⚡ Cache & Use the personality pointer

demos/applications/multi_levels.cpp

@@ -51,17 +51,14 @@ std::array<signature*, 9> functions = {
   &funct_group3_0, &funct_group4_0, &funct_group5_0,
   &funct_group6_0, &funct_group7_0, &funct_group8_0,
 #if 0
-  funct_group9_0,  funct_group10_0, funct_group11_0,
-  funct_group12_0, funct_group13_0, funct_group14_0, funct_group15_0,
-  funct_group16_0,
-  funct_group17_0, funct_group18_0, funct_group19_0,
-  funct_group20_0, funct_group21_0, funct_group22_0, funct_group23_0,
-  funct_group24_0
+  &funct_group9_0,
+  &funct_group10_0, &funct_group11_0, &funct_group12_0, &funct_group13_0,
+  &funct_group14_0, &funct_group15_0, &funct_group16_0, &funct_group17_0,
+  &funct_group18_0, &funct_group19_0, &funct_group20_0, &funct_group21_0,
+  &funct_group22_0, &funct_group23_0, &funct_group24_0
 #endif
 };
 
-std::uint64_t allocation_cycles = 0;
-
 void application(resource_list& p_resources)
 {
   resources = &p_resources;
@@ -71,17 +68,12 @@ void application(resource_list& p_resources)
   for (std::size_t i = 0; i < functions.size(); i++) {
     try {
       functions.at(i)();
-      // NOTE to Khalil before submission. Something is wrong with the unwinder
-      // and we are jumping to different locations when it completes the first
-      // time. Local variables are probably being damaged or the stack pointer
-      // is not in the correct location.
     } catch ([[maybe_unused]] my_error_t const& p_error) {
       end_cycles = resources->clock->uptime();
       cycle_map[i] = end_cycles - start_cycles;
     }
   }
 
-#if 1
   for (std::size_t i = 0; i < functions.size(); i++) {
     bool was_caught = false;
     try {
@@ -96,7 +88,6 @@ void application(resource_list& p_resources)
       happy_cycle_map[i] = end_cycles - start_cycles;
     }
   }
-#endif
 
   while (true) {
     continue;
@@ -11407,4 +11398,5 @@ int funct_group24_95()
 
   return side_effect;
 }
-#endif
+
+#endif

notes.md

@@ -7,4 +7,4 @@
 - Reduce the instructions for `restore_cpu_state`
 - Remove shift variable in `read_uleb128`
 
-- I've turned destructors back on and we are terminating. Looks like the encoding byte has 0x15 which we don't support. 0x5 for the encoding type is not present. So we need to figure out what that is. Its either us reading the wrong data OR a new format we need to handle.
+- I've turned destructors back on and we are terminating. Looks like the encoding byte has 0x15 which we don't support. 0x5 for the encoding type is not present. So we need to figure out what that is. Its either us reading the wrong data OR a new format we need to handle.

src/arm_cortex/estell/exception.cpp

@@ -495,7 +495,8 @@ inline void restore_cpu_core(ke::cortex_m_cpu& p_cpu_core)
 
 inline void enter_function(exception_object& p_exception_object)
 {
-  auto const* lsda_word = p_exception_object.cache.entry_ptr->lsda_data();
+  auto const* lsda_word =
+    index_entry_t::lsda_data(p_exception_object.cache.personality);
   auto const* lsda_data = reinterpret_cast<std::uint8_t const*>(lsda_word);
 
 #if 0
@@ -630,7 +631,7 @@ inline lsda_header_info parse_header(std::uint8_t const** p_lsda)
 inline auto const* to_lsda(exception_object& p_exception_object)
 {
   return reinterpret_cast<std::uint8_t const*>(
-    p_exception_object.cache.entry_ptr->lsda_data());
+    index_entry_t::lsda_data(p_exception_object.cache.personality));
 }
 
 inline auto calculate_relative_pc(exception_object& p_exception_object)
@@ -1973,15 +1974,20 @@ void raise_exception(exception_object& p_exception_object)
       case runtime_state::get_next_frame: {
         auto const& index_entry = get_index_entry(p_exception_object.cpu.pc);
         p_exception_object.cache.entry_ptr = &index_entry;
+        // SU16 data
         if (index_entry.has_inlined_personality()) {
           p_exception_object.cache.state(runtime_state::unwind_frame);
           break;
         }
-        auto const* descriptor_start = index_entry.descriptor_start();
+        p_exception_object.cache.personality = index_entry.personality();
+        auto const* descriptor_start =
+          index_entry_t::descriptor_start(p_exception_object.cache.personality);
+        // LU16 data no LSDA
         if (*descriptor_start == 0x0000'0000) {
           p_exception_object.cache.state(runtime_state::unwind_frame);
           break;
         }
+        // LSDA
         p_exception_object.cache.relative_address(
           (p_exception_object.cpu.pc - index_entry.function()));
         p_exception_object.cache.state(runtime_state::enter_function);

src/arm_cortex/estell/internal.hpp

@@ -133,7 +133,7 @@ struct function_t
 
   bool operator<(function_t const& p_other) const
   {
-    return address < p_other.address;
+    return address < p_other.address;  // NOLINT
   }
 
   bool operator==(function_t const& p_other) const
@@ -182,11 +182,12 @@ struct index_entry_t
     return to_absolute_address_ptr(&personality_offset);
   }
 
-  [[gnu::always_inline]] inline std::uint32_t const* lsda_data() const
+  [[gnu::always_inline]] static inline std::uint32_t const* lsda_data(
+    std::uint32_t const* p_personality)
   {
     constexpr auto personality_type = hal::bit_mask::from<24, 27>();
     // +1 to skip the prel31 offset to the personality function
-    auto const* header = personality() + 1;
+    auto const* header = p_personality + 1;
     if (hal::bit_extract<personality_type>(*header) == 0x0) {
       return header + 1;
     }
@@ -199,22 +200,22 @@ struct index_entry_t
     return header + 3;
   }
 
-  [[gnu::always_inline]] inline std::uint32_t const* descriptor_start() const
+  [[gnu::always_inline]] inline static std::uint32_t const* descriptor_start(
+    std::uint32_t const* p_personality)
   {
     constexpr auto type_mask = hal::bit_mask{ .position = 24, .width = 8 };
 
-    auto* personality_address = personality();
-    auto type = hal::bit_extract<type_mask>(*personality_address);
+    auto type = hal::bit_extract<type_mask>(*p_personality);
 
     // TODO(kammce): comment why each of these works!
     if (type == 0x0) {
-      return personality_address + 1;
+      return p_personality + 1;
     }
 
     // The limit for ARM exceptions instructions is 7. LD optimizes the ARM
     // exception spec by removing the "word length" specifier allowing the
     // instructions to fit in 2 words.
-    return personality_address + 2;
+    return p_personality + 2;
   }
 
   [[gnu::always_inline]] function_t function() const
@@ -262,8 +263,9 @@ enum class runtime_state : std::uint8_t
 
 struct cache_t
 {
-  std::uint32_t rel_address;
   index_entry_t const* entry_ptr = nullptr;
+  std::uint32_t const* personality = nullptr;
+  std::uint32_t rel_address;
   runtime_state inner_state;
   bool previously_rethrown = false;