Add __divmoddi4 and __udivmoddi4 for 32-bit arch

gcc-7 seems to use __udivmoddi4 for 64-bit division on 32-bit arch. This
patch implement them so we don't get undefined reference error.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Closes zfsonlinux/zfs#6417
Closes #636

diff --git a/module/spl/spl-generic.c b/module/spl/spl-generic.c
index 10061620e7168d8d5bf8b683086db75dbab99e79..f6782dae73af08eec0b54c2da385ece22c405812 100644 (file)
--- a/module/spl/spl-generic.c
+++ b/module/spl/spl-generic.c
@@ -277,6 +277,49 @@ __umoddi3(uint64_t dividend, uint64_t divisor)
 }
 EXPORT_SYMBOL(__umoddi3);
 
+/*
+ * Implementation of 64-bit unsigned division/modulo for 32-bit machines.
+ */
+uint64_t
+__udivmoddi4(uint64_t n, uint64_t d, uint64_t *r)
+{
+       uint64_t q = __udivdi3(n, d);
+       if (r)
+               *r = n - d * q;
+       return (q);
+}
+EXPORT_SYMBOL(__udivmoddi4);
+
+/*
+ * Implementation of 64-bit signed division/modulo for 32-bit machines.
+ */
+int64_t
+__divmoddi4(int64_t n, int64_t d, int64_t *r)
+{
+       int64_t q, rr;
+       boolean_t nn = B_FALSE;
+       boolean_t nd = B_FALSE;
+       if (n < 0) {
+               nn = B_TRUE;
+               n = -n;
+       }
+       if (d < 0) {
+               nd = B_TRUE;
+               d = -d;
+       }
+
+       q = __udivmoddi4(n, d, (uint64_t *)&rr);
+
+       if (nn != nd)
+               q = -q;
+       if (nn)
+               rr = -rr;
+       if (r)
+               *r = rr;
+       return (q);
+}
+EXPORT_SYMBOL(__divmoddi4);
+
 #if defined(__arm) || defined(__arm__)
 /*
  * Implementation of 64-bit (un)signed division for 32-bit arm machines.