[Open64-devel] help on ALAT

[Jin L. <ji...@cs...>]

Hi,

I have one question on handling procedure using ALAT. Considering the
following code:

C Code

 if (func()== NO_ERROR)
 {
   x=*a;
 }
 y=x+5

 Assembly Code,
 Combined Speculation

     ld.sa    r3=[r40]
     br.call  b0=func
     mov      r5=NO_ERROR;;
     cmp.eq   p1,p0=r8,r5
 (p1)chk.a    r3, CORRECTION_CODE
     adds r5=0x5, r3


 I am not sure how to prevent the entry r3 in ALAT from being replaced in
 the procedure func(). Suppose there exists one instruction ld.sa r3=[r50]
 executed in procedure func, it will replace the old entry in ALAT. If the
 load is successful and the data is validated, when it returns to the call
 site, the speculation will claim successful. However, the value is not
 correct. Will this happen?

Thanks for any comments in advance.

Jin