| Right now there is no documentation for the GCC tree -> rtl interfaces |
| (or more generally the interfaces for adding new languages). |
| |
| Such documentation would be of great benefit to the project. Until such |
| time as we can formally start documenting the interface this file will |
| serve as a repository for information on these interface and any incompatible |
| changes we've made. |
| |
| 2004-09-09: |
| In an effort to decrease execution time, single char tree code |
| classes were changed to enumerated values. |
| |
| Old way: |
| |
| DEFTREECODE (CLASS_METHOD_DECL, "class_method_decl", 'd', 0) |
| |
| New way: |
| |
| DEFTREECODE (CLASS_METHOD_DECL, "class_method_decl", tcc_declaration, 0) |
| |
| 2001-02-26: |
| A DECL_INITIAL of NULL_TREE or error_mark_node in a VAR_DECL is no longer |
| taken to signify a tentative definition which should not be emitted until |
| end-of-file. Frontends which want that behavior should set |
| DECL_DEFER_OUTPUT before calling rest_of_decl_compilation. |
| |
| Feb 1, 1998: |
| |
| GCC used to store structure sizes & offsets to elements as bitsize |
| quantities. This causes problems because a structure can only be |
| (target memsize / 8) bytes long (this may effect arrays too). This |
| is particularly problematical on machines with small address spaces. |
| |
| So: |
| |
| All trees that represent sizes in bits should have a TREE_TYPE of |
| bitsizetype (rather than sizetype). |
| |
| Accordingly, when such values are computed / initialized, care has to |
| be takes to use / compute the proper type. |
| |
| When a size in bits is converted into a size in bytes, which is expressed |
| in trees, care should be taken to change the tree's type again to sizetype. |
| |
| ?? 1997: |
| |
| In an effort to decrease cache thrashing and useless loads we've changed the |
| third argument to the DEFTREECODE macro to be a single char. This will |
| affect languages that defined their own tree codes (usually in a .def file). |
| |
| Old way: |
| |
| DEFTREECODE (CLASS_METHOD_DECL, "class_method_decl", "d", 0) |
| |
| New way: |
| |
| DEFTREECODE (CLASS_METHOD_DECL, "class_method_decl", 'd', 0) |
| |
| |
| Copyright (C) 1998-2019 Free Software Foundation, Inc. |
| |
| Copying and distribution of this file, with or without modification, |
| are permitted in any medium without royalty provided the copyright |
| notice and this notice are preserved. |