Messages in this thread | | | Date | Wed, 01 Dec 2021 07:56:29 +0000 | From | Marc Zyngier <> | Subject | Re: [PATCH 09/15] irq: arm: perform irqentry in entry code |
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On 2021-11-30 08:49, Vladimir Murzin wrote:
> One month and a week later... > > I observe that in terms of performance > > MRS r0, ipsr > > is equivalent to readl_relaxed(BASEADDR_V7M_SCB + V7M_SCB_ICSR) > > MOV.W r3, #3758153728 > LDR.W r0, [r3, #3332] > > Old compilers can produce less performant sequence like > > LDR r3,0xbcc0 > ADD.W r3,r3,#0xaf00 > LDR r0,[r3,#0] > > So, what would be your preference?
If there is no significant overhead to reading the MMIO register and that you see a benefit in enabling COMPILE_TEST, then this probably is the way to go.
Thanks,
M. -- Jazz is not dead. It just smells funny...
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