Merge pull request #191 from TomHarte/Precache

Introduces more aggressive caching of sectors in the MFM decoder, improves CPC static analysis further

Components/8272/i8272.cpp

@@ -247,6 +247,7 @@ void i8272::posit_event(int event_type) {
 
 		// Establishes the drive and head being addressed, and whether in double density mode; populates the internal
 		// cylinder, head, sector and size registers from the command stream.
+			status_[0] = status_[1] = status_[2] = 0;
 			SET_DRIVE_HEAD_MFM();
 			cylinder_ = command_[2];
 			head_ = command_[3];

NumberTheory/Factors.hpp

@@ -9,14 +9,17 @@
 #ifndef Factors_hpp
 #define Factors_hpp
 
+#include <numeric>
 #include <utility>
 
 namespace NumberTheory {
 	/*!
-		@returns The greatest common divisor of @c a and @c b as computed by Euclid's algorithm.
+		@returns The greatest common divisor of @c a and @c b.
 	*/
 	template<class T> T greatest_common_divisor(T a, T b) {
-		// TODO: replace with the C++17 GCD function, once available.
+#if __cplusplus > 201402L
+		return std::gcd(a, b);
+#else
 		if(a < b) {
 			std::swap(a, b);
 		}
@@ -29,11 +32,12 @@ namespace NumberTheory {
 			a = b;
 			b = remainder;
 		}
+#endif
 	}
 
 	/*!
-		@returns The least common multiple of @c a and @c b computed indirectly via Euclid's greatest
-		common divisor algorithm.
+		@returns The least common multiple of @c a and @c b computed indirectly via the greatest
+		common divisor.
 	*/
 	template<class T> T least_common_multiple(T a, T b) {
 		if(a == b) return a;

OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj

@@ -3037,6 +3037,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
+				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_WARN_ASSIGN_ENUM = YES;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
@@ -3065,6 +3066,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
+				CLANG_CXX_LANGUAGE_STANDARD = "c++14";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_WARN_ASSIGN_ENUM = YES;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;

Outputs/CRT/Internals/Shaders/Shader.cpp

@@ -29,7 +29,7 @@ GLuint Shader::compile_shader(const std::string &source, GLenum type) {
 		GLint logLength;
 		glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &logLength);
 		if(logLength > 0) {
-			GLchar *log = new GLchar[logLength];
+			GLchar *log = new GLchar[(size_t)logLength];
 			glGetShaderInfoLog(shader, logLength, &logLength, log);
 			printf("Compile log:\n%s\n", log);
 			delete[] log;
@@ -66,7 +66,7 @@ Shader::Shader(const std::string &vertex_shader, const std::string &fragment_sha
 		GLint logLength;
 		glGetProgramiv(shader_program_, GL_INFO_LOG_LENGTH, &logLength);
 		if(logLength > 0) {
-			GLchar *log = new GLchar[logLength];
+			GLchar *log = new GLchar[(size_t)logLength];
 			glGetProgramInfoLog(shader_program_, logLength, &logLength, log);
 			printf("Link log:\n%s\n", log);
 			delete[] log;

StaticAnalyser/AmstradCPC/StaticAnalyser.cpp

@@ -7,7 +7,9 @@
 //
 
 #include "StaticAnalyser.hpp"
+
 #include "../../Storage/Disk/Parsers/CPM.hpp"
+#include "../../Storage/Disk/Encodings/MFM.hpp"
 
 static bool strcmp_insensitive(const char *a, const char *b) {
 	if(strlen(a) != strlen(b)) return false;
@@ -37,6 +39,10 @@ static void InspectDataCatalogue(
 	size_t last_implicit_suffixed_file = 0;
 
 	for(size_t c = 0; c < data_catalogue->files.size(); c++) {
+		// Files with nothing but spaces in their name can't be loaded by the user, so disregard them.
+		if(data_catalogue->files[c].type == "   " && data_catalogue->files[c].name == "        ")
+			continue;
+
 		// Check for whether this is [potentially] BASIC.
 		if(data_catalogue->files[c].data.size() >= 128 && !((data_catalogue->files[c].data[18] >> 1) & 7)) {
 			basic_files++;
@@ -64,10 +70,17 @@ static void InspectDataCatalogue(
 }
 
 static void InspectSystemCatalogue(
-	const std::unique_ptr<Storage::Disk::CPM::Catalogue> &data_catalogue,
+	const std::shared_ptr<Storage::Disk::Disk> &disk,
+	const std::unique_ptr<Storage::Disk::CPM::Catalogue> &catalogue,
 	StaticAnalyser::Target &target) {
-	// If this is a system disk, then launch it as though it were CP/M.
-	target.loadingCommand = "|cpm\n";
+	Storage::Encodings::MFM::Parser parser(true, disk);
+	// Check that the boot sector exists.
+	if(parser.get_sector(0, 0, 0x41) != nullptr) {
+		// This is a system disk, then launch it as though it were CP/M.
+		target.loadingCommand = "|cpm\n";
+	} else {
+		InspectDataCatalogue(catalogue, target);
+	}
 }
 
 void StaticAnalyser::AmstradCPC::AddTargets(
@@ -114,7 +127,7 @@ void StaticAnalyser::AmstradCPC::AddTargets(
 
 			std::unique_ptr<Storage::Disk::CPM::Catalogue> system_catalogue = Storage::Disk::CPM::GetCatalogue(target.disks.front(), system_format);
 			if(system_catalogue) {
-				InspectSystemCatalogue(data_catalogue, target);
+				InspectSystemCatalogue(target.disks.front(), data_catalogue, target);
 			}
 		}
 	}

Storage/Disk/Encodings/MFM.cpp

@@ -266,6 +266,26 @@ void Parser::seek_to_track(uint8_t track) {
 }
 
 std::shared_ptr<Sector> Parser::get_sector(uint8_t head, uint8_t track, uint8_t sector) {
+	// Switch head and track if necessary.
+	if(head_ != head) {
+		drive_->set_head(head);
+		invalidate_track();
+	}
+	seek_to_track(track);
+	int track_index = get_index(head, track, 0);
+
+	// Populate the sector cache if it's not already populated.
+	if(decoded_tracks_.find(track_index) == decoded_tracks_.end()) {
+		std::shared_ptr<Sector> first_sector = get_next_sector();
+		if(first_sector) {
+			while(1) {
+				std::shared_ptr<Sector> next_sector = get_next_sector();
+				if(!next_sector || next_sector->sector == first_sector->sector) break;
+			}
+		}
+		decoded_tracks_.insert(track_index);
+	}
+
 	// Check cache for sector.
 	int index = get_index(head, track, sector);
 	auto cached_sector = sectors_by_index_.find(index);
@@ -273,14 +293,8 @@ std::shared_ptr<Sector> Parser::get_sector(uint8_t head, uint8_t track, uint8_t
 		return cached_sector->second;
 	}
 
-	// Failing that, set the proper head and track, and search for the sector. get_sector automatically
-	// inserts everything found into sectors_by_index_.
-	if(head_ != head) {
-		drive_->set_head(head);
-		invalidate_track();
-	}
-	seek_to_track(track);
-	return get_sector(sector);
+	// If it wasn't found, it doesn't exist.
+	return nullptr;
 }
 
 std::vector<uint8_t> Parser::get_track(uint8_t track) {

Storage/Disk/Encodings/MFM.hpp

@@ -140,6 +140,7 @@ class Parser: public Storage::Disk::Controller {
 		std::vector<uint8_t> get_track();
 
 		std::map<int, std::shared_ptr<Storage::Encodings::MFM::Sector>> sectors_by_index_;
+		std::set<int> decoded_tracks_;
 		int get_index(uint8_t head, uint8_t track, uint8_t sector);
 };
 

Storage/FileHolder.cpp

@@ -80,9 +80,8 @@ uint16_t FileHolder::fgetc16be() {
 void FileHolder::ensure_file_is_at_least_length(long length) {
 	fseek(file_, 0, SEEK_END);
 	long bytes_to_write = length - ftell(file_);
-	if(bytes_to_write > 0)
-	{
-		uint8_t *empty = new uint8_t[bytes_to_write];
+	if(bytes_to_write > 0) {
+		uint8_t *empty = new uint8_t[(size_t)bytes_to_write];
 		memset(empty, 0, (size_t)bytes_to_write);
 		fwrite(empty, sizeof(uint8_t), (size_t)bytes_to_write, file_);
 		delete[] empty;

Storage/TimedEventLoop.cpp

@@ -43,10 +43,12 @@ void TimedEventLoop::set_next_event_time_interval(Time interval) {
 		(int64_t)subcycles_until_event_.clock_rate * (int64_t)input_clock_rate_ * (int64_t)interval.length +
 		(int64_t)interval.clock_rate * (int64_t)subcycles_until_event_.length;
 
-	// Simplify now, to prepare for stuffing into possibly 32-bit quantities
-	int64_t common_divisor = NumberTheory::greatest_common_divisor(numerator % denominator, denominator);
-	denominator /= common_divisor;
-	numerator /= common_divisor;
+	// Simplify if necessary.
+	if(denominator > std::numeric_limits<unsigned int>::max()) {
+		int64_t common_divisor = NumberTheory::greatest_common_divisor(numerator % denominator, denominator);
+		denominator /= common_divisor;
+		numerator /= common_divisor;
+	}
 
 	// So this event will fire in the integral number of cycles from now, putting us at the remainder
 	// number of subcycles