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Added FIXMATH_NO_64BIT macro. 

Implemented multiplication and signed multiplication in 32-bit.
This commit is contained in:
flatmush 2011-02-28 09:59:36 +00:00
parent 5dd63f37ce
commit 8737eb5fe2
1 changed files with 36 additions and 0 deletions
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36
libfixmath/fix16.c
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@ -28,15 +28,33 @@ fix16_t fix16_sadd(fix16_t inArg0, fix16_t inArg1) {
fix16_t fix16_mul(fix16_t inArg0, fix16_t inArg1) {
#ifndef FIXMATH_NO_64BIT
int64_t tempResult = ((int64_t)inArg0 * (int64_t)inArg1);
#ifndef FIXMATH_NO_ROUNDING
tempResult += (fix16_one >> 1);
#endif
tempResult >>= 16;
return tempResult;
#else
int16_t hi[2] = { (inArg0 >> 16), (inArg1 >> 16) };
uint16_t lo[2] = { (inArg0 & 0xFFFF), (inArg1 & 0xFFFF) };
int32_t r_hi = hi[0] * hi[1];
int32_t r_md = (hi[0] * lo[1]) + (hi[1] * lo[0]);
uint32_t r_lo = lo[0] * lo[1];
#ifndef FIXMATH_NO_ROUNDING
r_lo += 0xFFFF;
#endif
r_md += (r_hi & 0xFFFF) << 16;
r_md += (r_lo >> 16);
return r_md;
#endif
}
fix16_t fix16_smul(fix16_t inArg0, fix16_t inArg1) {
#ifndef FIXMATH_NO_64BIT
int64_t tempResult = ((int64_t)inArg0 * (int64_t)inArg1);
#ifndef FIXMATH_NO_ROUNDING
tempResult += (fix16_one >> 1);
@ -47,6 +65,24 @@ fix16_t fix16_smul(fix16_t inArg0, fix16_t inArg1) {
if(tempResult > fix16_MAX)
return fix16_MAX;
return tempResult;
#else
int16_t hi[2] = { (inArg0 >> 16), (inArg1 >> 16) };
int32_t r_hi = hi[0] * hi[1];
if(r_hi >> 16)
return (r_hi < 0 ? fix16_MIN : fix16_MAX);
uint16_t lo[2] = { (inArg0 & 0xFFFF), (inArg1 & 0xFFFF) };
int32_t r_md = (hi[0] * lo[1]) + (hi[1] * lo[0]);
uint32_t r_lo = lo[0] * lo[1];
#ifndef FIXMATH_NO_ROUNDING
r_lo += 0xFFFF;
#endif
r_md += (r_hi & 0xFFFF) << 16;
r_md += (r_lo >> 16);
return r_md;
#endif
}