OpenE2K/binutils-gdb
12
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Correcte dscription of hi() reloc prefix. Added description of hi0() reloc prefix.

Browse Source
This commit is contained in:
Nick Clifton 1997-09-09 23:54:40 +00:00
parent b303e1053f
commit 73a0402821
2 changed files with 28 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
gas/ChangeLog
View File

@ -1,5 +1,8 @@
Tue Sep 9 10:19:37 1997 Nick Clifton <nickc@cygnus.com>
* doc/c-v850.texi (V850 Opcodes): Document hi0() reloc prefix.
Correct description of hi() reloc prefix.
start-sanitize-v850e
* doc/c-v850.texi (V850 Opcodes): Document new reloc prefix.
* config/tc-v850.c (v850_reloc_prefix): Add hilo() reloc prefix.

28
gas/doc/c-v850.texi
View File

@ -249,12 +249,12 @@ such code with code assembled for other processors.
@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
@ -272,6 +272,28 @@ computes the difference between the address of labels 'here' and
'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.
@c start-santize-v850e
@cindex @code{hilo} pseudo-op, V850
@item hilo()