PATCH to cp/ir.texi: Document complex numbers

[Gabriel Dos Reis]

This patchlet documents __complex__ and related macros and data types
inside gcc/g++.  OK?

-- Gaby
CodeSourcery, LLC                             http://www.codesourcery.com


2000-04-22  Gabriel Dos Reis <gdr@codesourcery.com>

	* ir.texi:  Document complex number representation.

Index: ir.texi
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/ir.texi,v
retrieving revision 1.26
diff -p -r1.26 ir.texi
*** ir.texi	2000/02/17 20:45:49	1.26
--- ir.texi	2000/04/21 22:03:44
*************** double} types.  The number of bits in th
*** 442,448 ****
  is given by @code{TYPE_PRECISION}, as in the @code{INTEGER_TYPE} case.
  
  @item COMPLEX_TYPE
! FIXME: The __complex__ extension is supported in G++.  Document.
  
  @item ENUMERAL_TYPE
  Used to represent an enumeration type.  The @code{TYPE_PRECISION} gives
--- 442,449 ----
  is given by @code{TYPE_PRECISION}, as in the @code{INTEGER_TYPE} case.
  
  @item COMPLEX_TYPE
! Used to represent GCC builtin @code{__complex__} data types.  The 
! @code{TREE_TYPE} is the type of the real and imaginary parts.
  
  @item ENUMERAL_TYPE
  Used to represent an enumeration type.  The @code{TYPE_PRECISION} gives
*************** The @code{WHILE_BODY} is the body of the
*** 1459,1464 ****
--- 1460,1466 ----
  @findex tree_int_cst_lt
  @findex tree_int_cst_equal
  @tindex REAL_CST
+ @tindex COMPLEX_CST
  @tindex STRING_CST
  @findex TREE_STRING_LENGTH
  @findex TREE_STRING_POINTER
*************** The @code{WHILE_BODY} is the body of the
*** 1473,1478 ****
--- 1475,1484 ----
  @tindex INDIRECT_REF
  @tindex FIX_TRUNC_EXPR
  @tindex FLOAT_EXPR
+ @tindex COMPLEX_EXPR
+ @tindex CONJ_EXPR
+ @tindex REALPART_EXPR
+ @tindex IMAGPART_EXPR
  @tindex NOP_EXPR
  @tindex CONVERT_EXPR
  @tindex THROW_EXPR
*************** its bit-pattern.
*** 1591,1596 ****
--- 1597,1608 ----
  FIXME: Talk about how to obtain representations of this constant, do
  comparisons, and so forth.
  
+ @item COMPLEX_CST
+ These nodes are used to represent complex number constants, that is a
+ @code{__complex__} whose parts are constant nodes.  The 
+ @code{TREE_REALPART} (resp. @code@TREE_IMAGPART}) returns the real part
+ (resp. the imaginary part).
+ 
  @item STRING_CST
  These nodes represent string-constants.  The @code{TREE_STRING_LENGTH}
  returns the length of the string, as an @code{int}.  The
*************** the complete expression will have a floa
*** 1681,1686 ****
--- 1693,1711 ----
  
  FIXME: How is the operand supposed to be rounded?  Is this dependent on
  -mieee?
+ 
+ @item COMPLEX_EXPR
+ These nodes are used to represent complex numbers constructed from two
+ expressions of the same (integer or real) type.  The first operand is the
+ real part and the second operand is the imaginary part.
+ 
+ @item CONJ_EXPR
+ These nodes represent the conjugate of their operand.
+ 
+ @item REALPART_EXPR
+ @item IMAGPART_EXPR
+ These nodes represent respectively the real and the imaginary parts
+ of complex numbers (their sole argument).
  
  @item NON_LVALUE_EXPR
  These nodes indicate that their one and only operand is not an lvalue.