Reviewers: titzer, Yang,
Message:
PTAL. Most of the code is from r19603, but instead of checking for context
equality it now checks for code equality.
This addresses Ben's comments from
https://codereview.chromium.org/184923002:
titzer 2014/03/03 12:02:44
This code is relying on the code appearing only once in this optimized
code
map,
which is an invariant that should hold, but based on my investigation,
looks
quite fragile.
Can we put an extra level of checking in this loop?
I.e. either go through the entire map and remove _all_ occurrences, or
assert
there is only one.
I would prefer the former, since we have to loop over the entire array
anyway,
even if we found it.
Description:
Make EvictFromOptimizedCodeMap more robust.
This removes all occurences of the specified optimized code from the
optimized
code map.
Please review this at https://codereview.chromium.org/181493004/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+28, -24 lines):
M src/objects.cc
Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index
94a80f7d7a2aea73db5b600c6c21fcb1d3d2218f..0a5b69f925acaf07d64269a9eb05fd4abab887b1
100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9640,38 +9640,42 @@ void
SharedFunctionInfo::EvictFromOptimizedCodeMap(Code* optimized_code,
const char* reason) {
if (optimized_code_map()->IsSmi()) return;
- int i;
- bool removed_entry = false;
FixedArray* code_map = FixedArray::cast(optimized_code_map());
- for (i = kEntriesStart; i < code_map->length(); i += kEntryLength) {
- ASSERT(code_map->get(i)->IsNativeContext());
- if (Code::cast(code_map->get(i + 1)) == optimized_code) {
+ int dst = kEntriesStart;
+ int length = code_map->length();
+ for (int src = kEntriesStart; src < length; src += kEntryLength) {
+ ASSERT(code_map->get(src)->IsNativeContext());
+ if (Code::cast(code_map->get(src + kCachedCodeOffset)) ==
optimized_code) {
+ // Evict the src entry by not copying it to the dst entry.
if (FLAG_trace_opt) {
PrintF("[evicting entry from optimizing code map (%s) for ",
reason);
ShortPrint();
- PrintF("]\n");
+ BailoutId osr(Smi::cast(code_map->get(src +
kOsrAstIdOffset))->value());
+ if (osr.IsNone()) {
+ PrintF("]\n");
+ } else {
+ PrintF(" (osr ast id %d)]\n", osr.ToInt());
+ }
}
- removed_entry = true;
- break;
+ } else {
+ // Keep the src entry by copying it to the dst entry.
+ if (dst != src) {
+ code_map->set(dst + kContextOffset,
+ code_map->get(src + kContextOffset));
+ code_map->set(dst + kCachedCodeOffset,
+ code_map->get(src + kCachedCodeOffset));
+ code_map->set(dst + kLiteralsOffset,
+ code_map->get(src + kLiteralsOffset));
+ code_map->set(dst + kOsrAstIdOffset,
+ code_map->get(src + kOsrAstIdOffset));
+ }
+ dst += kEntryLength;
}
}
- while (i < (code_map->length() - kEntryLength)) {
- code_map->set(i + kContextOffset,
- code_map->get(i + kContextOffset + kEntryLength));
- code_map->set(i + kCachedCodeOffset,
- code_map->get(i + kCachedCodeOffset + kEntryLength));
- code_map->set(i + kLiteralsOffset,
- code_map->get(i + kLiteralsOffset + kEntryLength));
- code_map->set(i + kOsrAstIdOffset,
- code_map->get(i + kOsrAstIdOffset + kEntryLength));
- i += kEntryLength;
- }
- if (removed_entry) {
+ if (dst != length) {
// Always trim even when array is cleared because of heap verifier.
- RightTrimFixedArray<FROM_MUTATOR>(GetHeap(), code_map, kEntryLength);
- if (code_map->length() == kEntriesStart) {
- ClearOptimizedCodeMap();
- }
+ RightTrimFixedArray<FROM_MUTATOR>(GetHeap(), code_map, length - dst);
+ if (code_map->length() == kEntriesStart) ClearOptimizedCodeMap();
}
}
--
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