ORCALib/math2.asm
2021-03-09 00:24:26 -06:00

156 lines
2.9 KiB
NASM

keep obj/math2
mcopy math2.macros
case on
****************************************************************
*
* Math2 - additional math routines
*
* This code provides additional functions from <math.h>
* (including internal helper functions used by macros),
* supplementing the ones in SysFloat.
*
****************************************************************
math2 private dummy segment
end
****************************************************************
*
* int __fpclassifyf(float x);
*
* Classify a float value
*
* Inputs:
* val - the number to classify
*
* Outputs:
* one of the FP_* classification values
*
****************************************************************
*
__fpclassifyf start
csubroutine (10:val),0
tdc
clc
adc #val
ldy #0
phy
pha
phy
pha
phy
pha
FX2S
FCLASSS
txa
and #$00FF
cmp #$00FC
bne lb1
inc a
lb1 sta val
creturn 2:val
end
****************************************************************
*
* int __fpclassifyd(double x);
*
* Classify a double value
*
* Inputs:
* val - the number to classify
*
* Outputs:
* one of the FP_* classification values
*
****************************************************************
*
__fpclassifyd start
csubroutine (10:val),0
tdc
clc
adc #val
ldy #0
phy
pha
phy
pha
phy
pha
FX2D
FCLASSD
txa
and #$00FF
cmp #$00FC
bne lb1
inc a
lb1 sta val
creturn 2:val
end
****************************************************************
*
* int __fpclassifyl(long double x);
*
* Classify a long double value
*
* Inputs:
* val - the number to classify
*
* Outputs:
* one of the FP_* classification values
*
****************************************************************
*
__fpclassifyl start
csubroutine (10:val),0
tdc
clc
adc #val
pea 0
pha
FCLASSX
txa
and #$00FF
cmp #$00FC
bne lb1
inc a
lb1 sta val
creturn 2:val
end
****************************************************************
*
* int __signbit(long double x);
*
* Get the sign bit of a floating-point value
*
* Inputs:
* val - the number
*
* Outputs:
* 0 if positive, non-zero if negative
*
****************************************************************
*
__signbit start
csubroutine (10:val),0
lda val+8
and #$8000
sta val
creturn 2:val
end