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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
parent17b931468729df6921981700bf18c75609c2f6af (diff)
downloadlinux-3370d82f3b3ff04d082a9c343a80019282e41261.tar.gz
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')
-rw-r--r--arch/microblaze/lib/muldi3.S121
-rw-r--r--arch/microblaze/lib/muldi3.c60
2 files changed, 60 insertions, 121 deletions
diff --git a/arch/microblaze/lib/muldi3.S b/arch/microblaze/lib/muldi3.S
deleted file mode 100644
index ceeaa8c407f..00000000000
--- a/arch/microblaze/lib/muldi3.S
+++ /dev/null
@@ -1,121 +0,0 @@
-#include <linux/linkage.h>
-
-/*
- * Multiply operation for 64 bit integers, for devices with hard multiply
- * Input : Operand1[H] in Reg r5
- * Operand1[L] in Reg r6
- * Operand2[H] in Reg r7
- * Operand2[L] in Reg r8
- * Output: Result[H] in Reg r3
- * Result[L] in Reg r4
- *
- * Explaination:
- *
- * Both the input numbers are divided into 16 bit number as follows
- * op1 = A B C D
- * op2 = E F G H
- * result = D * H
- * + (C * H + D * G) << 16
- * + (B * H + C * G + D * F) << 32
- * + (A * H + B * G + C * F + D * E) << 48
- *
- * Only 64 bits of the output are considered
- */
-
- .text
- .globl __muldi3
- .type __muldi3, @function
- .ent __muldi3
-
-__muldi3:
- addi r1, r1, -40
-
-/* Save the input operands on the caller's stack */
- swi r5, r1, 44
- swi r6, r1, 48
- swi r7, r1, 52
- swi r8, r1, 56
-
-/* Store all the callee saved registers */
- sw r20, r1, r0
- swi r21, r1, 4
- swi r22, r1, 8
- swi r23, r1, 12
- swi r24, r1, 16
- swi r25, r1, 20
- swi r26, r1, 24
- swi r27, r1, 28
-
-/* Load all the 16 bit values for A thru H */
- lhui r20, r1, 44 /* A */
- lhui r21, r1, 46 /* B */
- lhui r22, r1, 48 /* C */
- lhui r23, r1, 50 /* D */
- lhui r24, r1, 52 /* E */
- lhui r25, r1, 54 /* F */
- lhui r26, r1, 56 /* G */
- lhui r27, r1, 58 /* H */
-
-/* D * H ==> LSB of the result on stack ==> Store1 */
- mul r9, r23, r27
- swi r9, r1, 36 /* Pos2 and Pos3 */
-
-/* Hi (Store1) + C * H + D * G ==> Store2 ==> Pos1 and Pos2 */
-/* Store the carry generated in position 2 for Pos 3 */
- lhui r11, r1, 36 /* Pos2 */
- mul r9, r22, r27 /* C * H */
- mul r10, r23, r26 /* D * G */
- add r9, r9, r10
- addc r12, r0, r0
- add r9, r9, r11
- addc r12, r12, r0 /* Store the Carry */
- shi r9, r1, 36 /* Store Pos2 */
- swi r9, r1, 32
- lhui r11, r1, 32
- shi r11, r1, 34 /* Store Pos1 */
-
-/* Hi (Store2) + B * H + C * G + D * F ==> Store3 ==> Pos0 and Pos1 */
- mul r9, r21, r27 /* B * H */
- mul r10, r22, r26 /* C * G */
- mul r7, r23, r25 /* D * F */
- add r9, r9, r11
- add r9, r9, r10
- add r9, r9, r7
- swi r9, r1, 32 /* Pos0 and Pos1 */
-
-/* Hi (Store3) + A * H + B * G + C * F + D * E ==> Store3 ==> Pos0 */
- lhui r11, r1, 32 /* Pos0 */
- mul r9, r20, r27 /* A * H */
- mul r10, r21, r26 /* B * G */
- mul r7, r22, r25 /* C * F */
- mul r8, r23, r24 /* D * E */
- add r9, r9, r11
- add r9, r9, r10
- add r9, r9, r7
- add r9, r9, r8
- sext16 r9, r9 /* Sign extend the MSB */
- shi r9, r1, 32
-
-/* Move results to r3 and r4 */
- lhui r3, r1, 32
- add r3, r3, r12
- shi r3, r1, 32
- lwi r3, r1, 32 /* Hi Part */
- lwi r4, r1, 36 /* Lo Part */
-
-/* Restore Callee saved registers */
- lw r20, r1, r0
- lwi r21, r1, 4
- lwi r22, r1, 8
- lwi r23, r1, 12
- lwi r24, r1, 16
- lwi r25, r1, 20
- lwi r26, r1, 24
- lwi r27, r1, 28
-
-/* Restore Frame and return */
- rtsd r15, 8
- addi r1, r1, 40
-
-.size __muldi3, . - __muldi3
-.end __muldi3
diff --git a/arch/microblaze/lib/muldi3.c b/arch/microblaze/lib/muldi3.c
new file mode 100644
index 00000000000..d4860e154d2
--- /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;
+}