diff options
Diffstat (limited to 'opcodes')
| -rw-r--r-- | opcodes/ChangeLog | 9 | ||||
| -rw-r--r-- | opcodes/m68k-opc.c | 19 |
2 files changed, 27 insertions, 1 deletions
diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog index 95e3fb2..82ca249 100644 --- a/opcodes/ChangeLog +++ b/opcodes/ChangeLog @@ -1,3 +1,12 @@ +Fri Jan 24 12:08:21 1997 J.T. Conklin <jtc@cygnus.com> + + * m68k-opc.c (m68k_opcodes): Changed operand specifier for the + coldfire moveb instruction to not allow an address register as + destination. Although the documentation does not indicate that + this is invalid, experiments uncovered unexpected behavior. + Added a comment explaining the situation. Thanks to Andreas + Schwab for pointing this out to me. + start-sanitize-tic80 Wed Jan 22 20:13:51 1997 Fred Fish <fnf@cygnus.com> diff --git a/opcodes/m68k-opc.c b/opcodes/m68k-opc.c index 6c5716a..4a9220f 100644 --- a/opcodes/m68k-opc.c +++ b/opcodes/m68k-opc.c @@ -1230,6 +1230,23 @@ const struct m68k_opcode m68k_opcodes[] = {"lsrl", one(0160210), one(0170770), "QdDs", m68000up | mcf5200 }, {"lsrl", one(0160250), one(0170770), "DdDs", m68000up | mcf5200 }, +/* NOTE: The mcf5200 family programmer's reference manual does not + indicate the byte form of the movea instruction is invalid (as it + is on 68000 family cpus). However, experiments on the 5202 yeild + unexpected results. The value is copied, but it is not sign extended + (as is done with movea.w) and the top three bytes in the address + register are not disturbed. I don't know if this is the intended + behavior --- it could be a hole in instruction decoding (Motorola + decided not to trap all invalid instructions for performance reasons) + --- but I suspect that it is not. + + I reported this to Motorola ISD Technical Communications Support, + which replied that other coldfire assemblers reject movea.b. For + this reason I've decided to not allow moveab. + + jtc@cygnus.com - 97/01/24 + */ + {"moveal", one(0020100), one(0170700), "*lAd", m68000up | mcf5200 }, {"moveaw", one(0030100), one(0170700), "*wAd", m68000up | mcf5200 }, @@ -1268,7 +1285,7 @@ const struct m68k_opcode m68k_opcodes[] = /* The move opcode can generate the movea and moveq instructions. */ {"moveb", one(0010000), one(0170000), ";b$d", m68000up }, -{"moveb", one(0010000), one(0170000), "ms%d", mcf5200 }, +{"moveb", one(0010000), one(0170000), "ms$d", mcf5200 }, {"moveb", one(0010000), one(0170000), "nspd", mcf5200 }, {"moveb", one(0010000), one(0170000), "obmd", mcf5200 }, |