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; This test covers the behavior of 40-bit mode for a variety of values.
; It takes a while to run completely (~5 minutes), but progress is indicated via mail shown at the
; top of the screen in DSPSpy. The value will go from 80000000 to 8041ffff.
incdir "tests"
include "dsp_base.inc"
test_main:
LRI $ar0, #0
LRI $ar1, #0
LRI $ar2, #0
LRI $ar3, #0
LRI $ix0, #0
LRI $ix1, #0
LRI $ix2, #0
LRI $ix3, #0
; Test with $ac0.l from 0xfff0 to 0x0010
LRI $ac0.l, #0xfff0
BLOOPI #0x21, first_loop_last_ins
CALL test_saturation
IAR $ar0
first_loop_last_ins:
INC $acc0
; Test with $ac0.l from 0x7ff0 to 0x8010
LRI $ac0.l, #0xfff0
BLOOPI #0x21, second_loop_last_ins
CALL test_saturation
IAR $ar0
second_loop_last_ins:
INC $acc0
; We're done. Report the test results.
; $ix1 should be 0, or else saturation occurred on $ac0.l or $ac0.h.
; $ix2 should be 0, or else sign-extension occurred on $ac0.l or $ac0.h.
; $ix3 should be 0, or else we incorrectly predicted saturation on $ac0.m.
; $ar1/$ar2/$ar3 records the number of times it happened
CALL send_back
; We're done, DO NOT DELETE THIS LINE
JMP end_of_test
test_saturation:
; We start with $ac0.h at -0x80 since we can use the overflow flag to check when wrapping around
; occurs; starting at 0 and ending when it wraps back to 0 doesn't work since we can't check the
; zero flag since $ac0.l may be nonzero ($ac0.l is used as an input to this subroutine)
LRI $ac0.m, #0
LRI $ac0.h, #-0x80
loop_start:
; Compare the value of $ac0.m when in SET16 mode and in SET40 mode
SET40
; Reading $ac0.m in SET40 mode results in saturation if $ac0.h doesn't match the sign-extension
; of $ac0.h. Also, storing to $ac1.m in SET40 mode clears $ac1.l and sets $ac1.h to the
; sign-extension of $ac1.m, and $ac1.l.
MRR $ac1.m, $ac0.m
SET16
; Attempt to compute the saturated value of $ac1.m in $ax1.h,
; using what we know of $acc0.
TST'MV $acc0 : $ax1.h, $ac0.m
JL negative_acc0
; $acc0 is nonnegative.
JMPx8 check_saturated_ax1h ; If the above s32 bit is not set, we don't need to saturate
; If the above s32 bit _is_ set, then saturate $ax1.h.
LRI $ax1.h, #0x7fff
JMP check_saturated_ax1h
negative_acc0:
JMPx8 check_saturated_ax1h ; If the above s32 bit is not set, we don't need to saturate
LRI $ax1.h, #0x8000
; Fall through to check_saturated_ax1h
check_saturated_ax1h:
; $acc1 has the value of $ac0.m in SET40 mode.
; And, $ax1.h has what we computed that value should be, and CMPAXH always sign-extends $ax1.h
; (and ignores $ax1.l), so we can compare using it directly.
CMPAXH $acc1, $ax1.h
JZ check_read_low
; Our prediction was wrong (shouldn't happen)
LRI $ix3, #1
IAR $ar3
TST $acc0
CALL send_back
; Fall through to check_read_low
check_read_low:
SET40
MRR $ac1.m, $ac0.l
SET16
MRR $ax1.h, $ac0.l
CMPAXH $acc1, $ax1.h
JZ check_read_high
; Reading $ac0.l gave different results in SET40 and SET16 modes (shouldn't happen)
LRI $ix1, #1
IAR $ar1
TST $acc0
CALL send_back
; Fall through to check_read_high
check_read_high:
SET40
MRR $ac1.m, $ac0.h
SET16
MRR $ax1.h, $ac0.h
CMPAXH $acc1, $ax1.h
JZ check_write_low
; Reading $ac0.h gave different results in SET40 and SET16 modes (shouldn't happen)
LRI $ix1, #1
IAR $ar1
TST $acc0
CALL send_back
; Fall through to check_write_low
check_write_low:
MOV $acc1, $acc0
SET40
MRR $ac1.l, $ac0.l
SET16
CMP
JZ check_write_high
; Writing to $ac1.l caused $acc1 to not match $acc0 (shouldn't happen)
LRI $ix2, #1
IAR $ar2
CALL send_back
; Fall through to check_write_high
check_write_high:
MOV $acc1, $acc0
SET40
MRR $ac1.h, $ac0.h
SET16
CMP
JZ increment_loop
; Writing to $ac1.h caused $acc1 to not match $acc0 (shouldn't happen)
LRI $ix2, #1
IAR $ar2
CALL send_back
; Fall through to increment_loop
increment_loop:
INCM $ac0.m
; If incrementing results in overflowing, then we're done.
RETO
; If ($ac0.m & 0x00ff) != 0, continue the loop without sending mail.
ANDF $ac0.m, #0x00ff
JLNZ loop_start
; Otherwise, send mail to report the progress. (This shows at the top of the screen in DSPSpy,
; but otherwise isn't handled in any meaningful way.)
MOV $acc1, $acc0
LSR $acc1, #-8
; Compensate for starting at INT_MIN (0x80'0000'0000) and ending at INT_MAX (0x7f'0000'0000)
; instead of going from 0 (0x00'0000'0000) to -1 (0xff'ffff'ffff)
XORI $ac1.m, #0x8000
SR @DMBH, $ar0
SR @DMBL, $ac1.m
SI @DIRQ, #0x0001
; We don't wait for the mail to be read, because we don't care about the response.
JMP loop_start
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