len0rd/rockbox
1
0
Fork 1
mirror of https://github.com/Rockbox/rockbox.git synced 2025-12-08 12:45:26 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

Add an unsigned 32*32->top32 bit multiply for resizing on SH1, and switch to 32 bit precision using that.

Browse source 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20012 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jens Arnold 2009-02-15 17:07:18 +00:00
parent d70902feb8
commit 789b0a2eb9
1 changed files with 41 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

42
apps/recorder/resize.h
View file

@ -59,7 +59,47 @@
t; \
})
#elif (CONFIG_CPU == SH7034)
#define SC_SHIFT 24
/* multiply two unsigned 32 bit values and return the top 32 bit
* of the 64 bit result */
static inline unsigned sc_mul32(unsigned a, unsigned b)
{
unsigned r, t1, t2, t3;
asm (
"swap.w %[a], %[t1] \n" /* t1 = ba */
"mulu %[t1], %[b] \n" /* a * d */
"swap.w %[b], %[t3] \n" /* t3 = dc */
"sts macl, %[t2] \n" /* t2 = a * d */
"mulu %[t1], %[t3] \n" /* a * c */
"sts macl, %[r] \n" /* hi = a * c */
"mulu %[a], %[t3] \n" /* b * c */
"clrt \n"
"sts macl, %[t3] \n" /* t3 = b * c */
"addc %[t2], %[t3] \n" /* t3 += t2, carry -> t2 */
"movt %[t2] \n"
"mulu %[a], %[b] \n" /* b * d */
"mov %[t3], %[t1] \n" /* t2t3 <<= 16 */
"xtrct %[t2], %[t1] \n"
"mov %[t1], %[t2] \n"
"shll16 %[t3] \n"
"sts macl, %[t1] \n" /* lo = b * d */
"clrt \n" /* hi.lo += t2t3 */
"addc %[t3], %[t1] \n"
"addc %[t2], %[r] \n"
: /* outputs */
[r] "=&r"(r),
[t1]"=&r"(t1),
[t2]"=&r"(t2),
[t3]"=&r"(t3)
: /* inputs */
[a] "r" (a),
[b] "r" (b)
);
return r;
}
#define SC_MUL(x, y) sc_mul32(x, y)
#define SC_MUL_INIT
#define SC_MUL_END
#endif
#ifndef SC_SHIFT