Index: src/compiler/bytecode-loop-analysis.cc |
diff --git a/src/compiler/bytecode-loop-analysis.cc b/src/compiler/bytecode-loop-analysis.cc |
index 76b90f882ef44543cec21bd16f39de62f8dca6a8..0a353ac443f18eb9d8988d455be17943838ec0a2 100644 |
--- a/src/compiler/bytecode-loop-analysis.cc |
+++ b/src/compiler/bytecode-loop-analysis.cc |
@@ -37,18 +37,32 @@ void BytecodeLoopAnalysis::Analyze() { |
} |
void BytecodeLoopAnalysis::AddLoopEntry(int entry_offset) { |
+ if (found_current_backedge_) { |
+ // We assume that all backedges of a loop must occur together and before |
+ // another loop entry or an outer loop backedge. |
Jarin
2016/08/18 12:49:50
Could you explain how you guard against the assump
klaasb
2016/08/18 13:38:01
The combination of the DCHECKs on 58, 60 and 63 do
|
+ // Thus here, the current loop actually ended before. |
+ current_loop_offset_ = loop_header_to_parent_[current_loop_offset_]; |
+ } |
loop_header_to_parent_[entry_offset] = current_loop_offset_; |
current_loop_offset_ = entry_offset; |
+ found_current_backedge_ = false; |
} |
void BytecodeLoopAnalysis::AddBranch(int origin_offset, int target_offset) { |
- // If this is a backedge, record it and update the current loop to the parent. |
+ // If this is a backedge, record it. |
if (target_offset < origin_offset) { |
backedge_to_header_[origin_offset] = target_offset; |
- // Check that we are finishing the current loop. This assumes that |
- // there is one backedge for each loop. |
- DCHECK_EQ(target_offset, current_loop_offset_); |
- current_loop_offset_ = loop_header_to_parent_[target_offset]; |
+ // Check whether this is actually a backedge of the outer loop and we have |
+ // already finished the current loop. |
+ if (target_offset < current_loop_offset_) { |
+ DCHECK(found_current_backedge_); |
+ int parent_offset = loop_header_to_parent_[current_loop_offset_]; |
+ DCHECK_EQ(target_offset, parent_offset); |
+ current_loop_offset_ = parent_offset; |
+ } else { |
+ DCHECK_EQ(target_offset, current_loop_offset_); |
+ found_current_backedge_ = true; |
+ } |
} |
} |