commit 802ac606e7766263bb5aa46d2871f681ec06d302
author Santiago Aboy Solanes <solanes@google.com> Thu Dec 15 18:45:33 2022 +0000
committer Santiago Aboy Solanes <solanes@google.com> Fri Dec 16 14:51:27 2022 +0000
tree 0353babbf3c00509f4a2de331ebb266cfd5f5208
parent bf778f0cc4d91b93ebd877db0a3f4187d482be4b

Add irreducible loop check in CanInlineBody

In aosp/2335809 we moved splitting the critical edge (aka adding
the extra goto) from the builder to InlineInto. We need to
also move the irreducible loop check from there to inliner.cc.

Bug: 262725735
Fixes: 262725735
Test: dex2oat compiling the apps in the bug
Test: art/test/testrunner/testrunner.py --host --64 --optimizing -b
Change-Id: I94eebfb21cd94b1199ba996d458b897b7917840e

compiler/optimizing/inliner.cc

diff --git a/compiler/optimizing/inliner.cc b/compiler/optimizing/inliner.cc
index 2645cf1..3992ff4 100644
--- a/compiler/optimizing/inliner.cc
+++ b/compiler/optimizing/inliner.cc
@@ -1896,11 +1896,25 @@
   bool has_one_return = false;
   for (HBasicBlock* predecessor : exit_block->GetPredecessors()) {
     const HInstruction* last_instruction = predecessor->GetLastInstruction();
-    // On inlinees, we can have Throw -> TryBoundary -> Exit. To check for the actual last
-    // instruction, we have to skip it.
+    // On inlinees, we can have Return/ReturnVoid/Throw -> TryBoundary -> Exit. To check for the
+    // actual last instruction, we have to skip the TryBoundary instruction.
     if (last_instruction->IsTryBoundary()) {
       predecessor = predecessor->GetSinglePredecessor();
       last_instruction = predecessor->GetLastInstruction();
+
+      // If the last instruction chain is Return/ReturnVoid -> TryBoundary -> Exit we will have to
+      // split a critical edge in InlineInto and might recompute loop information, which is
+      // unsupported for irreducible loops.
+      if (!last_instruction->IsThrow() && graph_->HasIrreducibleLoops()) {
+        DCHECK(last_instruction->IsReturn() || last_instruction->IsReturnVoid());
+        // TODO(ngeoffray): Support re-computing loop information to graphs with
+        // irreducible loops?
+        LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedIrreducibleLoopCaller)
+            << "Method " << resolved_method->PrettyMethod()
+            << " could not be inlined because we will have to recompute the loop information and"
+            << " the caller has irreducible loops";
+        return false;
+      }
     }
 
     if (last_instruction->IsThrow()) {
@@ -1914,9 +1928,10 @@
       } else if (graph_->HasIrreducibleLoops()) {
         // TODO(ngeoffray): Support re-computing loop information to graphs with
         // irreducible loops?
-        VLOG(compiler) << "Method " << resolved_method->PrettyMethod()
-                       << " could not be inlined because one branch always throws and"
-                       << " caller has irreducible loops";
+        LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedIrreducibleLoopCaller)
+            << "Method " << resolved_method->PrettyMethod()
+            << " could not be inlined because one branch always throws and"
+            << " the caller has irreducible loops";
         return false;
       }
     } else {
@@ -1952,7 +1967,7 @@
       if (block->GetLoopInformation()->IsIrreducible()) {
         // Don't inline methods with irreducible loops, they could prevent some
         // optimizations to run.
-        LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedIrreducibleLoop)
+        LOG_FAIL(stats_, MethodCompilationStat::kNotInlinedIrreducibleLoopCallee)
             << "Method " << resolved_method->PrettyMethod()
             << " could not be inlined because it contains an irreducible loop";
         return false;

compiler/optimizing/optimizing_compiler_stats.h

diff --git a/compiler/optimizing/optimizing_compiler_stats.h b/compiler/optimizing/optimizing_compiler_stats.h
index c741b02..100441a 100644
--- a/compiler/optimizing/optimizing_compiler_stats.h
+++ b/compiler/optimizing/optimizing_compiler_stats.h
@@ -92,7 +92,8 @@
   kNotInlinedEnvironmentBudget,
   kNotInlinedInstructionBudget,
   kNotInlinedLoopWithoutExit,
-  kNotInlinedIrreducibleLoop,
+  kNotInlinedIrreducibleLoopCallee,
+  kNotInlinedIrreducibleLoopCaller,
   kNotInlinedAlwaysThrows,
   kNotInlinedInfiniteLoop,
   kNotInlinedTryCatchCallee,