shader: implement RDNA2 frexp exponent

tests/ShaderRecompilerComputeTests.cpp

@@ -13527,6 +13527,44 @@ TestCase VectorFloatConversionOps() {
            O::SEndpgm}};
 }
 
+TestCase VectorFrexpExpI32F32Edges() {
+  using O = ShaderOpcode;
+
+  const std::vector<u32> inputs = {
+      0x00000000u, 0x80000000u, 0x3f000000u, 0xbf800000u,
+      0x40800000u, 0xc1000000u, 0x00800000u, 0x007fffffu,
+      0x00000001u, 0x7f800000u, 0x7fc00000u,
+  };
+  std::vector<u32> code;
+  for (u32 i = 0; i < static_cast<u32>(inputs.size()); i++) {
+    AppendVMovU32(&code, 31, i * sizeof(u32));
+    AppendBufferLoadDword(&code, i == 3u ? 23u : i, 31);
+  }
+  for (u32 i = 0; i < static_cast<u32>(inputs.size()); i++) {
+    const auto dst = 16u + i;
+    if (dst == 19u) {
+      code.push_back(0x7e267ef9u); // captured v_frexp_exp_i32_f32 v19, abs(v23)
+      code.push_back(0x00260617u);
+    } else {
+      code.push_back(EncodeVop1(0x3f, dst, Vgpr(i)));
+    }
+    AppendStoreVgpr(&code, dst, i);
+  }
+  AppendEnd(&code);
+
+  TestCase test;
+  test.name = "VectorFrexpExpI32F32Edges";
+  test.code = std::move(code);
+  test.initial = inputs;
+  test.expected = {0u,          0u,          0u,          1u, 3u, 4u,
+                   0xffffff83u, 0xffffff82u, 0xffffff6cu, 0u, 0u};
+  test.opcodes = {O::VMovB32, O::BufferLoadDword, O::VFrexpExpI32F32,
+                  O::BufferStoreDword, O::SEndpgm};
+  test.decoded_counts = {{"v_frexp_exp_i32_f32", inputs.size()}};
+  test.required_spirv = {"FindUMsb", "OpBitFieldUExtract"};
+  return test;
+}
+
 TestCase CvtF32ToIntSaturatesNaNAndOutOfRange() {
   using O = ShaderOpcode;
 
@@ -17842,6 +17880,7 @@ std::vector<TestCase> MakeCases() {
   AddCase(VectorMinMaxF32NanAndSignedZeroEdges);
   AddCase(VectorMed3F32NanUsesMin3Path);
   AddCase(VectorFloatConversionOps);
+  AddCase(VectorFrexpExpI32F32Edges);
   AddCase(CvtF32ToIntSaturatesNaNAndOutOfRange);
   AddCase(VectorSpecialF32FlushesDenormalInputs);
   AddCase(VectorRcpIflagF32IntegerReciprocal);