aboutsummaryrefslogtreecommitdiff
path: root/gas/doc
diff options
context:
space:
mode:
authorDJ Delorie <dj@redhat.com>2005-07-26 03:21:53 +0000
committerDJ Delorie <dj@redhat.com>2005-07-26 03:21:53 +0000
commitfd54057a29e296d29e662780fc6079e42c742228 (patch)
tree1a109b9e7d8a9108edda9722d9e1f392e74cf070 /gas/doc
parent030cf60a5d8687b18dbe76050ee33490fc96e075 (diff)
downloadgdb-fd54057a29e296d29e662780fc6079e42c742228.zip
gdb-fd54057a29e296d29e662780fc6079e42c742228.tar.gz
gdb-fd54057a29e296d29e662780fc6079e42c742228.tar.bz2
[bfd]
* reloc.c: Remove unused M32C relocs, add BFD_RELOC_M32C_HI8. * libbfd.h: Regenerate. * bfd-in2.h: Regenerate. * elf32-m32c.c (m32c_elf_howto_table): Add R_M32C_8, R_M32C_LO16, R_M32C_HI8, R_M32C_HI16. (m32c_reloc_map): Likewise. (m32c_elf_relocate_section): Add R_M32C_HI8 and R_M32C_HI16. [cpu] * m32c.opc (parse_unsigned8): Add %dsp8(). (parse_signed8): Add %hi8(). (parse_unsigned16): Add %dsp16(). (parse_signed16): Add %lo16() and %hi16(). (parse_lab_5_3): Make valuep a bfd_vma *. [gas] * config/tc-m32c.c (md_cgen_lookup_reloc): Add 8 bit operands. Support %mod() modifiers from opcodes. * doc/c-m32c.texi (M32C-Modifiers): New section. [include/elf] * m32c.h: Add R_M32C_8, R_M32C_LO16, R_M32C_HI8, and R_M32C_HI16. [opcodes] * m32c-asm.c Regenerate. * m32c-dis.c Regenerate.
Diffstat (limited to 'gas/doc')
-rw-r--r--gas/doc/c-m32c.texi68
1 files changed, 68 insertions, 0 deletions
diff --git a/gas/doc/c-m32c.texi b/gas/doc/c-m32c.texi
index 83cda7d..a49fe20 100644
--- a/gas/doc/c-m32c.texi
+++ b/gas/doc/c-m32c.texi
@@ -21,6 +21,7 @@ change the default to the M32C microprocessor.
@menu
* M32C-Opts:: M32C Options
+* M32C-Modifiers:: Symbolic Operand Modifiers
@end menu
@node M32C-Opts
@@ -46,3 +47,70 @@ Assemble M32C instructions.
Assemble M16C instructions (default).
@end table
+
+@node M32C-Modifiers
+@section Symbolic Operand Modifiers
+
+@cindex M32C modifiers
+@cindex syntax, M32C
+
+The assembler supports several modifiers when using symbol addresses
+in M32C instruction operands. The general syntax is the following:
+
+@smallexample
+%modifier(symbol)
+@end smallexample
+
+@table @code
+@cindex symbol modifiers
+
+@item %dsp8
+@itemx %dsp16
+
+These modifiers override the assembler's assumptions about how big a
+symbol's address is. Normally, when it sees an operand like
+@samp{sym[a0]} it assumes @samp{sym} may require the widest
+displacement field (16 bits for @samp{-m16c}, 24 bits for
+@samp{-m32c}). These modifiers tell it to assume the address will fit
+in an 8 or 16 bit (respectively) unsigned displacement. Note that, of
+course, if it doesn't actually fit you will get linker errors. Example:
+
+@smallexample
+mov.w %dsp8(sym)[a0],r1
+mov.b #0,%dsp8(sym)[a0]
+@end smallexample
+
+@item %hi8
+
+This modifier allows you to load bits 16 through 23 of a 24 bit
+address into an 8 bit register. This is useful with, for example, the
+M16C @samp{smovf} instruction, which expects a 20 bit address in
+@samp{r1h} and @samp{a0}. Example:
+
+@smallexample
+mov.b #%hi8(sym),r1h
+mov.w #%lo16(sym),a0
+smovf.b
+@end smallexample
+
+@item %lo16
+
+Likewise, this modifier allows you to load bits 0 through 15 of a 24
+bit address into a 16 bit register.
+
+@item %hi16
+
+This modifier allows you to load bits 16 through 31 of a 32 bit
+address into a 16 bit register. While the M32C family only has 24
+bits of address space, it does support addresses in pairs of 16 bit
+registers (like @samp{a1a0} for the @samp{lde} instruction). This
+modifier is for loading the upper half in such cases. Example:
+
+@smallexample
+mov.w #%hi16(sym),a1
+mov.w #%lo16(sym),a0
+@dots{}
+lde.w [a1a0],r1
+@end smallexample
+
+@end table