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-rw-r--r--compiler/optimizing/dead_code_elimination.cc195
-rw-r--r--compiler/optimizing/dead_code_elimination.h47
-rw-r--r--compiler/optimizing/optimizing_compiler_stats.h1
-rw-r--r--test/2255-checker-branch-redirection/expected-stderr.txt0
-rw-r--r--test/2255-checker-branch-redirection/expected-stdout.txt0
-rw-r--r--test/2255-checker-branch-redirection/info.txt2
-rw-r--r--test/2255-checker-branch-redirection/src/Main.java282
7 files changed, 484 insertions, 43 deletions
diff --git a/compiler/optimizing/dead_code_elimination.cc b/compiler/optimizing/dead_code_elimination.cc
index 8e3010d934..5437d9bd93 100644
--- a/compiler/optimizing/dead_code_elimination.cc
+++ b/compiler/optimizing/dead_code_elimination.cc
@@ -313,54 +313,45 @@ bool HDeadCodeElimination::SimplifyAlwaysThrows() {
return false;
}
-// Simplify the pattern:
-//
-// B1 B2 ...
-// goto goto goto
-// \ | /
-// \ | /
-// B3
-// i1 = phi(input, input)
-// (i2 = condition on i1)
-// if i1 (or i2)
-// / \
-// / \
-// B4 B5
-//
-// Into:
-//
-// B1 B2 ...
-// | | |
-// B4 B5 B?
-//
-// Note that individual edges can be redirected (for example B2->B3
-// can be redirected as B2->B5) without applying this optimization
-// to other incoming edges.
-//
-// This simplification cannot be applied to catch blocks, because
-// exception handler edges do not represent normal control flow.
-// Though in theory this could still apply to normal control flow
-// going directly to a catch block, we cannot support it at the
-// moment because the catch Phi's inputs do not correspond to the
-// catch block's predecessors, so we cannot identify which
-// predecessor corresponds to a given statically evaluated input.
-//
-// We do not apply this optimization to loop headers as this could
-// create irreducible loops. We rely on the suspend check in the
-// loop header to prevent the pattern match.
-//
-// Note that we rely on the dead code elimination to get rid of B3.
bool HDeadCodeElimination::SimplifyIfs() {
bool simplified_one_or_more_ifs = false;
bool rerun_dominance_and_loop_analysis = false;
- for (HBasicBlock* block : graph_->GetReversePostOrder()) {
+ // Iterating in PostOrder it's better for MaybeAddPhi as it can add a Phi for multiple If
+ // instructions in a chain without updating the dominator chain. The branch redirection itself can
+ // work in PostOrder or ReversePostOrder without issues.
+ for (HBasicBlock* block : graph_->GetPostOrder()) {
+ if (block->IsCatchBlock()) {
+ // This simplification cannot be applied to catch blocks, because exception handler edges do
+ // not represent normal control flow. Though in theory this could still apply to normal
+ // control flow going directly to a catch block, we cannot support it at the moment because
+ // the catch Phi's inputs do not correspond to the catch block's predecessors, so we cannot
+ // identify which predecessor corresponds to a given statically evaluated input.
+ continue;
+ }
+
HInstruction* last = block->GetLastInstruction();
- HInstruction* first = block->GetFirstInstruction();
- if (!block->IsCatchBlock() &&
- last->IsIf() &&
- block->HasSinglePhi() &&
+ if (!last->IsIf()) {
+ continue;
+ }
+
+ if (block->IsLoopHeader()) {
+ // We do not apply this optimization to loop headers as this could create irreducible loops.
+ continue;
+ }
+
+ // We will add a Phi which allows the simplification to take place in cases where it wouldn't.
+ MaybeAddPhi(block);
+
+ // TODO(solanes): Investigate support for multiple phis in `block`. We can potentially "push
+ // downwards" existing Phis into the true/false branches. For example, let's say we have another
+ // Phi: Phi(x1,x2,x3,x4,x5,x6). This could turn into Phi(x1,x2) in the true branch, Phi(x3,x4)
+ // in the false branch, and remain as Phi(x5,x6) in `block` (for edges that we couldn't
+ // redirect). We might even be able to remove some phis altogether as they will have only one
+ // value.
+ if (block->HasSinglePhi() &&
block->GetFirstPhi()->HasOnlyOneNonEnvironmentUse()) {
+ HInstruction* first = block->GetFirstInstruction();
bool has_only_phi_and_if = (last == first) && (last->InputAt(0) == block->GetFirstPhi());
bool has_only_phi_condition_and_if =
!has_only_phi_and_if &&
@@ -371,7 +362,6 @@ bool HDeadCodeElimination::SimplifyIfs() {
first->HasOnlyOneNonEnvironmentUse();
if (has_only_phi_and_if || has_only_phi_condition_and_if) {
- DCHECK(!block->IsLoopHeader());
HPhi* phi = block->GetFirstPhi()->AsPhi();
bool phi_input_is_left = (first->InputAt(0) == phi);
@@ -456,6 +446,125 @@ bool HDeadCodeElimination::SimplifyIfs() {
return simplified_one_or_more_ifs;
}
+void HDeadCodeElimination::MaybeAddPhi(HBasicBlock* block) {
+ DCHECK(block->GetLastInstruction()->IsIf());
+ HIf* if_instruction = block->GetLastInstruction()->AsIf();
+ if (if_instruction->InputAt(0)->IsConstant()) {
+ // Constant values are handled in RemoveDeadBlocks.
+ return;
+ }
+
+ if (block->GetNumberOfPredecessors() < 2u) {
+ // Nothing to redirect.
+ return;
+ }
+
+ if (!block->GetPhis().IsEmpty()) {
+ // SimplifyIf doesn't currently work with multiple phis. Adding a phi here won't help that
+ // optimization.
+ return;
+ }
+
+ HBasicBlock* dominator = block->GetDominator();
+ if (!dominator->EndsWithIf()) {
+ return;
+ }
+
+ HInstruction* input = if_instruction->InputAt(0);
+ HInstruction* dominator_input = dominator->GetLastInstruction()->AsIf()->InputAt(0);
+ const bool same_input = dominator_input == input;
+ if (!same_input) {
+ // Try to see if the dominator has the opposite input (e.g. if(cond) and if(!cond)). If that's
+ // the case, we can perform the optimization with the false and true branches reversed.
+ if (!dominator_input->IsCondition() || !input->IsCondition()) {
+ return;
+ }
+
+ HCondition* block_cond = input->AsCondition();
+ HCondition* dominator_cond = dominator_input->AsCondition();
+
+ if (block_cond->GetLeft() != dominator_cond->GetLeft() ||
+ block_cond->GetRight() != dominator_cond->GetRight() ||
+ block_cond->GetOppositeCondition() != dominator_cond->GetCondition()) {
+ return;
+ }
+ }
+
+ if (kIsDebugBuild) {
+ // `block`'s successors should have only one predecessor. Otherwise, we have a critical edge in
+ // the graph.
+ for (HBasicBlock* succ : block->GetSuccessors()) {
+ DCHECK_EQ(succ->GetNumberOfPredecessors(), 1u);
+ }
+ }
+
+ const size_t pred_size = block->GetNumberOfPredecessors();
+ HPhi* new_phi = new (graph_->GetAllocator())
+ HPhi(graph_->GetAllocator(), kNoRegNumber, pred_size, DataType::Type::kInt32);
+
+ for (size_t index = 0; index < pred_size; index++) {
+ HBasicBlock* pred = block->GetPredecessors()[index];
+ const bool dominated_by_true =
+ dominator->GetLastInstruction()->AsIf()->IfTrueSuccessor()->Dominates(pred);
+ const bool dominated_by_false =
+ dominator->GetLastInstruction()->AsIf()->IfFalseSuccessor()->Dominates(pred);
+ if (dominated_by_true == dominated_by_false) {
+ // In this case, we can't know if we are coming from the true branch, or the false branch. It
+ // happens in cases like:
+ // 1 (outer if)
+ // / \
+ // 2 3 (inner if)
+ // | / \
+ // | 4 5
+ // \/ |
+ // 6 |
+ // \ |
+ // 7 (has the same if(cond) as 1)
+ // |
+ // 8
+ // `7` (which would be `block` in this example), and `6` will come from both the true path and
+ // the false path of `1`. We bumped into something similar in SelectGenerator. See
+ // HSelectGenerator::TryFixupDoubleDiamondPattern.
+ // TODO(solanes): Figure out if we can fix up the graph into a double diamond in a generic way
+ // so that DeadCodeElimination and SelectGenerator can take advantage of it.
+
+ if (!same_input) {
+ // `1` and `7` having the opposite condition is a case we are missing. We could potentially
+ // add a BooleanNot instruction to be able to add the Phi, but it seems like overkill since
+ // this case is not that common.
+ return;
+ }
+
+ // The Phi will have `0`, `1`, and `cond` as inputs. If SimplifyIf redirects 0s and 1s, we
+ // will end up with Phi(cond,...,cond) which will be replaced by `cond`. Effectively, we will
+ // redirect edges that we are able to redirect and the rest will remain as before (i.e. we
+ // won't have an extra Phi).
+ new_phi->SetRawInputAt(index, input);
+ } else {
+ // Redirect to either the true branch (1), or the false branch (0).
+ // Given that `dominated_by_true` is the exact opposite of `dominated_by_false`,
+ // `(same_input && dominated_by_true) || (!same_input && dominated_by_false)` is equivalent to
+ // `same_input == dominated_by_true`.
+ new_phi->SetRawInputAt(
+ index,
+ same_input == dominated_by_true ? graph_->GetIntConstant(1) : graph_->GetIntConstant(0));
+ }
+ }
+
+ block->AddPhi(new_phi);
+ if_instruction->ReplaceInput(new_phi, 0);
+
+ // Remove the old input now, if possible. This allows the branch redirection in SimplifyIf to
+ // work without waiting for another pass of DCE.
+ if (input->IsDeadAndRemovable()) {
+ DCHECK(!same_input)
+ << " if both blocks have the same condition, it shouldn't be dead and removable since the "
+ << "dominator block's If instruction would be using that condition.";
+ input->GetBlock()->RemoveInstruction(input);
+ }
+ MaybeRecordStat(stats_, MethodCompilationStat::kSimplifyIfAddedPhi);
+}
+
void HDeadCodeElimination::ConnectSuccessiveBlocks() {
// Order does not matter. Skip the entry block by starting at index 1 in reverse post order.
for (size_t i = 1u, size = graph_->GetReversePostOrder().size(); i != size; ++i) {
diff --git a/compiler/optimizing/dead_code_elimination.h b/compiler/optimizing/dead_code_elimination.h
index b91006be0d..ddd01f7103 100644
--- a/compiler/optimizing/dead_code_elimination.h
+++ b/compiler/optimizing/dead_code_elimination.h
@@ -46,6 +46,31 @@ class HDeadCodeElimination : public HOptimization {
bool RemoveDeadBlocks(bool force_recomputation = false, bool force_loop_recomputation = false);
void RemoveDeadInstructions();
bool SimplifyAlwaysThrows();
+ // Simplify the pattern:
+ //
+ // B1 B2 ...
+ // goto goto goto
+ // \ | /
+ // \ | /
+ // B3
+ // i1 = phi(input, input)
+ // (i2 = condition on i1)
+ // if i1 (or i2)
+ // / \
+ // / \
+ // B4 B5
+ //
+ // Into:
+ //
+ // B1 B2 ...
+ // | | |
+ // B4 B5 B?
+ //
+ // Note that individual edges can be redirected (for example B2->B3
+ // can be redirected as B2->B5) without applying this optimization
+ // to other incoming edges.
+ //
+ // Note that we rely on the dead code elimination to get rid of B3.
bool SimplifyIfs();
void ConnectSuccessiveBlocks();
// Updates the graph flags related to instructions (e.g. HasSIMD()) since we may have eliminated
@@ -75,6 +100,28 @@ class HDeadCodeElimination : public HOptimization {
// instructions.
bool RemoveUnneededTries();
+ // Adds a phi in `block`, if `block` and its dominator have the same (or opposite) condition.
+ // For example it turns:
+ // if(cond)
+ // / \
+ // B1 B2
+ // \ /
+ // if(cond)
+ // / \
+ // B3 B4
+ //
+ // into:
+ // if(cond)
+ // / \
+ // B1 B2
+ // \ /
+ // if(Phi(1, 0))
+ // / \
+ // B3 B4
+ //
+ // Following this, SimplifyIfs is able to connect B1->B3 and B2->B4 effectively skipping an if.
+ void MaybeAddPhi(HBasicBlock* block);
+
DISALLOW_COPY_AND_ASSIGN(HDeadCodeElimination);
};
diff --git a/compiler/optimizing/optimizing_compiler_stats.h b/compiler/optimizing/optimizing_compiler_stats.h
index 866c88382a..a1d0a5a845 100644
--- a/compiler/optimizing/optimizing_compiler_stats.h
+++ b/compiler/optimizing/optimizing_compiler_stats.h
@@ -82,6 +82,7 @@ enum class MethodCompilationStat {
kImplicitNullCheckGenerated,
kExplicitNullCheckGenerated,
kSimplifyIf,
+ kSimplifyIfAddedPhi,
kSimplifyThrowingInvoke,
kInstructionSunk,
kNotInlinedUnresolvedEntrypoint,
diff --git a/test/2255-checker-branch-redirection/expected-stderr.txt b/test/2255-checker-branch-redirection/expected-stderr.txt
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/2255-checker-branch-redirection/expected-stderr.txt
diff --git a/test/2255-checker-branch-redirection/expected-stdout.txt b/test/2255-checker-branch-redirection/expected-stdout.txt
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/2255-checker-branch-redirection/expected-stdout.txt
diff --git a/test/2255-checker-branch-redirection/info.txt b/test/2255-checker-branch-redirection/info.txt
new file mode 100644
index 0000000000..10b71ef0a7
--- /dev/null
+++ b/test/2255-checker-branch-redirection/info.txt
@@ -0,0 +1,2 @@
+Tests that we can redirect branches if the block and its dominator
+have the same condition, or the exact opposite condition.
diff --git a/test/2255-checker-branch-redirection/src/Main.java b/test/2255-checker-branch-redirection/src/Main.java
new file mode 100644
index 0000000000..bfc6381942
--- /dev/null
+++ b/test/2255-checker-branch-redirection/src/Main.java
@@ -0,0 +1,282 @@
+/*
+ * Copyright (C) 2023 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(40, $noinline$testEliminateIf(20, 40));
+ assertEquals(30, $noinline$testEliminateIf(20, 10));
+ assertEquals(40, $noinline$testEliminateIfTwiceInARow(20, 40));
+ assertEquals(30, $noinline$testEliminateIfTwiceInARow(20, 10));
+ assertEquals(40, $noinline$testEliminateIfThreePredecessors(20, 40));
+ assertEquals(30, $noinline$testEliminateIfThreePredecessors(20, 10));
+ assertEquals(40, $noinline$testEliminateIfOppositeCondition(20, 40));
+ assertEquals(30, $noinline$testEliminateIfOppositeCondition(20, 10));
+ assertEquals(40, $noinline$testEliminateIfParameter(20, 40, 20 < 40));
+ assertEquals(30, $noinline$testEliminateIfParameter(20, 10, 20 < 10));
+ assertEquals(40, $noinline$testEliminateIfParameterReverseCondition(20, 40, 20 < 40));
+ assertEquals(30, $noinline$testEliminateIfParameterReverseCondition(20, 10, 20 < 10));
+ assertEquals(40, $noinline$testEliminateIfParameterOppositeCondition(20, 40, 20 < 40));
+ assertEquals(30, $noinline$testEliminateIfParameterOppositeCondition(20, 10, 20 < 10));
+ assertEquals(40, $noinline$testEliminateIfParameterOppositeCondition_2(20, 40, 20 < 40));
+ assertEquals(30, $noinline$testEliminateIfParameterOppositeCondition_2(20, 10, 20 < 10));
+ }
+
+ private static int $noinline$emptyMethod(int a) {
+ return a;
+ }
+
+ /// CHECK-START: int Main.$noinline$testEliminateIf(int, int) dead_code_elimination$after_gvn (before)
+ /// CHECK: If
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIf(int, int) dead_code_elimination$after_gvn (after)
+ /// CHECK: If
+ /// CHECK-NOT: If
+ private static int $noinline$testEliminateIf(int a, int b) {
+ int result = 0;
+ if (a < b) {
+ $noinline$emptyMethod(a + b);
+ } else {
+ $noinline$emptyMethod(a - b);
+ }
+ if (a < b) {
+ result += $noinline$emptyMethod(a * 2);
+ } else {
+ result += $noinline$emptyMethod(b * 3);
+ }
+ return result;
+ }
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfTwiceInARow(int, int) dead_code_elimination$after_gvn (before)
+ /// CHECK: If
+ /// CHECK: If
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfTwiceInARow(int, int) dead_code_elimination$after_gvn (after)
+ /// CHECK: If
+ /// CHECK-NOT: If
+ private static int $noinline$testEliminateIfTwiceInARow(int a, int b) {
+ int result = 0;
+ if (a < b) {
+ $noinline$emptyMethod(a + b);
+ } else {
+ $noinline$emptyMethod(a - b);
+ }
+ if (a < b) {
+ $noinline$emptyMethod(a * 2);
+ } else {
+ $noinline$emptyMethod(b * 3);
+ }
+ if (a < b) {
+ result += $noinline$emptyMethod(40);
+ } else {
+ result += $noinline$emptyMethod(30);
+ }
+ return result;
+ }
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfThreePredecessors(int, int) dead_code_elimination$after_gvn (before)
+ /// CHECK: If
+ /// CHECK: If
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfThreePredecessors(int, int) dead_code_elimination$after_gvn (after)
+ /// CHECK: If
+ /// CHECK: If
+ /// CHECK-NOT: If
+ private static int $noinline$testEliminateIfThreePredecessors(int a, int b) {
+ int result = 0;
+ if (a < b) {
+ $noinline$emptyMethod(a + b);
+ } else {
+ if (b < 5) {
+ $noinline$emptyMethod(a - b);
+ } else {
+ $noinline$emptyMethod(a * b);
+ }
+ }
+ if (a < b) {
+ result += $noinline$emptyMethod(a * 2);
+ } else {
+ result += $noinline$emptyMethod(b * 3);
+ }
+ return result;
+ }
+
+ // Note that we can perform this optimization in dead_code_elimination$initial since we don't
+ // rely on gvn to de-duplicate the values.
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfOppositeCondition(int, int) dead_code_elimination$initial (before)
+ /// CHECK: If
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfOppositeCondition(int, int) dead_code_elimination$initial (after)
+ /// CHECK: If
+ /// CHECK-NOT: If
+ private static int $noinline$testEliminateIfOppositeCondition(int a, int b) {
+ int result = 0;
+ if (a < b) {
+ $noinline$emptyMethod(a + b);
+ } else {
+ $noinline$emptyMethod(a - b);
+ }
+ if (a >= b) {
+ result += $noinline$emptyMethod(b * 3);
+ } else {
+ result += $noinline$emptyMethod(a * 2);
+ }
+ return result;
+ }
+
+ // In this scenario, we have a BooleanNot before the If instructions so we have to wait until
+ // the following pass to perform the optimization. The BooleanNot is dead at this time (even
+ // when starting DCE), but RemoveDeadInstructions runs after SimplifyIfs so the optimization
+ // doesn't trigger.
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameter(int, int, boolean) dead_code_elimination$initial (before)
+ /// CHECK: BooleanNot
+ /// CHECK: If
+ /// CHECK: BooleanNot
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameter(int, int, boolean) dead_code_elimination$initial (after)
+ /// CHECK: If
+ /// CHECK: Phi
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameter(int, int, boolean) dead_code_elimination$initial (after)
+ /// CHECK-NOT: BooleanNot
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameter(int, int, boolean) dead_code_elimination$after_gvn (before)
+ /// CHECK: If
+ /// CHECK: Phi
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameter(int, int, boolean) dead_code_elimination$after_gvn (after)
+ /// CHECK: If
+ /// CHECK-NOT: If
+ private static int $noinline$testEliminateIfParameter(int a, int b, boolean condition) {
+ int result = 0;
+ if (condition) {
+ $noinline$emptyMethod(a + b);
+ } else {
+ $noinline$emptyMethod(a - b);
+ }
+ if (condition) {
+ result += $noinline$emptyMethod(a * 2);
+ } else {
+ result += $noinline$emptyMethod(b * 3);
+ }
+ return result;
+ }
+
+ // Same in the following two cases: we do it in dead_code_elimination$initial since GVN is not
+ // needed.
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameterReverseCondition(int, int, boolean) dead_code_elimination$initial (before)
+ /// CHECK: If
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameterReverseCondition(int, int, boolean) dead_code_elimination$initial (after)
+ /// CHECK: If
+ /// CHECK-NOT: If
+ private static int $noinline$testEliminateIfParameterReverseCondition(
+ int a, int b, boolean condition) {
+ int result = 0;
+ if (!condition) {
+ $noinline$emptyMethod(a + b);
+ } else {
+ $noinline$emptyMethod(a - b);
+ }
+ if (!condition) {
+ result += $noinline$emptyMethod(b * 3);
+ } else {
+ result += $noinline$emptyMethod(a * 2);
+ }
+ return result;
+ }
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameterOppositeCondition(int, int, boolean) dead_code_elimination$initial (before)
+ /// CHECK: If
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameterOppositeCondition(int, int, boolean) dead_code_elimination$initial (after)
+ /// CHECK: If
+ /// CHECK-NOT: If
+ private static int $noinline$testEliminateIfParameterOppositeCondition(
+ int a, int b, boolean condition) {
+ int result = 0;
+ if (condition) {
+ $noinline$emptyMethod(a + b);
+ } else {
+ $noinline$emptyMethod(a - b);
+ }
+ if (!condition) {
+ result += $noinline$emptyMethod(b * 3);
+ } else {
+ result += $noinline$emptyMethod(a * 2);
+ }
+ return result;
+ }
+
+ // In this scenario, we have a BooleanNot before the If instructions so we have to wait until
+ // the following pass to perform the optimization. The BooleanNot is dead at this time (even
+ // when starting DCE), but RemoveDeadInstructions runs after SimplifyIfs so the optimization
+ // doesn't trigger.
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameterOppositeCondition_2(int, int, boolean) dead_code_elimination$initial (before)
+ /// CHECK: If
+ /// CHECK: BooleanNot
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameterOppositeCondition_2(int, int, boolean) dead_code_elimination$initial (after)
+ /// CHECK: If
+ /// CHECK: Phi
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameterOppositeCondition_2(int, int, boolean) dead_code_elimination$initial (after)
+ /// CHECK-NOT: BooleanNot
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameterOppositeCondition_2(int, int, boolean) dead_code_elimination$after_gvn (before)
+ /// CHECK: If
+ /// CHECK: Phi
+ /// CHECK: If
+
+ /// CHECK-START: int Main.$noinline$testEliminateIfParameterOppositeCondition_2(int, int, boolean) dead_code_elimination$after_gvn (after)
+ /// CHECK: If
+ /// CHECK-NOT: If
+ private static int $noinline$testEliminateIfParameterOppositeCondition_2(
+ int a, int b, boolean condition) {
+ int result = 0;
+ if (!condition) {
+ $noinline$emptyMethod(a + b);
+ } else {
+ $noinline$emptyMethod(a - b);
+ }
+ if (condition) {
+ result += $noinline$emptyMethod(a * 2);
+ } else {
+ result += $noinline$emptyMethod(b * 3);
+ }
+ return result;
+ }
+
+ public static void assertEquals(int expected, int result) {
+ if (expected != result) {
+ throw new Error("Expected: " + expected + ", found: " + result);
+ }
+ }
+}
generated by cgit v1.2.3-59-g8ed1b (git 2.39.0) at 2025-10-19 13:36:07 +0000