-@c Copyright (C) 1997 Free Software Foundation, Inc.
+@c Copyright (C) 1997, 1998 Free Software Foundation, Inc.
@c This is part of the GAS manual.
@c For copying conditions, see the file as.texinfo.
-@node v850 Machine Dependencies
+@node V850-Dependent
@chapter v850 Dependent Features
@cindex V850 support
@section Options
@cindex V850 options (none)
@cindex options for V850 (none)
-@code{@value{AS}} has no additional command-line options for the V850
-processor family.
+@code{@value{AS}} supports the following additional command-line options
+for the V850 processor family:
+
+@cindex command line options, V850
+@cindex V850 command line options
+@table @code
+
+@cindex @code{-wsigned_overflow} command line option, V850
+@item -wsigned_overflow
+Causes warnings to be produced when signed immediate values overflow the
+space available for then within their opcodes. By default this option
+is disabled as it is possible to receive spurious warnings due to using
+exact bit patterns as immediate constants.
+
+@cindex @code{-wunsigned_overflow} command line option, V850
+@item -wunsigned_overflow
+Causes warnings to be produced when unsigned immediate values overflow
+the space available for then within their opcodes. By default this
+option is disabled as it is possible to receive spurious warnings due to
+using exact bit patterns as immediate constants.
+
+@cindex @code{-mv850} command line option, V850
+@item -mv850
+Specifies that the assembled code should be marked as being targeted at
+the V850 processor. This allows the linker to detect attempts to link
+such code with code assembled for other processors.
+
+@cindex @code{-mv850e} command line option, V850
+@item -mv850e
+Specifies that the assembled code should be marked as being targeted at
+the V850E processor. This allows the linker to detect attempts to link
+such code with code assembled for other processors.
+
+@cindex @code{-mv850any} command line option, V850
+@item -mv850any
+Specifies that the assembled code should be marked as being targeted at
+the V850 processor but support instructions that are specific to the
+extended variants of the process. This allows the production of
+binaries that contain target specific code, but which are also intended
+to be used in a generic fashion. For example libgcc.a contains generic
+routines used by the code produced by GCC for all versions of the v850
+architecture, together with support routines only used by the V850E
+architecture.
+
+@end table
+
@node V850 Syntax
@section Syntax
@cindex @code{psw} register, V850
@item system register 5
psw
-@c start-santize-v850e
@cindex @code{ctpc} register, V850
@item system register 16
ctpc
@cindex @code{ctbp} register, V850
@item system register 20
ctbp
-@c end-santize-v850e
@end table
@node V850 Floating Point
current section to be <type> and creates an alias for this section
called "name".
+@cindex @code{.v850} directive, V850
+@item .v850
+Specifies that the assembled code should be marked as being targeted at
+the V850 processor. This allows the linker to detect attempts to link
+such code with code assembled for other processors.
+
+@cindex @code{.v850e} directive, V850
+@item .v850e
+Specifies that the assembled code should be marked as being targeted at
+the V850E processor. This allows the linker to detect attempts to link
+such code with code assembled for other processors.
+
@end table
@node V850 Opcodes
@table @code
-@cindex @code{hi} pseudo-op, V850
-@item hi()
+@cindex @code{hi0} pseudo-op, V850
+@item hi0()
Computes the higher 16 bits of the given expression and stores it into
the immediate operand field of the given instruction. For example:
- @samp{mulhi hi(here - there), r5, r6}
+ @samp{mulhi hi0(here - there), r5, r6}
computes the difference between the address of labels 'here' and
'there', takes the upper 16 bits of this difference, shifts it down 16
bits and then mutliplies it by the lower 16 bits in register 5, putting
the result into register 6.
-
@cindex @code{lo} pseudo-op, V850
@item lo()
Computes the lower 16 bits of the given expression and stores it into
'there', takes the lower 16 bits of this difference and adds it to
register 5, putting the result into register 6.
+@cindex @code{hi} pseudo-op, V850
+@item hi()
+Computes the higher 16 bits of the given expression and then adds the
+value of the most significant bit of the lower 16 bits of the expression
+and stores the result into the immediate operand field of the given
+instruction. For example the following code can be used to compute the
+address of the label 'here' and store it into register 6:
+
+ @samp{movhi hi(here), r0, r6}
+ @samp{movea lo(here), r6, r6}
+
+The reason for this special behaviour is that movea performs a sign
+extention on its immediate operand. So for example if the address of
+'here' was 0xFFFFFFFF then without the special behaviour of the hi()
+pseudo-op the movhi instruction would put 0xFFFF0000 into r6, then the
+movea instruction would takes its immediate operand, 0xFFFF, sign extend
+it to 32 bits, 0xFFFFFFFF, and then add it into r6 giving 0xFFFEFFFF
+which is wrong (the fifth nibble is E). With the hi() pseudo op adding
+in the top bit of the lo() pseudo op, the movhi instruction actually
+stores 0 into r6 (0xFFFF + 1 = 0x0000), so that the movea instruction
+stores 0xFFFFFFFF into r6 - the right value.
+
+@cindex @code{hilo} pseudo-op, V850
+@item hilo()
+Computes the 32 bit value of the given expression and stores it into
+the immediate operand field of the given instruction (which must be a
+mov instruction). For example:
+
+ @samp{mov hilo(here), r6}
+
+computes the absolute address of label 'here' and puts the result into
+register 6.
+
@cindex @code{sdaoff} pseudo-op, V850
@item sdaoff()
Computes the offset of the named variable from the start of the Small
into register 6, provided that the label is located somewhere within +/-
32K of the address held in the GP register. [Note the linker assumes
that the GP register contains a fixed address set to the address of the
-label called '__gp'].
+label called '__gp'. This can either be set up automatically by the
+linker, or specifically set by using the @samp{--defsym __gp=<value>}
+command line option].
@cindex @code{tdaoff} pseudo-op, V850
@item tdaoff()
Computes the offset of the named variable from the start of the Tiny
Data Area (whoes address is held in register 30, the EP register) and
-stores the result as a 4,5,7 or 8 bit unsigned value in the immediate
+stores the result as a 4,5, 7 or 8 bit unsigned value in the immediate
operand field of the given instruction. For example:
@samp{sld.w tdaoff(_a_variable)[ep],r6}
loads the contents of the location pointed to by the label '_a_variable'
-into register 6, provided that the label is located somewhere within 256
+into register 6, provided that the label is located somewhere within +256
bytes of the address held in the EP register. [Note the linker assumes
that the EP register contains a fixed address set to the address of the
-label called '__ep'].
+label called '__ep'. This can either be set up automatically by the
+linker, or specifically set by using the @samp{--defsym __ep=<value>}
+command line option].
@cindex @code{zdaoff} pseudo-op, V850
@item zdaoff()
@samp{movea zdaoff(_a_variable),zero,r6}
puts the address of the label '_a_variable' into register 6, assuming
-that the label is somewhere within the first 32K of memory.
+that the label is somewhere within the first 32K of memory. (Strictly
+speaking it also possible to access the last 32K of memory as well, as
+the offsets are signed).
+
+@cindex @code{ctoff} pseudo-op, V850
+@item ctoff()
+Computes the offset of the named variable from the start of the Call
+Table Area (whoes address is helg in system register 20, the CTBP
+register) and stores the result a 6 or 16 bit unsigned value in the
+immediate field of then given instruction or piece of data. For
+example:
+
+ @samp{callt ctoff(table_func1)}
+
+will put the call the function whoes address is held in the call table
+at the location labeled 'table_func1'.
@end table
-For information on the V850 or Thumb instruction sets, see @cite{V850
+For information on the V850 instruction set, see @cite{V850
Family 32-/16-Bit single-Chip Microcontroller Architecture Manual} from NEC.
Ltd.
projects / deliverable / binutils-gdb.git / blobdiff