File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/microblaze/lib/udivsi3.S b/arch/microblaze/lib/udivsi3.S
new file mode 100644
index 0000000..64cf57e
--- /dev/null
+++ b/arch/microblaze/lib/udivsi3.S
@@ -0,0 +1,84 @@
+#include <linux/linkage.h>
+
+/*
+* Unsigned divide operation.
+* Input : Divisor in Reg r5
+* Dividend in Reg r6
+* Output: Result in Reg r3
+*/
+
+ .text
+ .globl __udivsi3
+ .type __udivsi3, @function
+ .ent __udivsi3
+
+__udivsi3:
+
+ .frame r1, 0, r15
+
+ addik r1, r1, -12
+ swi r29, r1, 0
+ swi r30, r1, 4
+ swi r31, r1, 8
+
+ beqi r6, div_by_zero /* div_by_zero /* division error */
+ beqid r5, result_is_zero /* result is zero */
+ addik r30, r0, 0 /* clear mod */
+ addik r29, r0, 32 /* initialize the loop count */
+
+/* check if r6 and r5 are equal - if yes, return 1 */
+ rsub r18, r5, r6
+ beqid r18, return_here
+ addik r3, r0, 1
+
+/* check if (uns)r6 is greater than (uns)r5. in that case, just return 0 */
+ xor r18, r5, r6
+ bgeid r18, 16
+ add r3, r0, r0 /* we would anyways clear r3 */
+ blti r6, return_here /* r6[bit 31 = 1] hence is greater */
+ bri checkr6
+ rsub r18, r6, r5 /* microblazecmp */
+ blti r18, return_here
+
+/* if r6 [bit 31] is set, then return result as 1 */
+checkr6:
+ bgti r6, div0
+ brid return_here
+ addik r3, r0, 1
+
+/* first part try to find the first '1' in the r5 */
+div0:
+ blti r5, div2
+div1:
+ add r5, r5, r5 /* left shift logical r5 */
+ bgtid r5, div1
+ addik r29, r29, -1
+div2:
+/* left shift logical r5 get the '1' into the carry */
+ add r5, r5, r5
+ addc r30, r30, r30 /* move that bit into the mod register */
+ rsub r31, r6, r30 /* try to subtract (r30 a r6) */
+ blti r31, mod_too_small
+/* move the r31 to mod since the result was positive */
+ or r30, r0, r31
+ addik r3, r3, 1
+mod_too_small:
+ addik r29, r29, -1
+ beqi r29, loop_end
+ add r3, r3, r3 /* shift in the '1' into div */
+ bri div2 /* div2 */
+loop_end:
+ bri return_here
+div_by_zero:
+result_is_zero:
+ or r3, r0, r0 /* set result to 0 */
+return_here:
+/* restore values of csrs and that of r3 and the divisor and the dividend */
+ lwi r29, r1, 0
+ lwi r30, r1, 4
+ lwi r31, r1, 8
+ rtsd r15, 8
+ addik r1, r1, 12
+
+.size __udivsi3, . - __udivsi3
+.end __udivsi3