diff --git a/core/libs/prx/libSceAgcDriver/CMakeLists.txt b/core/libs/prx/libSceAgcDriver/CMakeLists.txt
index 52cd05e97..cf8c2fd70 100644
--- a/core/libs/prx/libSceAgcDriver/CMakeLists.txt
+++ b/core/libs/prx/libSceAgcDriver/CMakeLists.txt
@@ -625,6 +625,14 @@ if(BUILD_TESTING)
         set_tests_properties(scalar_saveexec PROPERTIES ENVIRONMENT_MODIFICATION
             "PATH=path_list_prepend:$<TARGET_FILE_DIR:libc>")
     endif()
+    add_test_executable(scalar_bitcount64_tests ${LIBS_INCLUDE_DIR}/tests/ScalarBitCount64.cpp)
+    target_link_libraries(scalar_bitcount64_tests PRIVATE shader_recompiler_agc_driver libc)
+    configure_windows_unwind(scalar_bitcount64_tests)
+    add_test(NAME scalar_bitcount64 COMMAND scalar_bitcount64_tests)
+    if(WIN32)
+        set_tests_properties(scalar_bitcount64 PROPERTIES ENVIRONMENT_MODIFICATION
+            "PATH=path_list_prepend:$<TARGET_FILE_DIR:libc>")
+    endif()
     add_test_executable(image_sample_gather_tests ${LIBS_INCLUDE_DIR}/tests/ImageSampleGather.cpp)
     target_link_libraries(image_sample_gather_tests PRIVATE shader_recompiler_agc_driver libc)
     configure_windows_unwind(image_sample_gather_tests)
diff --git a/core/libs/tests/ScalarBitCount64.cpp b/core/libs/tests/ScalarBitCount64.cpp
new file mode 100644
index 000000000..f3e657835
--- /dev/null
+++ b/core/libs/tests/ScalarBitCount64.cpp
@@ -0,0 +1,26 @@
+#include "Translation/TranslationContext.hpp"
+#include "RdnaDecoder/RdnaScalarOpDecoder.hpp"
+#include <array>
+#include <stdexcept>
+
+using namespace ShaderRecompiler;
+static void Require(bool value) { if (!value) throw std::runtime_error("scalar bit-count regression"); }
+static void Check(std::uint32_t encoding, RdnaOpcode opcode, IrOpcode expected) {
+    const std::array<std::uint32_t, 1> code{0x80000000u | (10u << 16u) | (encoding << 8u) | 12u};
+    const RdnaInstruction instruction = DecodeRdnaSop1(0u, code, 0u);
+    Require(instruction.op == opcode);
+    Require(instruction.family == RdnaInstructionFamily::SOP1);
+    Require(IsScalarAluOpcode(instruction.op));
+    IrProgram program;
+    auto& block = program.CreateBlock();
+    program.SetEntryBlock(block);
+    TranslationContext context(program, block, 256);
+    context.TranslateInstruction(instruction);
+    bool found = false;
+    for (auto* value : block.Instructions()) found = found || value->Opcode() == expected;
+    Require(found);
+}
+int main() {
+    Check(0x0eu, RdnaOpcode::SBcnt0I32B64, IrOpcode::BitCount32);
+    Check(0x12u, RdnaOpcode::SFf0I32B64, IrOpcode::FindILsb32);
+}