ORCA-C/CGC.asm
Stephen Heumann b43036409e Add a new optimize flag for FP math optimizations that break IEEE rules.
There were several existing optimizations that could change behavior in ways that violated the IEEE standard with regard to infinities, NaNs, or signed zeros. They are now gated behind a new #pragma optimize flag. This change allows intermediate code peephole optimization and common subexpression elimination to be used while maintaining IEEE conformance, but also keeps the rule-breaking optimizations available if desired.

See section F.9.2 of recent C standards for a discussion of how these optimizations violate IEEE rules.
2021-11-29 20:31:15 -06:00

276 lines
6.7 KiB
NASM

mcopy cgc.macros
****************************************************************
*
* CnvSX - Convert floating point to SANE extended
*
* Inputs:
* rec - pointer to a record
*
****************************************************************
*
CnvSX start cg
rec equ 4 record containing values
rec_real equ 0 disp to real (extended) value
rec_ext equ 10 disp to extended (SANE) value
tsc set up DP
phd
tcd
ph4 rec push addr of real number
clc push addr of SANE number
lda rec
adc #rec_ext
tax
lda rec+2
adc #0
pha
phx
fx2x convert TOS to extended
move4 0,4 return
pld
pla
pla
rtl
end
****************************************************************
*
* CnvSC - Convert floating point to SANE comp
*
* Inputs:
* rec - pointer to a record
*
* Note: This avoids calling FX2C on negative numbers,
* because it is buggy for certain values.
*
****************************************************************
*
CnvSC start cg
rec equ 4 record containing values
rec_real equ 0 disp to real (extended) value
rec_ext equ 10 disp to extended (SANE) value
rec_cmp equ 20 disp to comp (SANE) value
tsc set up DP
phd
tcd
ldy #rec_real+8
lda [rec],y
pha save sign of real number
and #$7fff
sta [rec],y set sign of real number to positive
ph4 rec push addr of real number
clc push addr of SANE comp number
lda rec
adc #rec_cmp
tax
lda rec+2
adc #0
pha
phx
fx2c convert TOS to SANE comp number
pla
bpl ret if real number was negative
ldy #rec_real+8 restore original sign of real number
sta [rec],y
sec negate the comp value
ldy #rec_cmp
ldx #0
txa
sbc [rec],y
sta [rec],y
iny
iny
txa
sbc [rec],y
sta [rec],y
iny
iny
txa
sbc [rec],y
sta [rec],y
iny
iny
txa
sbc [rec],y
sta [rec],y
ret move4 0,4 return
pld
pla
pla
rtl
end
****************************************************************
*
* procedure CnvXLL (var result: longlong; val: extended);
*
* Convert floating point to long long
*
* Inputs:
* result - longlong to hold the converted value
* val - the real value
*
****************************************************************
CnvXLL start cg
subroutine (4:result,10:val),0
pei (val+8)
pei (val+6)
pei (val+4)
pei (val+2)
pei (val)
jsl ~CnvRealLongLong
pl8 [result]
return
end
****************************************************************
*
* procedure CnvXULL (var result: longlong; val: extended);
*
* Convert floating point to unsigned long long
*
* Inputs:
* result - longlong to hold the converted value
* val - the real value
*
****************************************************************
CnvXULL start cg
subroutine (4:result,10:val),0
pei (val+8)
pei (val+6)
pei (val+4)
pei (val+2)
pei (val)
jsl ~CnvRealULongLong
pl8 [result]
return
end
****************************************************************
*
* function CnvLLX (val: longlong): extended;
*
* convert a long long to a real number
*
* Inputs:
* val - the long long value
*
****************************************************************
CnvLLX start cg
subroutine (4:val),0
ph8 [val]
jsl ~CnvLongLongReal
pla
sta >rval
pla
sta >rval+2
pla
sta >rval+4
pla
sta >rval+6
pla
sta >rval+8
lla val,rval
return 4:val
rval ds 10
end
****************************************************************
*
* function CnvULLX (val: longlong): extended;
*
* convert an unsigned long long to a real number
*
* Inputs:
* val - the unsigned long long value
*
****************************************************************
CnvULLX start cg
subroutine (4:val),0
ph8 [val]
jsl ~CnvULongLongReal
pla
sta >rval
pla
sta >rval+2
pla
sta >rval+4
pla
sta >rval+6
pla
sta >rval+8
lla val,rval
return 4:val
rval ds 10
end
datachk off
****************************************************************
*
* InitLabels - initialize the labels array
*
* Outputs:
* labelTab - initialized
* intLabel - initialized
*
****************************************************************
*
InitLabels start cg
maxLabel equ 3200
! with labelTab[0] do begin
lda #-1 val := -1;
sta labelTab+6
sta labelTab+8
stz labelTab defined := false;
stz labelTab+2 chain := nil;
stz labelTab+4
! end; {with}
ldx #labelTab for i := 1 to maxLabel do
ldy #labelTab+10 labelTab[i] := labelTab[0];
lda #maxLabel*10-1
mvn labelTab,labelTab
stz intLabel intLabel := 0;
rtl
end
datachk on
****************************************************************
*
* function SignBit (val: extended): integer;
*
* returns the sign bit of a floating-point number
* (0 for positive, 1 for negative)
*
****************************************************************
*
SignBit start cg
subroutine (10:val),0
asl val+8
stz val
rol val
return 2:val
end