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[turbofan] Use binary search in handler table lookup.

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R=clemensb@chromium.org

Change-Id: I38c851f258b49de75f538a9b893ab24b7a4d0586
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1883894
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64611}
This commit is contained in:
Michael Starzinger 2019-10-29 13:28:58 +01:00 committed by Commit Bot
parent f5fb0e740b
commit 30ec6a8937
1 changed files with 29 additions and 7 deletions
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36
src/codegen/handler-table.cc
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@ -4,8 +4,10 @@
#include "src/codegen/handler-table.h"
#include <algorithm>
#include <iomanip>
#include "src/base/iterator.h"
#include "src/codegen/assembler-inl.h"
#include "src/objects/code-inl.h"
#include "src/objects/objects-inl.h"
@ -187,15 +189,35 @@ int HandlerTable::LookupRange(int pc_offset, int* data_out,
return innermost_handler;
}
// TODO(turbofan): Make sure table is sorted and use binary search.
int HandlerTable::LookupReturn(int pc_offset) {
for (int i = 0; i < NumberOfReturnEntries(); ++i) {
int return_offset = GetReturnOffset(i);
if (pc_offset == return_offset) {
return GetReturnHandler(i);
// We only implement the methods needed by the standard libraries we care
// about. This is not technically a full random access iterator by the spec.
struct Iterator : base::iterator<std::random_access_iterator_tag, int> {
Iterator(HandlerTable* tbl, int idx) : table(tbl), index(idx) {}
value_type operator*() const { return table->GetReturnOffset(index); }
bool operator!=(const Iterator& other) const { return !(*this == other); }
bool operator==(const Iterator& other) const {
return index == other.index;
}
}
return -1;
Iterator& operator++() {
index++;
return *this;
}
Iterator& operator+=(difference_type offset) {
index += offset;
return *this;
}
difference_type operator-(const Iterator& other) const {
return index - other.index;
}
HandlerTable* table;
int index;
};
Iterator begin{this, 0}, end{this, NumberOfReturnEntries()};
SLOW_DCHECK(std::is_sorted(begin, end)); // Must be sorted.
Iterator result = std::lower_bound(begin, end, pc_offset);
bool exact_match = result != end && *result == pc_offset;
return exact_match ? GetReturnHandler(result.index) : -1;
}
#ifdef ENABLE_DISASSEMBLER