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Diffstat (limited to 'arch/sparc/lib/sdiv.S')
| -rw-r--r-- | arch/sparc/lib/sdiv.S | 381 |
1 files changed, 0 insertions, 381 deletions
diff --git a/arch/sparc/lib/sdiv.S b/arch/sparc/lib/sdiv.S deleted file mode 100644 index f0a0d4e4db78..000000000000 --- a/arch/sparc/lib/sdiv.S +++ /dev/null @@ -1,381 +0,0 @@ -/* - * sdiv.S: This routine was taken from glibc-1.09 and is covered - * by the GNU Library General Public License Version 2. - */ - - -/* This file is generated from divrem.m4; DO NOT EDIT! */ -/* - * Division and remainder, from Appendix E of the Sparc Version 8 - * Architecture Manual, with fixes from Gordon Irlam. - */ - -/* - * Input: dividend and divisor in %o0 and %o1 respectively. - * - * m4 parameters: - * .div name of function to generate - * div div=div => %o0 / %o1; div=rem => %o0 % %o1 - * true true=true => signed; true=false => unsigned - * - * Algorithm parameters: - * N how many bits per iteration we try to get (4) - * WORDSIZE total number of bits (32) - * - * Derived constants: - * TOPBITS number of bits in the top decade of a number - * - * Important variables: - * Q the partial quotient under development (initially 0) - * R the remainder so far, initially the dividend - * ITER number of main division loop iterations required; - * equal to ceil(log2(quotient) / N). Note that this - * is the log base (2^N) of the quotient. - * V the current comparand, initially divisor*2^(ITER*N-1) - * - * Cost: - * Current estimate for non-large dividend is - * ceil(log2(quotient) / N) * (10 + 7N/2) + C - * A large dividend is one greater than 2^(31-TOPBITS) and takes a - * different path, as the upper bits of the quotient must be developed - * one bit at a time. - */ - - - .globl .div - .globl _Div -.div: -_Div: /* needed for export */ - ! compute sign of result; if neither is negative, no problem - orcc %o1, %o0, %g0 ! either negative? - bge 2f ! no, go do the divide - xor %o1, %o0, %g2 ! compute sign in any case - - tst %o1 - bge 1f - tst %o0 - ! %o1 is definitely negative; %o0 might also be negative - bge 2f ! if %o0 not negative... - sub %g0, %o1, %o1 ! in any case, make %o1 nonneg -1: ! %o0 is negative, %o1 is nonnegative - sub %g0, %o0, %o0 ! make %o0 nonnegative -2: - - ! Ready to divide. Compute size of quotient; scale comparand. - orcc %o1, %g0, %o5 - bne 1f - mov %o0, %o3 - - ! Divide by zero trap. If it returns, return 0 (about as - ! wrong as possible, but that is what SunOS does...). - ta ST_DIV0 - retl - clr %o0 - -1: - cmp %o3, %o5 ! if %o1 exceeds %o0, done - blu Lgot_result ! (and algorithm fails otherwise) - clr %o2 - - sethi %hi(1 << (32 - 4 - 1)), %g1 - - cmp %o3, %g1 - blu Lnot_really_big - clr %o4 - - ! Here the dividend is >= 2**(31-N) or so. We must be careful here, - ! as our usual N-at-a-shot divide step will cause overflow and havoc. - ! The number of bits in the result here is N*ITER+SC, where SC <= N. - ! Compute ITER in an unorthodox manner: know we need to shift V into - ! the top decade: so do not even bother to compare to R. - 1: - cmp %o5, %g1 - bgeu 3f - mov 1, %g7 - - sll %o5, 4, %o5 - - b 1b - add %o4, 1, %o4 - - ! Now compute %g7. - 2: - addcc %o5, %o5, %o5 - bcc Lnot_too_big - add %g7, 1, %g7 - - ! We get here if the %o1 overflowed while shifting. - ! This means that %o3 has the high-order bit set. - ! Restore %o5 and subtract from %o3. - sll %g1, 4, %g1 ! high order bit - srl %o5, 1, %o5 ! rest of %o5 - add %o5, %g1, %o5 - - b Ldo_single_div - sub %g7, 1, %g7 - - Lnot_too_big: - 3: - cmp %o5, %o3 - blu 2b - nop - - be Ldo_single_div - nop - /* NB: these are commented out in the V8-Sparc manual as well */ - /* (I do not understand this) */ - ! %o5 > %o3: went too far: back up 1 step - ! srl %o5, 1, %o5 - ! dec %g7 - ! do single-bit divide steps - ! - ! We have to be careful here. We know that %o3 >= %o5, so we can do the - ! first divide step without thinking. BUT, the others are conditional, - ! and are only done if %o3 >= 0. Because both %o3 and %o5 may have the high- - ! order bit set in the first step, just falling into the regular - ! division loop will mess up the first time around. - ! So we unroll slightly... - Ldo_single_div: - subcc %g7, 1, %g7 - bl Lend_regular_divide - nop - - sub %o3, %o5, %o3 - mov 1, %o2 - - b Lend_single_divloop - nop - Lsingle_divloop: - sll %o2, 1, %o2 - - bl 1f - srl %o5, 1, %o5 - ! %o3 >= 0 - sub %o3, %o5, %o3 - - b 2f - add %o2, 1, %o2 - 1: ! %o3 < 0 - add %o3, %o5, %o3 - sub %o2, 1, %o2 - 2: - Lend_single_divloop: - subcc %g7, 1, %g7 - bge Lsingle_divloop - tst %o3 - - b,a Lend_regular_divide - -Lnot_really_big: -1: - sll %o5, 4, %o5 - cmp %o5, %o3 - bleu 1b - addcc %o4, 1, %o4 - - be Lgot_result - sub %o4, 1, %o4 - - tst %o3 ! set up for initial iteration -Ldivloop: - sll %o2, 4, %o2 - ! depth 1, accumulated bits 0 - bl L.1.16 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - ! depth 2, accumulated bits 1 - bl L.2.17 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - ! depth 3, accumulated bits 3 - bl L.3.19 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - ! depth 4, accumulated bits 7 - bl L.4.23 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - b 9f - add %o2, (7*2+1), %o2 - -L.4.23: - ! remainder is negative - addcc %o3,%o5,%o3 - b 9f - add %o2, (7*2-1), %o2 - -L.3.19: - ! remainder is negative - addcc %o3,%o5,%o3 - ! depth 4, accumulated bits 5 - bl L.4.21 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - b 9f - add %o2, (5*2+1), %o2 - -L.4.21: - ! remainder is negative - addcc %o3,%o5,%o3 - b 9f - add %o2, (5*2-1), %o2 - -L.2.17: - ! remainder is negative - addcc %o3,%o5,%o3 - ! depth 3, accumulated bits 1 - bl L.3.17 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - ! depth 4, accumulated bits 3 - bl L.4.19 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - b 9f - add %o2, (3*2+1), %o2 - -L.4.19: - ! remainder is negative - addcc %o3,%o5,%o3 - b 9f - add %o2, (3*2-1), %o2 - - -L.3.17: - ! remainder is negative - addcc %o3,%o5,%o3 - ! depth 4, accumulated bits 1 - bl L.4.17 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - b 9f - add %o2, (1*2+1), %o2 - -L.4.17: - ! remainder is negative - addcc %o3,%o5,%o3 - b 9f - add %o2, (1*2-1), %o2 - -L.1.16: - ! remainder is negative - addcc %o3,%o5,%o3 - ! depth 2, accumulated bits -1 - bl L.2.15 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - ! depth 3, accumulated bits -1 - bl L.3.15 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - ! depth 4, accumulated bits -1 - bl L.4.15 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - b 9f - add %o2, (-1*2+1), %o2 - -L.4.15: - ! remainder is negative - addcc %o3,%o5,%o3 - b 9f - add %o2, (-1*2-1), %o2 - -L.3.15: - ! remainder is negative - addcc %o3,%o5,%o3 - ! depth 4, accumulated bits -3 - bl L.4.13 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - b 9f - add %o2, (-3*2+1), %o2 - -L.4.13: - ! remainder is negative - addcc %o3,%o5,%o3 - b 9f - add %o2, (-3*2-1), %o2 - -L.2.15: - ! remainder is negative - addcc %o3,%o5,%o3 - ! depth 3, accumulated bits -3 - bl L.3.13 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - ! depth 4, accumulated bits -5 - bl L.4.11 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - b 9f - add %o2, (-5*2+1), %o2 - -L.4.11: - ! remainder is negative - addcc %o3,%o5,%o3 - b 9f - add %o2, (-5*2-1), %o2 - -L.3.13: - ! remainder is negative - addcc %o3,%o5,%o3 - ! depth 4, accumulated bits -7 - bl L.4.9 - srl %o5,1,%o5 - ! remainder is positive - subcc %o3,%o5,%o3 - b 9f - add %o2, (-7*2+1), %o2 - -L.4.9: - ! remainder is negative - addcc %o3,%o5,%o3 - b 9f - add %o2, (-7*2-1), %o2 - - 9: -Lend_regular_divide: - subcc %o4, 1, %o4 - bge Ldivloop - tst %o3 - - bl,a Lgot_result - ! non-restoring fixup here (one instruction only!) - sub %o2, 1, %o2 - -Lgot_result: - ! check to see if answer should be < 0 - tst %g2 - bl,a 1f - sub %g0, %o2, %o2 -1: - retl - mov %o2, %o0 - - .globl .div_patch -.div_patch: - sra %o0, 0x1f, %o2 - wr %o2, 0x0, %y - nop - nop - nop - sdivcc %o0, %o1, %o0 - bvs,a 1f - xnor %o0, %g0, %o0 -1: retl - nop |