f8dac6eb3f
* expr.c (get_inner_reference): Use sbitsizetype for type sizes.
* fold-const.c (size_int): Replace with
(size_int_wide).
(make_bit_field_ref): Use bitsize_int for bit position.
* stor-layout.c (sizetype): Delete.
(sizetype_tab, sbitsizetype, ubitsizetype): Declare.
(layout_record, layout_union, layout_type):
Use bitsize_int for bit size.
(set_sizetype): New function.
(make_signed_type, make_unsigned_type): Use it.
* c-decl.c (init_decl_processing): Likewise.
* tree.h (size_int): Don't delcare, #define.
(size_int_wide, sizetype_tab, sbitsize, ubitsize): Declare.
(set_sizetype): Declare.
(bitsize_int, size_int_2, BITS_PER_UNIT_LOG, sizetype, bitsizetype):
Define.
* c-typeck.c (c_sizeof, c_sizeof_nowarn, c_size_in_bytes):
Convert result to sizetype.
(really_start_incremental_init, push_init_level):
Set type of constructor_bit_index to sbitsizetype.
(push_init_level): Use unsigned arithmetic to determine padding.
(output_init_element): Likewise.
From-SVN: r17577
33 lines
1.2 KiB
Plaintext
33 lines
1.2 KiB
Plaintext
Right now there is no documentation for the GCC tree -> rtl interfaces
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(or more generally the interfaces for adding new languages).
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Such documentation would be of great benefit to the project. Until such
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time as we can formally start documenting the interface this file will
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serve as a repository for information on these interface and any incompatable
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changes we've made.
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Feb 1, 1998:
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GCC used to store structure sizes & offsets to elements as bitsize
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quantities. This causes problems because a structure can only be
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(target memsize / 8) bytes long (this may effect arrays too). This
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is particularly problematical on machines with small address spaces.
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So:
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All trees that represent sizes in bits should have a TREE_TYPE of
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bitsizetype (rather than sizetype).
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Accordingly, when such values are computed / initialized, care has to
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be takes to use / compute the proper type.
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When a size in bits is converted into a size in bytes, which is expressed
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in trees, care should be taken to change the tree's type again to sizetype.
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We've updated C, C++, Fortran & Objective-C to work with the new
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scheme. Other languages will need to be updated accordingly.
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Contact amylaar@cygnus.com for additional information.
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