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Re: ARM setjmp and r12

Hi Shaun,

On the ARM, why does setjmp preserve r12 (ip)?  I believe r12 is
caller-preserved, not callee-preserved.

arm/setjmp.S:122
	/* Save all the callee-preserved registers into the jump buffer.  */
	stmea		a1!, { v1-v7, fp, ip, sp, lr }

I *think* that this is because GCC uses it as the static chain register for nested functions (when operating in ARM mode).

Cheers
  Nick

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