MIPS: Separate two consecutive loads in memset.S

partial_fixup is used in noreorder block.

Separating two consecutive loads can save one cycle on processors with
GPR intrelock and can fix load-use on processors that need a load delay slot.

Also do so for fwd_fixup.

[Ralf: Only R2000/R3000 class processors are lacking the the load-user
interlock and even some of those got it retrofitted.  With R2000/R3000
being fairly uncommon these days the impact of this bug should be minor.]

Signed-off-by: Tony Wu <tung7970@gmail.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1768/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/lib/memset.S b/arch/mips/lib/memset.S
index 77dc3b2..606c8a9 100644 (file)
--- a/arch/mips/lib/memset.S
+++ b/arch/mips/lib/memset.S
@@ -161,16 +161,16 @@ FEXPORT(__bzero)
 
 .Lfwd_fixup:
        PTR_L           t0, TI_TASK($28)
-       LONG_L          t0, THREAD_BUADDR(t0)
        andi            a2, 0x3f
+       LONG_L          t0, THREAD_BUADDR(t0)
        LONG_ADDU       a2, t1
        jr              ra
         LONG_SUBU      a2, t0
 
 .Lpartial_fixup:
        PTR_L           t0, TI_TASK($28)
-       LONG_L          t0, THREAD_BUADDR(t0)
        andi            a2, LONGMASK
+       LONG_L          t0, THREAD_BUADDR(t0)
        LONG_ADDU       a2, t1
        jr              ra
         LONG_SUBU      a2, t0