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| author | David S. Miller <davem@davemloft.net> | 2012-05-15 20:23:01 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-05-15 20:23:47 +0200 |
| commit | 1b35a57b1c1781f0fc8fc554f732b3a5408c5244 (patch) | |
| tree | 80e5616798e0dc5ec138f020e6aa9ae482378462 /arch/sparc/kernel/entry.S | |
| parent | sparc32: Build kernel with -mcpu=v8 (diff) | |
| download | linux-1b35a57b1c1781f0fc8fc554f732b3a5408c5244.tar.xz linux-1b35a57b1c1781f0fc8fc554f732b3a5408c5244.zip | |
sparc32: Kill off software 32-bit multiply/divide routines.
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>
Diffstat (limited to 'arch/sparc/kernel/entry.S')
| -rw-r--r-- | arch/sparc/kernel/entry.S | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/arch/sparc/kernel/entry.S b/arch/sparc/kernel/entry.S index 773f3f05bf26..3f3976e0e98f 100644 --- a/arch/sparc/kernel/entry.S +++ b/arch/sparc/kernel/entry.S @@ -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 |