Index: speex/libspeex/pseudofloat.h |
=================================================================== |
--- speex/libspeex/pseudofloat.h (revision 0) |
+++ speex/libspeex/pseudofloat.h (revision 0) |
@@ -0,0 +1,379 @@ |
+/* Copyright (C) 2005 Jean-Marc Valin */ |
+/** |
+ @file pseudofloat.h |
+ @brief Pseudo-floating point |
+ * This header file provides a lightweight floating point type for |
+ * use on fixed-point platforms when a large dynamic range is |
+ * required. The new type is not compatible with the 32-bit IEEE format, |
+ * it is not even remotely as accurate as 32-bit floats, and is not |
+ * even guaranteed to produce even remotely correct results for code |
+ * other than Speex. It makes all kinds of shortcuts that are acceptable |
+ * for Speex, but may not be acceptable for your application. You're |
+ * quite welcome to reuse this code and improve it, but don't assume |
+ * it works out of the box. Most likely, it doesn't. |
+ */ |
+/* |
+ Redistribution and use in source and binary forms, with or without |
+ modification, are permitted provided that the following conditions |
+ are met: |
+ |
+ - Redistributions of source code must retain the above copyright |
+ notice, this list of conditions and the following disclaimer. |
+ |
+ - Redistributions in binary form must reproduce the above copyright |
+ notice, this list of conditions and the following disclaimer in the |
+ documentation and/or other materials provided with the distribution. |
+ |
+ - Neither the name of the Xiph.org Foundation nor the names of its |
+ contributors may be used to endorse or promote products derived from |
+ this software without specific prior written permission. |
+ |
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
+ ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR |
+ CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
+ EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
+ PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
+ PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
+ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
+ NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
+*/ |
+ |
+#ifndef PSEUDOFLOAT_H |
+#define PSEUDOFLOAT_H |
+ |
+#include "arch.h" |
+#include "os_support.h" |
+#include "math_approx.h" |
+#include <math.h> |
+ |
+#ifdef FIXED_POINT |
+ |
+typedef struct { |
+ spx_int16_t m; |
+ spx_int16_t e; |
+} spx_float_t; |
+ |
+static const spx_float_t FLOAT_ZERO = {0,0}; |
+static const spx_float_t FLOAT_ONE = {16384,-14}; |
+static const spx_float_t FLOAT_HALF = {16384,-15}; |
+ |
+#define MIN(a,b) ((a)<(b)?(a):(b)) |
+static inline spx_float_t PSEUDOFLOAT(spx_int32_t x) |
+{ |
+ int e=0; |
+ int sign=0; |
+ if (x<0) |
+ { |
+ sign = 1; |
+ x = -x; |
+ } |
+ if (x==0) |
+ { |
+ spx_float_t r = {0,0}; |
+ return r; |
+ } |
+ e = spx_ilog2(ABS32(x))-14; |
+ x = VSHR32(x, e); |
+ if (sign) |
+ { |
+ spx_float_t r; |
+ r.m = -x; |
+ r.e = e; |
+ return r; |
+ } |
+ else |
+ { |
+ spx_float_t r; |
+ r.m = x; |
+ r.e = e; |
+ return r; |
+ } |
+} |
+ |
+ |
+static inline spx_float_t FLOAT_ADD(spx_float_t a, spx_float_t b) |
+{ |
+ spx_float_t r; |
+ if (a.m==0) |
+ return b; |
+ else if (b.m==0) |
+ return a; |
+ if ((a).e > (b).e) |
+ { |
+ r.m = ((a).m>>1) + ((b).m>>MIN(15,(a).e-(b).e+1)); |
+ r.e = (a).e+1; |
+ } |
+ else |
+ { |
+ r.m = ((b).m>>1) + ((a).m>>MIN(15,(b).e-(a).e+1)); |
+ r.e = (b).e+1; |
+ } |
+ if (r.m>0) |
+ { |
+ if (r.m<16384) |
+ { |
+ r.m<<=1; |
+ r.e-=1; |
+ } |
+ } else { |
+ if (r.m>-16384) |
+ { |
+ r.m<<=1; |
+ r.e-=1; |
+ } |
+ } |
+ /*printf ("%f + %f = %f\n", REALFLOAT(a), REALFLOAT(b), REALFLOAT(r));*/ |
+ return r; |
+} |
+ |
+static inline spx_float_t FLOAT_SUB(spx_float_t a, spx_float_t b) |
+{ |
+ spx_float_t r; |
+ if (a.m==0) |
+ return b; |
+ else if (b.m==0) |
+ return a; |
+ if ((a).e > (b).e) |
+ { |
+ r.m = ((a).m>>1) - ((b).m>>MIN(15,(a).e-(b).e+1)); |
+ r.e = (a).e+1; |
+ } |
+ else |
+ { |
+ r.m = ((a).m>>MIN(15,(b).e-(a).e+1)) - ((b).m>>1); |
+ r.e = (b).e+1; |
+ } |
+ if (r.m>0) |
+ { |
+ if (r.m<16384) |
+ { |
+ r.m<<=1; |
+ r.e-=1; |
+ } |
+ } else { |
+ if (r.m>-16384) |
+ { |
+ r.m<<=1; |
+ r.e-=1; |
+ } |
+ } |
+ /*printf ("%f + %f = %f\n", REALFLOAT(a), REALFLOAT(b), REALFLOAT(r));*/ |
+ return r; |
+} |
+ |
+static inline int FLOAT_LT(spx_float_t a, spx_float_t b) |
+{ |
+ if (a.m==0) |
+ return b.m>0; |
+ else if (b.m==0) |
+ return a.m<0; |
+ if ((a).e > (b).e) |
+ return ((a).m>>1) < ((b).m>>MIN(15,(a).e-(b).e+1)); |
+ else |
+ return ((b).m>>1) > ((a).m>>MIN(15,(b).e-(a).e+1)); |
+ |
+} |
+ |
+static inline int FLOAT_GT(spx_float_t a, spx_float_t b) |
+{ |
+ return FLOAT_LT(b,a); |
+} |
+ |
+static inline spx_float_t FLOAT_MULT(spx_float_t a, spx_float_t b) |
+{ |
+ spx_float_t r; |
+ r.m = (spx_int16_t)((spx_int32_t)(a).m*(b).m>>15); |
+ r.e = (a).e+(b).e+15; |
+ if (r.m>0) |
+ { |
+ if (r.m<16384) |
+ { |
+ r.m<<=1; |
+ r.e-=1; |
+ } |
+ } else { |
+ if (r.m>-16384) |
+ { |
+ r.m<<=1; |
+ r.e-=1; |
+ } |
+ } |
+ /*printf ("%f * %f = %f\n", REALFLOAT(a), REALFLOAT(b), REALFLOAT(r));*/ |
+ return r; |
+} |
+ |
+static inline spx_float_t FLOAT_AMULT(spx_float_t a, spx_float_t b) |
+{ |
+ spx_float_t r; |
+ r.m = (spx_int16_t)((spx_int32_t)(a).m*(b).m>>15); |
+ r.e = (a).e+(b).e+15; |
+ return r; |
+} |
+ |
+ |
+static inline spx_float_t FLOAT_SHL(spx_float_t a, int b) |
+{ |
+ spx_float_t r; |
+ r.m = a.m; |
+ r.e = a.e+b; |
+ return r; |
+} |
+ |
+static inline spx_int16_t FLOAT_EXTRACT16(spx_float_t a) |
+{ |
+ if (a.e<0) |
+ return EXTRACT16((EXTEND32(a.m)+(EXTEND32(1)<<(-a.e-1)))>>-a.e); |
+ else |
+ return a.m<<a.e; |
+} |
+ |
+static inline spx_int32_t FLOAT_EXTRACT32(spx_float_t a) |
+{ |
+ if (a.e<0) |
+ return (EXTEND32(a.m)+(EXTEND32(1)<<(-a.e-1)))>>-a.e; |
+ else |
+ return EXTEND32(a.m)<<a.e; |
+} |
+ |
+static inline spx_int32_t FLOAT_MUL32(spx_float_t a, spx_word32_t b) |
+{ |
+ return VSHR32(MULT16_32_Q15(a.m, b),-a.e-15); |
+} |
+ |
+static inline spx_float_t FLOAT_MUL32U(spx_word32_t a, spx_word32_t b) |
+{ |
+ int e1, e2; |
+ spx_float_t r; |
+ if (a==0 || b==0) |
+ { |
+ return FLOAT_ZERO; |
+ } |
+ e1 = spx_ilog2(ABS32(a)); |
+ a = VSHR32(a, e1-14); |
+ e2 = spx_ilog2(ABS32(b)); |
+ b = VSHR32(b, e2-14); |
+ r.m = MULT16_16_Q15(a,b); |
+ r.e = e1+e2-13; |
+ return r; |
+} |
+ |
+/* Do NOT attempt to divide by a negative number */ |
+static inline spx_float_t FLOAT_DIV32_FLOAT(spx_word32_t a, spx_float_t b) |
+{ |
+ int e=0; |
+ spx_float_t r; |
+ if (a==0) |
+ { |
+ return FLOAT_ZERO; |
+ } |
+ e = spx_ilog2(ABS32(a))-spx_ilog2(b.m-1)-15; |
+ a = VSHR32(a, e); |
+ if (ABS32(a)>=SHL32(EXTEND32(b.m-1),15)) |
+ { |
+ a >>= 1; |
+ e++; |
+ } |
+ r.m = DIV32_16(a,b.m); |
+ r.e = e-b.e; |
+ return r; |
+} |
+ |
+ |
+/* Do NOT attempt to divide by a negative number */ |
+static inline spx_float_t FLOAT_DIV32(spx_word32_t a, spx_word32_t b) |
+{ |
+ int e0=0,e=0; |
+ spx_float_t r; |
+ if (a==0) |
+ { |
+ return FLOAT_ZERO; |
+ } |
+ if (b>32767) |
+ { |
+ e0 = spx_ilog2(b)-14; |
+ b = VSHR32(b, e0); |
+ e0 = -e0; |
+ } |
+ e = spx_ilog2(ABS32(a))-spx_ilog2(b-1)-15; |
+ a = VSHR32(a, e); |
+ if (ABS32(a)>=SHL32(EXTEND32(b-1),15)) |
+ { |
+ a >>= 1; |
+ e++; |
+ } |
+ e += e0; |
+ r.m = DIV32_16(a,b); |
+ r.e = e; |
+ return r; |
+} |
+ |
+/* Do NOT attempt to divide by a negative number */ |
+static inline spx_float_t FLOAT_DIVU(spx_float_t a, spx_float_t b) |
+{ |
+ int e=0; |
+ spx_int32_t num; |
+ spx_float_t r; |
+ if (b.m<=0) |
+ { |
+ speex_warning_int("Attempted to divide by", b.m); |
+ return FLOAT_ONE; |
+ } |
+ num = a.m; |
+ a.m = ABS16(a.m); |
+ while (a.m >= b.m) |
+ { |
+ e++; |
+ a.m >>= 1; |
+ } |
+ num = num << (15-e); |
+ r.m = DIV32_16(num,b.m); |
+ r.e = a.e-b.e-15+e; |
+ return r; |
+} |
+ |
+static inline spx_float_t FLOAT_SQRT(spx_float_t a) |
+{ |
+ spx_float_t r; |
+ spx_int32_t m; |
+ m = SHL32(EXTEND32(a.m), 14); |
+ r.e = a.e - 14; |
+ if (r.e & 1) |
+ { |
+ r.e -= 1; |
+ m <<= 1; |
+ } |
+ r.e >>= 1; |
+ r.m = spx_sqrt(m); |
+ return r; |
+} |
+ |
+#else |
+ |
+#define spx_float_t float |
+#define FLOAT_ZERO 0.f |
+#define FLOAT_ONE 1.f |
+#define FLOAT_HALF 0.5f |
+#define PSEUDOFLOAT(x) (x) |
+#define FLOAT_MULT(a,b) ((a)*(b)) |
+#define FLOAT_AMULT(a,b) ((a)*(b)) |
+#define FLOAT_MUL32(a,b) ((a)*(b)) |
+#define FLOAT_DIV32(a,b) ((a)/(b)) |
+#define FLOAT_EXTRACT16(a) (a) |
+#define FLOAT_EXTRACT32(a) (a) |
+#define FLOAT_ADD(a,b) ((a)+(b)) |
+#define FLOAT_SUB(a,b) ((a)-(b)) |
+#define REALFLOAT(x) (x) |
+#define FLOAT_DIV32_FLOAT(a,b) ((a)/(b)) |
+#define FLOAT_MUL32U(a,b) ((a)*(b)) |
+#define FLOAT_SHL(a,b) (a) |
+#define FLOAT_LT(a,b) ((a)<(b)) |
+#define FLOAT_GT(a,b) ((a)>(b)) |
+#define FLOAT_DIVU(a,b) ((a)/(b)) |
+#define FLOAT_SQRT(a) (spx_sqrt(a)) |
+ |
+#endif |
+ |
+#endif |
Property changes on: speex/libspeex/pseudofloat.h |
___________________________________________________________________ |
Name: svn:executable |
+ * |