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src/util: Switch _mesa_half_to_float() to u_half.h's version.

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The two implementations differ across the entire input range only in
that u_half.h preserves mantissa bits for NaNs.  The u_half.h version
shaves 15% off of the text size of half_float.o.

Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
This commit is contained in:
Eric Anholt 2019-06-27 15:53:53 -07:00
parent bb5801ad98
commit 628f55717b
1 changed files with 2 additions and 43 deletions
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45
src/util/half_float.c
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@ -27,6 +27,7 @@
#include <math.h>
#include <assert.h>
#include "half_float.h"
#include "util/u_half.h"
#include "rounding.h"
#include "macros.h"
@ -134,49 +135,7 @@ _mesa_float_to_half(float val)
float
_mesa_half_to_float(uint16_t val)
{
/* XXX could also use a 64K-entry lookup table */
const int m = val & 0x3ff;
const int e = (val >> 10) & 0x1f;
const int s = (val >> 15) & 0x1;
int flt_m, flt_e, flt_s;
fi_type fi;
float result;
/* sign bit */
flt_s = s;
/* handle special cases */
if ((e == 0) && (m == 0)) {
/* zero */
flt_m = 0;
flt_e = 0;
}
else if ((e == 0) && (m != 0)) {
/* denorm -- denorm half will fit in non-denorm single */
const float half_denorm = 1.0f / 16384.0f; /* 2^-14 */
float mantissa = ((float) (m)) / 1024.0f;
float sign = s ? -1.0f : 1.0f;
return sign * mantissa * half_denorm;
}
else if ((e == 31) && (m == 0)) {
/* infinity */
flt_e = 0xff;
flt_m = 0;
}
else if ((e == 31) && (m != 0)) {
/* NaN */
flt_e = 0xff;
flt_m = 1;
}
else {
/* regular */
flt_e = e + 112;
flt_m = m << 13;
}
fi.i = (flt_s << 31) | (flt_e << 23) | flt_m;
result = fi.f;
return result;
return util_half_to_float(val);
}
/**