diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 058eb16400029..4cd42efe5a69c 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -38,9 +38,14 @@ jobs:
         make -j4
         make install
 
+    - name: Test libgccjit
+      run: |
+        cd gcc
+        make check-jit -j4
+
     - name: Build Debian package
       run: |
-        cd ..
+        cd ../..
         mkdir install/DEBIAN
         cat > install/DEBIAN/control << EOF
         Package: gcc-15
diff --git a/contrib/download_prerequisites b/contrib/download_prerequisites
index b83fcc9db5dde..ce7efe1d1edc9 100755
--- a/contrib/download_prerequisites
+++ b/contrib/download_prerequisites
@@ -33,7 +33,11 @@ mpc='mpc-1.2.1.tar.gz'
 isl='isl-0.24.tar.bz2'
 gettext='gettext-0.22.tar.gz'
 
-base_url='http://gcc.gnu.org/pub/gcc/infrastructure/'
+#base_url='http://gcc.gnu.org/pub/gcc/infrastructure/'
+# We use rust-lang mirrors because the GCC infrastructure is unreliable.
+# When dependencies are changed, we have to modify our mirrors.
+# Please contact t-infra for that.
+base_url='https://ci-mirrors.rust-lang.org/rustc/gcc/'
 
 echo_archives() {
     echo "${gettext}"
diff --git a/gcc/config/i386/i386-rust-and-jit.inc b/gcc/config/i386/i386-rust-and-jit.inc
index 998f44cfa3f52..0a701a0ba179e 100644
--- a/gcc/config/i386/i386-rust-and-jit.inc
+++ b/gcc/config/i386/i386-rust-and-jit.inc
@@ -91,3 +91,5 @@ if (TARGET_CMPXCHG16B)
   ADD_TARGET_INFO ("target_feature", "cmpxchg16b");
 if (TARGET_MOVBE)
   ADD_TARGET_INFO ("target_feature", "movbe");
+if (TARGET_80387)
+  ADD_TARGET_INFO ("target_feature", "x87");
diff --git a/gcc/jit/jit-playback.cc b/gcc/jit/jit-playback.cc
index 347f9f9a78278..6901c24b14ddf 100644
--- a/gcc/jit/jit-playback.cc
+++ b/gcc/jit/jit-playback.cc
@@ -583,6 +583,10 @@ const char* fn_attribute_to_string (gcc_jit_fn_attribute attr)
       return "weak";
     case GCC_JIT_FN_ATTRIBUTE_NONNULL:
       return "nonnull";
+    case GCC_JIT_FN_ATTRIBUTE_MS_ABI:
+      return "ms_abi";
+    case GCC_JIT_FN_ATTRIBUTE_SYSV_ABI:
+      return "sysv_abi";
     case GCC_JIT_FN_ATTRIBUTE_MAX:
       return NULL;
   }
diff --git a/gcc/jit/jit-recording.cc b/gcc/jit/jit-recording.cc
index 4ac5d6b602f0a..b842d901c2eaf 100644
--- a/gcc/jit/jit-recording.cc
+++ b/gcc/jit/jit-recording.cc
@@ -2671,7 +2671,7 @@ recording::memento_of_get_type::get_size ()
       break;
     case GCC_JIT_TYPE_FLOAT:
       m = targetm.c.mode_for_floating_type (TI_FLOAT_TYPE);
-      size = GET_MODE_PRECISION (m).to_constant ();
+      size = GET_MODE_UNIT_SIZE (m) * BITS_PER_UNIT;
       break;
 #ifdef HAVE_BFmode
     case GCC_JIT_TYPE_BFLOAT16:
@@ -2679,11 +2679,11 @@ recording::memento_of_get_type::get_size ()
 #endif
     case GCC_JIT_TYPE_DOUBLE:
       m = targetm.c.mode_for_floating_type (TI_DOUBLE_TYPE);
-      size = GET_MODE_PRECISION (m).to_constant ();
+      size = GET_MODE_UNIT_SIZE (m) * BITS_PER_UNIT;
       break;
     case GCC_JIT_TYPE_LONG_DOUBLE:
       m = targetm.c.mode_for_floating_type (TI_LONG_DOUBLE_TYPE);
-      size = GET_MODE_PRECISION (m).to_constant ();
+      size = GET_MODE_UNIT_SIZE (m) * BITS_PER_UNIT;
       break;
     case GCC_JIT_TYPE_FLOAT16:
       size = 16;
@@ -4954,6 +4954,8 @@ static const char * const fn_attribute_reproducer_strings[] =
   "GCC_JIT_FN_ATTRIBUTE_CONST",
   "GCC_JIT_FN_ATTRIBUTE_WEAK",
   "GCC_JIT_FN_ATTRIBUTE_NONNULL",
+  "GCC_JIT_FN_ATTRIBUTE_MS_ABI",
+  "GCC_JIT_FN_ATTRIBUTE_SYSV_ABI",
 };
 
 std::string
diff --git a/gcc/jit/libgccjit.h b/gcc/jit/libgccjit.h
index 9ecd201c4d0cd..17bd85f920f2d 100644
--- a/gcc/jit/libgccjit.h
+++ b/gcc/jit/libgccjit.h
@@ -2169,6 +2169,10 @@ enum gcc_jit_fn_attribute
   GCC_JIT_FN_ATTRIBUTE_WEAK,
   GCC_JIT_FN_ATTRIBUTE_NONNULL,
 
+  // x86 attributes.
+  GCC_JIT_FN_ATTRIBUTE_MS_ABI,
+  GCC_JIT_FN_ATTRIBUTE_SYSV_ABI,
+
   /* Maximum value of this enum, should always be last. */
   GCC_JIT_FN_ATTRIBUTE_MAX,
 };