LANGUAGES revision 1.1.1.1.4.2
1 1.1.1.1.4.2 yamt Right now there is no documentation for the GCC tree -> rtl interfaces 2 1.1.1.1.4.2 yamt (or more generally the interfaces for adding new languages). 3 1.1.1.1.4.2 yamt 4 1.1.1.1.4.2 yamt Such documentation would be of great benefit to the project. Until such 5 1.1.1.1.4.2 yamt time as we can formally start documenting the interface this file will 6 1.1.1.1.4.2 yamt serve as a repository for information on these interface and any incompatable 7 1.1.1.1.4.2 yamt changes we've made. 8 1.1.1.1.4.2 yamt 9 1.1.1.1.4.2 yamt 2004-09-09: 10 1.1.1.1.4.2 yamt In an effort to decrease execution time, single char tree code 11 1.1.1.1.4.2 yamt classes were changed to enumerated values. 12 1.1.1.1.4.2 yamt 13 1.1.1.1.4.2 yamt Old way: 14 1.1.1.1.4.2 yamt 15 1.1.1.1.4.2 yamt DEFTREECODE (CLASS_METHOD_DECL, "class_method_decl", 'd', 0) 16 1.1.1.1.4.2 yamt 17 1.1.1.1.4.2 yamt New way: 18 1.1.1.1.4.2 yamt 19 1.1.1.1.4.2 yamt DEFTREECODE (CLASS_METHOD_DECL, "class_method_decl", tcc_declaration, 0) 20 1.1.1.1.4.2 yamt 21 1.1.1.1.4.2 yamt 2001-02-26: 22 1.1.1.1.4.2 yamt A DECL_INITIAL of NULL_TREE or error_mark_node in a VAR_DECL is no longer 23 1.1.1.1.4.2 yamt taken to signify a tentative definition which should not be emitted until 24 1.1.1.1.4.2 yamt end-of-file. Frontends which want that behavior should set 25 1.1.1.1.4.2 yamt DECL_DEFER_OUTPUT before calling rest_of_decl_compilation. 26 1.1.1.1.4.2 yamt 27 1.1.1.1.4.2 yamt Feb 1, 1998: 28 1.1.1.1.4.2 yamt 29 1.1.1.1.4.2 yamt GCC used to store structure sizes & offsets to elements as bitsize 30 1.1.1.1.4.2 yamt quantities. This causes problems because a structure can only be 31 1.1.1.1.4.2 yamt (target memsize / 8) bytes long (this may effect arrays too). This 32 1.1.1.1.4.2 yamt is particularly problematical on machines with small address spaces. 33 1.1.1.1.4.2 yamt 34 1.1.1.1.4.2 yamt So: 35 1.1.1.1.4.2 yamt 36 1.1.1.1.4.2 yamt All trees that represent sizes in bits should have a TREE_TYPE of 37 1.1.1.1.4.2 yamt bitsizetype (rather than sizetype). 38 1.1.1.1.4.2 yamt 39 1.1.1.1.4.2 yamt Accordingly, when such values are computed / initialized, care has to 40 1.1.1.1.4.2 yamt be takes to use / compute the proper type. 41 1.1.1.1.4.2 yamt 42 1.1.1.1.4.2 yamt When a size in bits is converted into a size in bytes, which is expressed 43 1.1.1.1.4.2 yamt in trees, care should be taken to change the tree's type again to sizetype. 44 1.1.1.1.4.2 yamt 45 1.1.1.1.4.2 yamt ?? 1997: 46 1.1.1.1.4.2 yamt 47 1.1.1.1.4.2 yamt In an effort to decrease cache thrashing and useless loads we've changed the 48 1.1.1.1.4.2 yamt third argument to the DEFTREECODE macro to be a single char. This will 49 1.1.1.1.4.2 yamt affect languages that defined their own tree codes (usually in a .def file). 50 1.1.1.1.4.2 yamt 51 1.1.1.1.4.2 yamt Old way: 52 1.1.1.1.4.2 yamt 53 1.1.1.1.4.2 yamt DEFTREECODE (CLASS_METHOD_DECL, "class_method_decl", "d", 0) 54 1.1.1.1.4.2 yamt 55 1.1.1.1.4.2 yamt New way: 56 1.1.1.1.4.2 yamt 57 1.1.1.1.4.2 yamt DEFTREECODE (CLASS_METHOD_DECL, "class_method_decl", 'd', 0) 58 1.1.1.1.4.2 yamt 59 1.1.1.1.4.2 yamt 61 1.1.1.1.4.2 yamt Copyright (C) 1998, 2001, 2002, 2004 Free Software Foundation, Inc. 62 1.1.1.1.4.2 yamt 63 1.1.1.1.4.2 yamt Copying and distribution of this file, with or without modification, 64 1.1.1.1.4.2 yamt are permitted in any medium without royalty provided the copyright 65 notice and this notice are preserved. 66
Indexes created Mon Aug 10 00:24:53 UTC 2026