1 @c Copyright (C) 2007-2014 Free Software Foundation, Inc. 2 @c This is part of the GAS manual. 3 @c For copying conditions, see the file as.texinfo. 4 5 @ifset GENERIC 6 @page 7 @node CR16-Dependent 8 @chapter CR16 Dependent Features 9 @end ifset 10 @ifclear GENERIC 11 @node Machine Dependencies 12 @chapter CR16 Dependent Features 13 @end ifclear 14 15 @cindex CR16 support 16 @menu 17 * CR16 Operand Qualifiers:: CR16 Machine Operand Qualifiers 18 * CR16 Syntax:: Syntax for the CR16 19 @end menu 20 21 @node CR16 Operand Qualifiers 22 @section CR16 Operand Qualifiers 23 @cindex CR16 Operand Qualifiers 24 25 The National Semiconductor CR16 target of @code{@value{AS}} has a few machine dependent operand qualifiers. 26 27 Operand expression type qualifier is an optional field in the instruction operand, to determines the type of the expression field of an operand. The @code{@@} is required. CR16 architecture uses one of the following expression qualifiers: 28 29 @table @code 30 @item s 31 - @code{Specifies expression operand type as small} 32 @item m 33 - @code{Specifies expression operand type as medium} 34 @item l 35 - @code{Specifies expression operand type as large} 36 @item c 37 - @code{Specifies the CR16 Assembler generates a relocation entry for the operand, where pc has implied bit, the expression is adjusted accordingly. The linker uses the relocation entry to update the operand address at link time.} 38 @item got/GOT 39 - @code{Specifies the CR16 Assembler generates a relocation entry for the operand, offset from Global Offset Table. The linker uses this relocation entry to update the operand address at link time} 40 @item cgot/cGOT 41 - @code{Specifies the CompactRISC Assembler generates a relocation entry for the operand, where pc has implied bit, the expression is adjusted accordingly. The linker uses the relocation entry to update the operand address at link time.} 42 @end table 43 44 CR16 target operand qualifiers and its size (in bits): 45 46 @table @samp 47 @item Immediate Operand: s 48 4 bits. 49 50 @item Immediate Operand: m 51 16 bits, for movb and movw instructions. 52 53 @item Immediate Operand: m 54 20 bits, movd instructions. 55 56 @item Immediate Operand: l 57 32 bits. 58 59 @item Absolute Operand: s 60 Illegal specifier for this operand. 61 62 @item Absolute Operand: m 63 20 bits, movd instructions. 64 65 @item Displacement Operand: s 66 8 bits. 67 68 @item Displacement Operand: m 69 16 bits. 70 71 @item Displacement Operand: l 72 24 bits. 73 74 @end table 75 76 For example: 77 @example 78 1 @code{movw $_myfun@@c,r1} 79 80 This loads the address of _myfun, shifted right by 1, into r1. 81 82 2 @code{movd $_myfun@@c,(r2,r1)} 83 84 This loads the address of _myfun, shifted right by 1, into register-pair r2-r1. 85 86 3 @code{_myfun_ptr:} 87 @code{.long _myfun@@c} 88 @code{loadd _myfun_ptr, (r1,r0)} 89 @code{jal (r1,r0)} 90 91 This .long directive, the address of _myfunc, shifted right by 1 at link time. 92 93 4 @code{loadd _data1@@GOT(r12), (r1,r0)} 94 95 This loads the address of _data1, into global offset table (ie GOT) and its offset value from GOT loads into register-pair r2-r1. 96 97 5 @code{loadd _myfunc@@cGOT(r12), (r1,r0)} 98 99 This loads the address of _myfun, shifted right by 1, into global offset table (ie GOT) and its offset value from GOT loads into register-pair r1-r0. 100 @end example 101 102 @node CR16 Syntax 103 @section CR16 Syntax 104 @menu 105 * CR16-Chars:: Special Characters 106 @end menu 107 108 @node CR16-Chars 109 @subsection Special Characters 110 111 @cindex line comment character, CR16 112 @cindex CR16 line comment character 113 The presence of a @samp{#} on a line indicates the start of a comment 114 that extends to the end of the current line. If the @samp{#} appears 115 as the first character of a line, the whole line is treated as a 116 comment, but in this case the line can also be a logical line number 117 directive (@pxref{Comments}) or a preprocessor control command 118 (@pxref{Preprocessing}). 119 120 @cindex line separator, CR16 121 @cindex statement separator, CR16 122 @cindex CR16 line separator 123 The @samp{;} character can be used to separate statements on the same 124 line. 125
