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bfloat16 wip

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~d6 2022-01-17 22:52:44 -05:00
parent 9b63c1eb6c
commit 9ab32991ed
1 changed files with 39 additions and 38 deletions
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bfloat16.tal
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@ -152,18 +152,6 @@
%EXPONENT { #10 SFT2 POP } %EXPONENT { #10 SFT2 POP }
%MANTISSA { NIP #7f AND } %MANTISSA { NIP #7f AND }
( returns sign: #00 or #01 )
@sign ( x* -> sgn^ )
SIGN JMP2r
( returns exp: #00 to #ff )
@exponent ( x* -> exp^ )
EXPONENT JMP2r
( returns mta: #00 to #7f )
@mantissa ( x* -> mta^ )
MANTISSA JMP2r
( returns full mta: #00 to #ff ) ( returns full mta: #00 to #ff )
( normal numbers will be >= #80 ) ( normal numbers will be >= #80 )
( subnormal numbers will be < #80 ) ( subnormal numbers will be < #80 )
@ -175,11 +163,14 @@
@negate-bf16 ( x* -> z* ) @negate-bf16 ( x* -> z* )
#8000 EOR2 JMP2r #8000 EOR2 JMP2r
@abs-bf16 ( x* -> z* )
#7fff AND2 JMP2r
@is-zero ( x* -> bool^ ) @is-zero ( x* -> bool^ )
#7fff AND2 #0000 EQU2 #7fff AND2 #0000 EQU2 JMP2r
@non-zero ( x* -> bool^ ) @non-zero ( x* -> bool^ )
#7fff AND2 #0000 NEQ2 #7fff AND2 #0000 NEQ2 JMP2r
( Shift mantissa m right by n bits, with rounding ) ( Shift mantissa m right by n bits, with rounding )
( ) ( )
@ -262,19 +253,19 @@
@ne-bf16 ( x* y* -> bool^ ) @ne-bf16 ( x* y* -> bool^ )
;eq-bf16 JSR2 #00 EQU JMP2r ;eq-bf16 JSR2 #00 EQU JMP2r
( rules for sentinels (in order): ) ( rules for sentinels (in order): )
( 1. x < x is false ) ( 1. x < x is false )
( 2a. nan < x is false ) ( 2a. nan < x is false )
( 2b. x < nan is false ) ( 2b. x < nan is false )
( 3a. x < +inf is true ) ( 3a. x < +inf is true )
( 3b. +inf < x is false ) ( 3b. +inf < x is false )
( 4a. -inf < x is true ) ( 4a. -inf < x is true )
( 4b. x < -inf is false ) ( 4b. x < -inf is false )
( 5. -0 < +0 is false ) ( 5. -0 < +0 is false )
( 6. -x < +x (or 0) ) ( 6. -x < +x (or 0) )
( 7. 0 < +x ) ( 7. 0 < +x )
( 8. x*2^p < y*2^q if p < q ) ( 8. x*2^p < y*2^q if p < q )
( 9. x*2^p < y*2^p if x < y ) ( 9. x*2^p < y*2^p if x < y )
@lt-bf16 ( x* y* -> bool^ ) @lt-bf16 ( x* y* -> bool^ )
,&y STR2 ,&x STR2 ,&y STR2 ,&x STR2
,&y LDR2 ;non-nan JSR2 ( is y not nan? ) ,&y LDR2 ;non-nan JSR2 ( is y not nan? )
@ -285,16 +276,26 @@
,&x ;non-zero JSR2 ( is x non-zero? ) ,&x ;non-zero JSR2 ( is x non-zero? )
ORA ,&not-zero JCN #00 JMP2r ( false if x and y are zero ) ORA ,&not-zero JCN #00 JMP2r ( false if x and y are zero )
&not-zero &not-zero
,&x LDR2 ;sign JSR2 ( sign of x ) ,&x LDR2 SIGN ( sign of x )
,&y LDR2 ;sign JSR2 ( sign of y ) ,&y LDR2 SIGN ( sign of y )
EQUk ,&same-sign JCN GTH JMP2r ( return unless signs are eq ) EQUk ,&same-sign JCN GTH JMP2r ( return unless signs are eq )
[ &x $2 &y $2 ] [ &x $2 &y $2 ]
&same-sign POP &same-sign
,&x LDR2 ;exponent JSR2 ( exponent of x ) POP ,&is-negative JCN
,&y LDR2 ;exponent JSR2 ( exponent of y ) ,&x LDR2 ,&y LDR2 LTH2 JMP2r ( for positives, use integer x < y )
EQUk ,&exp-eq JCN LTH JMP2r ( return ex < ey unless exps are eq ) &is-negative
&exp-eq POP ,&x LDR2 ,&y LDR2 GTH2 JMP2r ( for negatives, use integer x > y )
,&x LDR2 ;mantissa JSR2 ( mantissa of x )
,&y LDR2 ;exponent JSR2 ( mantissa of y )
LTH JMP2r ( mx < my )
( see lt-bf16; (x < y) = (y < x) )
@gt-bf16 ( x* y* -> bool^ )
SWP2 ;lt-bf16 JMP2
( special cases: )
( 1. x + y = y + x )
( 2. nan + x = nan )
( 3. 0 + x = x )
( 4. inf + (-inf) = nan )
( 5. inf + x = inf )
( 6. -inf + x = -inf )
@add-bf16 ( x* y* -> z* )
JMP2r