Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Use __emul under msvc x86 for fast 64 = 32 * 32 #550

Merged
merged 1 commit into from
Jul 27, 2015
Merged

Use __emul under msvc x86 for fast 64 = 32 * 32 #550

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 6 additions & 2 deletions src/lib/openjp2/opj_includes.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -162,12 +162,16 @@ static INLINE long opj_lrintf(float f) {
}
#endif



#if defined(_MSC_VER) && (_MSC_VER < 1400)
#define vsnprintf _vsnprintf
#endif

/* MSVC x86 is really bad at doing int64 = int32 * int32 on its own. Use intrinsic. */
#if defined(_MSC_VER) && (_MSC_VER >= 1400) && !defined(__INTEL_COMPILER) && defined(_M_IX86)
# include <intrin.h>
# pragma intrinsic(__emul)
#endif

#include "opj_inttypes.h"
#include "opj_clock.h"
#include "opj_malloc.h"
Expand Down
8 changes: 8 additions & 0 deletions src/lib/openjp2/opj_intmath.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -184,15 +184,23 @@ Multiply two fixed-precision rational numbers.
@return Returns a * b
*/
static INLINE OPJ_INT32 opj_int_fix_mul(OPJ_INT32 a, OPJ_INT32 b) {
#if defined(_MSC_VER) && (_MSC_VER >= 1400) && !defined(__INTEL_COMPILER) && defined(_M_IX86)
OPJ_INT64 temp = __emul(a, b);
#else
OPJ_INT64 temp = (OPJ_INT64) a * (OPJ_INT64) b ;
#endif
temp += 4096;
assert((temp >> 13) <= (OPJ_INT64)0x7FFFFFFF);
assert((temp >> 13) >= (-(OPJ_INT64)0x7FFFFFFF - (OPJ_INT64)1));
return (OPJ_INT32) (temp >> 13);
}

static INLINE OPJ_INT32 opj_int_fix_mul_t1(OPJ_INT32 a, OPJ_INT32 b) {
#if defined(_MSC_VER) && (_MSC_VER >= 1400) && !defined(__INTEL_COMPILER) && defined(_M_IX86)
OPJ_INT64 temp = __emul(a, b);
#else
OPJ_INT64 temp = (OPJ_INT64) a * (OPJ_INT64) b ;
#endif
temp += 4096;
assert((temp >> (13 + 11 - T1_NMSEDEC_FRACBITS)) <= (OPJ_INT64)0x7FFFFFFF);
assert((temp >> (13 + 11 - T1_NMSEDEC_FRACBITS)) >= (-(OPJ_INT64)0x7FFFFFFF - (OPJ_INT64)1));
Expand Down