clover/llvm: Use the highest supported SPIR-V version (v4)

v2:
   a) Move `supported_spirv_verssions()` to `spirv::` (Francisco Jerez)
   b) Introduce a `SPV_MAKE_VERSION` macro to avoid making mistakes and
     making it more readable than its uint representation.
v3: Replaced an if-statement with a `std::min()` in
    `spirv::get_spirv_translator_options()` (Karol Herbst)
v4: Turn `SPV_MAKE_VERSION()` into a function (Francisco Jerez)

Signed-off-by: Pierre Moreau <dev@pmoreau.org>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5038>

src/gallium/frontends/clover/llvm/invocation.cpp

@@ -307,6 +307,18 @@ namespace {
 
       return act.takeModule();
    }
+
+#ifdef HAVE_CLOVER_SPIRV
+   SPIRV::TranslatorOpts
+   get_spirv_translator_options(const device &dev) {
+      const auto supported_versions = spirv::supported_versions();
+      const auto maximum_spirv_version =
+         std::min(static_cast<SPIRV::VersionNumber>(supported_versions.back()),
+                  SPIRV::VersionNumber::MaximumVersion);
+
+      return SPIRV::TranslatorOpts(maximum_spirv_version);
+   }
+#endif
 }
 
 module
@@ -438,6 +450,8 @@ clover::llvm::compile_to_spirv(const std::string &source,
    if (has_flag(debug::llvm))
       debug::log(".ll", print_module_bitcode(*mod));
 
+   const auto spirv_options = get_spirv_translator_options(dev);
+
    std::string error_msg;
    if (!::llvm::regularizeLlvmForSpirv(mod.get(), error_msg)) {
       r_log += "Failed to regularize LLVM IR for SPIR-V: " + error_msg + ".\n";
@@ -445,7 +459,7 @@ clover::llvm::compile_to_spirv(const std::string &source,
    }
 
    std::ostringstream os;
-   if (!::llvm::writeSpirv(mod.get(), os, error_msg)) {
+   if (!::llvm::writeSpirv(mod.get(), spirv_options, os, error_msg)) {
       r_log += "Translation from LLVM IR to SPIR-V failed: " + error_msg + ".\n";
       throw error(CL_INVALID_VALUE);
    }

src/gallium/frontends/clover/spirv/invocation.cpp

@@ -49,6 +49,12 @@ using namespace clover;
 #ifdef HAVE_CLOVER_SPIRV
 namespace {
 
+   uint32_t
+   make_spirv_version(uint8_t major, uint8_t minor) {
+      return (static_cast<uint32_t>(major) << 16u) |
+             (static_cast<uint32_t>(minor) << 8u);
+   }
+
    template<typename T>
    T get(const char *source, size_t index) {
       const uint32_t *word_ptr = reinterpret_cast<const uint32_t *>(source);
@@ -715,6 +721,11 @@ clover::spirv::supported_extensions() {
    };
 }
 
+std::vector<uint32_t>
+clover::spirv::supported_versions() {
+   return { make_spirv_version(1u, 0u) };
+}
+
 #else
 bool
 clover::spirv::is_valid_spirv(const std::vector<char> &/*binary*/,
@@ -748,4 +759,9 @@ std::unordered_set<std::string>
 clover::spirv::supported_extensions() {
    return {};
 }
+
+std::vector<uint32_t>
+clover::spirv::supported_versions() {
+   return {};
+}
 #endif

src/gallium/frontends/clover/spirv/invocation.hpp

@@ -55,6 +55,10 @@ namespace clover {
 
       // Returns a set of supported SPIR-V extensions.
       std::unordered_set<std::string> supported_extensions();
+
+      // Returns a vector (sorted in increasing order) of supported SPIR-V
+      // versions.
+      std::vector<uint32_t> supported_versions();
    }
 }