HLASM: V1R6 Language Ref

DC instruction—Binary floating-point special valuesHowever, literal constants differ from DC operands in the following ways:v Literals must be preceded by an equal sign.v Multiple operands are not allowed.v The duplication factor must not be zero.v Symbols used in the duplication factor or length modifier must be previouslydefined. Scale and Exponent modifiers do not need pre-definition.v If an address-type literal constant specifies a duplication factor greater than oneand a nominal value containing the location counter reference, the value of thelocation counter reference is not incremented, but remains the same for eachduplication.v The assembler groups literals together by size. If you use a literal constant, thealignment of the constant can be different than might be the case for an explicitconstant. See “Literal pool” on page 43.DROPinstructionThe DROP instruction ends the domain of a USING instruction. This:v Frees base registers previously assigned by the USING instruction for otherprogramming purposesv Ensures that the assembler uses the base register you want in a particular codingsituation, for example, when two USING ranges overlap or coincidev If a control section has not been established, DROP will initiate an unnamed(private) control section►►sequence_symbolDROP,►◄▼base_registerlabelsequence_symbolis a sequence symbol.base_registeris an absolute expression whose value represents one of the general registers 0through 15. The expression in base_register indicates a general register,previously specified in the operand of an ordinary USING statement, that is nolonger to be used for base addressing.labelis one of the following:v An ordinary symbolv A variable symbol that has been assigned a character string with a value thatis valid for an ordinary symbolThe ordinary symbol denoted by label must be a symbol previously used in thename field of a labeled USING statement or a labeled dependent USINGstatement.Chapter 5. Assembler instruction statements 171