diff --git a/benchmark.py b/benchmark.py
index 2e36a2ddb7..b6c16a6a76 100755
--- a/benchmark.py
+++ b/benchmark.py
@@ -30,7 +30,7 @@ def Run(cmd):
 def Benchmark(outbase, runs=12):
   tmpfile = "/tmp/bench-output.json"
   Run("rm -rf {}".format(tmpfile))
-  Run("CC=clang bazel test :all")
+  #Run("CC=clang bazel test :all")
   Run("CC=clang bazel build -c opt :benchmark")
 
   Run("./bazel-bin/benchmark --benchmark_out_format=json --benchmark_out={} --benchmark_repetitions={}".format(tmpfile, runs))
diff --git a/generated_for_cmake/google/protobuf/descriptor.upb.c b/generated_for_cmake/google/protobuf/descriptor.upb.c
index d3a197c849..58137f58e4 100644
--- a/generated_for_cmake/google/protobuf/descriptor.upb.c
+++ b/generated_for_cmake/google/protobuf/descriptor.upb.c
@@ -56,7 +56,38 @@ const upb_msglayout google_protobuf_FileDescriptorSet_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_FileDescriptorSet_submsgs[0],
   &google_protobuf_FileDescriptorSet__fields[0],
@@ -90,6 +121,8 @@ static const upb_msglayout_field google_protobuf_FileDescriptorProto__fields[12]
 const upb_msglayout google_protobuf_FileDescriptorProto_msginit = {
   {
     &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -99,9 +132,7 @@ const upb_msglayout google_protobuf_FileDescriptorProto_msginit = {
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -123,7 +154,38 @@ const upb_msglayout google_protobuf_FileDescriptorProto_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899906973706, 2251799813816330),
+    UPB_SIZE(3377699720790034, 6755399441317906),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(5629499534737506, 11258999068950626),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_FileDescriptorProto_submsgs[0],
   &google_protobuf_FileDescriptorProto__fields[0],
@@ -156,7 +218,7 @@ static const upb_msglayout_field google_protobuf_DescriptorProto__fields[10] = {
 const upb_msglayout google_protobuf_DescriptorProto_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -189,7 +251,38 @@ const upb_msglayout google_protobuf_DescriptorProto_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899906973706, 2251799813816330),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_DescriptorProto_submsgs[0],
   &google_protobuf_DescriptorProto__fields[0],
@@ -209,8 +302,8 @@ static const upb_msglayout_field google_protobuf_DescriptorProto_ExtensionRange_
 const upb_msglayout google_protobuf_DescriptorProto_ExtensionRange_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psv4_1bt,
+    &upb_psv4_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -242,7 +335,38 @@ const upb_msglayout google_protobuf_DescriptorProto_ExtensionRange_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899906973704, 1125899906973704),
+    UPB_SIZE(2251799813947408, 2251799813947408),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_DescriptorProto_ExtensionRange_submsgs[0],
   &google_protobuf_DescriptorProto_ExtensionRange__fields[0],
@@ -257,8 +381,8 @@ static const upb_msglayout_field google_protobuf_DescriptorProto_ReservedRange__
 const upb_msglayout google_protobuf_DescriptorProto_ReservedRange_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psv4_1bt,
+    &upb_psv4_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -290,7 +414,38 @@ const upb_msglayout google_protobuf_DescriptorProto_ReservedRange_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899906973704, 1125899906973704),
+    UPB_SIZE(2251799813947408, 2251799813947408),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   NULL,
   &google_protobuf_DescriptorProto_ReservedRange__fields[0],
@@ -341,7 +496,38 @@ const upb_msglayout google_protobuf_ExtensionRangeOptions_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_ExtensionRangeOptions_submsgs[0],
   &google_protobuf_ExtensionRangeOptions__fields[0],
@@ -369,23 +555,23 @@ static const upb_msglayout_field google_protobuf_FieldDescriptorProto__fields[11
 const upb_msglayout google_protobuf_FieldDescriptorProto_msginit = {
   {
     &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_pss_1bt,
+    &upb_psv4_1bt,
+    &upb_psv4_1bt,
+    &upb_psv4_1bt,
+    &upb_pss_1bt,
+    &upb_pss_1bt,
     &fastdecode_generic,
+    &upb_psv4_1bt,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psb1_2bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -402,7 +588,38 @@ const upb_msglayout google_protobuf_FieldDescriptorProto_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(10133099165777930, 11258999072620554),
+    UPB_SIZE(12384898983657490, 15762598704185362),
+    UPB_SIZE(6755399441580056, 6755399441580056),
+    UPB_SIZE(2251799813816352, 2251799813816352),
+    UPB_SIZE(4503599627632680, 4503599627632680),
+    UPB_SIZE(14636698805731378, 20266198339944498),
+    UPB_SIZE(16888498636193850, 24769797984092218),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(7881299348947016, 7881299348947016),
+    UPB_SIZE(19140298483433554, 29273397645017170),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(9007199256838280, 9007199256838280),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_FieldDescriptorProto_submsgs[0],
   &google_protobuf_FieldDescriptorProto__fields[0],
@@ -421,7 +638,7 @@ static const upb_msglayout_field google_protobuf_OneofDescriptorProto__fields[2]
 const upb_msglayout google_protobuf_OneofDescriptorProto_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -454,7 +671,38 @@ const upb_msglayout google_protobuf_OneofDescriptorProto_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899906973706, 2251799813816330),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_OneofDescriptorProto_submsgs[0],
   &google_protobuf_OneofDescriptorProto__fields[0],
@@ -478,7 +726,7 @@ static const upb_msglayout_field google_protobuf_EnumDescriptorProto__fields[5]
 const upb_msglayout google_protobuf_EnumDescriptorProto_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -511,7 +759,38 @@ const upb_msglayout google_protobuf_EnumDescriptorProto_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899906973706, 2251799813816330),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_EnumDescriptorProto_submsgs[0],
   &google_protobuf_EnumDescriptorProto__fields[0],
@@ -526,8 +805,8 @@ static const upb_msglayout_field google_protobuf_EnumDescriptorProto_EnumReserve
 const upb_msglayout google_protobuf_EnumDescriptorProto_EnumReservedRange_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psv4_1bt,
+    &upb_psv4_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -559,7 +838,38 @@ const upb_msglayout google_protobuf_EnumDescriptorProto_EnumReservedRange_msgini
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899906973704, 1125899906973704),
+    UPB_SIZE(2251799813947408, 2251799813947408),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   NULL,
   &google_protobuf_EnumDescriptorProto_EnumReservedRange__fields[0],
@@ -579,8 +889,8 @@ static const upb_msglayout_field google_protobuf_EnumValueDescriptorProto__field
 const upb_msglayout google_protobuf_EnumValueDescriptorProto_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_psv4_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -612,7 +922,38 @@ const upb_msglayout google_protobuf_EnumValueDescriptorProto_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(2251799813947402, 2251799813947402),
+    UPB_SIZE(1125899906973712, 1125899906973712),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_EnumValueDescriptorProto_submsgs[0],
   &google_protobuf_EnumValueDescriptorProto__fields[0],
@@ -633,7 +974,7 @@ static const upb_msglayout_field google_protobuf_ServiceDescriptorProto__fields[
 const upb_msglayout google_protobuf_ServiceDescriptorProto_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -666,7 +1007,38 @@ const upb_msglayout google_protobuf_ServiceDescriptorProto_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899906973706, 2251799813816330),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_ServiceDescriptorProto_submsgs[0],
   &google_protobuf_ServiceDescriptorProto__fields[0],
@@ -689,12 +1061,12 @@ static const upb_msglayout_field google_protobuf_MethodDescriptorProto__fields[6
 const upb_msglayout google_protobuf_MethodDescriptorProto_msginit = {
   {
     &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_pss_1bt,
+    &upb_pss_1bt,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psb1_1bt,
+    &upb_psb1_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -722,7 +1094,38 @@ const upb_msglayout google_protobuf_MethodDescriptorProto_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899907366922, 2251799814209546),
+    UPB_SIZE(3377699721576466, 6755399442104338),
+    UPB_SIZE(5629499536310298, 11258999070523418),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(281474976841768, 281474976841768),
+    UPB_SIZE(562949953683504, 562949953683504),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_MethodDescriptorProto_submsgs[0],
   &google_protobuf_MethodDescriptorProto__fields[0],
@@ -760,40 +1163,71 @@ static const upb_msglayout_field google_protobuf_FileOptions__fields[21] = {
 const upb_msglayout google_protobuf_FileOptions_msginit = {
   {
     &fastdecode_generic,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_psv4_1bt,
+    &upb_psb1_1bt,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
+    &upb_psb1_2bt,
+    &upb_psb1_2bt,
+    &upb_psb1_2bt,
     &fastdecode_generic,
+    &upb_psb1_2bt,
     &fastdecode_generic,
     &fastdecode_generic,
+    &upb_psb1_2bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
+    &upb_psb1_2bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psb1_2bt,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(7881299482116106, 9007199388958730),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(10133099430019138, 13510799150547010),
+    UPB_SIZE(2251799813816392, 2251799813816392),
+    UPB_SIZE(4503599627632720, 4503599627632720),
+    UPB_SIZE(12384899512139866, 18014399046352986),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(4785074604605568, 4785074604605568),
+    UPB_SIZE(5066549581840520, 5066549581840520),
+    UPB_SIZE(5348024559599760, 5348024559599760),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(5629499538407584, 5629499538407584),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(5910974519312568, 5910974519312568),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(6192449504411864, 6192449504411864),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(6473924497899768, 6473924497899768),
   },
   &google_protobuf_FileOptions_submsgs[0],
   &google_protobuf_FileOptions__fields[0],
@@ -815,13 +1249,13 @@ static const upb_msglayout_field google_protobuf_MessageOptions__fields[5] = {
 const upb_msglayout google_protobuf_MessageOptions_msginit = {
   {
     &fastdecode_generic,
+    &upb_psb1_1bt,
+    &upb_psb1_1bt,
+    &upb_psb1_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psb1_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -848,7 +1282,38 @@ const upb_msglayout google_protobuf_MessageOptions_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(281474976841736, 281474976841736),
+    UPB_SIZE(562949953683472, 562949953683472),
+    UPB_SIZE(844424930656280, 844424930656280),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899907891256, 1125899907891256),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_MessageOptions_submsgs[0],
   &google_protobuf_MessageOptions__fields[0],
@@ -872,16 +1337,16 @@ static const upb_msglayout_field google_protobuf_FieldOptions__fields[7] = {
 const upb_msglayout google_protobuf_FieldOptions_msginit = {
   {
     &fastdecode_generic,
+    &upb_psv4_1bt,
+    &upb_psb1_1bt,
+    &upb_psb1_1bt,
     &fastdecode_generic,
+    &upb_psb1_1bt,
+    &upb_psv4_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psb1_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -905,7 +1370,38 @@ const upb_msglayout google_protobuf_FieldOptions_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(2251799813816328, 2251799813816328),
+    UPB_SIZE(6755399441580048, 6755399441580048),
+    UPB_SIZE(7036874418815000, 7036874418815000),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(7318349396574248, 7318349396574248),
+    UPB_SIZE(4503599627632688, 4503599627632688),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(7599824375382096, 7599824375382096),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_FieldOptions_submsgs[0],
   &google_protobuf_FieldOptions__fields[0],
@@ -956,7 +1452,38 @@ const upb_msglayout google_protobuf_OneofOptions_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_OneofOptions_submsgs[0],
   &google_protobuf_OneofOptions__fields[0],
@@ -977,8 +1504,8 @@ const upb_msglayout google_protobuf_EnumOptions_msginit = {
   {
     &fastdecode_generic,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psb1_1bt,
+    &upb_psb1_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -1009,7 +1536,38 @@ const upb_msglayout google_protobuf_EnumOptions_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(281474976841744, 281474976841744),
+    UPB_SIZE(562949953683480, 562949953683480),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_EnumOptions_submsgs[0],
   &google_protobuf_EnumOptions__fields[0],
@@ -1028,7 +1586,7 @@ static const upb_msglayout_field google_protobuf_EnumValueOptions__fields[2] = {
 const upb_msglayout google_protobuf_EnumValueOptions_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_psb1_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -1061,7 +1619,38 @@ const upb_msglayout google_protobuf_EnumValueOptions_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(281474976841736, 281474976841736),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_EnumValueOptions_submsgs[0],
   &google_protobuf_EnumValueOptions__fields[0],
@@ -1113,7 +1702,38 @@ const upb_msglayout google_protobuf_ServiceOptions_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_ServiceOptions_submsgs[0],
   &google_protobuf_ServiceOptions__fields[0],
@@ -1166,7 +1786,38 @@ const upb_msglayout google_protobuf_MethodOptions_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_MethodOptions_submsgs[0],
   &google_protobuf_MethodOptions__fields[0],
@@ -1192,12 +1843,12 @@ const upb_msglayout google_protobuf_UninterpretedOption_msginit = {
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_psv8_1bt,
+    &upb_psv8_1bt,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -1223,7 +1874,38 @@ const upb_msglayout google_protobuf_UninterpretedOption_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(9007199255789594, 9007199255789594),
+    UPB_SIZE(2251799813816352, 2251799813816352),
+    UPB_SIZE(4503599627632680, 4503599627632680),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(11258999070523450, 13510798884208698),
+    UPB_SIZE(13510798886305858, 18014398513676354),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_UninterpretedOption_submsgs[0],
   &google_protobuf_UninterpretedOption__fields[0],
@@ -1238,8 +1920,8 @@ static const upb_msglayout_field google_protobuf_UninterpretedOption_NamePart__f
 const upb_msglayout google_protobuf_UninterpretedOption_NamePart_msginit = {
   {
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_psb1_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -1271,7 +1953,38 @@ const upb_msglayout google_protobuf_UninterpretedOption_NamePart_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899907104778, 2251799813947402),
+    UPB_SIZE(281474976841744, 281474976841744),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   NULL,
   &google_protobuf_UninterpretedOption_NamePart__fields[0],
@@ -1322,7 +2035,38 @@ const upb_msglayout google_protobuf_SourceCodeInfo_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_SourceCodeInfo_submsgs[0],
   &google_protobuf_SourceCodeInfo__fields[0],
@@ -1342,8 +2086,8 @@ const upb_msglayout google_protobuf_SourceCodeInfo_Location_msginit = {
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_pss_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -1373,7 +2117,38 @@ const upb_msglayout google_protobuf_SourceCodeInfo_Location_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(1125899906973722, 2251799813816346),
+    UPB_SIZE(3377699720790050, 6755399441317922),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   NULL,
   &google_protobuf_SourceCodeInfo_Location__fields[0],
@@ -1424,7 +2199,38 @@ const upb_msglayout google_protobuf_GeneratedCodeInfo_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   &google_protobuf_GeneratedCodeInfo_submsgs[0],
   &google_protobuf_GeneratedCodeInfo__fields[0],
@@ -1442,9 +2248,9 @@ const upb_msglayout google_protobuf_GeneratedCodeInfo_Annotation_msginit = {
   {
     &fastdecode_generic,
     &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
-    &fastdecode_generic,
+    &upb_pss_1bt,
+    &upb_psv4_1bt,
+    &upb_psv4_1bt,
     &fastdecode_generic,
     &fastdecode_generic,
     &fastdecode_generic,
@@ -1474,7 +2280,38 @@ const upb_msglayout google_protobuf_GeneratedCodeInfo_Annotation_msginit = {
     &fastdecode_generic,
   },
   {
-    0
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(3377699721052178, 4503599627894802),
+    UPB_SIZE(1125899906973720, 1125899906973720),
+    UPB_SIZE(2251799813947424, 2251799813947424),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
+    UPB_SIZE(0, 0),
   },
   NULL,
   &google_protobuf_GeneratedCodeInfo_Annotation__fields[0],
diff --git a/tests/test_generated_code.c b/tests/test_generated_code.c
index c6f024a61f..c25f7cc8a1 100644
--- a/tests/test_generated_code.c
+++ b/tests/test_generated_code.c
@@ -47,8 +47,11 @@ static void test_scalars() {
   msg2 = protobuf_test_messages_proto3_TestAllTypesProto3_parse(
       serialized.data, serialized.size, arena);
 
+  ASSERT(msg2);
   ASSERT(protobuf_test_messages_proto3_TestAllTypesProto3_optional_int32(
              msg2) == 10);
+  fprintf(stderr, "optional_int64: %d\n", (int)protobuf_test_messages_proto3_TestAllTypesProto3_optional_int64(
+             msg2));
   ASSERT(protobuf_test_messages_proto3_TestAllTypesProto3_optional_int64(
              msg2) == 20);
   ASSERT(protobuf_test_messages_proto3_TestAllTypesProto3_optional_uint32(
diff --git a/upb/decode.c b/upb/decode.c
index 6e0779bf2a..8b87ed2a01 100644
--- a/upb/decode.c
+++ b/upb/decode.c
@@ -146,6 +146,11 @@ static const char *decode_msg(upb_decstate *d, const char *ptr, upb_msg *msg,
 
 UPB_NORETURN static void decode_err(upb_decstate *d) { longjmp(d->err, 1); }
 
+const char *fastdecode_err(upb_decstate *d) {
+  longjmp(d->err, 1);
+  return NULL;
+}
+
 void decode_verifyutf8(upb_decstate *d, const char *buf, int len) {
   static const uint8_t utf8_offset[] = {
       1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
@@ -596,8 +601,9 @@ UPB_NOINLINE
 const char *fastdecode_generic(upb_decstate *d, const char *ptr, upb_msg *msg,
                                const upb_msglayout *table, uint64_t hasbits,
                                uint64_t data) {
-  if (hasbits) *(uint32_t*)msg |= hasbits;  /* Sync hasbits. */
+  *(uint32_t*)msg |= hasbits >> 16;  /* Sync hasbits. */
   (void)data;
+  if (ptr == d->limit) return ptr;
   ptr = decode_field(d, ptr, msg, table);
   return fastdecode_dispatch(d, ptr, msg, table, hasbits);
 }
@@ -605,12 +611,7 @@ const char *fastdecode_generic(upb_decstate *d, const char *ptr, upb_msg *msg,
 UPB_NOINLINE
 static const char *decode_msg(upb_decstate *d, const char *ptr, upb_msg *msg,
                               const upb_msglayout *layout) {
-  while (1) {
-    ptr = fastdecode_dispatch(d, ptr, msg, layout, 0);
-    if (ptr == d->limit) break;
-    ptr = decode_field(d, ptr, msg, layout);
-  }
-
+  ptr = fastdecode_dispatch(d, ptr, msg, layout, 0);
   if (ptr != d->limit) decode_err(d);
   return ptr;
 }
diff --git a/upb/decode.h b/upb/decode.h
index 29194534b4..9a8473e026 100644
--- a/upb/decode.h
+++ b/upb/decode.h
@@ -18,13 +18,10 @@ bool upb_decode(const char *buf, size_t size, upb_msg *msg,
 
 /* Internal only: data pertaining to the parse. */
 typedef struct upb_decstate {
-  char *arena_ptr, *arena_end;
-  const void *rep_end;
   const char *limit;       /* End of delimited region or end of buffer. */
   const char *fastlimit;   /* End of delimited region or end of buffer. */
   const char *fastend;
   upb_array *arr;
-  _upb_field_parser *resume;
   upb_arena *arena;
   int depth;
   uint32_t end_group; /* Set to field number of END_GROUP tag, if any. */
@@ -36,6 +33,39 @@ const char *fastdecode_dispatch(upb_decstate *d, const char *ptr, upb_msg *msg,
 const char *fastdecode_generic(upb_decstate *d, const char *ptr, upb_msg *msg,
                                const upb_msglayout *table, uint64_t hasbits,
                                uint64_t data);
+const char *fastdecode_err(upb_decstate *d);
+
+#define UPB_PARSE_PARAMS                                                      \
+  upb_decstate *d, const char *ptr, upb_msg *msg, const upb_msglayout *table, \
+      uint64_t hasbits, uint64_t data
+
+#define F(card, type, valbytes, tagbytes) \
+  const char *upb_p##card##type##valbytes##_##tagbytes##bt(UPB_PARSE_PARAMS);
+
+#define TYPES(card, tagbytes) \
+  F(card, b, 1, tagbytes)     \
+  F(card, v, 4, tagbytes)     \
+  F(card, v, 8, tagbytes)     \
+  F(card, z, 4, tagbytes)     \
+  F(card, z, 8, tagbytes)
+
+#define TAGBYTES(card) \
+  TYPES(card, 1)       \
+  TYPES(card, 2)
+
+TAGBYTES(s)
+TAGBYTES(o)
+//TAGBYTES(r)
+
+const char *upb_pss_1bt(UPB_PARSE_PARAMS);
+const char *upb_pss_2bt(UPB_PARSE_PARAMS);
+const char *upb_pos_1bt(UPB_PARSE_PARAMS);
+const char *upb_pos_2bt(UPB_PARSE_PARAMS);
+
+#undef F
+#undef TYPES
+#undef TAGBYTES
+#undef UPB_PARSE_PARAMS
 
 #ifdef __cplusplus
 }  /* extern "C" */
diff --git a/upb/decode_fast.c b/upb/decode_fast.c
index 1b9e6ead3f..5a851f428f 100644
--- a/upb/decode_fast.c
+++ b/upb/decode_fast.c
@@ -9,28 +9,28 @@
 
 #define UPB_PARSE_ARGS d, ptr, msg, table, hasbits, data
 
+typedef enum {
+  CARD_s = 0,
+  CARD_o = 1,
+  CARD_r = 2,
+  CARD_p = 3
+} upb_card;
+
 UPB_NOINLINE
 const char *fastdecode_dispatch(upb_decstate *d, const char *ptr, upb_msg *msg,
                                 const upb_msglayout *table, uint64_t hasbits) {
   uint16_t tag;
-  uint64_t data;
+  uint64_t data = 0;;
   size_t idx;
-  if (UPB_UNLIKELY(ptr >= d->fastlimit)) return ptr;
+  if (UPB_UNLIKELY(ptr >= d->fastlimit)) {
+    return fastdecode_generic(UPB_PARSE_ARGS);
+  }
   memcpy(&tag, ptr, 2);
   idx = (tag & 0xf8) >> 3;
   data = table->field_data[idx] ^ tag;
   return table->field_parser[idx](UPB_PARSE_ARGS);
 }
 
-#if 0
-
-const char *fastdecode_err(upb_decstate *d);
-
-const char *fastdecode_reallocarr(upb_decstate *d, const char *ptr,
-                                  upb_msg *msg, upb_msglayout *table,
-                                  size_t needbytes);
-
-
 UPB_FORCEINLINE
 static bool fastdecode_checktag(uint64_t data, int tagbytes) {
   if (tagbytes == 1) {
@@ -40,337 +40,6 @@ static bool fastdecode_checktag(uint64_t data, int tagbytes) {
   }
 }
 
-UPB_FORCEINLINE
-bool fastdecode_boundscheck(const char *ptr, unsigned len, const char *end) {
-  uintptr_t uptr = (uintptr_t)ptr;
-  uintptr_t uend = (uintptr_t)end;
-  uintptr_t res = uptr + len;
-  return res < uptr || res > uend;
-}
-
-UPB_FORCEINLINE
-static bool fastdecode_readlongsize(const char *ptr, uint32_t *size,
-                                    const char **out) {
-  int i;
-  *size = ptr[0];
-  UPB_ASSERT(ptr[0] < 0);
-  for (i = 1; i < 5; i++) {
-    uint32_t byte = ptr[i];
-    (*size) += (byte - 1) << (7 * i);
-    if (UPB_LIKELY(byte < 128)) {
-      *out = ptr + i + 1;
-      return true;
-    }
-  }
-  return false;
-}
-
-UPB_FORCEINLINE
-static uint16_t fastdecode_readtag(const char *ptr, int tagbytes) {
-  uint16_t ret = 0;
-  memcpy(&ret, ptr, tagbytes);
-  return ret;
-}
-
-typedef enum {
-  CARD_s = 0,
-  CARD_o = 1,
-  CARD_r = 2,
-  CARD_p = 3
-} upb_card;
-
-UPB_FORCEINLINE
-static void *fastdecode_getfield(upb_decstate *d, const char *ptr, upb_msg *msg,
-                                 uint64_t *data, uint64_t *hasbits,
-                                 upb_card card, int tagbytes, int valbytes,
-                                 bool store_len) {
-  void *field = (char *)msg + (*data >> 48);
-
-  switch (card) {
-    case CARD_s:
-      *hasbits |= *data;
-      return field;
-    case CARD_o: {
-      uint32_t *case_ptr = UPB_PTR_AT(msg, (*data >> 16) & 0xffff, uint32_t);
-      *case_ptr = (*data >> 32) & 0xffff;
-      return field;
-    }
-    case CARD_r: {
-      upb_array **arr_p = field;
-      upb_array *arr;
-      uint64_t elem_avail;
-      uint16_t expected_tag;
-      *hasbits >>= 16;
-      *(uint32_t*)msg |= *hasbits;
-      *hasbits = 0;
-      if (UPB_LIKELY(!*arr_p)) {
-        size_t need = (valbytes * 4) + sizeof(upb_array);
-        if (UPB_UNLIKELY((size_t)(d->arena_end - d->arena_ptr) < need)) {
-          *data = 0;
-          return NULL;
-        }
-        arr = (void*)d->arena_ptr;
-        field = arr + 1;
-        arr->data = (uintptr_t)field;
-        *arr_p = arr;
-        arr->size = 4;
-        if (store_len) arr->len = 5;
-        elem_avail = 4;
-        d->arena_ptr += need;
-      } else {
-        arr = *arr_p;
-        field = _upb_array_ptr(arr);
-        elem_avail = arr->size - arr->len;
-        field = (char*)field + (arr->len * valbytes);
-        if (store_len) arr->len = arr->size + 1;
-      }
-      expected_tag = fastdecode_readtag(ptr, tagbytes);
-      *data = elem_avail | ((uint64_t)expected_tag << 32);
-      d->arr = arr;
-      return field;
-    }
-    default:
-      UPB_UNREACHABLE();
-  }
-}
-
-/* string fields **************************************************************/
-
-UPB_NOINLINE
-static const char *fastdecode_longstring(upb_decstate *d, const char *ptr,
-                                         upb_msg *msg, upb_msglayout *table,
-                                         uint64_t hasbits, upb_strview *dst) {
-  uint32_t len;
-  if (!fastdecode_readlongsize(ptr, &len, &ptr)) {
-    return fastdecode_err(d);
-  }
-  dst->data = ptr;
-  dst->size = len;
-  if (UPB_UNLIKELY(fastdecode_boundscheck(ptr, len, d->limit))) {
-    return fastdecode_err(d);
-  }
-  ptr += len;
-  return fastdecode_dispatch(d, ptr, msg, table, hasbits);
-}
-
-UPB_FORCEINLINE
-static const char *fastdecode_string(UPB_PARSE_PARAMS, int tagbytes,
-                                     upb_card card) {
-  upb_strview *dst;
-
-  if (UPB_UNLIKELY(!fastdecode_checktag(data, tagbytes))) {
-    return ptr;
-  }
-
-  dst = fastdecode_getfield(d, ptr, msg, &data, &hasbits, card, tagbytes,
-                            sizeof(upb_strview), true);
-
-again:
-  if (card == CARD_r) {
-    if (UPB_UNLIKELY((uint32_t)data == 0)) {
-      return fastdecode_reallocarr(d, ptr, msg, table, sizeof(upb_strview));
-    }
-  }
-
-  {
-    int64_t len = ptr[tagbytes];
-    if (UPB_UNLIKELY(len < 0)) {
-      if (card == CARD_r) {
-        d->arr->len -= (uint32_t)data;
-      }
-      return fastdecode_longstring(d, ptr, msg, table, hasbits, dst);
-    }
-    ptr += tagbytes + 1;
-    dst->data = ptr;
-    dst->size = len;
-    if (UPB_UNLIKELY(!fastdecode_boundscheck(ptr, len, d->limit))) {
-      return fastdecode_err(d);
-    }
-    ptr += len;
-  }
-
-
-  if (card == CARD_r) {
-    if (UPB_LIKELY(ptr < d->fastlimit) &&
-        fastdecode_readtag(ptr, tagbytes) == (uint16_t)(data >> 32)) {
-      data--;
-      dst++;
-      goto again;
-    }
-    d->arr->len -= (uint32_t)data;
-  }
-
-  return fastdecode_dispatch(d, ptr, msg, table, hasbits);
-}
-
-const char *upb_pss_1bt(UPB_PARSE_PARAMS) {
-  return fastdecode_string(UPB_PARSE_ARGS, 1, CARD_s);
-}
-
-const char *upb_pos_1bt(UPB_PARSE_PARAMS) {
-  return fastdecode_string(UPB_PARSE_ARGS, 1, CARD_o);
-}
-
-const char *upb_prs_1bt(UPB_PARSE_PARAMS) {
-  return fastdecode_string(UPB_PARSE_ARGS, 1, CARD_r);
-}
-
-const char *upb_pss_2bt(UPB_PARSE_PARAMS) {
-  return fastdecode_string(UPB_PARSE_ARGS, 2, CARD_s);
-}
-
-const char *upb_pos_2bt(UPB_PARSE_PARAMS) {
-  return fastdecode_string(UPB_PARSE_ARGS, 2, CARD_o);
-}
-
-const char *upb_prs_2bt(UPB_PARSE_PARAMS) {
-  return fastdecode_string(UPB_PARSE_ARGS, 2, CARD_r);
-}
-
-/* fixed fields ***************************************************************/
-
-UPB_FORCEINLINE
-static const char *fastdecode_fixed(UPB_PARSE_PARAMS, int tagbytes, int valbytes,
-                                    upb_card card, _upb_field_parser *fallback) {
-  char *dst;
-
-  if (UPB_UNLIKELY(!fastdecode_checktag(data, tagbytes))) {
-    if (fallback) {
-      // Patch data to amtch packed wiretype.
-      data ^= 0x2 ^ (valbytes == 4 ? 5 : 1);
-      return fallback(UPB_PARSE_ARGS);
-    } else {
-      return ptr;
-    }
-  }
-
-  dst = fastdecode_getfield(d, ptr, msg, &data, &hasbits, card, tagbytes,
-                            valbytes, true);
-
-again:
-  if (card == CARD_r) {
-    if (UPB_UNLIKELY((uint32_t)data == 0)) {
-      return fastdecode_reallocarr(d, ptr, msg, table, valbytes);
-    }
-  }
-
-  {
-    ptr += tagbytes;
-    memcpy(dst, ptr, valbytes);
-    ptr += valbytes;
-  }
-
-  if (card == CARD_r) {
-    if (UPB_LIKELY(ptr < d->fastlimit) &&
-        fastdecode_readtag(ptr, tagbytes) == (uint16_t)(data >> 32)) {
-      data--;
-      dst += valbytes;
-      goto again;
-    }
-    d->arr->len -= (uint32_t)data;
-  }
-
-  return fastdecode_dispatch(d, ptr, msg, table, hasbits);
-}
-
-UPB_NOINLINE
-const char *fastdecode_longfixedpacked(upb_decstate *d, const char *ptr,
-                                       upb_msg *msg, upb_msglayout *table,
-                                       uint64_t hasbits, void *dst);
-
-UPB_FORCEINLINE
-static const char *fastdecode_fixedpacked(UPB_PARSE_PARAMS, int tagbytes, int valbytes,
-                                          _upb_field_parser *fallback) {
-  char *dst;
-  char *end;
-  uint32_t len;
-
-  if (UPB_UNLIKELY(!fastdecode_checktag(data, tagbytes))) {
-    if (fallback) {
-      // Patch data to amtch packed wiretype.
-      data ^= 0x2 ^ (valbytes == 4 ? 5 : 1);
-      return fallback(UPB_PARSE_ARGS);
-    } else {
-      return ptr;
-    }
-  }
-
-  dst = fastdecode_getfield(d, ptr, msg, &data, &hasbits, CARD_r, tagbytes,
-                            valbytes, false);
-
-  len = ptr[tagbytes];
-  if (UPB_UNLIKELY(len < 0)) {
-    return fastdecode_longfixedpacked(d, ptr, msg, table, hasbits, dst);
-  }
-
-  if (UPB_UNLIKELY(len > (size_t)(uint32_t)data * valbytes)) {
-    return fastdecode_reallocarr(d, ptr, msg, table, len);
-  }
-
-  ptr += tagbytes;
-
-  if (UPB_UNLIKELY((len & (valbytes - 1)) != 0 || /* Non-multiple length. */
-                   fastdecode_boundscheck(ptr, len, d->limit))) {
-    return fastdecode_err(d);
-  }
-
-  end = dst + len;
-  d->arr->len += len / valbytes;
-
-  while (dst < end) {
-    memcpy(dst, ptr, valbytes);  /* Inline memcpy() loop */
-    dst += valbytes;
-    ptr += valbytes;
-  }
-
-  return fastdecode_dispatch(d, ptr, msg, table, hasbits);
-}
-
-UPB_NOINLINE
-const char *upb_prf8_1bt(UPB_PARSE_PARAMS);
-
-UPB_NOINLINE
-const char *upb_ppf8_1bt(UPB_PARSE_PARAMS) {
-  return fastdecode_fixedpacked(UPB_PARSE_ARGS, 1, 8, &upb_prf8_1bt);
-}
-
-UPB_NOINLINE
-const char *upb_psf8_1bt(UPB_PARSE_PARAMS) {
-  return fastdecode_fixed(UPB_PARSE_ARGS, 1, 8, CARD_s, NULL);
-}
-
-UPB_NOINLINE
-const char *upb_pof8_1bt(UPB_PARSE_PARAMS) {
-  return fastdecode_fixed(UPB_PARSE_ARGS, 1, 8, CARD_o, NULL);
-}
-
-UPB_NOINLINE
-const char *upb_prf8_1bt(UPB_PARSE_PARAMS) {
-  return fastdecode_fixed(UPB_PARSE_ARGS, 1, 8, CARD_r, &upb_ppf8_1bt);
-}
-
-// Generate all fixed functions.
-// {s,o,r,p} x {f4,f8} x {1bt,2bt}
-
-#define F(card, valbytes, tagbytes)                                           \
-  const char *upb_p##card##f##valbytes##_##tagbytes##bt(UPB_PARSE_PARAMS) {   \
-    return fastdecode_fixed(UPB_PARSE_ARGS, tagbytes, valbytes, CARD_##card); \
-  }
-
-#define TYPES(card, tagbytes) \
-  F(card, 4, tagbytes)        \
-  F(card, 8, tagbytes)
-
-#define TAGBYTES(card) \
-  TYPES(card, 1)       \
-  TYPES(card, 2)
-
-TAGBYTES(s)
-TAGBYTES(o)
-TAGBYTES(r)
-TAGBYTES(p)
-
-
 UPB_FORCEINLINE uint64_t fastdecode_munge(uint64_t val, int valbytes, bool zigzag) {
   if (valbytes == 1) {
     return val != 0;
@@ -387,155 +56,44 @@ UPB_FORCEINLINE uint64_t fastdecode_munge(uint64_t val, int valbytes, bool zigza
 }
 
 UPB_FORCEINLINE
-static const char *fastdecode_longvarint_impl(const char *ptr, void *field,
-                                              int valbytes) {
-  // The algorithm relies on sign extension to set all high bits when the varint
-  // continues. This way it can use "and" to aggregate in to the result.
-  const int8_t *p = (const int8_t*)(ptr);
-  int64_t res1 = *p;
-  uint64_t ones = res1;  // save the useful high bit 1's in res1
-  uint64_t byte;
-  int64_t res2, res3;
-  int sign_bit;
-
-  // However this requires the low bits after shifting to be 1's as well. On
-  // x86_64 a shld from a single register filled with enough 1's in the high
-  // bits can accomplish all this in one instruction. It so happens that res1
-  // has 57 high bits of ones, which is enough for the largest shift done.
-  assert(res1 >> 7 == -1);
+static void *fastdecode_getfield(upb_msg *msg, uint64_t *data,
+                                 uint64_t *hasbits, upb_card card) {
+  size_t ofs = (*data >> 48);
+  void *field = (char *)msg + ofs;
 
-#define SHLD(n) byte = ((byte << (n * 7)) | (ones >> (64 - (n * 7))))
-
-  // Micro benchmarks show a substantial improvement to capture the sign
-  // of the result in the case of just assigning the result of the shift
-  // (ie first 2 steps).
-#if defined(__GCC_ASM_FLAG_OUTPUTS__) && defined(__x86_64__)
-#define SHLD_SIGN(n)                  \
-  __asm__("shldq %3, %2, %1"              \
-      : "=@ccs"(sign_bit), "+r"(byte) \
-      : "r"(ones), "i"(n * 7))
-#else
-#define SHLD_SIGN(n)                \
-  do {                              \
-    SHLD(n);                        \
-    sign_bit = (int64_t)(byte) < 0; \
-  } while (0)
-#endif
-  byte = p[1];
-  SHLD_SIGN(1);
-  res2 = byte;
-  if (!sign_bit) goto done2;
-  byte = p[2];
-  SHLD_SIGN(2);
-  res3 = byte;
-  if (!sign_bit) goto done3;
-  byte = p[3];
-  SHLD(3);
-  res1 &= byte;
-  if (res1 >= 0) goto done4;
-  byte = p[4];
-  SHLD(4);
-  res2 &= byte;
-  if (res2 >= 0) goto done5;
-  byte = p[5];
-  SHLD(5);
-  res3 &= byte;
-  if (res3 >= 0) goto done6;
-  byte = p[6];
-  SHLD(6);
-  res1 &= byte;
-  if (res1 >= 0) goto done7;
-  byte = p[7];
-  SHLD(7);
-  res2 &= byte;
-  if (res2 >= 0) goto done8;
-  byte = p[8];
-  SHLD(8);
-  res3 &= byte;
-  if (res3 >= 0) goto done9;
-  byte = p[9];
-  // Last byte only contains 0 or 1 for valid 64bit varints. If it's 0 it's
-  // a denormalized varint that shouldn't happen. The continuation bit of byte
-  // 9 has already the right value hence just expect byte to be 1.
-  if (UPB_LIKELY(byte == 1)) goto done10;
-  if (byte == 0) {
-    res3 ^= (uint64_t)(1) << 63;
-    goto done10;
+  switch (card) {
+    case CARD_s:
+      *hasbits |= *data;
+      return field;
+    case CARD_o: {
+      uint32_t *case_ptr = UPB_PTR_AT(msg, (*data >> 16) & 0xffff, uint32_t);
+      *case_ptr = (*data >> 32) & 0xffff;
+      return field;
+    }
+    case CARD_r:
+      UPB_ASSERT(false);  /* NYI */
+    default:
+      UPB_UNREACHABLE();
   }
-
-  return NULL;  // Value is too long to be a varint64
-
-#define DONE(n)                        \
-  done##n : {                          \
-    uint64_t val = res1 & res2 & res3; \
-    memcpy(field, &val, valbytes);     \
-    return (const char *)p + n;        \
-  };
-
-done2 : {
-  uint64_t val = res1 & res2;
-  memcpy(field, &val, valbytes);
-  return (const char*)p + 2;
-}
-
-  DONE(3)
-  DONE(4)
-  DONE(5)
-  DONE(6)
-  DONE(7)
-  DONE(8)
-  DONE(9)
-  DONE(10)
-
-#undef DONE
-#undef SHLD
-#undef SHLD_SIGN
 }
 
-UPB_NOINLINE
-static const char *fastdecode_longvarint32(UPB_PARSE_PARAMS) {
-  (void)d;
-  (void)msg;
-  (void)table;
-  (void)hasbits;
-  return fastdecode_longvarint_impl(ptr, (void*)data, 4);
-}
-
-UPB_NOINLINE
-static const char *fastdecode_longvarint64(UPB_PARSE_PARAMS) {
-  (void)d;
-  (void)msg;
-  (void)table;
-  (void)hasbits;
-  return fastdecode_longvarint_impl(ptr, (void*)data, 8);
-}
-
-UPB_FORCEINLINE
-static const char *fastdecode_longvarint(UPB_PARSE_PARAMS, int valbytes) {
-  if (valbytes == 4) {
-    return fastdecode_longvarint32(UPB_PARSE_ARGS);
-  } else if (valbytes == 8) {
-    return fastdecode_longvarint64(UPB_PARSE_ARGS);
-  }
-  UPB_UNREACHABLE();
-}
+/* varint fields **************************************************************/
 
 UPB_FORCEINLINE
 static const char *fastdecode_varint(UPB_PARSE_PARAMS, int tagbytes,
-                                     int valbytes, bool zigzag, bool oneof) {
+                                     int valbytes, upb_card card, bool zigzag) {
   uint64_t val = 0;
-  void *field;
-  if (UPB_UNLIKELY(!fastdecode_checktag(data, tagbytes))) return ptr;
-  ptr += tagbytes;
-  fastdecode_getfield(msg, data, &hasbits, oneof);
-  field = (char*)msg + (data >> 48);
-  if (UPB_UNLIKELY(*ptr < 0)) {
-    return fastdecode_longvarint(d, ptr, msg, table, hasbits, (uint64_t)field,
-                                 valbytes);
+  void *dst;
+  if (UPB_UNLIKELY(!fastdecode_checktag(data, tagbytes))) {
+    return fastdecode_generic(UPB_PARSE_ARGS);;
   }
-  val = fastdecode_munge(*ptr, valbytes, zigzag);
-  memcpy(field, &val, valbytes);
-  return fastdecode_dispatch(d, ptr + 1, msg, table, hasbits);
+  dst = fastdecode_getfield(msg, &data, &hasbits, card);
+  if (UPB_UNLIKELY(ptr[tagbytes] < 0)) {
+    return fastdecode_generic(UPB_PARSE_ARGS);
+  }
+  val = fastdecode_munge(ptr[tagbytes], valbytes, zigzag);
+  memcpy(dst, &val, valbytes);
+  return fastdecode_dispatch(d, ptr + tagbytes + 1, msg, table, hasbits);
 }
 
 // Generate all varint functions.
@@ -547,8 +105,8 @@ static const char *fastdecode_varint(UPB_PARSE_PARAMS, int tagbytes,
 
 #define F(card, type, valbytes, tagbytes)                                      \
   const char *upb_p##card##type##valbytes##_##tagbytes##bt(UPB_PARSE_PARAMS) { \
-    return fastdecode_varint(UPB_PARSE_ARGS, tagbytes, valbytes, type##_ZZ,    \
-                             card##_ONEOF);                                    \
+    return fastdecode_varint(UPB_PARSE_ARGS, tagbytes, valbytes, CARD_##card,  \
+                             type##_ZZ);                                       \
   }
 
 #define TYPES(card, tagbytes) \
@@ -564,7 +122,7 @@ static const char *fastdecode_varint(UPB_PARSE_PARAMS, int tagbytes,
 
 TAGBYTES(s)
 TAGBYTES(o)
-TAGBYTES(r)
+//TAGBYTES(r)
 
 #undef z_ZZ
 #undef b_ZZ
@@ -576,4 +134,52 @@ TAGBYTES(r)
 #undef TYPES
 #undef TAGBYTES
 
-#endif
+/* string fields **************************************************************/
+
+UPB_FORCEINLINE
+bool fastdecode_boundscheck(const char *ptr, unsigned len, const char *end) {
+  uintptr_t uptr = (uintptr_t)ptr;
+  uintptr_t uend = (uintptr_t)end;
+  uintptr_t res = uptr + len;
+  return res < uptr || res > uend;
+}
+
+UPB_FORCEINLINE
+static const char *fastdecode_string(UPB_PARSE_PARAMS, int tagbytes,
+                                     upb_card card) {
+  upb_strview *dst;
+  int64_t len;
+  if (UPB_UNLIKELY(!fastdecode_checktag(data, tagbytes))) {
+    return fastdecode_generic(UPB_PARSE_ARGS);
+  }
+
+  dst = fastdecode_getfield(msg, &data, &hasbits, card);
+  len = ptr[tagbytes];
+  if (UPB_UNLIKELY(len < 0)) {
+    return fastdecode_generic(UPB_PARSE_ARGS);
+  }
+  ptr += tagbytes + 1;
+  dst->data = ptr;
+  dst->size = len;
+  if (UPB_UNLIKELY(fastdecode_boundscheck(ptr, len, d->limit))) {
+    return fastdecode_err(d);
+  }
+  ptr += len;
+  return fastdecode_dispatch(d, ptr, msg, table, hasbits);
+}
+
+const char *upb_pss_1bt(UPB_PARSE_PARAMS) {
+  return fastdecode_string(UPB_PARSE_ARGS, 1, CARD_s);
+}
+
+const char *upb_pos_1bt(UPB_PARSE_PARAMS) {
+  return fastdecode_string(UPB_PARSE_ARGS, 1, CARD_o);
+}
+
+const char *upb_pss_2bt(UPB_PARSE_PARAMS) {
+  return fastdecode_string(UPB_PARSE_ARGS, 2, CARD_s);
+}
+
+const char *upb_pos_2bt(UPB_PARSE_PARAMS) {
+  return fastdecode_string(UPB_PARSE_ARGS, 2, CARD_o);
+}
diff --git a/upbc/generator.cc b/upbc/generator.cc
index cd247a2ad7..6fd1c85451 100644
--- a/upbc/generator.cc
+++ b/upbc/generator.cc
@@ -703,6 +703,101 @@ int TableDescriptorType(const protobuf::FieldDescriptor* field) {
   }
 }
 
+typedef std::pair<std::string, MessageLayout::Size> TableEntry;
+
+void TryFillTableEntry(const protobuf::Descriptor* message,
+                       const MessageLayout& layout, int num, TableEntry& ent) {
+  const protobuf::FieldDescriptor* field = message->FindFieldByNumber(num);
+  if (!field) return;
+
+  std::string type = "";
+  std::string cardinality = "";
+  uint8_t wire_type = 0;
+  switch (field->type()) {
+    case protobuf::FieldDescriptor::TYPE_BOOL:
+      type = "b1";
+      break;
+    case protobuf::FieldDescriptor::TYPE_INT32:
+    case protobuf::FieldDescriptor::TYPE_ENUM:
+    case protobuf::FieldDescriptor::TYPE_UINT32:
+      type = "v4";
+      break;
+    case protobuf::FieldDescriptor::TYPE_INT64:
+    case protobuf::FieldDescriptor::TYPE_UINT64:
+      type = "v8";
+      break;
+    case protobuf::FieldDescriptor::TYPE_SINT32:
+      type = "z4";
+      break;
+    case protobuf::FieldDescriptor::TYPE_SINT64:
+      type = "z8";
+      break;
+    case protobuf::FieldDescriptor::TYPE_STRING:
+    case protobuf::FieldDescriptor::TYPE_BYTES:
+      type = "s";
+      wire_type = 2;
+      break;
+    default:
+      return;  // Not supported yet.
+  }
+
+  switch (field->label()) {
+    case protobuf::FieldDescriptor::LABEL_REPEATED:
+      return;  // Not supported yet.
+    case protobuf::FieldDescriptor::LABEL_OPTIONAL:
+    case protobuf::FieldDescriptor::LABEL_REQUIRED:
+      if (field->real_containing_oneof()) {
+        cardinality = "o";
+      } else {
+        cardinality = "s";
+      }
+      break;
+  }
+
+  uint16_t expected_tag = (num << 3) | wire_type;
+  if (num > 15) num |= 0x100;
+  MessageLayout::Size offset = layout.GetFieldOffset(field);
+
+  MessageLayout::Size data;
+  data.size32 = ((uint64_t)offset.size32 << 48) | expected_tag;
+  data.size64 = ((uint64_t)offset.size64 << 48) | expected_tag;
+
+  if (field->real_containing_oneof()) {
+    MessageLayout::Size case_ofs =
+        layout.GetOneofCaseOffset(field->real_containing_oneof());
+    data.size32 |= ((uint64_t)num << 32) | (case_ofs.size32 << 16);
+    data.size64 |= ((uint64_t)num << 32) | (case_ofs.size64 << 16);
+  } else {
+    uint32_t hasbit_mask = 0;
+
+    if (layout.HasHasbit(field)) {
+      int index = layout.GetHasbitIndex(field);
+      if (index > 31) return;
+      hasbit_mask = 1 << index;
+    }
+
+    data.size32 |= (uint64_t)hasbit_mask << 16;
+    data.size64 |= (uint64_t)hasbit_mask << 16;
+  }
+
+  ent.first = absl::Substitute("upb_p$0$1_$2bt", cardinality, type,
+                               (num < 15) ? "1" : "2");
+  ent.second = data;
+}
+
+std::vector<TableEntry> FastDecodeTable(const protobuf::Descriptor* message,
+                                        const MessageLayout& layout) {
+  std::vector<TableEntry> table;
+  MessageLayout::Size empty_size;
+  empty_size.size32 = 0;
+  empty_size.size64 = 0;
+  for (int i = 0; i < 32; i++) {
+    table.emplace_back(TableEntry{"fastdecode_generic", empty_size});
+    TryFillTableEntry(message, layout, i, table.back());
+  }
+  return table;
+}
+
 void WriteSource(const protobuf::FileDescriptor* file, Output& output) {
   EmitFileWarning(file, output);
 
@@ -803,14 +898,18 @@ void WriteSource(const protobuf::FileDescriptor* file, Output& output) {
       output("};\n\n");
     }
 
+    std::vector<TableEntry> table = FastDecodeTable(message, layout);
+
     output("const upb_msglayout $0 = {\n", MessageInit(message));
     output("  {\n");
-    for (int i = 0; i < 32; i++) {
-      output("    &fastdecode_generic,\n");
+    for (const auto& ent : table) {
+      output("    &$0,\n", ent.first);
     }
     output("  },\n");
     output("  {\n");
-    output("    0\n");
+    for (const auto& ent : table) {
+      output("    $0,\n", GetSizeInit(ent.second));
+    }
     output("  },\n");
     output("  $0,\n", submsgs_array_ref);
     output("  $0,\n", fields_array_ref);