Added RISC-V IsaDescriptor class, and adjusted RISC-V GPR count depending on ISA base.

src/Targets/RiscV/IsaDescriptor.hpp

@@ -0,0 +1,86 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <string_view>
+#include <unordered_map>
+#include <optional>
+#include <functional>
+
+namespace Targets::RiscV
+{
+    enum class IsaBase: std::uint8_t
+    {
+        RV32I,
+        RV32E,
+        RV64I,
+        RV64E,
+    };
+
+    /**
+     * I've not covered all standard extensions here, as I really don't think Bloom will ever need them. If that ever
+     * changes, I will add the others as and when I need them.
+     */
+    enum class IsaExtension: std::uint8_t
+    {
+        INTEGER_MULTIPLICATION_DIVISION,
+        ATOMICS,
+        SINGLE_PRECISION_FLOATING_POINT,
+        DOUBLE_PRECISION_FLOATING_POINT,
+        BIT_MANIPULATION,
+        COMPRESSED_INSTRUCTIONS,
+        CRYPTOGRAPHY,
+        CSR_INSTRUCTIONS,
+        INSTRUCTION_FETCH_FENCE,
+    };
+
+    struct IsaVersionNumber
+    {
+        std::uint16_t major = 0;
+        std::uint16_t minor = 0;
+    };
+
+    struct IsaBaseDescriptor
+    {
+        IsaBase base;
+        IsaVersionNumber versionNumber;
+    };
+
+    struct IsaExtensionDescriptor
+    {
+        IsaExtension extension;
+        IsaVersionNumber versionNumber;
+    };
+
+    struct IsaDescriptor
+    {
+        IsaBaseDescriptor baseDescriptor;
+        std::unordered_map<IsaExtension, IsaExtensionDescriptor> extensionDescriptorsByExtension;
+
+        explicit IsaDescriptor(std::string_view isaString);
+
+        bool hasExtension(IsaExtension extension) const;
+        bool isReduced() const;
+
+        std::optional<std::reference_wrapper<const IsaExtensionDescriptor>> tryGetExtensionDescriptor(
+            IsaExtension extension
+        ) const;
+        const IsaExtensionDescriptor& getExtensionDescriptor(IsaExtension extension) const;
+
+    private:
+        IsaDescriptor(std::string_view isaStringLower, std::size_t stringOffset);
+
+        static IsaBaseDescriptor extractBaseDescriptorFromIsaString(
+            std::string_view isaStringLower,
+            std::size_t& stringOffset
+        );
+        static std::unordered_map<IsaExtension, IsaExtensionDescriptor> extractExtensionDescriptorsFromIsaString(
+            std::string_view isaStringLower,
+            std::size_t& stringOffset
+        );
+        static std::optional<IsaVersionNumber> extractVersionNumberFromIsaString(
+            std::string_view isaStringLower,
+            std::size_t& stringOffset
+        );
+    };
+}