECK: Throw
/// CHECK-START: int Main.$noinline$testOptimizeAfterOneBranchDisappears(int, boolean) dead_code_elimination$initial (before)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testOptimizeAfterOneBranchDisappears(int, boolean) dead_code_elimination$initial (before)
/// CHECK: flags "catch_block"
/// CHECK-NOT: flags "catch_block"
/// CHECK-START: int Main.$noinline$testOptimizeAfterOneBranchDisappears(int, boolean) dead_code_elimination$initial (after)
/// CHECK-NOT: Throw
/// CHECK-START: int Main.$noinline$testOptimizeAfterOneBranchDisappears(int, boolean) dead_code_elimination$initial (after)
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testOptimizeAfterOneBranchDisappears(int, boolean) dead_code_elimination$initial (after)
/// CHECK-NOT: flags "catch_block"
public static int $noinline$testOptimizeAfterOneBranchDisappears(int a, boolean val) {
try {
for (int i = 0; i < 4; i++) {
// TryBoundary kind:entry
a /= 3;
// TryBoundary kind:exit
}
if (val && !val) {
// TryBoundary kind:entry
throw new Error();
// TryBoundary kind:exit
}
} catch (Error e) {
return -1000;
}
return a;
}
/// CHECK-START: int Main.$noinline$testRemoveTryBoundaryNested(int) dead_code_elimination$initial (before)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testRemoveTryBoundaryNested(int) dead_code_elimination$initial (before)
/// CHECK: flags "catch_block"
/// CHECK: flags "catch_block"
/// CHECK-NOT: flags "catch_block"
/// CHECK-START: int Main.$noinline$testRemoveTryBoundaryNested(int) dead_code_elimination$initial (after)
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testRemoveTryBoundaryNested(int) dead_code_elimination$initial (after)
/// CHECK-NOT: flags "catch_block"
public static int $noinline$testRemoveTryBoundaryNested(int a) {
try {
// TryBoundary kind:entry
a /= 2;
// TryBoundary kind:exit
try {
// TryBoundary kind:entry
a /= 3;
// TryBoundary kind:exit
} catch (Error e) {
return -2000;
}
} catch (Exception e) {
return -1000;
}
return a;
}
// We can remove the `TryBoundary` instructions surrounding `a /= 2;` but since the inner try can
// throw, we must keep both the inner and outer catches as they are catch handlers of the inner
// try.
/// CHECK-START: int Main.$noinline$testRemoveTryBoundaryNestedButNotCatch(int, boolean) dead_code_elimination$initial (before)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testRemoveTryBoundaryNestedButNotCatch(int, boolean) dead_code_elimination$initial (before)
/// CHECK: flags "catch_block"
/// CHECK: flags "catch_block"
/// CHECK-NOT: flags "catch_block"
/// CHECK-START: int Main.$noinline$testRemoveTryBoundaryNestedButNotCatch(int, boolean) dead_code_elimination$initial (after)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testRemoveTryBoundaryNestedButNotCatch(int, boolean) dead_code_elimination$initial (after)
/// CHECK: flags "catch_block"
/// CHECK: flags "catch_block"
/// CHECK-NOT: flags "catch_block"
public static int $noinline$testRemoveTryBoundaryNestedButNotCatch(int a, boolean val) {
try {
// TryBoundary kind:entry
a /= 2;
// TryBoundary kind:exit
try {
if (val) {
// TryBoundary kind:entry
throw new Error();
// TryBoundary kind:exit
}
// TryBoundary kind:exit
} catch (Error e) {
return -2000;
}
} catch (Exception e) {
return -1000;
}
return a;
}
// We eliminate the return -1000 catch block which is outside of the loop in
// dead_code_elimination$initial. We can do so since we eliminated the TryBoundary of `a /= 2;`.
/// CHECK-START: int Main.$noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(int, boolean) dead_code_elimination$initial (before)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(int, boolean) dead_code_elimination$initial (before)
/// CHECK: flags "catch_block"
/// CHECK: flags "catch_block"
/// CHECK: flags "catch_block"
/// CHECK-NOT: flags "catch_block"
/// CHECK-START: int Main.$noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(int, boolean) dead_code_elimination$initial (before)
/// CHECK: IntConstant -1000
/// CHECK-START: int Main.$noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(int, boolean) dead_code_elimination$initial (after)
/// CHECK: TryBoundary
/// CHECK: TryBoundary
/// CHECK-NOT: TryBoundary
/// CHECK-START: int Main.$noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(int, boolean) dead_code_elimination$initial (after)
/// CHECK: flags "catch_block"
/// CHECK: flags "catch_block"
/// CHECK-NOT: flags "catch_block"
/// CHECK-START: int Main.$noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(int, boolean) dead_code_elimination$initial (after)
/// CHECK-NOT: IntConstant -1000
// When removing that block, we are removing a block outside of a loop but we still need to update
// the loop information in the graph since we removed TryBoundary instructions inside of a loop
// and now `a /= 2;` is not considered part of a loop (Cannot throw so it will not `continue` and
// will always return).
/// CHECK-START: int Main.$noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(int, boolean) dead_code_elimination$initial (before)
/// CHECK: Div loop:B2
/// CHECK-START: int Main.$noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(int, boolean) dead_code_elimination$initial (after)
/// CHECK-NOT: Div loop:B2
/// CHECK-START: int Main.$noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(int, boolean) dead_code_elimination$initial (after)
/// CHECK: Div
/// CHECK-NOT: Div
public static int $noinline$testNestedTryBoundariesWithLoopAndCatchOutsideOfLoop(
int a, boolean val) {
try {
for (int i = 0; i < 4; ++i) {
try {
try {
if (val) {
// TryBoundary kind:entry
throw new Error();
// TryBoundary kind:exit
}
// TryBoundary kind:exit
} catch (Exception e) {
continue;
}
// TryBoundary kind:entry
a /= 2;
// TryBoundary kind:exit
return a;
} catch (Error e) {
continue;
}
}
} catch (Exception e) {
return -1000;
}
return a;
}
}
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