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remove preprocessor_math.h 

Compiler are pretty smart today. sqrt is precalculated for constant values.
E.g. you need to #include <math.h>. But no need to link the libmath.
cos/sin and other stuff should also work.
This commit is contained in:
Nico Tonnhofer 2017-12-02 00:05:04 +01:00
parent 3b13eb342f
commit e23a9b3e23
2 changed files with 4 additions and 53 deletions
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9
dda.c
View File

@ -9,7 +9,6 @@
#include <math.h> #include <math.h>
#include "dda_maths.h" #include "dda_maths.h"
#include "preprocessor_math.h"
#include "dda_kinematics.h" #include "dda_kinematics.h"
#include "dda_lookahead.h" #include "dda_lookahead.h"
#include "cpu.h" #include "cpu.h"
@ -64,10 +63,10 @@ static const axes_uint32_t PROGMEM maximum_feedrate_P = {
/// \brief Initialization constant for the ramping algorithm. Timer cycles for /// \brief Initialization constant for the ramping algorithm. Timer cycles for
/// first step interval. /// first step interval.
static const axes_uint32_t PROGMEM c0_P = { static const axes_uint32_t PROGMEM c0_P = {
(uint32_t)((double)F_CPU / SQRT((double)STEPS_PER_M_X * ACCELERATION / 2000.)), (uint32_t)((double)F_CPU / sqrt((double)STEPS_PER_M_X * ACCELERATION / 2000.)),
(uint32_t)((double)F_CPU / SQRT((double)STEPS_PER_M_Y * ACCELERATION / 2000.)), (uint32_t)((double)F_CPU / sqrt((double)STEPS_PER_M_Y * ACCELERATION / 2000.)),
(uint32_t)((double)F_CPU / SQRT((double)STEPS_PER_M_Z * ACCELERATION / 2000.)), (uint32_t)((double)F_CPU / sqrt((double)STEPS_PER_M_Z * ACCELERATION / 2000.)),
(uint32_t)((double)F_CPU / SQRT((double)STEPS_PER_M_E * ACCELERATION / 2000.)) (uint32_t)((double)F_CPU / sqrt((double)STEPS_PER_M_E * ACCELERATION / 2000.))
}; };
#endif #endif

48
preprocessor_math.h
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@ -1,48 +0,0 @@
/** \file
\brief Math functions meant to be calculated in the C preprocessor.
\details Math functions presented here avoid library calls, which means they
can be solved at compile time and as such used to initialise
constants. When used for intitialising, their cost at runtime is
zero, as they resolve into a single number.
*/
#ifndef _PREPROCESSOR_MATH_H
#define _PREPROCESSOR_MATH_H
/*! Preprocessor square root.
(uint32_t)(SQRT(i) + .5)
equals
(uint32_t)(sqrt(i) + .5)
These two provide identical results for all tested numbers across the
uint32 range. Casting to other sizes is also possible.
Can principally be used for calculations at runtime, too, but its compiled
size is prohibitively large (more than 20kB per instance).
Initial version found on pl.comp.lang.c, posted by Jean-Louis PATANE.
*/
#define SQR00(x) (((x) > 65535) ? (double)65535 : (double)(x) / 2)
#define SQR01(x) ((SQR00(x) + ((x) / SQR00(x))) / 2)
#define SQR02(x) ((SQR01(x) + ((x) / SQR01(x))) / 2)
#define SQR03(x) ((SQR02(x) + ((x) / SQR02(x))) / 2)
#define SQR04(x) ((SQR03(x) + ((x) / SQR03(x))) / 2)
#define SQR05(x) ((SQR04(x) + ((x) / SQR04(x))) / 2)
#define SQR06(x) ((SQR05(x) + ((x) / SQR05(x))) / 2)
#define SQR07(x) ((SQR06(x) + ((x) / SQR06(x))) / 2)
#define SQR08(x) ((SQR07(x) + ((x) / SQR07(x))) / 2)
#define SQR09(x) ((SQR08(x) + ((x) / SQR08(x))) / 2)
#define SQR10(x) ((SQR09(x) + ((x) / SQR09(x))) / 2)
#define SQR11(x) ((SQR10(x) + ((x) / SQR10(x))) / 2)
#define SQR12(x) ((SQR11(x) + ((x) / SQR11(x))) / 2)
// We use 9 iterations, note how SQR10() and up get ignored. You can add more
// iterations here, but beware, the length of the preprocessed term
// explodes, leading to several seconds compile time above about SQR10().
#define SQRT(x) ((SQR09(x) + ((x) / SQR09(x))) / 2)
#endif /* _PREPROCESSOR_MATH_H */