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authorDavid Mosberger-Tang <davidm@hpl.hp.com>2005-04-27 21:15:13 -0700
committerTony Luck <tony.luck@intel.com>2005-04-27 21:15:13 -0700
commit3c79c8b1d92a9ae3edf3cbcd2c43c553ee0f1d83 (patch)
tree50a6d59383a15d92aa054371a247112e3e539bc5 /arch
parent9ec1a7ad434fa951ff845dbee3397cf6ad4f76df (diff)
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[IA64] Schedule fp-clearing insns at least 6 cycles after reading ar.bsp.
Decreases syscall overhead by approximately 6 cycles. Signed-off-by: David Mosberger-Tang <davidm@hpl.hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/ia64/kernel/entry.S25
1 files changed, 15 insertions, 10 deletions
diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
index c0f2833..0c84bed 100644
--- a/arch/ia64/kernel/entry.S
+++ b/arch/ia64/kernel/entry.S
@@ -705,15 +705,15 @@ ENTRY(ia64_leave_syscall)
// start restoring the state saved on the kernel stack (struct pt_regs):
ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
ld8 r11=[r3],PT(CR_IIP)-PT(R11)
- mov f6=f0 // clear f6
+ nop.i 0
;;
invala // M0|1 invalidate ALAT
rsm psr.i | psr.ic // M2 initiate turning off of interrupt and interruption collection
- mov f9=f0 // clear f9
+ nop.i 0
ld8 r29=[r2],16 // load cr.ipsr
ld8 r28=[r3],16 // load cr.iip
- mov f8=f0 // clear f8
+ mov r22=r0 // clear r22
;;
ld8 r30=[r2],16 // M0|1 load cr.ifs
ld8 r25=[r3],16 // M0|1 load ar.unat
@@ -721,15 +721,15 @@ ENTRY(ia64_leave_syscall)
;;
ld8 r26=[r2],PT(B0)-PT(AR_PFS) // M0|1 load ar.pfs
(pKStk) mov r22=psr // M2 read PSR now that interrupts are disabled
- mov f10=f0 // clear f10
+(pUStk) add r14=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
;;
ld8 r21=[r2],PT(AR_RNAT)-PT(B0) // load b0
ld8 r27=[r3],PT(PR)-PT(AR_RSC) // load ar.rsc
- mov f11=f0 // clear f11
+ mov f6=f0 // clear f6
;;
ld8 r24=[r2],PT(AR_FPSR)-PT(AR_RNAT) // load ar.rnat (may be garbage)
ld8 r31=[r3],PT(R1)-PT(PR) // load predicates
-(pUStk) add r14=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
+ mov f7=f0 // clear f7
;;
ld8 r20=[r2],PT(R12)-PT(AR_FPSR) // load ar.fpsr
ld8.fill r1=[r3],16 // load r1
@@ -737,24 +737,29 @@ ENTRY(ia64_leave_syscall)
;;
srlz.d // M0 ensure interruption collection is off
ld8.fill r13=[r3],16
- mov f7=f0 // clear f7
+ mov f8=f0 // clear f8
;;
ld8.fill r12=[r2] // restore r12 (sp)
mov.m ar.ssd=r0 // M2 clear ar.ssd
- mov r22=r0 // clear r22
+ mov b6=r18 // I0 restore b6
+ nop.m 0
+ mov f9=f0 // clear f9
+ shr.u r18=r19,16 // I0|1 get byte size of existing "dirty" partition
+ ;;
ld8.fill r15=[r3] // restore r15
(pUStk) st1 [r14]=r17
addl r3=THIS_CPU(ia64_phys_stacked_size_p8),r0
;;
(pUStk) ld4 r17=[r3] // r17 = cpu_data->phys_stacked_size_p8
mov.m ar.csd=r0 // M2 clear ar.csd
- mov b6=r18 // I0 restore b6
+ mov f10=f0 // clear f10
;;
mov r14=r0 // clear r14
- shr.u r18=r19,16 // I0|1 get byte size of existing "dirty" partition
+ mov f11=f0 // clear f11
(pKStk) br.cond.dpnt.many skip_rbs_switch
+
mov.m ar.ccv=r0 // clear ar.ccv
(pNonSys) br.cond.dpnt.many dont_preserve_current_frame
br.cond.sptk.many rbs_switch