Index: native_client_sdk/src/doc/reference/pnacl-c-cpp-language-support.rst |
diff --git a/native_client_sdk/src/doc/reference/pnacl-c-cpp-language-support.rst b/native_client_sdk/src/doc/reference/pnacl-c-cpp-language-support.rst |
index b147cca150f2bae078811640da8915b85cb6536e..03c4ff105c986752f399038ccfde58f447ef45af 100644 |
--- a/native_client_sdk/src/doc/reference/pnacl-c-cpp-language-support.rst |
+++ b/native_client_sdk/src/doc/reference/pnacl-c-cpp-language-support.rst |
@@ -225,6 +225,19 @@ mostly IEEE-754 compliant. There are a few caveats: |
currently doesn't, use hardware support if fast-math were provided |
in the *pexe*. |
+Computed ``goto`` |
+================= |
+ |
+PNaCl supports computed ``goto``, a non-standard GCC extension to C used |
+by some interpreters, by lowering them to ``switch`` statements. The |
+resulting use of ``switch`` might not be as fast as the original |
+indirect branches. If you are compiling a program that has a |
+compile-time option for using computed ``goto``, it's possible that the |
+program will run faster with the option turned off (e.g., if the program |
+does extra work to take advantage of computed ``goto``). |
+ |
+NaCl supports computed ``goto`` without any transformation. |
+ |
Future Directions |
================= |
@@ -273,11 +286,3 @@ POSIX-style signal handling really consists of two different features: |
If PNaCl were to support either of these, the interaction of |
``volatile`` and atomics with same-thread signal handling would need |
to be carefully detailed. |
- |
-Computed ``goto`` |
------------------ |
- |
-PNaCl currently doesn't support computed ``goto``, a non-standard |
-extension to C used by some interpreters. |
- |
-NaCl supports computed ``goto``. |