Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1870

PMAXUB: Packed Unsigned Integer Byte Maximum
Opcode
0F,DE, /r
Operation: mm1[7-0]
mm1[15-8]
mm1[23-16]
mm1[31-24]
mm1[39-32]
mm1[47-40]
mm1[55-48]
mm1[63-56]
The PMAXUB instruction returns the maximum between the eight unsigned words in
Description:
MM1 and MM2/Mem.
None.
Numeric Exceptions:
Protected Mode Exceptions:
#GP(0) for an illegal memory operand effective address in the CS, DS, ES, FS or GS
segments; #SS(0) for an illegal address in the SS segment; #PF (fault-code) for a page
fault; #UD if CR0.EM = 1; #NM if TS bit in CR0 is set; #MF if there is a pending FPU
exception #AC for unaligned memory reference. To enable #AC exceptions, three
conditions must be true(CR0.AM is set; EFLAGS.AC is set; current CPL is 3).
Real Address Mode Exceptions:
Interrupt 13 if any part of the operand would lie outside of the effective address space
from 0 to 0FFFFH; #UD if CR0.EM = 1; #NM if TS bit in CR0 is set. #MF if there is a
pending FPU exception.
Virtual 8086 Mode Exceptions:
Same exceptions as in Real Address Mode; #PF(fault-code) for a page fault; #AC for
unaligned memory reference if the current privilege level is 3.
Additional Itanium System Environment Exceptions
Itanium Reg Faults
Itanium Mem Faults VHPT Data Fault, Data TLB Fault, Alternate Data TLB Fault, Data
4:568
Instruction
PMAXUB mm1, mm2/m64
= (mm1[7-0] > mm2/m64[7-0]) ? mm1[7-0] : mm2/m64[7-0];
= (mm1[15-8] > mm2/m64[15-8]) ? mm1[15-8] : mm2/m64[15-8];
= (mm1[23-16] > mm2/m64[23-16]) ? mm1[23-16] : mm2/m64[23-16];
= (mm1[31-24] > mm2/m64[31-24]) ? mm1[31-24] : mm2/m64[31-24];
= (mm1[39-32] > mm2/m64[39-32]) ? mm1[39-32] : mm2/m64[39-32];
= (mm1[47-40] > mm2/m64[47-40]) ? mm1[47-40] : mm2/m64[47-40];
= (mm1[55-48] > mm2/m64[55-48]) ? mm1[55-48] : mm2/m64[55-48];
= (mm1[63-56] > mm2/m64[63-56]) ? mm1[63-56] : mm2/m64[63-56];
Disabled FP Register Fault if PSR.dfl is 1, NaT Register
Consumption Fault
Page Not Present Fault, Data NaT Page Consumption Abort, Data
Key Miss Fault, Data Key Permission Fault, Data Access Rights
Fault, Data Access Bit Fault
Description
Return the maximum bytes between MM2/Mem and MM1.
Volume 4: IA-32 SSE Instruction Reference