Add proc-scoped channel support to channel legalization pass.

Incidentally change the way in which channels are named. The data, predicate and completion channels are now numbered consistently. For example, the channels associated with the 42nd op instance of channel `foo` are: `foo__data_42`, `foo__pred_42` and `foo__condition_42`, PiperOrigin-RevId: 683721323
google · Oct 8, 2024 · 825f277 · 825f277
1 parent 600dfac
commit 825f277
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Showing 8 changed files with 826 additions and 287 deletions.
diff --git a/xls/ir/BUILD b/xls/ir/BUILD
@@ -1583,6 +1583,7 @@ cc_library(
         "//xls/common/status:ret_check",
         "@com_google_absl//absl/algorithm:container",
         "@com_google_absl//absl/log",
+        "@com_google_absl//absl/log:check",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
@@ -1896,6 +1897,7 @@ cc_library(
         "//xls/common/status:status_macros",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/container:flat_hash_set",
+        "@com_google_absl//absl/log",
         "@com_google_absl//absl/log:check",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",

diff --git a/xls/ir/channel.cc b/xls/ir/channel.cc
@@ -22,6 +22,7 @@
 #include <variant>
 #include <vector>
 
+#include "absl/log/check.h"
 #include "absl/log/log.h"
 #include "absl/status/status.h"
 #include "absl/status/statusor.h"
@@ -229,6 +230,38 @@ std::ostream& operator<<(std::ostream& os, Direction direction) {
   return os;
 }
 
+ChannelRef AsChannelRef(SendChannelRef ref) {
+  if (std::holds_alternative<SendChannelReference*>(ref)) {
+    return std::get<SendChannelReference*>(ref);
+  }
+  return std::get<Channel*>(ref);
+}
+
+ChannelRef AsChannelRef(ReceiveChannelRef ref) {
+  if (std::holds_alternative<ReceiveChannelReference*>(ref)) {
+    return std::get<ReceiveChannelReference*>(ref);
+  }
+  return std::get<Channel*>(ref);
+}
+
+SendChannelRef AsSendChannelRefOrDie(ChannelRef ref) {
+  if (std::holds_alternative<ChannelReference*>(ref)) {
+    ChannelReference* cref = std::get<ChannelReference*>(ref);
+    CHECK_EQ(cref->direction(), Direction::kSend);
+    return down_cast<SendChannelReference*>(cref);
+  }
+  return std::get<Channel*>(ref);
+}
+
+ReceiveChannelRef AsReceiveChannelRefOrDie(ChannelRef ref) {
+  if (std::holds_alternative<ChannelReference*>(ref)) {
+    ChannelReference* cref = std::get<ChannelReference*>(ref);
+    CHECK_EQ(cref->direction(), Direction::kReceive);
+    return down_cast<ReceiveChannelReference*>(cref);
+  }
+  return std::get<Channel*>(ref);
+}
+
 std::string_view ChannelRefName(ChannelRef ref) {
   return absl::visit([](const auto& ch) { return ch->name(); }, ref);
 }
@@ -247,6 +280,17 @@ ChannelKind ChannelRefKind(ChannelRef ref) {
   return std::get<Channel*>(ref)->kind();
 }
 
+std::optional<ChannelStrictness> ChannelRefStrictness(ChannelRef ref) {
+  if (std::holds_alternative<ChannelReference*>(ref)) {
+    return std::get<ChannelReference*>(ref)->strictness();
+  }
+  if (auto streaming_channel =
+          down_cast<StreamingChannel*>(std::get<Channel*>(ref))) {
+    return streaming_channel->GetStrictness();
+  }
+  return std::nullopt;
+}
+
 std::string ChannelReference::ToString() const {
   std::vector<std::string> keyword_strs;
   keyword_strs.push_back(

diff --git a/xls/ir/channel.h b/xls/ir/channel.h
@@ -420,10 +420,20 @@ using ChannelRef = std::variant<Channel*, ChannelReference*>;
 using SendChannelRef = std::variant<Channel*, SendChannelReference*>;
 using ReceiveChannelRef = std::variant<Channel*, ReceiveChannelReference*>;
 
+// Converts a send/receive ChannelRef into a generic ChannelRef.
+ChannelRef AsChannelRef(SendChannelRef ref);
+ChannelRef AsChannelRef(ReceiveChannelRef ref);
+
+// Converts a base ChannelRef into a send/receive form. CHECK fails if the
+// ChannelRef is not of the appropriate direction.
+SendChannelRef AsSendChannelRefOrDie(ChannelRef ref);
+ReceiveChannelRef AsReceiveChannelRefOrDie(ChannelRef ref);
+
 // Return the name/type/kind of a channel reference.
 std::string_view ChannelRefName(ChannelRef ref);
 Type* ChannelRefType(ChannelRef ref);
 ChannelKind ChannelRefKind(ChannelRef ref);
+std::optional<ChannelStrictness> ChannelRefStrictness(ChannelRef ref);
 
 }  // namespace xls
 

diff --git a/xls/ir/package.cc b/xls/ir/package.cc
@@ -768,6 +768,7 @@ absl::Status Package::AddChannel(std::unique_ptr<Channel> channel, Proc* proc) {
 }
 
 absl::StatusOr<Channel*> Package::GetChannel(int64_t id) const {
+  XLS_RET_CHECK(!ChannelsAreProcScoped());
   for (Channel* ch : channels()) {
     if (ch->id() == id) {
       return ch;
@@ -777,6 +778,7 @@ absl::StatusOr<Channel*> Package::GetChannel(int64_t id) const {
 }
 
 std::vector<std::string> Package::GetChannelNames() const {
+  CHECK(!ChannelsAreProcScoped());
   std::vector<std::string> names;
   names.reserve(channels().size());
   for (Channel* ch : channels()) {
@@ -786,6 +788,7 @@ std::vector<std::string> Package::GetChannelNames() const {
 }
 
 absl::StatusOr<Channel*> Package::GetChannel(std::string_view name) const {
+  XLS_RET_CHECK(!ChannelsAreProcScoped());
   auto it = channels_.find(name);
   if (it != channels_.end()) {
     return it->second.get();

diff --git a/xls/ir/proc_elaboration.cc b/xls/ir/proc_elaboration.cc
@@ -25,6 +25,7 @@
 
 #include "absl/container/flat_hash_map.h"
 #include "absl/container/flat_hash_set.h"
+#include "absl/log/log.h"
 #include "absl/status/status.h"
 #include "absl/status/statusor.h"
 #include "absl/strings/str_cat.h"

diff --git a/xls/passes/BUILD b/xls/passes/BUILD
@@ -2909,13 +2909,15 @@ cc_library(
         "//xls/ir:name_uniquer",
         "//xls/ir:node_util",
         "//xls/ir:op",
+        "//xls/ir:proc_elaboration",
         "//xls/ir:source_location",
         "//xls/ir:value",
         "@com_google_absl//absl/container:btree",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/container:flat_hash_set",
         "@com_google_absl//absl/log",
         "@com_google_absl//absl/log:check",
+        "@com_google_absl//absl/memory",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
@@ -2993,6 +2995,7 @@ cc_test(
         "//xls/ir:ir_matcher",
         "//xls/ir:ir_parser",
         "//xls/ir:ir_test_base",
+        "//xls/ir:proc_elaboration",
         "//xls/ir:value",
         "//xls/ir:verifier",
         "@com_google_absl//absl/container:flat_hash_map",