reader/spirv: Optimize FindUnusedDerivedName()
Store the last search id suffix so that we don't research the same suffixes over and over again.
Bug: oss-fuzz:38098
Bug: oss-fuzz:38606
Bug: oss-fuzz:39300
Bug: oss-fuzz:40339
Change-Id: I295147d91bb9f805170c49114267033bbb781e4d
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/75427
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
diff --git a/src/reader/spirv/namer.cc b/src/reader/spirv/namer.cc
index 4d819b4..c2b2e98 100644
--- a/src/reader/spirv/namer.cc
+++ b/src/reader/spirv/namer.cc
@@ -104,20 +104,24 @@
return result;
}
-std::string Namer::FindUnusedDerivedName(const std::string& base_name) const {
+std::string Namer::FindUnusedDerivedName(const std::string& base_name) {
// Ensure uniqueness among names.
std::string derived_name;
- int i = 0;
- do {
+ uint32_t& i = next_unusued_derived_name_id_[base_name];
+ while (i != 0xffffffff) {
std::stringstream new_name_stream;
new_name_stream << base_name;
if (i > 0) {
new_name_stream << "_" << i;
}
- i++;
derived_name = new_name_stream.str();
- } while (IsRegistered(derived_name));
- return derived_name;
+ if (!IsRegistered(derived_name)) {
+ return derived_name;
+ }
+ i++;
+ }
+ TINT_ASSERT(Reader, false /* FindUnusedDerivedName() overflowed u32 */);
+ return "<u32 overflow>";
}
std::string Namer::MakeDerivedName(const std::string& base_name) {
diff --git a/src/reader/spirv/namer.h b/src/reader/spirv/namer.h
index 1d231f4..c17d9f0 100644
--- a/src/reader/spirv/namer.h
+++ b/src/reader/spirv/namer.h
@@ -92,7 +92,7 @@
/// Returns an unregistered name based on a given base name.
/// @param base_name the base name
/// @returns a new name
- std::string FindUnusedDerivedName(const std::string& base_name) const;
+ std::string FindUnusedDerivedName(const std::string& base_name);
/// Returns a newly registered name based on a given base name.
/// In the internal table `name_to_id_`, it is mapped to the invalid
@@ -152,6 +152,10 @@
// If entry k in the vector is an empty string, then a suggestion
// was recorded for a higher-numbered index, but not for index k.
std::unordered_map<uint32_t, std::vector<std::string>> struct_member_names_;
+
+ // Saved search id suffix for a given base name. Used by
+ // FindUnusedDerivedName().
+ std::unordered_map<std::string, uint32_t> next_unusued_derived_name_id_;
};
} // namespace spirv