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sparc32: Kill off software 32-bit multiply/divide routines.

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For the explicit calls to .udiv/.umul in assembler, I made a
mechanical (read as: safe) transformation.  I didn't attempt
to make any simplifications.

In particular, __ndelay and __udelay can be simplified significantly.
Some of the %y reads are unnecessary and these routines have no need
any longer for allocating a register window, they can be leaf
functions.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
2012-05-15 11:23:01 -07:00
parent 2119ff6d2b
commit 1b35a57b1c
17 changed files with 24 additions and 2129 deletions
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27
arch/sparc/kernel/entry.S
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@@ -1161,11 +1161,13 @@ fpload:
.globl __ndelay
__ndelay:
save %sp, -STACKFRAME_SZ, %sp
mov %i0, %o0
call .umul ! round multiplier up so large ns ok
mov 0x1ae, %o1 ! 2**32 / (1 000 000 000 / HZ)
call .umul
mov %i1, %o1 ! udelay_val
mov %i0, %o0 ! round multiplier up so large ns ok
mov 0x1ae, %o1 ! 2**32 / (1 000 000 000 / HZ)
umul %o0, %o1, %o0
rd %y, %o1
mov %i1, %o1 ! udelay_val
umul %o0, %o1, %o0
rd %y, %o1
ba delay_continue
mov %o1, %o0 ! >>32 later for better resolution
@@ -1174,18 +1176,21 @@ __udelay:
save %sp, -STACKFRAME_SZ, %sp
mov %i0, %o0
sethi %hi(0x10c7), %o1 ! round multiplier up so large us ok
call .umul
or %o1, %lo(0x10c7), %o1 ! 2**32 / 1 000 000
call .umul
mov %i1, %o1 ! udelay_val
or %o1, %lo(0x10c7), %o1 ! 2**32 / 1 000 000
umul %o0, %o1, %o0
rd %y, %o1
mov %i1, %o1 ! udelay_val
umul %o0, %o1, %o0
rd %y, %o1
sethi %hi(0x028f4b62), %l0 ! Add in rounding constant * 2**32,
or %g0, %lo(0x028f4b62), %l0
addcc %o0, %l0, %o0 ! 2**32 * 0.009 999
bcs,a 3f
add %o1, 0x01, %o1
3:
call .umul
mov HZ, %o0 ! >>32 earlier for wider range
mov HZ, %o0 ! >>32 earlier for wider range
umul %o0, %o1, %o0
rd %y, %o1
delay_continue:
cmp %o0, 0x0