as: s390 Aliases
1
1 9.40.3.5 Instruction Aliases
1 ............................
1
1 A specific bit pattern can have multiple mnemonics, for example the bit
1 pattern '0xa7000000' has the mnemonics 'tmh' and 'tmlh'. In addition,
1 there are a number of mnemonics recognized by 'as' that are not present
1 in the Principles of Operation. These are the short forms of the branch
1 instructions, where the condition code mask operand is encoded in the
1 mnemonic. This is relevant for the branch instructions, the compare and
1 branch instructions, and the compare and trap instructions.
1
1 For the branch instructions there are 20 condition code strings that
1 can be used as part of the mnemonic in place of a mask operand in the
1 instruction format:
1
1 instruction short form
1 ----------------------------------------------
1 bcr M1,R2 b<m>r R2
1 bc M1,D2(X2,B2) b<m> D2(X2,B2)
1 brc M1,I2 j<m> I2
1 brcl M1,I2 jg<m> I2
1
1 In the mnemonic for a branch instruction the condition code string
1 <m> can be any of the following:
1
1 o jump on overflow / if ones
1 h jump on A high
1 p jump on plus
1 nle jump on not low or equal
1 l jump on A low
1 m jump on minus
1 nhe jump on not high or equal
1 lh jump on low or high
1 ne jump on A not equal B
1 nz jump on not zero / if not zeros
1 e jump on A equal B
1 z jump on zero / if zeroes
1 nlh jump on not low or high
1 he jump on high or equal
1 nl jump on A not low
1 nm jump on not minus / if not mixed
1 le jump on low or equal
1 nh jump on A not high
1 np jump on not plus
1 no jump on not overflow / if not ones
1
1 For the compare and branch, and compare and trap instructions there
1 are 12 condition code strings that can be used as part of the mnemonic
1 in place of a mask operand in the instruction format:
1
1 instruction short form
1 ------------------------------------------------------------
1 crb R1,R2,M3,D4(B4) crb<m> R1,R2,D4(B4)
1 cgrb R1,R2,M3,D4(B4) cgrb<m> R1,R2,D4(B4)
1 crj R1,R2,M3,I4 crj<m> R1,R2,I4
1 cgrj R1,R2,M3,I4 cgrj<m> R1,R2,I4
1 cib R1,I2,M3,D4(B4) cib<m> R1,I2,D4(B4)
1 cgib R1,I2,M3,D4(B4) cgib<m> R1,I2,D4(B4)
1 cij R1,I2,M3,I4 cij<m> R1,I2,I4
1 cgij R1,I2,M3,I4 cgij<m> R1,I2,I4
1 crt R1,R2,M3 crt<m> R1,R2
1 cgrt R1,R2,M3 cgrt<m> R1,R2
1 cit R1,I2,M3 cit<m> R1,I2
1 cgit R1,I2,M3 cgit<m> R1,I2
1 clrb R1,R2,M3,D4(B4) clrb<m> R1,R2,D4(B4)
1 clgrb R1,R2,M3,D4(B4) clgrb<m> R1,R2,D4(B4)
1 clrj R1,R2,M3,I4 clrj<m> R1,R2,I4
1 clgrj R1,R2,M3,I4 clgrj<m> R1,R2,I4
1 clib R1,I2,M3,D4(B4) clib<m> R1,I2,D4(B4)
1 clgib R1,I2,M3,D4(B4) clgib<m> R1,I2,D4(B4)
1 clij R1,I2,M3,I4 clij<m> R1,I2,I4
1 clgij R1,I2,M3,I4 clgij<m> R1,I2,I4
1 clrt R1,R2,M3 clrt<m> R1,R2
1 clgrt R1,R2,M3 clgrt<m> R1,R2
1 clfit R1,I2,M3 clfit<m> R1,I2
1 clgit R1,I2,M3 clgit<m> R1,I2
1
1 In the mnemonic for a compare and branch and compare and trap
1 instruction the condition code string <m> can be any of the following:
1
1 h jump on A high
1 nle jump on not low or equal
1 l jump on A low
1 nhe jump on not high or equal
1 ne jump on A not equal B
1 lh jump on low or high
1 e jump on A equal B
1 nlh jump on not low or high
1 nl jump on A not low
1 he jump on high or equal
1 nh jump on A not high
1 le jump on low or equal
1