This patch adds .abicalls and .set pic0 support which
affects the ELF ABI and its flags. In addition the patch uses
a common interface for both the MipsTargetSteamer and
MipsObjectStreamer that both the integrated and standalone
assemblers will use for the output for these directives.
llvm-svn: 198646
As we can't make a complete solution now it has been decided to enable .set directive to handle long jump expressions. This will cause parser to report errors when parsing integer based register assignments, for example:
.set r3, will be reported as error. Still, the need for expressions is higher priority as the integer based register assignments are Mips specific and can be avoided using register names.
llvm-svn: 196773
This patch handles LLVM standalone assembler (llvm-mc) ELF flag setting based on input file
directive processing.
Mips assembly requires processing inline directives that directly and
indirectly affect the output ELF header flags. This patch handles one
".abicalls".
To process these directives we are following the model the code generator
uses by storing state in a container as we go through processing and when
we detect the end of input file processing, AsmParser is notified and we
update the ELF header flags through a MipsELFStreamer method with a call from
MCTargetAsmParser::emitEndOfAsmFile(MCStreamer &OutStreamer).
This patch will allow other targets the same functionality.
Jack
llvm-svn: 191982
This patch solves the problem of numeric register values not being accepted:
../set_alias.s:1:11: error: expected valid expression after comma
.set r4,$4
^
The parsing of .set directive is changed and handling of symbols in code
as well to enable this feature.
The test example is added.
Patch by Vladimir Medic
llvm-svn: 182807
Mips have delayslots for certain instructions
like jumps and branches. These are instructions
that follow the branch or jump and are executed
before the jump or branch is completed.
Early Mips compilers could not cope with delayslots
and left them up to the assembler. The assembler would
fill the delayslots with the appropriate instruction,
usually just a nop to allow correct runtime behavior.
The default behavior for this is set with .set reorder.
To tell the assembler that you don't want it to mess with
the delayslot one used .set noreorder.
For backwards compatibility we need to support
.set reorder and have it be the default behavior in the
assembler.
Our support for it is to insert a NOP directly after an
instruction with a delayslot when in .set reorder mode.
Contributer: Vladimir Medic
llvm-svn: 180584
The .set directive in the Mips the assembler can be
used to set the value of a symbol to an expression.
This changes the symbol's value and type to conform
to the expression's.
Syntax: .set symbol, expression
This patch implements the parsing of the above syntax
and enables the parser to use defined symbols when
parsing operands.
Contributor: Vladimir Medic
llvm-svn: 177667
The constructs %hi() and %lo() represent the high and low 16
bits of the address.
Because the 16 bit offset field of an LW instruction is
interpreted as signed, if bit 15 of the low part is 1 then the
low part will act as a negative and 1 needs to be added to the
high part.
Contributer: Vladimir Medic
llvm-svn: 175707
excluding visibility bits.
Mips specific standalone assembler directive "set at".
This directive changes the general purpose register
that the assembler will use when given the symbolic
register name $at.
This does not include negative testing. That will come
in a future patch.
A side affect of this patch recognizes the different
GPR register names for temporaries between old abi
and new abi so a test case for that is included.
Contributer: Vladimir Medic
llvm-svn: 175686
.set option
The patch implements following options
at - lets the assembler use the $at register for macros,
but generates warnings if the source program uses $at
noat - let source programs use $at without issuingwarnings.
noreorder - prevents the assembler from reordering machine
language instructions.
nomacro - causes the assembler to print a warning whenever
an assembler operation generates more than one
machine language instruction.
macro - lets the assembler generate multiple machine instructions
from a single assembler instruction
reorder - lets the assembler reorder machine language
instructions to improve performance
The above variants are parsed and their boolean values set or unset.
The code to actually use them will come later.
Following options are not implemented yet:
nomips16
nomicromips
move
nomove
Contributer: Vladimir Medic
llvm-svn: 165194
Actually these are just stubs for parsing the directives.
Semantic support will come later.
Test cases included
Contributer: Vladimir Medic
llvm-svn: 163364
Matheus Almeida