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-rw-r--r--include/opcode/ChangeLog7
-rw-r--r--include/opcode/mips.h11
2 files changed, 12 insertions, 6 deletions
diff --git a/include/opcode/ChangeLog b/include/opcode/ChangeLog
index ad4411a..425abdb 100644
--- a/include/opcode/ChangeLog
+++ b/include/opcode/ChangeLog
@@ -1,4 +1,9 @@
-2006-04-07 Joerg Wunsch <j.gnu@uriah.heep.sax.de>
+2006-04-26 Thiemo Seufer <ths@networkno.de>
+
+ * mips.h: Improve comments describing the bitfield instruction
+ fields.
+
+2006-04-07 Joerg Wunsch <j.gnu@uriah.heep.sax.de>
* avr.h (AVR_ISA_PWMx): New.
diff --git a/include/opcode/mips.h b/include/opcode/mips.h
index 4bec5ed..ae3f437 100644
--- a/include/opcode/mips.h
+++ b/include/opcode/mips.h
@@ -268,19 +268,20 @@ struct mips_opcode
"x" accept and ignore register name
"z" must be zero register
"K" 5 bit Hardware Register (rdhwr instruction) (OP_*_RD)
- "+A" 5 bit ins/ext position, which becomes LSB (OP_*_SHAMT).
+ "+A" 5 bit ins/ext/dins/dext/dinsm/dextm position, which becomes
+ LSB (OP_*_SHAMT).
Enforces: 0 <= pos < 32.
- "+B" 5 bit ins size, which becomes MSB (OP_*_INSMSB).
+ "+B" 5 bit ins/dins size, which becomes MSB (OP_*_INSMSB).
Requires that "+A" or "+E" occur first to set position.
Enforces: 0 < (pos+size) <= 32.
- "+C" 5 bit ext size, which becomes MSBD (OP_*_EXTMSBD).
+ "+C" 5 bit ext/dext size, which becomes MSBD (OP_*_EXTMSBD).
Requires that "+A" or "+E" occur first to set position.
Enforces: 0 < (pos+size) <= 32.
(Also used by "dext" w/ different limits, but limits for
that are checked by the M_DEXT macro.)
- "+E" 5 bit dins/dext position, which becomes LSB-32 (OP_*_SHAMT).
+ "+E" 5 bit dinsu/dextu position, which becomes LSB-32 (OP_*_SHAMT).
Enforces: 32 <= pos < 64.
- "+F" 5 bit "dinsm" size, which becomes MSB-32 (OP_*_INSMSB).
+ "+F" 5 bit "dinsm/dinsu" size, which becomes MSB-32 (OP_*_INSMSB).
Requires that "+A" or "+E" occur first to set position.
Enforces: 32 < (pos+size) <= 64.
"+G" 5 bit "dextm" size, which becomes MSBD-32 (OP_*_EXTMSBD).