Specifications

Altera Corporation 8–7
October 2007 Nios II Processor Reference Handbook
Instruction Set Reference
Assembler
Macros
The Nios II assembler provides macros to extract halfwords from labels
and from 32-bit immediate values. Table 8–4 lists the available macros.
These macros return 16-bit signed values or 16-bit unsigned values
depending on where they are used. When used with an instruction that
requires a 16-bit signed immediate value, these macros return a value
ranging from –32768 to 32767. When used with an instruction that
requires a 16-bit unsigned immediate value, these macros return a value
ranging from 0 to 65535.
Table 8–4. Assembler Macros
Macro Description Operation
%lo(immed32)
Extract bits [15..0] of immed32 immed32 & 0xffff
%hi(immed32)
Extract bits [31..16] of immed32 (immed32 >> 16) & 0xffff
%hiadj(immed32)
Extract bits [31..16] and adds bit 15 of immed32 ((immed32 >> 16) & 0xffff) +
((immed32 >> 15) & 0x1)
%gprel(immed32)
Replace the immed32 address with an offset
from the global pointer
(1)
immed32 –_gp
Note to Ta bl e 8 – 4 :
(1) See the Application Binary Interface chapter of the Nios II Processor Reference Handbook for more
information about global pointers.