mirror of
https://github.com/autc04/Retro68.git
synced 2024-08-28 03:29:05 +00:00
865 lines
33 KiB
Plaintext
865 lines
33 KiB
Plaintext
@c Copyright 2009
|
|
@c Free Software Foundation, Inc.
|
|
@c This is part of the GAS manual.
|
|
@c For copying conditions, see the file as.texinfo.
|
|
@ifset GENERIC
|
|
@page
|
|
@node S/390-Dependent
|
|
@chapter IBM S/390 Dependent Features
|
|
@end ifset
|
|
@ifclear GENERIC
|
|
@node Machine Dependencies
|
|
@chapter IBM S/390 Dependent Features
|
|
@end ifclear
|
|
|
|
@cindex s390 support
|
|
|
|
The s390 version of @code{@value{AS}} supports two architectures modes
|
|
and seven chip levels. The architecture modes are the Enterprise System
|
|
Architecture (ESA) and the newer z/Architecture mode. The chip levels
|
|
are g5, g6, z900, z990, z9-109, z9-ec and z10.
|
|
|
|
@menu
|
|
* s390 Options:: Command-line Options.
|
|
* s390 Characters:: Special Characters.
|
|
* s390 Syntax:: Assembler Instruction syntax.
|
|
* s390 Directives:: Assembler Directives.
|
|
* s390 Floating Point:: Floating Point.
|
|
@end menu
|
|
|
|
@node s390 Options
|
|
@section Options
|
|
@cindex options for s390
|
|
@cindex s390 options
|
|
|
|
The following table lists all available s390 specific options:
|
|
|
|
@table @code
|
|
@cindex @samp{-m31} option, s390
|
|
@cindex @samp{-m64} option, s390
|
|
@item -m31 | -m64
|
|
Select 31- or 64-bit ABI implying a word size of 32- or 64-bit.
|
|
|
|
These options are only available with the ELF object file format, and
|
|
require that the necessary BFD support has been included (on a 31-bit
|
|
platform you must add --enable-64-bit-bfd on the call to the configure
|
|
script to enable 64-bit usage and use s390x as target platform).
|
|
|
|
@cindex @samp{-mesa} option, s390
|
|
@cindex @samp{-mzarch} option, s390
|
|
@item -mesa | -mzarch
|
|
Select the architecture mode, either the Enterprise System Architecture
|
|
(esa) mode or the z/Architecture mode (zarch).
|
|
|
|
The 64-bit instructions are only available with the z/Architecture mode.
|
|
The combination of @samp{-m64} and @samp{-mesa} results in a warning
|
|
message.
|
|
|
|
@cindex @samp{-march=} option, s390
|
|
@item -march=@var{CPU}
|
|
This option specifies the target processor. The following processor names
|
|
are recognized:
|
|
@code{g5},
|
|
@code{g6},
|
|
@code{z900},
|
|
@code{z990},
|
|
@code{z9-109},
|
|
@code{z9-ec} and
|
|
@code{z10}.
|
|
Assembling an instruction that is not supported on the target processor
|
|
results in an error message. Do not specify @code{g5} or @code{g6}
|
|
with @samp{-mzarch}.
|
|
|
|
@cindex @samp{-mregnames} option, s390
|
|
@item -mregnames
|
|
Allow symbolic names for registers.
|
|
|
|
@cindex @samp{-mno-regnames} option, s390
|
|
@item -mno-regnames
|
|
Do not allow symbolic names for registers.
|
|
|
|
@cindex @samp{-mwarn-areg-zero} option, s390
|
|
@item -mwarn-areg-zero
|
|
Warn whenever the operand for a base or index register has been specified
|
|
but evaluates to zero. This can indicate the misuse of general purpose
|
|
register 0 as an address register.
|
|
|
|
@end table
|
|
|
|
@node s390 Characters
|
|
@section Special Characters
|
|
@cindex line comment character, s390
|
|
@cindex s390 line comment character
|
|
|
|
@samp{#} is the line comment character.
|
|
|
|
@node s390 Syntax
|
|
@section Instruction syntax
|
|
@cindex instruction syntax, s390
|
|
@cindex s390 instruction syntax
|
|
|
|
The assembler syntax closely follows the syntax outlined in
|
|
Enterprise Systems Architecture/390 Principles of Operation (SA22-7201)
|
|
and the z/Architecture Principles of Operation (SA22-7832).
|
|
|
|
Each instruction has two major parts, the instruction mnemonic
|
|
and the instruction operands. The instruction format varies.
|
|
|
|
@menu
|
|
* s390 Register:: Register Naming
|
|
* s390 Mnemonics:: Instruction Mnemonics
|
|
* s390 Operands:: Instruction Operands
|
|
* s390 Formats:: Instruction Formats
|
|
* s390 Aliases:: Instruction Aliases
|
|
* s390 Operand Modifier:: Instruction Operand Modifier
|
|
* s390 Instruction Marker:: Instruction Marker
|
|
* s390 Literal Pool Entries:: Literal Pool Entries
|
|
@end menu
|
|
|
|
@node s390 Register
|
|
@subsection Register naming
|
|
@cindex register naming, s390
|
|
@cindex s390 register naming
|
|
|
|
The @code{@value{AS}} recognizes a number of predefined symbols for the
|
|
various processor registers. A register specification in one of the
|
|
instruction formats is an unsigned integer between 0 and 15. The specific
|
|
instruction and the position of the register in the instruction format
|
|
denotes the type of the register. The register symbols are prefixed with
|
|
@samp{%}:
|
|
|
|
@display
|
|
@multitable {%rN} {the 16 general purpose registers, 0 <= N <= 15}
|
|
@item %rN @tab the 16 general purpose registers, 0 <= N <= 15
|
|
@item %fN @tab the 16 floating point registers, 0 <= N <= 15
|
|
@item %aN @tab the 16 access registers, 0 <= N <= 15
|
|
@item %cN @tab the 16 control registers, 0 <= N <= 15
|
|
@item %lit @tab an alias for the general purpose register %r13
|
|
@item %sp @tab an alias for the general purpose register %r15
|
|
@end multitable
|
|
@end display
|
|
|
|
@node s390 Mnemonics
|
|
@subsection Instruction Mnemonics
|
|
@cindex instruction mnemonics, s390
|
|
@cindex s390 instruction mnemonics
|
|
|
|
All instructions documented in the Principles of Operation are supported
|
|
with the mnemonic and order of operands as described.
|
|
The instruction mnemonic identifies the instruction format
|
|
(@ref{s390 Formats}) and the specific operation code for the instruction.
|
|
For example, the @samp{lr} mnemonic denotes the instruction format @samp{RR}
|
|
with the operation code @samp{0x18}.
|
|
|
|
The definition of the various mnemonics follows a scheme, where the first
|
|
character usually hint at the type of the instruction:
|
|
|
|
@display
|
|
@multitable {sla, sll} {if r is the last character the instruction operates on registers}
|
|
@item a @tab add instruction, for example @samp{al} for add logical 32-bit
|
|
@item b @tab branch instruction, for example @samp{bc} for branch on condition
|
|
@item c @tab compare or convert instruction, for example @samp{cr} for compare
|
|
register 32-bit
|
|
@item d @tab divide instruction, for example @samp{dlr} devide logical register
|
|
64-bit to 32-bit
|
|
@item i @tab insert instruction, for example @samp{ic} insert character
|
|
@item l @tab load instruction, for example @samp{ltr} load and test register
|
|
@item mv @tab move instruction, for example @samp{mvc} move character
|
|
@item m @tab multiply instruction, for example @samp{mh} multiply halfword
|
|
@item n @tab and instruction, for example @samp{ni} and immediate
|
|
@item o @tab or instruction, for example @samp{oc} or character
|
|
@item sla, sll @tab shift left single instruction
|
|
@item sra, srl @tab shift right single instruction
|
|
@item st @tab store instruction, for example @samp{stm} store multiple
|
|
@item s @tab subtract instruction, for example @samp{slr} subtract
|
|
logical 32-bit
|
|
@item t @tab test or translate instruction, of example @samp{tm} test under mask
|
|
@item x @tab exclusive or instruction, for example @samp{xc} exclusive or
|
|
character
|
|
@end multitable
|
|
@end display
|
|
|
|
Certain characters at the end of the mnemonic may describe a property
|
|
of the instruction:
|
|
|
|
@display
|
|
@multitable {c} {if r is the last character the instruction operates on registers}
|
|
@item c @tab the instruction uses a 8-bit character operand
|
|
@item f @tab the instruction extends a 32-bit operand to 64 bit
|
|
@item g @tab the operands are treated as 64-bit values
|
|
@item h @tab the operand uses a 16-bit halfword operand
|
|
@item i @tab the instruction uses an immediate operand
|
|
@item l @tab the instruction uses unsigned, logical operands
|
|
@item m @tab the instruction uses a mask or operates on multiple values
|
|
@item r @tab if r is the last character, the instruction operates on registers
|
|
@item y @tab the instruction uses 20-bit displacements
|
|
@end multitable
|
|
@end display
|
|
|
|
There are many exceptions to the scheme outlined in the above lists, in
|
|
particular for the priviledged instructions. For non-priviledged
|
|
instruction it works quite well, for example the instruction @samp{clgfr}
|
|
c: compare instruction, l: unsigned operands, g: 64-bit operands,
|
|
f: 32- to 64-bit extension, r: register operands. The instruction compares
|
|
an 64-bit value in a register with the zero extended 32-bit value from
|
|
a second register.
|
|
For a complete list of all mnemonics see appendix B in the Principles
|
|
of Operation.
|
|
|
|
@node s390 Operands
|
|
@subsection Instruction Operands
|
|
@cindex instruction operands, s390
|
|
@cindex s390 instruction operands
|
|
|
|
Instruction operands can be grouped into three classes, operands located
|
|
in registers, immediate operands, and operands in storage.
|
|
|
|
A register operand can be located in general, floating-point, access,
|
|
or control register. The register is identified by a four-bit field.
|
|
The field containing the register operand is called the R field.
|
|
|
|
Immediate operands are contained within the instruction and can have
|
|
8, 16 or 32 bits. The field containing the immediate operand is called
|
|
the I field. Dependent on the instruction the I field is either signed
|
|
or unsigned.
|
|
|
|
A storage operand consists of an address and a length. The address of a
|
|
storage operands can be specified in any of these ways:
|
|
|
|
@itemize
|
|
@item The content of a single general R
|
|
@item The sum of the content of a general register called the base
|
|
register B plus the content of a displacement field D
|
|
@item The sum of the contents of two general registers called the
|
|
index register X and the base register B plus the content of a
|
|
displacement field
|
|
@item The sum of the current instruction address and a 32-bit signed
|
|
immediate field multiplied by two.
|
|
@end itemize
|
|
|
|
The length of a storage operand can be:
|
|
|
|
@itemize
|
|
@item Implied by the instruction
|
|
@item Specified by a bitmask
|
|
@item Specified by a four-bit or eight-bit length field L
|
|
@item Specified by the content of a general register
|
|
@end itemize
|
|
|
|
The notation for storage operand addresses formed from multiple fields is
|
|
as follows:
|
|
|
|
@table @code
|
|
@item Dn(Bn)
|
|
the address for operand number n is formed from the content of general
|
|
register Bn called the base register and the displacement field Dn.
|
|
@item Dn(Xn,Bn)
|
|
the address for operand number n is formed from the content of general
|
|
register Xn called the index register, general register Bn called the
|
|
base register and the displacement field Dn.
|
|
@item Dn(Ln,Bn)
|
|
the address for operand number n is formed from the content of general
|
|
regiser Bn called the base register and the displacement field Dn.
|
|
The length of the operand n is specified by the field Ln.
|
|
@end table
|
|
|
|
The base registers Bn and the index registers Xn of a storage operand can
|
|
be skipped. If Bn and Xn are skipped, a zero will be stored to the operand
|
|
field. The notation changes as follows:
|
|
|
|
@display
|
|
@multitable @columnfractions 0.30 0.30
|
|
@headitem full notation @tab short notation
|
|
@item Dn(0,Bn) @tab Dn(Bn)
|
|
@item Dn(0,0) @tab Dn
|
|
@item Dn(0) @tab Dn
|
|
@item Dn(Ln,0) @tab Dn(Ln)
|
|
@end multitable
|
|
@end display
|
|
|
|
|
|
@node s390 Formats
|
|
@subsection Instruction Formats
|
|
@cindex instruction formats, s390
|
|
@cindex s390 instruction formats
|
|
|
|
The Principles of Operation manuals lists 26 instruction formats where
|
|
some of the formats have multiple variants. For the @samp{.insn}
|
|
pseudo directive the assembler recognizes some of the formats.
|
|
Typically, the most general variant of the instruction format is used
|
|
by the @samp{.insn} directive.
|
|
|
|
The following table lists the abbreviations used in the table of
|
|
instruction formats:
|
|
|
|
@display
|
|
@multitable {OpCode / OpCd} {Displacement lower 12 bits for operand x.}
|
|
@item OpCode / OpCd @tab Part of the op code.
|
|
@item Bx @tab Base register number for operand x.
|
|
@item Dx @tab Displacement for operand x.
|
|
@item DLx @tab Displacement lower 12 bits for operand x.
|
|
@item DHx @tab Displacement higher 8-bits for operand x.
|
|
@item Rx @tab Register number for operand x.
|
|
@item Xx @tab Index register number for operand x.
|
|
@item Ix @tab Signed immediate for operand x.
|
|
@item Ux @tab Unsigned immediate for operand x.
|
|
@end multitable
|
|
@end display
|
|
|
|
An instruction is two, four, or six bytes in length and must be aligned
|
|
on a 2 byte boundary. The first two bits of the instruction specify the
|
|
length of the instruction, 00 indicates a two byte instruction, 01 and 10
|
|
indicates a four byte instruction, and 11 indicates a six byte instruction.
|
|
|
|
The following table lists the s390 instruction formats that are available
|
|
with the @samp{.insn} pseudo directive:
|
|
|
|
@table @code
|
|
@item E format
|
|
@verbatim
|
|
+-------------+
|
|
| OpCode |
|
|
+-------------+
|
|
0 15
|
|
@end verbatim
|
|
|
|
@item RI format: <insn> R1,I2
|
|
@verbatim
|
|
+--------+----+----+------------------+
|
|
| OpCode | R1 |OpCd| I2 |
|
|
+--------+----+----+------------------+
|
|
0 8 12 16 31
|
|
@end verbatim
|
|
|
|
@item RIE format: <insn> R1,R3,I2
|
|
@verbatim
|
|
+--------+----+----+------------------+--------+--------+
|
|
| OpCode | R1 | R3 | I2 |////////| OpCode |
|
|
+--------+----+----+------------------+--------+--------+
|
|
0 8 12 16 32 40 47
|
|
@end verbatim
|
|
|
|
@item RIL format: <insn> R1,I2
|
|
@verbatim
|
|
+--------+----+----+------------------------------------+
|
|
| OpCode | R1 |OpCd| I2 |
|
|
+--------+----+----+------------------------------------+
|
|
0 8 12 16 47
|
|
@end verbatim
|
|
|
|
@item RILU format: <insn> R1,U2
|
|
@verbatim
|
|
+--------+----+----+------------------------------------+
|
|
| OpCode | R1 |OpCd| U2 |
|
|
+--------+----+----+------------------------------------+
|
|
0 8 12 16 47
|
|
@end verbatim
|
|
|
|
@item RIS format: <insn> R1,I2,M3,D4(B4)
|
|
@verbatim
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
| OpCode | R1 | M3 | B4 | D4 | I2 | Opcode |
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
0 8 12 16 20 32 36 47
|
|
@end verbatim
|
|
|
|
@item RR format: <insn> R1,R2
|
|
@verbatim
|
|
+--------+----+----+
|
|
| OpCode | R1 | R2 |
|
|
+--------+----+----+
|
|
0 8 12 15
|
|
@end verbatim
|
|
|
|
@item RRE format: <insn> R1,R2
|
|
@verbatim
|
|
+------------------+--------+----+----+
|
|
| OpCode |////////| R1 | R2 |
|
|
+------------------+--------+----+----+
|
|
0 16 24 28 31
|
|
@end verbatim
|
|
|
|
@item RRF format: <insn> R1,R2,R3,M4
|
|
@verbatim
|
|
+------------------+----+----+----+----+
|
|
| OpCode | R3 | M4 | R1 | R2 |
|
|
+------------------+----+----+----+----+
|
|
0 16 20 24 28 31
|
|
@end verbatim
|
|
|
|
@item RRS format: <insn> R1,R2,M3,D4(B4)
|
|
@verbatim
|
|
+--------+----+----+----+-------------+----+----+--------+
|
|
| OpCode | R1 | R3 | B4 | D4 | M3 |////| OpCode |
|
|
+--------+----+----+----+-------------+----+----+--------+
|
|
0 8 12 16 20 32 36 40 47
|
|
@end verbatim
|
|
|
|
@item RS format: <insn> R1,R3,D2(B2)
|
|
@verbatim
|
|
+--------+----+----+----+-------------+
|
|
| OpCode | R1 | R3 | B2 | D2 |
|
|
+--------+----+----+----+-------------+
|
|
0 8 12 16 20 31
|
|
@end verbatim
|
|
|
|
@item RSE format: <insn> R1,R3,D2(B2)
|
|
@verbatim
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
| OpCode | R1 | R3 | B2 | D2 |////////| OpCode |
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
0 8 12 16 20 32 40 47
|
|
@end verbatim
|
|
|
|
@item RSI format: <insn> R1,R3,I2
|
|
@verbatim
|
|
+--------+----+----+------------------------------------+
|
|
| OpCode | R1 | R3 | I2 |
|
|
+--------+----+----+------------------------------------+
|
|
0 8 12 16 47
|
|
@end verbatim
|
|
|
|
@item RSY format: <insn> R1,R3,D2(B2)
|
|
@verbatim
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
| OpCode | R1 | R3 | B2 | DL2 | DH2 | OpCode |
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
0 8 12 16 20 32 40 47
|
|
@end verbatim
|
|
|
|
@item RX format: <insn> R1,D2(X2,B2)
|
|
@verbatim
|
|
+--------+----+----+----+-------------+
|
|
| OpCode | R1 | X2 | B2 | D2 |
|
|
+--------+----+----+----+-------------+
|
|
0 8 12 16 20 31
|
|
@end verbatim
|
|
|
|
@item RXE format: <insn> R1,D2(X2,B2)
|
|
@verbatim
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
| OpCode | R1 | X2 | B2 | D2 |////////| OpCode |
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
0 8 12 16 20 32 40 47
|
|
@end verbatim
|
|
|
|
@item RXF format: <insn> R1,R3,D2(X2,B2)
|
|
@verbatim
|
|
+--------+----+----+----+-------------+----+---+--------+
|
|
| OpCode | R3 | X2 | B2 | D2 | R1 |///| OpCode |
|
|
+--------+----+----+----+-------------+----+---+--------+
|
|
0 8 12 16 20 32 36 40 47
|
|
@end verbatim
|
|
|
|
@item RXY format: <insn> R1,D2(X2,B2)
|
|
@verbatim
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
| OpCode | R1 | X2 | B2 | DL2 | DH2 | OpCode |
|
|
+--------+----+----+----+-------------+--------+--------+
|
|
0 8 12 16 20 32 36 40 47
|
|
@end verbatim
|
|
|
|
@item S format: <insn> D2(B2)
|
|
@verbatim
|
|
+------------------+----+-------------+
|
|
| OpCode | B2 | D2 |
|
|
+------------------+----+-------------+
|
|
0 16 20 31
|
|
@end verbatim
|
|
|
|
@item SI format: <insn> D1(B1),I2
|
|
@verbatim
|
|
+--------+---------+----+-------------+
|
|
| OpCode | I2 | B1 | D1 |
|
|
+--------+---------+----+-------------+
|
|
0 8 16 20 31
|
|
@end verbatim
|
|
|
|
@item SIY format: <insn> D1(B1),U2
|
|
@verbatim
|
|
+--------+---------+----+-------------+--------+--------+
|
|
| OpCode | I2 | B1 | DL1 | DH1 | OpCode |
|
|
+--------+---------+----+-------------+--------+--------+
|
|
0 8 16 20 32 36 40 47
|
|
@end verbatim
|
|
|
|
@item SIL format: <insn> D1(B1),I2
|
|
@verbatim
|
|
+------------------+----+-------------+-----------------+
|
|
| OpCode | B1 | D1 | I2 |
|
|
+------------------+----+-------------+-----------------+
|
|
0 16 20 32 47
|
|
@end verbatim
|
|
|
|
@item SS format: <insn> D1(R1,B1),D2(B3),R3
|
|
@verbatim
|
|
+--------+----+----+----+-------------+----+------------+
|
|
| OpCode | R1 | R3 | B1 | D1 | B2 | D2 |
|
|
+--------+----+----+----+-------------+----+------------+
|
|
0 8 12 16 20 32 36 47
|
|
@end verbatim
|
|
|
|
@item SSE format: <insn> D1(B1),D2(B2)
|
|
@verbatim
|
|
+------------------+----+-------------+----+------------+
|
|
| OpCode | B1 | D1 | B2 | D2 |
|
|
+------------------+----+-------------+----+------------+
|
|
0 8 12 16 20 32 36 47
|
|
@end verbatim
|
|
|
|
@item SSF format: <insn> D1(B1),D2(B2),R3
|
|
@verbatim
|
|
+--------+----+----+----+-------------+----+------------+
|
|
| OpCode | R3 |OpCd| B1 | D1 | B2 | D2 |
|
|
+--------+----+----+----+-------------+----+------------+
|
|
0 8 12 16 20 32 36 47
|
|
@end verbatim
|
|
|
|
@end table
|
|
|
|
For the complete list of all instruction format variants see the
|
|
Principles of Operation manuals.
|
|
|
|
@node s390 Aliases
|
|
@subsection Instruction Aliases
|
|
@cindex instruction aliases, s390
|
|
@cindex s390 instruction aliases
|
|
|
|
A specific bit pattern can have multiple mnemonics, for example
|
|
the bit pattern @samp{0xa7000000} has the mnemonics @samp{tmh} and
|
|
@samp{tmlh}. In addition, there are a number of mnemonics recognized by
|
|
@code{@value{AS}} that are not present in the Principles of Operation.
|
|
These are the short forms of the branch instructions, where the condition
|
|
code mask operand is encoded in the mnemonic. This is relevant for the
|
|
branch instructions, the compare and branch instructions, and the
|
|
compare and trap instructions.
|
|
|
|
For the branch instructions there are 20 condition code strings that can
|
|
be used as part of the mnemonic in place of a mask operand in the instruction
|
|
format:
|
|
|
|
@display
|
|
@multitable @columnfractions .30 .30
|
|
@headitem instruction @tab short form
|
|
@item bcr M1,R2 @tab b<m>r R2
|
|
@item bc M1,D2(X2,B2) @tab b<m> D2(X2,B2)
|
|
@item brc M1,I2 @tab j<m> I2
|
|
@item brcl M1,I2 @tab jg<m> I2
|
|
@end multitable
|
|
@end display
|
|
|
|
In the mnemonic for a branch instruction the condition code string <m>
|
|
can be any of the following:
|
|
|
|
@display
|
|
@multitable {nle} {jump on not zero / if not zeros}
|
|
@item o @tab jump on overflow / if ones
|
|
@item h @tab jump on A high
|
|
@item p @tab jump on plus
|
|
@item nle @tab jump on not low or equal
|
|
@item l @tab jump on A low
|
|
@item m @tab jump on minus
|
|
@item nhe @tab jump on not high or equal
|
|
@item lh @tab jump on low or high
|
|
@item ne @tab jump on A not equal B
|
|
@item nz @tab jump on not zero / if not zeros
|
|
@item e @tab jump on A equal B
|
|
@item z @tab jump on zero / if zeroes
|
|
@item nlh @tab jump on not low or high
|
|
@item he @tab jump on high or equal
|
|
@item nl @tab jump on A not low
|
|
@item nm @tab jump on not minus / if not mixed
|
|
@item le @tab jump on low or equal
|
|
@item nh @tab jump on A not high
|
|
@item np @tab jump on not plus
|
|
@item no @tab jump on not overflow / if not ones
|
|
@end multitable
|
|
@end display
|
|
|
|
For the compare and branch, and compare and trap instructions there
|
|
are 12 condition code strings that can be used as part of the mnemonic in
|
|
place of a mask operand in the instruction format:
|
|
|
|
@display
|
|
@multitable @columnfractions .40 .40
|
|
@headitem instruction @tab short form
|
|
@item crb R1,R2,M3,D4(B4) @tab crb<m> R1,R2,D4(B4)
|
|
@item cgrb R1,R2,M3,D4(B4) @tab cgrb<m> R1,R2,D4(B4)
|
|
@item crj R1,R2,M3,I4 @tab crj<m> R1,R2,I4
|
|
@item cgrj R1,R2,M3,I4 @tab cgrj<m> R1,R2,I4
|
|
@item cib R1,I2,M3,D4(B4) @tab cib<m> R1,I2,D4(B4)
|
|
@item cgib R1,I2,M3,D4(B4) @tab cgib<m> R1,I2,D4(B4)
|
|
@item cij R1,I2,M3,I4 @tab cij<m> R1,I2,I4
|
|
@item cgij R1,I2,M3,I4 @tab cgij<m> R1,I2,I4
|
|
@item crt R1,R2,M3 @tab crt<m> R1,R2
|
|
@item cgrt R1,R2,M3 @tab cgrt<m> R1,R2
|
|
@item cit R1,I2,M3 @tab cit<m> R1,I2
|
|
@item cgit R1,I2,M3 @tab cgit<m> R1,I2
|
|
@item clrb R1,R2,M3,D4(B4) @tab clrb<m> R1,R2,D4(B4)
|
|
@item clgrb R1,R2,M3,D4(B4) @tab clgrb<m> R1,R2,D4(B4)
|
|
@item clrj R1,R2,M3,I4 @tab clrj<m> R1,R2,I4
|
|
@item clgrj R1,R2,M3,I4 @tab clgrj<m> R1,R2,I4
|
|
@item clib R1,I2,M3,D4(B4) @tab clib<m> R1,I2,D4(B4)
|
|
@item clgib R1,I2,M3,D4(B4) @tab clgib<m> R1,I2,D4(B4)
|
|
@item clij R1,I2,M3,I4 @tab clij<m> R1,I2,I4
|
|
@item clgij R1,I2,M3,I4 @tab clgij<m> R1,I2,I4
|
|
@item clrt R1,R2,M3 @tab clrt<m> R1,R2
|
|
@item clgrt R1,R2,M3 @tab clgrt<m> R1,R2
|
|
@item clfit R1,I2,M3 @tab clfit<m> R1,I2
|
|
@item clgit R1,I2,M3 @tab clgit<m> R1,I2
|
|
@end multitable
|
|
@end display
|
|
|
|
In the mnemonic for a compare and branch and compare and trap instruction
|
|
the condition code string <m> can be any of the following:
|
|
|
|
@display
|
|
@multitable {nle} {jump on not zero / if not zeros}
|
|
@item h @tab jump on A high
|
|
@item nle @tab jump on not low or equal
|
|
@item l @tab jump on A low
|
|
@item nhe @tab jump on not high or equal
|
|
@item ne @tab jump on A not equal B
|
|
@item lh @tab jump on low or high
|
|
@item e @tab jump on A equal B
|
|
@item nlh @tab jump on not low or high
|
|
@item nl @tab jump on A not low
|
|
@item he @tab jump on high or equal
|
|
@item nh @tab jump on A not high
|
|
@item le @tab jump on low or equal
|
|
@end multitable
|
|
@end display
|
|
|
|
@node s390 Operand Modifier
|
|
@subsection Instruction Operand Modifier
|
|
@cindex instruction operand modifier, s390
|
|
@cindex s390 instruction operand modifier
|
|
|
|
If a symbol modifier is attached to a symbol in an expression for an
|
|
instruction operand field, the symbol term is replaced with a reference
|
|
to an object in the global offset table (GOT) or the procedure linkage
|
|
table (PLT). The following expressions are allowed:
|
|
@samp{symbol@@modifier + constant},
|
|
@samp{symbol@@modifier + label + constant}, and
|
|
@samp{symbol@@modifier - label + constant}.
|
|
The term @samp{symbol} is the symbol that will be entered into the GOT or
|
|
PLT, @samp{label} is a local label, and @samp{constant} is an arbitrary
|
|
expression that the assembler can evaluate to a constant value.
|
|
|
|
The term @samp{(symbol + constant1)@@modifier +/- label + constant2}
|
|
is also accepted but a warning message is printed and the term is
|
|
converted to @samp{symbol@@modifier +/- label + constant1 + constant2}.
|
|
|
|
@table @code
|
|
@item @@got
|
|
@itemx @@got12
|
|
The @@got modifier can be used for displacement fields, 16-bit immediate
|
|
fields and 32-bit pc-relative immediate fields. The @@got12 modifier is
|
|
synonym to @@got. The symbol is added to the GOT. For displacement
|
|
fields and 16-bit immediate fields the symbol term is replaced with
|
|
the offset from the start of the GOT to the GOT slot for the symbol.
|
|
For a 32-bit pc-relative field the pc-relative offset to the GOT
|
|
slot from the current instruction address is used.
|
|
@item @@gotent
|
|
The @@gotent modifier can be used for 32-bit pc-relative immediate fields.
|
|
The symbol is added to the GOT and the symbol term is replaced with
|
|
the pc-relative offset from the current instruction to the GOT slot for the
|
|
symbol.
|
|
@item @@gotoff
|
|
The @@gotoff modifier can be used for 16-bit immediate fields. The symbol
|
|
term is replaced with the offset from the start of the GOT to the
|
|
address of the symbol.
|
|
@item @@gotplt
|
|
The @@gotplt modifier can be used for displacement fields, 16-bit immediate
|
|
fields, and 32-bit pc-relative immediate fields. A procedure linkage
|
|
table entry is generated for the symbol and a jump slot for the symbol
|
|
is added to the GOT. For displacement fields and 16-bit immediate
|
|
fields the symbol term is replaced with the offset from the start of the
|
|
GOT to the jump slot for the symbol. For a 32-bit pc-relative field
|
|
the pc-relative offset to the jump slot from the current instruction
|
|
address is used.
|
|
@item @@plt
|
|
The @@plt modifier can be used for 16-bit and 32-bit pc-relative immediate
|
|
fields. A procedure linkage table entry is generated for the symbol.
|
|
The symbol term is replaced with the relative offset from the current
|
|
instruction to the PLT entry for the symbol.
|
|
@item @@pltoff
|
|
The @@pltoff modifier can be used for 16-bit immediate fields. The symbol
|
|
term is replaced with the offset from the start of the PLT to the address
|
|
of the symbol.
|
|
@item @@gotntpoff
|
|
The @@gotntpoff modifier can be used for displacement fields. The symbol
|
|
is added to the static TLS block and the negated offset to the symbol
|
|
in the static TLS block is added to the GOT. The symbol term is replaced
|
|
with the offset to the GOT slot from the start of the GOT.
|
|
@item @@indntpoff
|
|
The @@indntpoff modifier can be used for 32-bit pc-relative immediate
|
|
fields. The symbol is added to the static TLS block and the negated offset
|
|
to the symbol in the static TLS block is added to the GOT. The symbol term
|
|
is replaced with the pc-relative offset to the GOT slot from the current
|
|
instruction address.
|
|
@end table
|
|
|
|
For more information about the thread local storage modifiers
|
|
@samp{gotntpoff} and @samp{indntpoff} see the ELF extension documentation
|
|
@samp{ELF Handling For Thread-Local Storage}.
|
|
|
|
@node s390 Instruction Marker
|
|
@subsection Instruction Marker
|
|
@cindex instruction marker, s390
|
|
@cindex s390 instruction marker
|
|
|
|
The thread local storage instruction markers are used by the linker to
|
|
perform code optimization.
|
|
|
|
@table @code
|
|
@item :tls_load
|
|
The :tls_load marker is used to flag the load instruction in the initial
|
|
exec TLS model that retrieves the offset from the thread pointer to a
|
|
thread local storage variable from the GOT.
|
|
@item :tls_gdcall
|
|
The :tls_gdcall marker is used to flag the branch-and-save instruction to
|
|
the __tls_get_offset function in the global dynamic TLS model.
|
|
@item :tls_ldcall
|
|
The :tls_ldcall marker is used to flag the branch-and-save instruction to
|
|
the __tls_get_offset function in the local dynamic TLS model.
|
|
@end table
|
|
|
|
For more information about the thread local storage instruction marker
|
|
and the linker optimizations see the ELF extension documentation
|
|
@samp{ELF Handling For Thread-Local Storage}.
|
|
|
|
@node s390 Literal Pool Entries
|
|
@subsection Literal Pool Entries
|
|
@cindex literal pool entries, s390
|
|
@cindex s390 literal pool entries
|
|
|
|
A literal pool is a collection of values. To access the values a pointer
|
|
to the literal pool is loaded to a register, the literal pool register.
|
|
Usually, register %r13 is used as the literal pool register
|
|
(@ref{s390 Register}). Literal pool entries are created by adding the
|
|
suffix :lit1, :lit2, :lit4, or :lit8 to the end of an expression for an
|
|
instruction operand. The expression is added to the literal pool and the
|
|
operand is replaced with the offset to the literal in the literal pool.
|
|
|
|
@table @code
|
|
@item :lit1
|
|
The literal pool entry is created as an 8-bit value. An operand modifier
|
|
must not be used for the original expression.
|
|
@item :lit2
|
|
The literal pool entry is created as a 16 bit value. The operand modifier
|
|
@@got may be used in the original expression. The term @samp{x@@got:lit2}
|
|
will put the got offset for the global symbol x to the literal pool as
|
|
16 bit value.
|
|
@item :lit4
|
|
The literal pool entry is created as a 32-bit value. The operand modifier
|
|
@@got and @@plt may be used in the original expression. The term
|
|
@samp{x@@got:lit4} will put the got offset for the global symbol x to the
|
|
literal pool as a 32-bit value. The term @samp{x@@plt:lit4} will put the
|
|
plt offset for the global symbol x to the literal pool as a 32-bit value.
|
|
@item :lit8
|
|
The literal pool entry is created as a 64-bit value. The operand modifier
|
|
@@got and @@plt may be used in the original expression. The term
|
|
@samp{x@@got:lit8} will put the got offset for the global symbol x to the
|
|
literal pool as a 64-bit value. The term @samp{x@@plt:lit8} will put the
|
|
plt offset for the global symbol x to the literal pool as a 64-bit value.
|
|
@end table
|
|
|
|
The assembler directive @samp{.ltorg} is used to emit all literal pool
|
|
entries to the current position.
|
|
|
|
@node s390 Directives
|
|
@section Assembler Directives
|
|
|
|
@code{@value{AS}} for s390 supports all of the standard ELF
|
|
assembler directives as outlined in the main part of this document.
|
|
Some directives have been extended and there are some additional
|
|
directives, which are only available for the s390 @code{@value{AS}}.
|
|
|
|
@table @code
|
|
@cindex @code{.insn} directive, s390
|
|
@item .insn
|
|
This directive permits the numeric representation of an instructions
|
|
and makes the assembler insert the operands according to one of the
|
|
instructions formats for @samp{.insn} (@ref{s390 Formats}).
|
|
For example, the instruction @samp{l %r1,24(%r15)} could be written as
|
|
@samp{.insn rx,0x58000000,%r1,24(%r15)}.
|
|
@cindex @code{.short} directive, s390
|
|
@cindex @code{.long} directive, s390
|
|
@cindex @code{.quad} directive, s390
|
|
@item .short
|
|
@itemx .long
|
|
@itemx .quad
|
|
This directive places one or more 16-bit (.short), 32-bit (.long), or
|
|
64-bit (.quad) values into the current section. If an ELF or TLS modifier
|
|
is used only the following expressions are allowed:
|
|
@samp{symbol@@modifier + constant},
|
|
@samp{symbol@@modifier + label + constant}, and
|
|
@samp{symbol@@modifier - label + constant}.
|
|
The following modifiers are available:
|
|
@table @code
|
|
@item @@got
|
|
@itemx @@got12
|
|
The @@got modifier can be used for .short, .long and .quad. The @@got12
|
|
modifier is synonym to @@got. The symbol is added to the GOT. The symbol
|
|
term is replaced with offset from the start of the GOT to the GOT slot for
|
|
the symbol.
|
|
@item @@gotoff
|
|
The @@gotoff modifier can be used for .short, .long and .quad. The symbol
|
|
term is replaced with the offset from the start of the GOT to the address
|
|
of the symbol.
|
|
@item @@gotplt
|
|
The @@gotplt modifier can be used for .long and .quad. A procedure linkage
|
|
table entry is generated for the symbol and a jump slot for the symbol
|
|
is added to the GOT. The symbol term is replaced with the offset from the
|
|
start of the GOT to the jump slot for the symbol.
|
|
@item @@plt
|
|
The @@plt modifier can be used for .long and .quad. A procedure linkage
|
|
table entry us generated for the symbol. The symbol term is replaced with
|
|
the address of the PLT entry for the symbol.
|
|
@item @@pltoff
|
|
The @@pltoff modifier can be used for .short, .long and .quad. The symbol
|
|
term is replaced with the offset from the start of the PLT to the address
|
|
of the symbol.
|
|
@item @@tlsgd
|
|
@itemx @@tlsldm
|
|
The @@tlsgd and @@tlsldm modifier can be used for .long and .quad. A
|
|
tls_index structure for the symbol is added to the GOT. The symbol term is
|
|
replaced with the offset from the start of the GOT to the tls_index structure.
|
|
@item @@gotntpoff
|
|
@itemx @@indntpoff
|
|
The @@gotntpoff and @@indntpoff modifier can be used for .long and .quad.
|
|
The symbol is added to the static TLS block and the negated offset to the
|
|
symbol in the static TLS block is added to the GOT. For @@gotntpoff the
|
|
symbol term is replaced with the offset from the start of the GOT to the
|
|
GOT slot, for @@indntpoff the symbol term is replaced with the address
|
|
of the GOT slot.
|
|
@item @@dtpoff
|
|
The @@dtpoff modifier can be used for .long and .quad. The symbol term
|
|
is replaced with the offset of the symbol relative to the start of the
|
|
TLS block it is contained in.
|
|
@item @@ntpoff
|
|
The @@ntpoff modifier can be used for .long and .quad. The symbol term
|
|
is replaced with the offset of the symbol relative to the TCB pointer.
|
|
@end table
|
|
|
|
For more information about the thread local storage modifiers see the
|
|
ELF extension documentation @samp{ELF Handling For Thread-Local Storage}.
|
|
|
|
@cindex @code{.ltorg} directive, s390
|
|
@item .ltorg
|
|
This directive causes the current contents of the literal pool to be
|
|
dumped to the current location (@ref{s390 Literal Pool Entries}).
|
|
@end table
|
|
|
|
@node s390 Floating Point
|
|
@section Floating Point
|
|
@cindex floating point, s390
|
|
@cindex s390 floating point
|
|
|
|
The assembler recognizes both the @sc{ieee} floating-point instruction and
|
|
the hexadecimal floating-point instructions. The floating-point constructors
|
|
@samp{.float}, @samp{.single}, and @samp{.double} always emit the
|
|
@sc{ieee} format. To assemble hexadecimal floating-point constants the
|
|
@samp{.long} and @samp{.quad} directives must be used.
|