diff options
Diffstat (limited to 'arch/s390/math-emu/qrnnd.S')
| -rw-r--r-- | arch/s390/math-emu/qrnnd.S | 77 |
1 files changed, 0 insertions, 77 deletions
diff --git a/arch/s390/math-emu/qrnnd.S b/arch/s390/math-emu/qrnnd.S deleted file mode 100644 index b01c2b6..0000000 --- a/arch/s390/math-emu/qrnnd.S +++ /dev/null @@ -1,77 +0,0 @@ -# S/390 __udiv_qrnnd - -# r2 : &__r -# r3 : upper half of 64 bit word n -# r4 : lower half of 64 bit word n -# r5 : divisor d -# the reminder r of the division is to be stored to &__r and -# the quotient q is to be returned - - .text - .globl __udiv_qrnnd -__udiv_qrnnd: - st %r2,24(%r15) # store pointer to reminder for later - lr %r0,%r3 # reload n - lr %r1,%r4 - ltr %r2,%r5 # reload and test divisor - jp 5f - # divisor >= 0x80000000 - srdl %r0,2 # n/4 - srl %r2,1 # d/2 - slr %r1,%r2 # special case if last bit of d is set - brc 3,0f # (n/4) div (n/2) can overflow by 1 - ahi %r0,-1 # trick: subtract n/2, then divide -0: dr %r0,%r2 # signed division - ahi %r1,1 # trick part 2: add 1 to the quotient - # now (n >> 2) = (d >> 1) * %r1 + %r0 - lhi %r3,1 - nr %r3,%r1 # test last bit of q - jz 1f - alr %r0,%r2 # add (d>>1) to r -1: srl %r1,1 # q >>= 1 - # now (n >> 2) = (d&-2) * %r1 + %r0 - lhi %r3,1 - nr %r3,%r5 # test last bit of d - jz 2f - slr %r0,%r1 # r -= q - brc 3,2f # borrow ? - alr %r0,%r5 # r += d - ahi %r1,-1 -2: # now (n >> 2) = d * %r1 + %r0 - alr %r1,%r1 # q <<= 1 - alr %r0,%r0 # r <<= 1 - brc 12,3f # overflow on r ? - slr %r0,%r5 # r -= d - ahi %r1,1 # q += 1 -3: lhi %r3,2 - nr %r3,%r4 # test next to last bit of n - jz 4f - ahi %r0,1 # r += 1 -4: clr %r0,%r5 # r >= d ? - jl 6f - slr %r0,%r5 # r -= d - ahi %r1,1 # q += 1 - # now (n >> 1) = d * %r1 + %r0 - j 6f -5: # divisor < 0x80000000 - srdl %r0,1 - dr %r0,%r2 # signed division - # now (n >> 1) = d * %r1 + %r0 -6: alr %r1,%r1 # q <<= 1 - alr %r0,%r0 # r <<= 1 - brc 12,7f # overflow on r ? - slr %r0,%r5 # r -= d - ahi %r1,1 # q += 1 -7: lhi %r3,1 - nr %r3,%r4 # isolate last bit of n - alr %r0,%r3 # r += (n & 1) - clr %r0,%r5 # r >= d ? - jl 8f - slr %r0,%r5 # r -= d - ahi %r1,1 # q += 1 -8: # now n = d * %r1 + %r0 - l %r2,24(%r15) - st %r0,0(%r2) - lr %r2,%r1 - br %r14 - .end __udiv_qrnnd |
