[avr-gcc-list] Compile problem...

[Tvrtko A. Ursulin]

What could cause GCC 3.2 to compile this function:

uint8_t i2c_send_block(uint8_t address, uint8_t *buffer, uint8_t len)
{
        uint8_t flags;
        
        irq_save(flags);
                        
        if ( i2c_start_transmission(address) )
                goto fail;
                
        do
        {
                uint8_t val = *buffer;          
                if ( i2c_transmit(val) )
                        goto fail;
                buffer++;
        } while ( --len );                      

        i2c_stop();
        irq_restore(flags);
        return I2C_NO_ERROR;
                        
        fail:
        i2c_stop();
        irq_restore(flags);
        return I2C_ERROR;
}

Into this piece of code:

uint8_t i2c_send_block(uint8_t address, uint8_t *buffer, uint8_t len)
{
 28e:   1f 93           push    r17
 290:   18 2f           mov     r17, r24
        uint8_t flags;

        irq_save(flags);
 292:   8f b7           in      r24, 0x3f       ; 63
 294:   f8 94           cli

        if ( i2c_start_transmission(address) )
 296:   92 df           rcall   .-220           ; 0x1bc
 298:   81 2f           mov     r24, r17
 29a:   a4 df           rcall   .-184           ; 0x1e4
 29c:   99 27           eor     r25, r25
                goto fail;

        do
        {
                uint8_t val = *buffer;
                if ( i2c_transmit(val) )
                        goto fail;
                buffer++;
        } while ( --len );

        i2c_stop();
        irq_restore(flags);
        return I2C_NO_ERROR;

        fail:
        i2c_stop();
        irq_restore(flags);
        return I2C_ERROR;
}
 29e:   1f 91           pop     r17
 2a0:   08 95           ret


??? This is with -O2, but -O0 doesn't help. Just produces bigger&slower code, 
the main loop is again forgotten.

Thanks!



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