Hi DJ,
There is a error in the RL78 G13 hardware manual. Section 14, Figure
14-3 lists the values of the MDBL registers as FFFF4H, FFFF5H and the
MDBH registers as FFFF6H, FFFF7H. This is incorrect. The correct
values are shown in Section 3, Table 3-5: MDBL => FFFF6H, FFFF7H,
MDBH => FFFF4H, FFFF5H.
GCC and the RL78 simulator currently use the values from section 14.
The patch below corrects GCC. A similar patch will be submitted to
update the sim.
Tested with no regressions (on an updated sim) using an rl78-elf
toolchain. OK to apply ?
Cheers
Nick
gcc/ChangeLog
2013-01-03 Nick Clifton <ni...@redhat.com>
* config/rl78/rl78.md (mulsi3_g13): Correct values for MDBL and
MDBH registers.
Index: gcc/config/rl78/rl78.md
===================================================================
--- gcc/config/rl78/rl78.md (revision 194833)
+++ gcc/config/rl78/rl78.md (working copy)
@@ -273,10 +273,10 @@
)
;; 0xFFFF0 is MDAL. 0xFFFF2 is MDAH.
-;; 0xFFFF4 is MDBL. 0xFFFF6 is MDBH.
+;; 0xFFFF6 is MDBL. 0xFFFF4 is MDBH.
;; 0xF00E0 is MDCL. 0xF00E2 is MDCH.
;; 0xF00E8 is MDUC.
-;; Warning: this matches the documentation, not the silicon.
+;; Warning: this matches the silicon not the documentation.
(define_insn "mulsi3_g13"
[(set (match_operand:SI 0 "register_operand" "=&v")
(mult:SI (match_operand:SI 1 "nonmemory_operand" "vi")
@@ -291,12 +291,12 @@
movw ax, %h2
movw 0xffff2, ax ; MDAH
nop ; mdb = mdal * mdah
- movw ax, 0xffff4 ; MDBL
+ movw ax, 0xffff6 ; MDBL
movw %h0, ax
mov a, #0x40
mov !0xf00e8, a ; MDUC
- movw ax, 0xffff6 ; MDBH
+ movw ax, 0xffff4 ; MDBH
movw !0xf00e0, ax ; MDCL
movw ax, #0
movw !0xf00e2, ax ; MDCL
