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authorMatt Turner <mattst88@gmail.com>2012-07-20 09:55:47 -0700
committerMatt Turner <mattst88@gmail.com>2012-07-21 08:23:38 -0700
commit948b1c541f32b12e8264b1eeb79ccbb696661f54 (patch)
treed830f2187a7af20b6c8cbefe106a45b597aea2d9 /src/mesa/main/imports.c
parentec79138138c3c88afb2052823b1e3f5271493085 (diff)
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Remove _mesa_sqrt* in favor of plain sqrt
Temporarily disabled since 2003 (see 386578c5b). This saves us from calling sqrt() 128 times to generate the sqrttab in one_time_init(). Reviewed-by: Brian Paul <brianp@vmware.com> Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Diffstat (limited to 'src/mesa/main/imports.c')
-rw-r--r--src/mesa/main/imports.c101
1 files changed, 0 insertions, 101 deletions
diff --git a/src/mesa/main/imports.c b/src/mesa/main/imports.c
index 2d592a6..fc30a6e 100644
--- a/src/mesa/main/imports.c
+++ b/src/mesa/main/imports.c
@@ -243,107 +243,6 @@ _mesa_memset16( unsigned short *dst, unsigned short val, size_t n )
/** \name Math */
/*@{*/
-/** Wrapper around sqrt() */
-double
-_mesa_sqrtd(double x)
-{
- return sqrt(x);
-}
-
-
-/*
- * A High Speed, Low Precision Square Root
- * by Paul Lalonde and Robert Dawson
- * from "Graphics Gems", Academic Press, 1990
- *
- * SPARC implementation of a fast square root by table
- * lookup.
- * SPARC floating point format is as follows:
- *
- * BIT 31 30 23 22 0
- * sign exponent mantissa
- */
-static short sqrttab[0x100]; /* declare table of square roots */
-
-void
-_mesa_init_sqrt_table(void)
-{
-#if defined(USE_IEEE) && !defined(DEBUG)
- unsigned short i;
- fi_type fi; /* to access the bits of a float in C quickly */
- /* we use a union defined in glheader.h */
-
- for(i=0; i<= 0x7f; i++) {
- fi.i = 0;
-
- /*
- * Build a float with the bit pattern i as mantissa
- * and an exponent of 0, stored as 127
- */
-
- fi.i = (i << 16) | (127 << 23);
- fi.f = _mesa_sqrtd(fi.f);
-
- /*
- * Take the square root then strip the first 7 bits of
- * the mantissa into the table
- */
-
- sqrttab[i] = (fi.i & 0x7fffff) >> 16;
-
- /*
- * Repeat the process, this time with an exponent of
- * 1, stored as 128
- */
-
- fi.i = 0;
- fi.i = (i << 16) | (128 << 23);
- fi.f = sqrt(fi.f);
- sqrttab[i+0x80] = (fi.i & 0x7fffff) >> 16;
- }
-#else
- (void) sqrttab; /* silence compiler warnings */
-#endif /*HAVE_FAST_MATH*/
-}
-
-
-/**
- * Single precision square root.
- */
-float
-_mesa_sqrtf( float x )
-{
-#if defined(USE_IEEE) && !defined(DEBUG)
- fi_type num;
- /* to access the bits of a float in C
- * we use a union from glheader.h */
-
- short e; /* the exponent */
- if (x == 0.0F) return 0.0F; /* check for square root of 0 */
- num.f = x;
- e = (num.i >> 23) - 127; /* get the exponent - on a SPARC the */
- /* exponent is stored with 127 added */
- num.i &= 0x7fffff; /* leave only the mantissa */
- if (e & 0x01) num.i |= 0x800000;
- /* the exponent is odd so we have to */
- /* look it up in the second half of */
- /* the lookup table, so we set the */
- /* high bit */
- e >>= 1; /* divide the exponent by two */
- /* note that in C the shift */
- /* operators are sign preserving */
- /* for signed operands */
- /* Do the table lookup, based on the quaternary mantissa,
- * then reconstruct the result back into a float
- */
- num.i = ((sqrttab[num.i >> 16]) << 16) | ((e + 127) << 23);
-
- return num.f;
-#else
- return (float) _mesa_sqrtd((double) x);
-#endif
-}
-
/**
inv_sqrt - A single precision 1/sqrt routine for IEEE format floats.