1. xerox 560 computer system - The UK Mirror Service

Condition code settings:2 3 4 Result in RExample 3, odd R field value:Before executionAfter execution0 0 Zero0 Negative0 PositiveED X 100000000 1 2345678 1 XI 00000000 1 2345678 1(R) xxxxxxxx XI 00000000 ICC xxxx xx 10LDLOAD DOUBLEWORD(Doubleword index alignment)LCHLOAD COMPLEMENT HALFWORD(Halfword index alignment)LOAD DOUBLEWORD loads the 32 low-order bits of theeffective doubleword into register Ru1 and then loadsthe 32 high-order bits of the effective doubleword intoregister R.If R is an odd value, the result in register R is the 32 highorderbits of the effective doubleword. The condition codesettings are based on the effective doubleword, rather thanthe final result in register R (see example 3, below).Affected: (R), (Ru1), CC3, CC4ED 32_ 63Ru1; ED O_ 31RLOAD COMPLEMENT HALFWORD extends the sign of theeffective halfword 16 bit positions to the left and then loadsthe 32-bit twols complement of the result into register R.(Overflow cannot occur. )Affected: (R), CC3, CC4{EHSEJ-RCondition code settings:2 3 4 Result in R- 0 0 ZeroCondition code settings:234o 0 Zero- 0 Negativeo PositiveLAH- 0 Negativeo PositiveLOAD ABSOLUTE HALFWORD(Halfword index alignment)Example 1, even R field value:Before execution After executionED X'0123456789ABCDEF' X'0123456789ABCDEF'(R) xxxxxxxx X I 0 1234567 1(Ru1) = xxxxxxxx X'89ABCDEF'CC xxxx xxlOExample 2, odd R field value:If the effective halfword is positive, LOAD ABSOLUTEHALFWORD extends the sign of the effective halfword16 bit positions to the left and then loads the 32-bit resultin register R. If the effective halfword is negative, LAHextends the sign of the effective halfword 16 bit positionsto the left and then loads the 32-bit twols complement ofthe result into register R. (Overflow cannot occur.)Affected: (R), CC3, CC4EHSE -RBefore executionAfter executionCondition code settings:ED X'0123456789ABCDEF' X'0123456789ABCDEF'2 3 4 Result in R(R) xxxxxxxx X'01234567 1o 0ZeroCC xxxx xx 10o NonzeroLoad/Store Instructi ons 51