powerpc: Fix a corner case in __div64_32
The code was incorrectly doing a division by 0 in the case where
the denominator was 0x100000000 and the divisor was 0xffffffff.
Thanks to Fred Liu of Motorola for pointing this out.
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/lib/div64.S b/arch/powerpc/lib/div64.S
index 3527569..83d9832 100644
--- a/arch/powerpc/lib/div64.S
+++ b/arch/powerpc/lib/div64.S
@@ -33,9 +33,10 @@
cntlzw r0,r5 # we are shifting the dividend right
li r10,-1 # to make it < 2^32, and shifting
srw r10,r10,r0 # the divisor right the same amount,
- add r9,r4,r10 # rounding up (so the estimate cannot
+ addc r9,r4,r10 # rounding up (so the estimate cannot
andc r11,r6,r10 # ever be too large, only too small)
andc r9,r9,r10
+ addze r9,r9
or r11,r5,r11
rotlw r9,r9,r0
rotlw r11,r11,r0