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authorMichal Simek <monstr@monstr.eu>2010-12-07 11:55:06 +0100
committerMichal Simek <monstr@monstr.eu>2011-01-03 10:30:31 +0100
commit3370d82f3b3ff04d082a9c343a80019282e41261 (patch)
tree4466336416d76206c29cfb78b05c21648845b33c /arch/microblaze/lib/muldi3.c
parent17b931468729df6921981700bf18c75609c2f6af (diff)
microblaze: Fix __muldi3 function for little-endian.
__muldi3 was written for big endian platforms. Code contained half word read/write instructions which are not compatible with little endian cpu. Asm __muldi3 implementation is replaced by C version. Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze/lib/muldi3.c')
-rw-r--r--arch/microblaze/lib/muldi3.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/microblaze/lib/muldi3.c b/arch/microblaze/lib/muldi3.c
new file mode 100644
index 000000000000..d4860e154d29
--- /dev/null
+++ b/arch/microblaze/lib/muldi3.c
@@ -0,0 +1,60 @@
+#include <linux/module.h>
+
+#include "libgcc.h"
+
+#define DWtype long long
+#define UWtype unsigned long
+#define UHWtype unsigned short
+
+#define W_TYPE_SIZE 32
+
+#define __ll_B ((UWtype) 1 << (W_TYPE_SIZE / 2))
+#define __ll_lowpart(t) ((UWtype) (t) & (__ll_B - 1))
+#define __ll_highpart(t) ((UWtype) (t) >> (W_TYPE_SIZE / 2))
+
+/* If we still don't have umul_ppmm, define it using plain C. */
+#if !defined(umul_ppmm)
+#define umul_ppmm(w1, w0, u, v) \
+ do { \
+ UWtype __x0, __x1, __x2, __x3; \
+ UHWtype __ul, __vl, __uh, __vh; \
+ \
+ __ul = __ll_lowpart(u); \
+ __uh = __ll_highpart(u); \
+ __vl = __ll_lowpart(v); \
+ __vh = __ll_highpart(v); \
+ \
+ __x0 = (UWtype) __ul * __vl; \
+ __x1 = (UWtype) __ul * __vh; \
+ __x2 = (UWtype) __uh * __vl; \
+ __x3 = (UWtype) __uh * __vh; \
+ \
+ __x1 += __ll_highpart(__x0); /* this can't give carry */\
+ __x1 += __x2; /* but this indeed can */ \
+ if (__x1 < __x2) /* did we get it? */ \
+ __x3 += __ll_B; /* yes, add it in the proper pos */ \
+ \
+ (w1) = __x3 + __ll_highpart(__x1); \
+ (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
+ } while (0)
+#endif
+
+#if !defined(__umulsidi3)
+#define __umulsidi3(u, v) ({ \
+ DWunion __w; \
+ umul_ppmm(__w.s.high, __w.s.low, u, v); \
+ __w.ll; \
+ })
+#endif
+
+DWtype __muldi3(DWtype u, DWtype v)
+{
+ const DWunion uu = {.ll = u};
+ const DWunion vv = {.ll = v};
+ DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
+
+ w.s.high += ((UWtype) uu.s.low * (UWtype) vv.s.high
+ + (UWtype) uu.s.high * (UWtype) vv.s.low);
+
+ return w.ll;
+}