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Diffstat (limited to 'arch/m68k/math-emu/fp_util.S')
| -rw-r--r-- | arch/m68k/math-emu/fp_util.S | 1455 |
1 files changed, 1455 insertions, 0 deletions
diff --git a/arch/m68k/math-emu/fp_util.S b/arch/m68k/math-emu/fp_util.S new file mode 100644 index 00000000000..a9f7f012906 --- /dev/null +++ b/arch/m68k/math-emu/fp_util.S @@ -0,0 +1,1455 @@ +/* + * fp_util.S + * + * Copyright Roman Zippel, 1997. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, and the entire permission notice in its entirety, + * including the disclaimer of warranties. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * ALTERNATIVELY, this product may be distributed under the terms of + * the GNU General Public License, in which case the provisions of the GPL are + * required INSTEAD OF the above restrictions. (This clause is + * necessary due to a potential bad interaction between the GPL and + * the restrictions contained in a BSD-style copyright.) + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <linux/config.h> +#include "fp_emu.h" + +/* + * Here are lots of conversion and normalization functions mainly + * used by fp_scan.S + * Note that these functions are optimized for "normal" numbers, + * these are handled first and exit as fast as possible, this is + * especially important for fp_normalize_ext/fp_conv_ext2ext, as + * it's called very often. + * The register usage is optimized for fp_scan.S and which register + * is currently at that time unused, be careful if you want change + * something here. %d0 and %d1 is always usable, sometimes %d2 (or + * only the lower half) most function have to return the %a0 + * unmodified, so that the caller can immediately reuse it. + */ + + .globl fp_ill, fp_end + + | exits from fp_scan: + | illegal instruction +fp_ill: + printf ,"fp_illegal\n" + rts + | completed instruction +fp_end: + tst.l (TASK_MM-8,%a2) + jmi 1f + tst.l (TASK_MM-4,%a2) + jmi 1f + tst.l (TASK_MM,%a2) + jpl 2f +1: printf ,"oops:%p,%p,%p\n",3,%a2@(TASK_MM-8),%a2@(TASK_MM-4),%a2@(TASK_MM) +2: clr.l %d0 + rts + + .globl fp_conv_long2ext, fp_conv_single2ext + .globl fp_conv_double2ext, fp_conv_ext2ext + .globl fp_normalize_ext, fp_normalize_double + .globl fp_normalize_single, fp_normalize_single_fast + .globl fp_conv_ext2double, fp_conv_ext2single + .globl fp_conv_ext2long, fp_conv_ext2short + .globl fp_conv_ext2byte + .globl fp_finalrounding_single, fp_finalrounding_single_fast + .globl fp_finalrounding_double + .globl fp_finalrounding, fp_finaltest, fp_final + +/* + * First several conversion functions from a source operand + * into the extended format. Note, that only fp_conv_ext2ext + * normalizes the number and is always called after the other + * conversion functions, which only move the information into + * fp_ext structure. + */ + + | fp_conv_long2ext: + | + | args: %d0 = source (32-bit long) + | %a0 = destination (ptr to struct fp_ext) + +fp_conv_long2ext: + printf PCONV,"l2e: %p -> %p(",2,%d0,%a0 + clr.l %d1 | sign defaults to zero + tst.l %d0 + jeq fp_l2e_zero | is source zero? + jpl 1f | positive? + moveq #1,%d1 + neg.l %d0 +1: swap %d1 + move.w #0x3fff+31,%d1 + move.l %d1,(%a0)+ | set sign / exp + move.l %d0,(%a0)+ | set mantissa + clr.l (%a0) + subq.l #8,%a0 | restore %a0 + printx PCONV,%a0@ + printf PCONV,")\n" + rts + | source is zero +fp_l2e_zero: + clr.l (%a0)+ + clr.l (%a0)+ + clr.l (%a0) + subq.l #8,%a0 + printx PCONV,%a0@ + printf PCONV,")\n" + rts + + | fp_conv_single2ext + | args: %d0 = source (single-precision fp value) + | %a0 = dest (struct fp_ext *) + +fp_conv_single2ext: + printf PCONV,"s2e: %p -> %p(",2,%d0,%a0 + move.l %d0,%d1 + lsl.l #8,%d0 | shift mantissa + lsr.l #8,%d1 | exponent / sign + lsr.l #7,%d1 + lsr.w #8,%d1 + jeq fp_s2e_small | zero / denormal? + cmp.w #0xff,%d1 | NaN / Inf? + jeq fp_s2e_large + bset #31,%d0 | set explizit bit + add.w #0x3fff-0x7f,%d1 | re-bias the exponent. +9: move.l %d1,(%a0)+ | fp_ext.sign, fp_ext.exp + move.l %d0,(%a0)+ | high lword of fp_ext.mant + clr.l (%a0) | low lword = 0 + subq.l #8,%a0 + printx PCONV,%a0@ + printf PCONV,")\n" + rts + | zeros and denormalized +fp_s2e_small: + | exponent is zero, so explizit bit is already zero too + tst.l %d0 + jeq 9b + move.w #0x4000-0x7f,%d1 + jra 9b + | infinities and NAN +fp_s2e_large: + bclr #31,%d0 | clear explizit bit + move.w #0x7fff,%d1 + jra 9b + +fp_conv_double2ext: +#ifdef FPU_EMU_DEBUG + getuser.l %a1@(0),%d0,fp_err_ua2,%a1 + getuser.l %a1@(4),%d1,fp_err_ua2,%a1 + printf PCONV,"d2e: %p%p -> %p(",3,%d0,%d1,%a0 +#endif + getuser.l (%a1)+,%d0,fp_err_ua2,%a1 + move.l %d0,%d1 + lsl.l #8,%d0 | shift high mantissa + lsl.l #3,%d0 + lsr.l #8,%d1 | exponent / sign + lsr.l #7,%d1 + lsr.w #5,%d1 + jeq fp_d2e_small | zero / denormal? + cmp.w #0x7ff,%d1 | NaN / Inf? + jeq fp_d2e_large + bset #31,%d0 | set explizit bit + add.w #0x3fff-0x3ff,%d1 | re-bias the exponent. +9: move.l %d1,(%a0)+ | fp_ext.sign, fp_ext.exp + move.l %d0,(%a0)+ + getuser.l (%a1)+,%d0,fp_err_ua2,%a1 + move.l %d0,%d1 + lsl.l #8,%d0 + lsl.l #3,%d0 + move.l %d0,(%a0) + moveq #21,%d0 + lsr.l %d0,%d1 + or.l %d1,-(%a0) + subq.l #4,%a0 + printx PCONV,%a0@ + printf PCONV,")\n" + rts + | zeros and denormalized +fp_d2e_small: + | exponent is zero, so explizit bit is already zero too + tst.l %d0 + jeq 9b + move.w #0x4000-0x3ff,%d1 + jra 9b + | infinities and NAN +fp_d2e_large: + bclr #31,%d0 | clear explizit bit + move.w #0x7fff,%d1 + jra 9b + + | fp_conv_ext2ext: + | originally used to get longdouble from userspace, now it's + | called before arithmetic operations to make sure the number + | is normalized [maybe rename it?]. + | args: %a0 = dest (struct fp_ext *) + | returns 0 in %d0 for a NaN, otherwise 1 + +fp_conv_ext2ext: + printf PCONV,"e2e: %p(",1,%a0 + printx PCONV,%a0@ + printf PCONV,"), " + move.l (%a0)+,%d0 + cmp.w #0x7fff,%d0 | Inf / NaN? + jeq fp_e2e_large + move.l (%a0),%d0 + jpl fp_e2e_small | zero / denorm? + | The high bit is set, so normalization is irrelevant. +fp_e2e_checkround: + subq.l #4,%a0 +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC + move.b (%a0),%d0 + jne fp_e2e_round +#endif + printf PCONV,"%p(",1,%a0 + printx PCONV,%a0@ + printf PCONV,")\n" + moveq #1,%d0 + rts +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC +fp_e2e_round: + fp_set_sr FPSR_EXC_INEX2 + clr.b (%a0) + move.w (FPD_RND,FPDATA),%d2 + jne fp_e2e_roundother | %d2 == 0, round to nearest + tst.b %d0 | test guard bit + jpl 9f | zero is closer + btst #0,(11,%a0) | test lsb bit + jne fp_e2e_doroundup | round to infinity + lsl.b #1,%d0 | check low bits + jeq 9f | round to zero +fp_e2e_doroundup: + addq.l #1,(8,%a0) + jcc 9f + addq.l #1,(4,%a0) + jcc 9f + move.w #0x8000,(4,%a0) + addq.w #1,(2,%a0) +9: printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts +fp_e2e_roundother: + subq.w #2,%d2 + jcs 9b | %d2 < 2, round to zero + jhi 1f | %d2 > 2, round to +infinity + tst.b (1,%a0) | to -inf + jne fp_e2e_doroundup | negative, round to infinity + jra 9b | positive, round to zero +1: tst.b (1,%a0) | to +inf + jeq fp_e2e_doroundup | positive, round to infinity + jra 9b | negative, round to zero +#endif + | zeros and subnormals: + | try to normalize these anyway. +fp_e2e_small: + jne fp_e2e_small1 | high lword zero? + move.l (4,%a0),%d0 + jne fp_e2e_small2 +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC + clr.l %d0 + move.b (-4,%a0),%d0 + jne fp_e2e_small3 +#endif + | Genuine zero. + clr.w -(%a0) + subq.l #2,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + moveq #1,%d0 + rts + | definitely subnormal, need to shift all 64 bits +fp_e2e_small1: + bfffo %d0{#0,#32},%d1 + move.w -(%a0),%d2 + sub.w %d1,%d2 + jcc 1f + | Pathologically small, denormalize. + add.w %d2,%d1 + clr.w %d2 +1: move.w %d2,(%a0)+ + move.w %d1,%d2 + jeq fp_e2e_checkround + | fancy 64-bit double-shift begins here + lsl.l %d2,%d0 + move.l %d0,(%a0)+ + move.l (%a0),%d0 + move.l %d0,%d1 + lsl.l %d2,%d0 + move.l %d0,(%a0) + neg.w %d2 + and.w #0x1f,%d2 + lsr.l %d2,%d1 + or.l %d1,-(%a0) +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC +fp_e2e_extra1: + clr.l %d0 + move.b (-4,%a0),%d0 + neg.w %d2 + add.w #24,%d2 + jcc 1f + clr.b (-4,%a0) + lsl.l %d2,%d0 + or.l %d0,(4,%a0) + jra fp_e2e_checkround +1: addq.w #8,%d2 + lsl.l %d2,%d0 + move.b %d0,(-4,%a0) + lsr.l #8,%d0 + or.l %d0,(4,%a0) +#endif + jra fp_e2e_checkround + | pathologically small subnormal +fp_e2e_small2: + bfffo %d0{#0,#32},%d1 + add.w #32,%d1 + move.w -(%a0),%d2 + sub.w %d1,%d2 + jcc 1f + | Beyond pathologically small, denormalize. + add.w %d2,%d1 + clr.w %d2 +1: move.w %d2,(%a0)+ + ext.l %d1 + jeq fp_e2e_checkround + clr.l (4,%a0) + sub.w #32,%d2 + jcs 1f + lsl.l %d1,%d0 | lower lword needs only to be shifted + move.l %d0,(%a0) | into the higher lword +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC + clr.l %d0 + move.b (-4,%a0),%d0 + clr.b (-4,%a0) + neg.w %d1 + add.w #32,%d1 + bfins %d0,(%a0){%d1,#8} +#endif + jra fp_e2e_checkround +1: neg.w %d1 | lower lword is splitted between + bfins %d0,(%a0){%d1,#32} | higher and lower lword +#ifndef CONFIG_M68KFPU_EMU_EXTRAPREC + jra fp_e2e_checkround +#else + move.w %d1,%d2 + jra fp_e2e_extra1 + | These are extremely small numbers, that will mostly end up as zero + | anyway, so this is only important for correct rounding. +fp_e2e_small3: + bfffo %d0{#24,#8},%d1 + add.w #40,%d1 + move.w -(%a0),%d2 + sub.w %d1,%d2 + jcc 1f + | Pathologically small, denormalize. + add.w %d2,%d1 + clr.w %d2 +1: move.w %d2,(%a0)+ + ext.l %d1 + jeq fp_e2e_checkround + cmp.w #8,%d1 + jcs 2f +1: clr.b (-4,%a0) + sub.w #64,%d1 + jcs 1f + add.w #24,%d1 + lsl.l %d1,%d0 + move.l %d0,(%a0) + jra fp_e2e_checkround +1: neg.w %d1 + bfins %d0,(%a0){%d1,#8} + jra fp_e2e_checkround +2: lsl.l %d1,%d0 + move.b %d0,(-4,%a0) + lsr.l #8,%d0 + move.b %d0,(7,%a0) + jra fp_e2e_checkround +#endif +1: move.l %d0,%d1 | lower lword is splitted between + lsl.l %d2,%d0 | higher and lower lword + move.l %d0,(%a0) + move.l %d1,%d0 + neg.w %d2 + add.w #32,%d2 + lsr.l %d2,%d0 + move.l %d0,-(%a0) + jra fp_e2e_checkround + | Infinities and NaNs +fp_e2e_large: + move.l (%a0)+,%d0 + jne 3f +1: tst.l (%a0) + jne 4f + moveq #1,%d0 +2: subq.l #8,%a0 + printf PCONV,"%p(",1,%a0 + printx PCONV,%a0@ + printf PCONV,")\n" + rts + | we have maybe a NaN, shift off the highest bit +3: lsl.l #1,%d0 + jeq 1b + | we have a NaN, clear the return value +4: clrl %d0 + jra 2b + + +/* + * Normalization functions. Call these on the output of general + * FP operators, and before any conversion into the destination + * formats. fp_normalize_ext has always to be called first, the + * following conversion functions expect an already normalized + * number. + */ + + | fp_normalize_ext: + | normalize an extended in extended (unpacked) format, basically + | it does the same as fp_conv_ext2ext, additionally it also does + | the necessary postprocessing checks. + | args: %a0 (struct fp_ext *) + | NOTE: it does _not_ modify %a0/%a1 and the upper word of %d2 + +fp_normalize_ext: + printf PNORM,"ne: %p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,"), " + move.l (%a0)+,%d0 + cmp.w #0x7fff,%d0 | Inf / NaN? + jeq fp_ne_large + move.l (%a0),%d0 + jpl fp_ne_small | zero / denorm? + | The high bit is set, so normalization is irrelevant. +fp_ne_checkround: + subq.l #4,%a0 +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC + move.b (%a0),%d0 + jne fp_ne_round +#endif + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC +fp_ne_round: + fp_set_sr FPSR_EXC_INEX2 + clr.b (%a0) + move.w (FPD_RND,FPDATA),%d2 + jne fp_ne_roundother | %d2 == 0, round to nearest + tst.b %d0 | test guard bit + jpl 9f | zero is closer + btst #0,(11,%a0) | test lsb bit + jne fp_ne_doroundup | round to infinity + lsl.b #1,%d0 | check low bits + jeq 9f | round to zero +fp_ne_doroundup: + addq.l #1,(8,%a0) + jcc 9f + addq.l #1,(4,%a0) + jcc 9f + addq.w #1,(2,%a0) + move.w #0x8000,(4,%a0) +9: printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts +fp_ne_roundother: + subq.w #2,%d2 + jcs 9b | %d2 < 2, round to zero + jhi 1f | %d2 > 2, round to +infinity + tst.b (1,%a0) | to -inf + jne fp_ne_doroundup | negative, round to infinity + jra 9b | positive, round to zero +1: tst.b (1,%a0) | to +inf + jeq fp_ne_doroundup | positive, round to infinity + jra 9b | negative, round to zero +#endif + | Zeros and subnormal numbers + | These are probably merely subnormal, rather than "denormalized" + | numbers, so we will try to make them normal again. +fp_ne_small: + jne fp_ne_small1 | high lword zero? + move.l (4,%a0),%d0 + jne fp_ne_small2 +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC + clr.l %d0 + move.b (-4,%a0),%d0 + jne fp_ne_small3 +#endif + | Genuine zero. + clr.w -(%a0) + subq.l #2,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts + | Subnormal. +fp_ne_small1: + bfffo %d0{#0,#32},%d1 + move.w -(%a0),%d2 + sub.w %d1,%d2 + jcc 1f + | Pathologically small, denormalize. + add.w %d2,%d1 + clr.w %d2 + fp_set_sr FPSR_EXC_UNFL +1: move.w %d2,(%a0)+ + move.w %d1,%d2 + jeq fp_ne_checkround + | This is exactly the same 64-bit double shift as seen above. + lsl.l %d2,%d0 + move.l %d0,(%a0)+ + move.l (%a0),%d0 + move.l %d0,%d1 + lsl.l %d2,%d0 + move.l %d0,(%a0) + neg.w %d2 + and.w #0x1f,%d2 + lsr.l %d2,%d1 + or.l %d1,-(%a0) +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC +fp_ne_extra1: + clr.l %d0 + move.b (-4,%a0),%d0 + neg.w %d2 + add.w #24,%d2 + jcc 1f + clr.b (-4,%a0) + lsl.l %d2,%d0 + or.l %d0,(4,%a0) + jra fp_ne_checkround +1: addq.w #8,%d2 + lsl.l %d2,%d0 + move.b %d0,(-4,%a0) + lsr.l #8,%d0 + or.l %d0,(4,%a0) +#endif + jra fp_ne_checkround + | May or may not be subnormal, if so, only 32 bits to shift. +fp_ne_small2: + bfffo %d0{#0,#32},%d1 + add.w #32,%d1 + move.w -(%a0),%d2 + sub.w %d1,%d2 + jcc 1f + | Beyond pathologically small, denormalize. + add.w %d2,%d1 + clr.w %d2 + fp_set_sr FPSR_EXC_UNFL +1: move.w %d2,(%a0)+ + ext.l %d1 + jeq fp_ne_checkround + clr.l (4,%a0) + sub.w #32,%d1 + jcs 1f + lsl.l %d1,%d0 | lower lword needs only to be shifted + move.l %d0,(%a0) | into the higher lword +#ifdef CONFIG_M68KFPU_EMU_EXTRAPREC + clr.l %d0 + move.b (-4,%a0),%d0 + clr.b (-4,%a0) + neg.w %d1 + add.w #32,%d1 + bfins %d0,(%a0){%d1,#8} +#endif + jra fp_ne_checkround +1: neg.w %d1 | lower lword is splitted between + bfins %d0,(%a0){%d1,#32} | higher and lower lword +#ifndef CONFIG_M68KFPU_EMU_EXTRAPREC + jra fp_ne_checkround +#else + move.w %d1,%d2 + jra fp_ne_extra1 + | These are extremely small numbers, that will mostly end up as zero + | anyway, so this is only important for correct rounding. +fp_ne_small3: + bfffo %d0{#24,#8},%d1 + add.w #40,%d1 + move.w -(%a0),%d2 + sub.w %d1,%d2 + jcc 1f + | Pathologically small, denormalize. + add.w %d2,%d1 + clr.w %d2 +1: move.w %d2,(%a0)+ + ext.l %d1 + jeq fp_ne_checkround + cmp.w #8,%d1 + jcs 2f +1: clr.b (-4,%a0) + sub.w #64,%d1 + jcs 1f + add.w #24,%d1 + lsl.l %d1,%d0 + move.l %d0,(%a0) + jra fp_ne_checkround +1: neg.w %d1 + bfins %d0,(%a0){%d1,#8} + jra fp_ne_checkround +2: lsl.l %d1,%d0 + move.b %d0,(-4,%a0) + lsr.l #8,%d0 + move.b %d0,(7,%a0) + jra fp_ne_checkround +#endif + | Infinities and NaNs, again, same as above. +fp_ne_large: + move.l (%a0)+,%d0 + jne 3f +1: tst.l (%a0) + jne 4f +2: subq.l #8,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts + | we have maybe a NaN, shift off the highest bit +3: move.l %d0,%d1 + lsl.l #1,%d1 + jne 4f + clr.l (-4,%a0) + jra 1b + | we have a NaN, test if it is signaling +4: bset #30,%d0 + jne 2b + fp_set_sr FPSR_EXC_SNAN + move.l %d0,(-4,%a0) + jra 2b + + | these next two do rounding as per the IEEE standard. + | values for the rounding modes appear to be: + | 0: Round to nearest + | 1: Round to zero + | 2: Round to -Infinity + | 3: Round to +Infinity + | both functions expect that fp_normalize was already + | called (and extended argument is already normalized + | as far as possible), these are used if there is different + | rounding precision is selected and before converting + | into single/double + + | fp_normalize_double: + | normalize an extended with double (52-bit) precision + | args: %a0 (struct fp_ext *) + +fp_normalize_double: + printf PNORM,"nd: %p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,"), " + move.l (%a0)+,%d2 + tst.w %d2 + jeq fp_nd_zero | zero / denormalized + cmp.w #0x7fff,%d2 + jeq fp_nd_huge | NaN / infinitive. + sub.w #0x4000-0x3ff,%d2 | will the exponent fit? + jcs fp_nd_small | too small. + cmp.w #0x7fe,%d2 + jcc fp_nd_large | too big. + addq.l #4,%a0 + move.l (%a0),%d0 | low lword of mantissa + | now, round off the low 11 bits. +fp_nd_round: + moveq #21,%d1 + lsl.l %d1,%d0 | keep 11 low bits. + jne fp_nd_checkround | Are they non-zero? + | nothing to do here +9: subq.l #8,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts + | Be careful with the X bit! It contains the lsb + | from the shift above, it is needed for round to nearest. +fp_nd_checkround: + fp_set_sr FPSR_EXC_INEX2 | INEX2 bit + and.w #0xf800,(2,%a0) | clear bits 0-10 + move.w (FPD_RND,FPDATA),%d2 | rounding mode + jne 2f | %d2 == 0, round to nearest + tst.l %d0 | test guard bit + jpl 9b | zero is closer + | here we test the X bit by adding it to %d2 + clr.w %d2 | first set z bit, addx only clears it + addx.w %d2,%d2 | test lsb bit + | IEEE754-specified "round to even" behaviour. If the guard + | bit is set, then the number is odd, so rounding works like + | in grade-school arithmetic (i.e. 1.5 rounds to 2.0) + | Otherwise, an equal distance rounds towards zero, so as not + | to produce an odd number. This is strange, but it is what + | the standard says. + jne fp_nd_doroundup | round to infinity + lsl.l #1,%d0 | check low bits + jeq 9b | round to zero +fp_nd_doroundup: + | round (the mantissa, that is) towards infinity + add.l #0x800,(%a0) + jcc 9b | no overflow, good. + addq.l #1,-(%a0) | extend to high lword + jcc 1f | no overflow, good. + | Yow! we have managed to overflow the mantissa. Since this + | only happens when %d1 was 0xfffff800, it is now zero, so + | reset the high bit, and increment the exponent. + move.w #0x8000,(%a0) + addq.w #1,-(%a0) + cmp.w #0x43ff,(%a0)+ | exponent now overflown? + jeq fp_nd_large | yes, so make it infinity. +1: subq.l #4,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts +2: subq.w #2,%d2 + jcs 9b | %d2 < 2, round to zero + jhi 3f | %d2 > 2, round to +infinity + | Round to +Inf or -Inf. High word of %d2 contains the + | sign of the number, by the way. + swap %d2 | to -inf + tst.b %d2 + jne fp_nd_doroundup | negative, round to infinity + jra 9b | positive, round to zero +3: swap %d2 | to +inf + tst.b %d2 + jeq fp_nd_doroundup | positive, round to infinity + jra 9b | negative, round to zero + | Exponent underflow. Try to make a denormal, and set it to + | the smallest possible fraction if this fails. +fp_nd_small: + fp_set_sr FPSR_EXC_UNFL | set UNFL bit + move.w #0x3c01,(-2,%a0) | 2**-1022 + neg.w %d2 | degree of underflow + cmp.w #32,%d2 | single or double shift? + jcc 1f + | Again, another 64-bit double shift. + move.l (%a0),%d0 + move.l %d0,%d1 + lsr.l %d2,%d0 + move.l %d0,(%a0)+ + move.l (%a0),%d0 + lsr.l %d2,%d0 + neg.w %d2 + add.w #32,%d2 + lsl.l %d2,%d1 + or.l %d1,%d0 + move.l (%a0),%d1 + move.l %d0,(%a0) + | Check to see if we shifted off any significant bits + lsl.l %d2,%d1 + jeq fp_nd_round | Nope, round. + bset #0,%d0 | Yes, so set the "sticky bit". + jra fp_nd_round | Now, round. + | Another 64-bit single shift and store +1: sub.w #32,%d2 + cmp.w #32,%d2 | Do we really need to shift? + jcc 2f | No, the number is too small. + move.l (%a0),%d0 + clr.l (%a0)+ + move.l %d0,%d1 + lsr.l %d2,%d0 + neg.w %d2 + add.w #32,%d2 + | Again, check to see if we shifted off any significant bits. + tst.l (%a0) + jeq 1f + bset #0,%d0 | Sticky bit. +1: move.l %d0,(%a0) + lsl.l %d2,%d1 + jeq fp_nd_round + bset #0,%d0 + jra fp_nd_round + | Sorry, the number is just too small. +2: clr.l (%a0)+ + clr.l (%a0) + moveq #1,%d0 | Smallest possible fraction, + jra fp_nd_round | round as desired. + | zero and denormalized +fp_nd_zero: + tst.l (%a0)+ + jne 1f + tst.l (%a0) + jne 1f + subq.l #8,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts | zero. nothing to do. + | These are not merely subnormal numbers, but true denormals, + | i.e. pathologically small (exponent is 2**-16383) numbers. + | It is clearly impossible for even a normal extended number + | with that exponent to fit into double precision, so just + | write these ones off as "too darn small". +1: fp_set_sr FPSR_EXC_UNFL | Set UNFL bit + clr.l (%a0) + clr.l -(%a0) + move.w #0x3c01,-(%a0) | i.e. 2**-1022 + addq.l #6,%a0 + moveq #1,%d0 + jra fp_nd_round | round. + | Exponent overflow. Just call it infinity. +fp_nd_large: + move.w #0x7ff,%d0 + and.w (6,%a0),%d0 + jeq 1f + fp_set_sr FPSR_EXC_INEX2 +1: fp_set_sr FPSR_EXC_OVFL + move.w (FPD_RND,FPDATA),%d2 + jne 3f | %d2 = 0 round to nearest +1: move.w #0x7fff,(-2,%a0) + clr.l (%a0)+ + clr.l (%a0) +2: subq.l #8,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts +3: subq.w #2,%d2 + jcs 5f | %d2 < 2, round to zero + jhi 4f | %d2 > 2, round to +infinity + tst.b (-3,%a0) | to -inf + jne 1b + jra 5f +4: tst.b (-3,%a0) | to +inf + jeq 1b +5: move.w #0x43fe,(-2,%a0) + moveq #-1,%d0 + move.l %d0,(%a0)+ + move.w #0xf800,%d0 + move.l %d0,(%a0) + jra 2b + | Infinities or NaNs +fp_nd_huge: + subq.l #4,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts + + | fp_normalize_single: + | normalize an extended with single (23-bit) precision + | args: %a0 (struct fp_ext *) + +fp_normalize_single: + printf PNORM,"ns: %p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,") " + addq.l #2,%a0 + move.w (%a0)+,%d2 + jeq fp_ns_zero | zero / denormalized + cmp.w #0x7fff,%d2 + jeq fp_ns_huge | NaN / infinitive. + sub.w #0x4000-0x7f,%d2 | will the exponent fit? + jcs fp_ns_small | too small. + cmp.w #0xfe,%d2 + jcc fp_ns_large | too big. + move.l (%a0)+,%d0 | get high lword of mantissa +fp_ns_round: + tst.l (%a0) | check the low lword + jeq 1f + | Set a sticky bit if it is non-zero. This should only + | affect the rounding in what would otherwise be equal- + | distance situations, which is what we want it to do. + bset #0,%d0 +1: clr.l (%a0) | zap it from memory. + | now, round off the low 8 bits of the hi lword. + tst.b %d0 | 8 low bits. + jne fp_ns_checkround | Are they non-zero? + | nothing to do here + subq.l #8,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts +fp_ns_checkround: + fp_set_sr FPSR_EXC_INEX2 | INEX2 bit + clr.b -(%a0) | clear low byte of high lword + subq.l #3,%a0 + move.w (FPD_RND,FPDATA),%d2 | rounding mode + jne 2f | %d2 == 0, round to nearest + tst.b %d0 | test guard bit + jpl 9f | zero is closer + btst #8,%d0 | test lsb bit + | round to even behaviour, see above. + jne fp_ns_doroundup | round to infinity + lsl.b #1,%d0 | check low bits + jeq 9f | round to zero +fp_ns_doroundup: + | round (the mantissa, that is) towards infinity + add.l #0x100,(%a0) + jcc 9f | no overflow, good. + | Overflow. This means that the %d1 was 0xffffff00, so it + | is now zero. We will set the mantissa to reflect this, and + | increment the exponent (checking for overflow there too) + move.w #0x8000,(%a0) + addq.w #1,-(%a0) + cmp.w #0x407f,(%a0)+ | exponent now overflown? + jeq fp_ns_large | yes, so make it infinity. +9: subq.l #4,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts + | check nondefault rounding modes +2: subq.w #2,%d2 + jcs 9b | %d2 < 2, round to zero + jhi 3f | %d2 > 2, round to +infinity + tst.b (-3,%a0) | to -inf + jne fp_ns_doroundup | negative, round to infinity + jra 9b | positive, round to zero +3: tst.b (-3,%a0) | to +inf + jeq fp_ns_doroundup | positive, round to infinity + jra 9b | negative, round to zero + | Exponent underflow. Try to make a denormal, and set it to + | the smallest possible fraction if this fails. +fp_ns_small: + fp_set_sr FPSR_EXC_UNFL | set UNFL bit + move.w #0x3f81,(-2,%a0) | 2**-126 + neg.w %d2 | degree of underflow + cmp.w #32,%d2 | single or double shift? + jcc 2f + | a 32-bit shift. + move.l (%a0),%d0 + move.l %d0,%d1 + lsr.l %d2,%d0 + move.l %d0,(%a0)+ + | Check to see if we shifted off any significant bits. + neg.w %d2 + add.w #32,%d2 + lsl.l %d2,%d1 + jeq 1f + bset #0,%d0 | Sticky bit. + | Check the lower lword +1: tst.l (%a0) + jeq fp_ns_round + clr (%a0) + bset #0,%d0 | Sticky bit. + jra fp_ns_round + | Sorry, the number is just too small. +2: clr.l (%a0)+ + clr.l (%a0) + moveq #1,%d0 | Smallest possible fraction, + jra fp_ns_round | round as desired. + | Exponent overflow. Just call it infinity. +fp_ns_large: + tst.b (3,%a0) + jeq 1f + fp_set_sr FPSR_EXC_INEX2 +1: fp_set_sr FPSR_EXC_OVFL + move.w (FPD_RND,FPDATA),%d2 + jne 3f | %d2 = 0 round to nearest +1: move.w #0x7fff,(-2,%a0) + clr.l (%a0)+ + clr.l (%a0) +2: subq.l #8,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts +3: subq.w #2,%d2 + jcs 5f | %d2 < 2, round to zero + jhi 4f | %d2 > 2, round to +infinity + tst.b (-3,%a0) | to -inf + jne 1b + jra 5f +4: tst.b (-3,%a0) | to +inf + jeq 1b +5: move.w #0x407e,(-2,%a0) + move.l #0xffffff00,(%a0)+ + clr.l (%a0) + jra 2b + | zero and denormalized +fp_ns_zero: + tst.l (%a0)+ + jne 1f + tst.l (%a0) + jne 1f + subq.l #8,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts | zero. nothing to do. + | These are not merely subnormal numbers, but true denormals, + | i.e. pathologically small (exponent is 2**-16383) numbers. + | It is clearly impossible for even a normal extended number + | with that exponent to fit into single precision, so just + | write these ones off as "too darn small". +1: fp_set_sr FPSR_EXC_UNFL | Set UNFL bit + clr.l (%a0) + clr.l -(%a0) + move.w #0x3f81,-(%a0) | i.e. 2**-126 + addq.l #6,%a0 + moveq #1,%d0 + jra fp_ns_round | round. + | Infinities or NaNs +fp_ns_huge: + subq.l #4,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts + + | fp_normalize_single_fast: + | normalize an extended with single (23-bit) precision + | this is only used by fsgldiv/fsgdlmul, where the + | operand is not completly normalized. + | args: %a0 (struct fp_ext *) + +fp_normalize_single_fast: + printf PNORM,"nsf: %p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,") " + addq.l #2,%a0 + move.w (%a0)+,%d2 + cmp.w #0x7fff,%d2 + jeq fp_nsf_huge | NaN / infinitive. + move.l (%a0)+,%d0 | get high lword of mantissa +fp_nsf_round: + tst.l (%a0) | check the low lword + jeq 1f + | Set a sticky bit if it is non-zero. This should only + | affect the rounding in what would otherwise be equal- + | distance situations, which is what we want it to do. + bset #0,%d0 +1: clr.l (%a0) | zap it from memory. + | now, round off the low 8 bits of the hi lword. + tst.b %d0 | 8 low bits. + jne fp_nsf_checkround | Are they non-zero? + | nothing to do here + subq.l #8,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts +fp_nsf_checkround: + fp_set_sr FPSR_EXC_INEX2 | INEX2 bit + clr.b -(%a0) | clear low byte of high lword + subq.l #3,%a0 + move.w (FPD_RND,FPDATA),%d2 | rounding mode + jne 2f | %d2 == 0, round to nearest + tst.b %d0 | test guard bit + jpl 9f | zero is closer + btst #8,%d0 | test lsb bit + | round to even behaviour, see above. + jne fp_nsf_doroundup | round to infinity + lsl.b #1,%d0 | check low bits + jeq 9f | round to zero +fp_nsf_doroundup: + | round (the mantissa, that is) towards infinity + add.l #0x100,(%a0) + jcc 9f | no overflow, good. + | Overflow. This means that the %d1 was 0xffffff00, so it + | is now zero. We will set the mantissa to reflect this, and + | increment the exponent (checking for overflow there too) + move.w #0x8000,(%a0) + addq.w #1,-(%a0) + cmp.w #0x407f,(%a0)+ | exponent now overflown? + jeq fp_nsf_large | yes, so make it infinity. +9: subq.l #4,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts + | check nondefault rounding modes +2: subq.w #2,%d2 + jcs 9b | %d2 < 2, round to zero + jhi 3f | %d2 > 2, round to +infinity + tst.b (-3,%a0) | to -inf + jne fp_nsf_doroundup | negative, round to infinity + jra 9b | positive, round to zero +3: tst.b (-3,%a0) | to +inf + jeq fp_nsf_doroundup | positive, round to infinity + jra 9b | negative, round to zero + | Exponent overflow. Just call it infinity. +fp_nsf_large: + tst.b (3,%a0) + jeq 1f + fp_set_sr FPSR_EXC_INEX2 +1: fp_set_sr FPSR_EXC_OVFL + move.w (FPD_RND,FPDATA),%d2 + jne 3f | %d2 = 0 round to nearest +1: move.w #0x7fff,(-2,%a0) + clr.l (%a0)+ + clr.l (%a0) +2: subq.l #8,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts +3: subq.w #2,%d2 + jcs 5f | %d2 < 2, round to zero + jhi 4f | %d2 > 2, round to +infinity + tst.b (-3,%a0) | to -inf + jne 1b + jra 5f +4: tst.b (-3,%a0) | to +inf + jeq 1b +5: move.w #0x407e,(-2,%a0) + move.l #0xffffff00,(%a0)+ + clr.l (%a0) + jra 2b + | Infinities or NaNs +fp_nsf_huge: + subq.l #4,%a0 + printf PNORM,"%p(",1,%a0 + printx PNORM,%a0@ + printf PNORM,")\n" + rts + + | conv_ext2int (macro): + | Generates a subroutine that converts an extended value to an + | integer of a given size, again, with the appropriate type of + | rounding. + + | Macro arguments: + | s: size, as given in an assembly instruction. + | b: number of bits in that size. + + | Subroutine arguments: + | %a0: source (struct fp_ext *) + + | Returns the integer in %d0 (like it should) + +.macro conv_ext2int s,b + .set inf,(1<<(\b-1))-1 | i.e. MAXINT + printf PCONV,"e2i%d: %p(",2,#\b,%a0 + printx PCONV,%a0@ + printf PCONV,") " + addq.l #2,%a0 + move.w (%a0)+,%d2 | exponent + jeq fp_e2i_zero\b | zero / denorm (== 0, here) + cmp.w #0x7fff,%d2 + jeq fp_e2i_huge\b | Inf / NaN + sub.w #0x3ffe,%d2 + jcs fp_e2i_small\b + cmp.w #\b,%d2 + jhi fp_e2i_large\b + move.l (%a0),%d0 + move.l %d0,%d1 + lsl.l %d2,%d1 + jne fp_e2i_round\b + tst.l (4,%a0) + jne fp_e2i_round\b + neg.w %d2 + add.w #32,%d2 + lsr.l %d2,%d0 +9: tst.w (-4,%a0) + jne 1f + tst.\s %d0 + jmi fp_e2i_large\b + printf PCONV,"-> %p\n",1,%d0 + rts +1: neg.\s %d0 + jeq 1f + jpl fp_e2i_large\b +1: printf PCONV,"-> %p\n",1,%d0 + rts +fp_e2i_round\b: + fp_set_sr FPSR_EXC_INEX2 | INEX2 bit + neg.w %d2 + add.w #32,%d2 + .if \b>16 + jeq 5f + .endif + lsr.l %d2,%d0 + move.w (FPD_RND,FPDATA),%d2 | rounding mode + jne 2f | %d2 == 0, round to nearest + tst.l %d1 | test guard bit + jpl 9b | zero is closer + btst %d2,%d0 | test lsb bit (%d2 still 0) + jne fp_e2i_doroundup\b + lsl.l #1,%d1 | check low bits + jne fp_e2i_doroundup\b + tst.l (4,%a0) + jeq 9b +fp_e2i_doroundup\b: + addq.l #1,%d0 + jra 9b + | check nondefault rounding modes +2: subq.w #2,%d2 + jcs 9b | %d2 < 2, round to zero + jhi 3f | %d2 > 2, round to +infinity + tst.w (-4,%a0) | to -inf + jne fp_e2i_doroundup\b | negative, round to infinity + jra 9b | positive, round to zero +3: tst.w (-4,%a0) | to +inf + jeq fp_e2i_doroundup\b | positive, round to infinity + jra 9b | negative, round to zero + | we are only want -2**127 get correctly rounded here, + | since the guard bit is in the lower lword. + | everything else ends up anyway as overflow. + .if \b>16 +5: move.w (FPD_RND,FPDATA),%d2 | rounding mode + jne 2b | %d2 == 0, round to nearest + move.l (4,%a0),%d1 | test guard bit + jpl 9b | zero is closer + lsl.l #1,%d1 | check low bits + jne fp_e2i_doroundup\b + jra 9b + .endif +fp_e2i_zero\b: + clr.l %d0 + tst.l (%a0)+ + jne 1f + tst.l (%a0) + jeq 3f +1: subq.l #4,%a0 + fp_clr_sr FPSR_EXC_UNFL | fp_normalize_ext has set this bit +fp_e2i_small\b: + fp_set_sr FPSR_EXC_INEX2 + clr.l %d0 + move.w (FPD_RND,FPDATA),%d2 | rounding mode + subq.w #2,%d2 + jcs 3f | %d2 < 2, round to nearest/zero + jhi 2f | %d2 > 2, round to +infinity + tst.w (-4,%a0) | to -inf + jeq 3f + subq.\s #1,%d0 + jra 3f +2: tst.w (-4,%a0) | to +inf + jne 3f + addq.\s #1,%d0 +3: printf PCONV,"-> %p\n",1,%d0 + rts +fp_e2i_large\b: + fp_set_sr FPSR_EXC_OPERR + move.\s #inf,%d0 + tst.w (-4,%a0) + jeq 1f + addq.\s #1,%d0 +1: printf PCONV,"-> %p\n",1,%d0 + rts +fp_e2i_huge\b: + move.\s (%a0),%d0 + tst.l (%a0) + jne 1f + tst.l (%a0) + jeq fp_e2i_large\b + | fp_normalize_ext has set this bit already + | and made the number nonsignaling +1: fp_tst_sr FPSR_EXC_SNAN + jne 1f + fp_set_sr FPSR_EXC_OPERR +1: printf PCONV,"-> %p\n",1,%d0 + rts +.endm + +fp_conv_ext2long: + conv_ext2int l,32 + +fp_conv_ext2short: + conv_ext2int w,16 + +fp_conv_ext2byte: + conv_ext2int b,8 + +fp_conv_ext2double: + jsr fp_normalize_double + printf PCONV,"e2d: %p(",1,%a0 + printx PCONV,%a0@ + printf PCONV,"), " + move.l (%a0)+,%d2 + cmp.w #0x7fff,%d2 + jne 1f + move.w #0x7ff,%d2 + move.l (%a0)+,%d0 + jra 2f +1: sub.w #0x3fff-0x3ff,%d2 + move.l (%a0)+,%d0 + jmi 2f + clr.w %d2 +2: lsl.w #5,%d2 + lsl.l #7,%d2 + lsl.l #8,%d2 + move.l %d0,%d1 + lsl.l #1,%d0 + lsr.l #4,%d0 + lsr.l #8,%d0 + or.l %d2,%d0 + putuser.l %d0,(%a1)+,fp_err_ua2,%a1 + moveq #21,%d0 + lsl.l %d0,%d1 + move.l (%a0),%d0 + lsr.l #4,%d0 + lsr.l #7,%d0 + or.l %d1,%d0 + putuser.l %d0,(%a1),fp_err_ua2,%a1 +#ifdef FPU_EMU_DEBUG + getuser.l %a1@(-4),%d0,fp_err_ua2,%a1 + getuser.l %a1@(0),%d1,fp_err_ua2,%a1 + printf PCONV,"%p(%08x%08x)\n",3,%a1,%d0,%d1 +#endif + rts + +fp_conv_ext2single: + jsr fp_normalize_single + printf PCONV,"e2s: %p(",1,%a0 + printx PCONV,%a0@ + printf PCONV,"), " + move.l (%a0)+,%d1 + cmp.w #0x7fff,%d1 + jne 1f + move.w #0xff,%d1 + move.l (%a0)+,%d0 + jra 2f +1: sub.w #0x3fff-0x7f,%d1 + move.l (%a0)+,%d0 + jmi 2f + clr.w %d1 +2: lsl.w #8,%d1 + lsl.l #7,%d1 + lsl.l #8,%d1 + bclr #31,%d0 + lsr.l #8,%d0 + or.l %d1,%d0 + printf PCONV,"%08x\n",1,%d0 + rts + + | special return addresses for instr that + | encode the rounding precision in the opcode + | (e.g. fsmove,fdmove) + +fp_finalrounding_single: + addq.l #8,%sp + jsr fp_normalize_ext + jsr fp_normalize_single + jra fp_finaltest + +fp_finalrounding_single_fast: + addq.l #8,%sp + jsr fp_normalize_ext + jsr fp_normalize_single_fast + jra fp_finaltest + +fp_finalrounding_double: + addq.l #8,%sp + jsr fp_normalize_ext + jsr fp_normalize_double + jra fp_finaltest + + | fp_finaltest: + | set the emulated status register based on the outcome of an + | emulated instruction. + +fp_finalrounding: + addq.l #8,%sp +| printf ,"f: %p\n",1,%a0 + jsr fp_normalize_ext + move.w (FPD_PREC,FPDATA),%d0 + subq.w #1,%d0 + jcs fp_finaltest + jne 1f + jsr fp_normalize_single + jra 2f +1: jsr fp_normalize_double +2:| printf ,"f: %p\n",1,%a0 +fp_finaltest: + | First, we do some of the obvious tests for the exception + | status byte and condition code bytes of fp_sr here, so that + | they do not have to be handled individually by every + | emulated instruction. + clr.l %d0 + addq.l #1,%a0 + tst.b (%a0)+ | sign + jeq 1f + bset #FPSR_CC_NEG-24,%d0 | N bit +1: cmp.w #0x7fff,(%a0)+ | exponent + jeq 2f + | test for zero + moveq #FPSR_CC_Z-24,%d1 + tst.l (%a0)+ + jne 9f + tst.l (%a0) + jne 9f + jra 8f + | infinitiv and NAN +2: moveq #FPSR_CC_NAN-24,%d1 + move.l (%a0)+,%d2 + lsl.l #1,%d2 | ignore high bit + jne 8f + tst.l (%a0) + jne 8f + moveq #FPSR_CC_INF-24,%d1 +8: bset %d1,%d0 +9: move.b %d0,(FPD_FPSR+0,FPDATA) | set condition test result + | move instructions enter here + | Here, we test things in the exception status byte, and set + | other things in the accrued exception byte accordingly. + | Emulated instructions can set various things in the former, + | as defined in fp_emu.h. +fp_final: + move.l (FPD_FPSR,FPDATA),%d0 +#if 0 + btst #FPSR_EXC_SNAN,%d0 | EXC_SNAN + jne 1f + btst #FPSR_EXC_OPERR,%d0 | EXC_OPERR + jeq 2f +1: bset #FPSR_AEXC_IOP,%d0 | set IOP bit +2: btst #FPSR_EXC_OVFL,%d0 | EXC_OVFL + jeq 1f + bset #FPSR_AEXC_OVFL,%d0 | set OVFL bit +1: btst #FPSR_EXC_UNFL,%d0 | EXC_UNFL + jeq 1f + btst #FPSR_EXC_INEX2,%d0 | EXC_INEX2 + jeq 1f + bset #FPSR_AEXC_UNFL,%d0 | set UNFL bit +1: btst #FPSR_EXC_DZ,%d0 | EXC_INEX1 + jeq 1f + bset #FPSR_AEXC_DZ,%d0 | set DZ bit +1: btst #FPSR_EXC_OVFL,%d0 | EXC_OVFL + jne 1f + btst #FPSR_EXC_INEX2,%d0 | EXC_INEX2 + jne 1f + btst #FPSR_EXC_INEX1,%d0 | EXC_INEX1 + jeq 2f +1: bset #FPSR_AEXC_INEX,%d0 | set INEX bit +2: move.l %d0,(FPD_FPSR,FPDATA) +#else + | same as above, greatly optimized, but untested (yet) + move.l %d0,%d2 + lsr.l #5,%d0 + move.l %d0,%d1 + lsr.l #4,%d1 + or.l %d0,%d1 + and.b #0x08,%d1 + move.l %d2,%d0 + lsr.l #6,%d0 + or.l %d1,%d0 + move.l %d2,%d1 + lsr.l #4,%d1 + or.b #0xdf,%d1 + and.b %d1,%d0 + move.l %d2,%d1 + lsr.l #7,%d1 + and.b #0x80,%d1 + or.b %d1,%d0 + and.b #0xf8,%d0 + or.b %d0,%d2 + move.l %d2,(FPD_FPSR,FPDATA) +#endif + move.b (FPD_FPSR+2,FPDATA),%d0 + and.b (FPD_FPCR+2,FPDATA),%d0 + jeq 1f + printf ,"send signal!!!\n" +1: jra fp_end |