Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1066

loadrs — Load Register Stack
loadrs
Format:
This instruction ensures that a specified number of bytes (registers values and/or NaT
Description:
collections) below the current BSP have been loaded from the backing store into the
stacked general registers. The loaded registers are placed into the dirty partition of the
register stack. All other stacked general registers are marked as invalid, without being
saved to the backing store.
The number of bytes to be loaded is specified in a sub-field of the RSC application
register (RSC.loadrs). Backing store addresses are always 8-byte aligned, and
therefore the low order 3 bits of the loadrs field (RSC.loadrs{2:0}) are ignored. This
instruction can be used to invalidate all stacked registers outside the current frame, by
setting RSC.loadrs to zero.
This instruction will fault with an Illegal Operation fault under any of the following
conditions:
• the RSE is not in enforced lazy mode (RSC.mode is non-zero).
• CFM.sof and RSC.loadrs are both non-zero.
• an attempt is made to load up more registers than are available in the physical
stacked register file.
This instruction must be the first instruction in an instruction group and must either be
in instruction slot 0 or in instruction slot 1 of a template having a stop after slot 0;
otherwise, the results are undefined. This instruction cannot be predicated.
Operation: if (AR[RSC].mode != 0)
illegal_operation_fault();
if ((CFM.sof != 0) && (AR[RSC].loadrs != 0))
illegal_operation_fault();
rse_ensure_regs_loaded(AR[RSC].loadrs);
AR[RNAT] = undefined();
Illegal Operation fault
Interruptions:
Unimplemented Data Address fault
Data Nested TLB fault
Alternate Data TLB fault
VHPT Data fault
Data TLB fault
Data Page Not Present fault
Volume 3: Instruction Reference
// can raise faults listed below
Data NaT Page Consumption fault
Data Key Miss fault
Data Key Permission fault
Data Access Rights fault
Data Access Bit fault
Data Debug fault
loadrs
M25
3:167