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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-25 13:07:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-25 13:07:24 -0700
commit55a7d4b85ca1f723d26b8956e8faeff730d0d240 (patch)
tree4f8e9460bbd2096971215b67321c14a14c3c1d3f /arch/h8300/lib/udivsi3.S
parentaefbef10e3ae6e2c6e3c54f906f10b34c73a2c66 (diff)
parent07834743f42b4f27a21010cf5bab483b3ae3d13d (diff)
Merge tag 'for-4.2' of git://git.sourceforge.jp/gitroot/uclinux-h8/linux
Pull Renesas H8/300 architecture re-introduction from Yoshinori Sato. We dropped arch/h8300 two years ago as stale and old, this is a new and more modern rewritten arch support for the same architecture. * tag 'for-4.2' of git://git.sourceforge.jp/gitroot/uclinux-h8/linux: (27 commits) h8300: fix typo. h8300: Always build dtb h8300: Remove ARCH_WANT_IPC_PARSE_VERSION sh-sci: Get register size from platform device clk: h8300: fix error handling in h8s2678_pll_clk_setup() h8300: Symbol name fix h8300: devicetree source h8300: configs h8300: IRQ chip driver h8300: clocksource h8300: clock driver h8300: Build scripts h8300: library functions h8300: Memory management h8300: miscellaneous functions h8300: process helpers h8300: compressed image support h8300: Low level entry h8300: kernel startup h8300: Interrupt and exceptions ...
Diffstat (limited to 'arch/h8300/lib/udivsi3.S')
-rw-r--r--arch/h8300/lib/udivsi3.S76
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/h8300/lib/udivsi3.S b/arch/h8300/lib/udivsi3.S
new file mode 100644
index 000000000000..bbe65610f316
--- /dev/null
+++ b/arch/h8300/lib/udivsi3.S
@@ -0,0 +1,76 @@
+#include "libgcc.h"
+
+ ;; This function also computes the remainder and stores it in er3.
+ .global __udivsi3
+__udivsi3:
+ mov.w A1E,A1E ; denominator top word 0?
+ bne DenHighNonZero
+
+ ; do it the easy way, see page 107 in manual
+ mov.w A0E,A2
+ extu.l A2P
+ divxu.w A1,A2P
+ mov.w A2E,A0E
+ divxu.w A1,A0P
+ mov.w A0E,A3
+ mov.w A2,A0E
+ extu.l A3P
+ rts
+
+ ; er0 = er0 / er1
+ ; er3 = er0 % er1
+ ; trashes er1 er2
+ ; expects er1 >= 2^16
+DenHighNonZero:
+ mov.l er0,er3
+ mov.l er1,er2
+#ifdef CONFIG_CPU_H8300H
+divmod_L21:
+ shlr.l er0
+ shlr.l er2 ; make divisor < 2^16
+ mov.w e2,e2
+ bne divmod_L21
+#else
+ shlr.l #2,er2 ; make divisor < 2^16
+ mov.w e2,e2
+ beq divmod_L22A
+divmod_L21:
+ shlr.l #2,er0
+divmod_L22:
+ shlr.l #2,er2 ; make divisor < 2^16
+ mov.w e2,e2
+ bne divmod_L21
+divmod_L22A:
+ rotxl.w r2
+ bcs divmod_L23
+ shlr.l er0
+ bra divmod_L24
+divmod_L23:
+ rotxr.w r2
+ shlr.l #2,er0
+divmod_L24:
+#endif
+ ;; At this point,
+ ;; er0 contains shifted dividend
+ ;; er1 contains divisor
+ ;; er2 contains shifted divisor
+ ;; er3 contains dividend, later remainder
+ divxu.w r2,er0 ; r0 now contains the approximate quotient (AQ)
+ extu.l er0
+ beq divmod_L25
+ subs #1,er0 ; er0 = AQ - 1
+ mov.w e1,r2
+ mulxu.w r0,er2 ; er2 = upper (AQ - 1) * divisor
+ sub.w r2,e3 ; dividend - 65536 * er2
+ mov.w r1,r2
+ mulxu.w r0,er2 ; compute er3 = remainder (tentative)
+ sub.l er2,er3 ; er3 = dividend - (AQ - 1) * divisor
+divmod_L25:
+ cmp.l er1,er3 ; is divisor < remainder?
+ blo divmod_L26
+ adds #1,er0
+ sub.l er1,er3 ; correct the remainder
+divmod_L26:
+ rts
+
+ .end