General-purpose registers are represented by predefined symbols of the
form GRnnn (for global registers) or LRnnn
(for local registers), where nnn represents a number between
0
and 127
, written with no leading zeros. The leading
letters may be in either upper or lower case; for example, gr13
and LR7 are both valid register names.
You may also refer to general-purpose registers by specifying the register number as the result of an expression (prefixed with %% to flag the expression as a register number):
%%expression
—where expression must be an absolute expression evaluating to a
number between 0
and 255
. The range [0, 127] refers to
global registers, and the range [128, 255] to local registers.
In addition, as
understands the following protected
special-purpose register names for the AMD 29K family:
vab chd pc0 ops chc pc1 cps rbp pc2 cfg tmc mmu cha tmr lru
These unprotected special-purpose register names are also recognized:
ipc alu fpe ipa bp inte ipb fc fps q cr exop