Re: [Qemu-devel] [PATCH 3/3] linux-user: Initialize Alpha FPCR register.

[Richard Henderson <rth@twiddle.net>]

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On 12/21/2009 02:33 AM, Aurelien Jarno wrote:
> On Sat, Dec 19, 2009 at 03:17:16PM -0800, Richard Henderson wrote:
>> Signed-off-by: Richard Henderson<rth@twiddle.net>
>> ---
>>   linux-user/main.c |    2 ++
>>   1 files changed, 2 insertions(+), 0 deletions(-)
>>
>> diff --git a/linux-user/main.c b/linux-user/main.c
>> index 12502ad..b67662c 100644
>> --- a/linux-user/main.c
>> +++ b/linux-user/main.c
>> @@ -3052,6 +3052,8 @@ int main(int argc, char **argv, char **envp)
>>           env->ir[30] = regs->usp;
>>           env->pc = regs->pc;
>>           env->unique = regs->unique;
>> +        cpu_alpha_store_fpcr(env, (FPCR_INVD | FPCR_DZED | FPCR_OVFD
>> +                                   | FPCR_UNFD | FPCR_INED | FPCR_DNOD));
>>       }
>
> This cpu initialization which does not depends on the binary being run
> is usually done in target-*/translate.c, using #if defined
> (CONFIG_USER_ONLY).

I didn't want to assume that bsd-user initializes the fpcr to the same 
value.  However, they probably do.  This appears to be what you wanted.


r~

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commit 033df7a558acdf39d81681f3858f13ebe2a92a6e
Author: Richard Henderson <rth@twiddle.net>
Date:   Mon Dec 21 12:48:43 2009 -0800

    target-alpha: Initialize fpcr.
    
    Linux, at least, disables exceptions by default.
    
    Signed-off-by: Richard Henderson <rth@twiddle.net>

diff --git a/target-alpha/translate.c b/target-alpha/translate.c
index 5e0647b..87813e7 100644
--- a/target-alpha/translate.c
+++ b/target-alpha/translate.c
@@ -2748,6 +2748,8 @@ CPUAlphaState * cpu_alpha_init (const char *cpu_model)
     env->ps = 0x1F00;
 #if defined (CONFIG_USER_ONLY)
     env->ps |= 1 << 3;
+    cpu_alpha_store_fpcr(env, (FPCR_INVD | FPCR_DZED | FPCR_OVFD
+                               | FPCR_UNFD | FPCR_INED | FPCR_DNOD));
 #endif
     pal_init(env);
     /* Initialize IPR */