[codegen] Factor out safepoint table printing

The logic for printing a safepoint table is currently duplicated for
Wasm code and on-heap code, with slight differences.
This CL provides a central {SafepointTable::Print} method that is used
in both scenarios.
The format is slightly changed to explicitly specify which bitmap
corresponds to stack slots and which one to registers.

R=jkummerow@chromium.org

Bug: v8:12401
Change-Id: I67366b1f9a92450a6ebec4210ab4811800a54f34
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3306976
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78159}

src/codegen/safepoint-table.cc

@@ -4,6 +4,8 @@
 
 #include "src/codegen/safepoint-table.h"
 
+#include <iomanip>
+
 #include "src/codegen/assembler-inl.h"
 #include "src/codegen/macro-assembler.h"
 #include "src/deoptimizer/deoptimizer.h"
@@ -71,12 +73,40 @@ SafepointEntry SafepointTable::FindEntry(Address pc) const {
   UNREACHABLE();
 }
 
-void SafepointTable::PrintEntry(int index, std::ostream& os) const {
+void SafepointTable::Print(std::ostream& os) const {
-  for (uint8_t bits : GetEntry(index).tagged_slots()) {
+  os << "Safepoints (entries = " << length_ << ", byte size = " << byte_size()
+     << ")\n";
+
+  for (int index = 0; index < length_; index++) {
+    SafepointEntry entry = GetEntry(index);
+    os << reinterpret_cast<const void*>(instruction_start_ + entry.pc()) << " "
+       << std::setw(6) << std::hex << entry.pc();
+
+    if (!entry.tagged_slots().empty()) {
+      os << "  slots (sp->fp): ";
+      for (uint8_t bits : entry.tagged_slots()) {
         for (int bit = 0; bit < kBitsPerByte; ++bit) {
           os << ((bits >> bit) & 1);
         }
       }
+    }
+
+    if (entry.tagged_register_indexes() != 0) {
+      os << "  registers: ";
+      uint32_t register_bits = entry.tagged_register_indexes();
+      int bits = 32 - base::bits::CountLeadingZeros32(register_bits);
+      for (int j = bits - 1; j >= 0; --j) {
+        os << ((register_bits >> j) & 1);
+      }
+    }
+
+    if (entry.has_deoptimization_index()) {
+      os << "  deopt " << std::setw(6) << entry.deoptimization_index()
+         << " trampoline: " << std::setw(6) << std::hex
+         << entry.trampoline_pc();
+    }
+    os << "\n";
+  }
 }
 
 Safepoint SafepointTableBuilder::DefineSafepoint(Assembler* assembler) {

src/codegen/safepoint-table.h

@@ -139,7 +139,7 @@ class SafepointTable {
   // Returns the entry for the given pc.
   SafepointEntry FindEntry(Address pc) const;
 
-  void PrintEntry(int index, std::ostream& os) const;
+  void Print(std::ostream&) const;
 
  private:
   // Layout information.

src/objects/code.cc

@@ -585,23 +585,7 @@ void Code::Disassemble(const char* name, std::ostream& os, Isolate* isolate,
 
   if (has_safepoint_info()) {
     SafepointTable table(isolate, current_pc, *this);
-    os << "Safepoints (entries = " << table.length()
+    table.Print(os);
-       << ", byte size = " << table.byte_size() << ")\n";
-    for (int i = 0; i < table.length(); i++) {
-      SafepointEntry entry = table.GetEntry(i);
-      os << reinterpret_cast<const void*>(InstructionStart() + entry.pc())
-         << "  " << std::setw(6) << std::hex << entry.pc() << "  ";
-      print_pc(os, entry.trampoline_pc());
-      os << std::dec << "  ";
-      table.PrintEntry(i, os);
-      os << " (sp -> fp)  ";
-      if (entry.has_deoptimization_index()) {
-        os << std::setw(6) << entry.deoptimization_index();
-      } else {
-        os << "<none>";
-      }
-      os << "\n";
-    }
     os << "\n";
   }
 

src/wasm/wasm-code-manager.cc

@@ -436,28 +436,7 @@ void WasmCode::Disassemble(const char* name, std::ostream& os,
 
   if (safepoint_table_offset_ > 0) {
     SafepointTable table(this);
-    // TODO(clemensb): Unify with printing in code.cc.
+    table.Print(os);
-    os << "Safepoints (entries = " << table.length()
-       << ", byte size = " << table.byte_size() << ")\n";
-    for (int i = 0; i < table.length(); i++) {
-      SafepointEntry entry = table.GetEntry(i);
-      os << reinterpret_cast<const void*>(instruction_start() + entry.pc())
-         << " " << std::setw(6) << std::hex << entry.pc() << "  ";
-      table.PrintEntry(i, os);
-      os << " (sp -> fp)";
-      if (entry.trampoline_pc() != SafepointEntry::kNoTrampolinePC) {
-        os << " trampoline: " << std::hex << entry.trampoline_pc() << std::dec;
-      }
-      if (entry.tagged_register_indexes() != 0) {
-        os << " registers: ";
-        uint32_t register_bits = entry.tagged_register_indexes();
-        int bits = 32 - base::bits::CountLeadingZeros32(register_bits);
-        for (int j = bits - 1; j >= 0; --j) {
-          os << ((register_bits >> j) & 1);
-        }
-      }
-      os << "\n";
-    }
     os << "\n";
   }