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  1. Embedded Software & Tools
  2. EXT_EP-10449

Optimizer drops part of a compound conditional expression controlling a loop

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    • Icon: Bug Bug
    • Resolution: Fixed
    • Icon: Medium Medium

      The attached test case contains this code ...

          for (u32 i = 0; (i < arrSize && i < CByteAligner::bitsToOctetsRoundUp(tbSize)); i++) /* PROBLEM FOR LOOP */ 
        localMem[i] = p_corruptedPdu[i];

      The generated code accounts for the i < CByteAligner::bitsToOctetsRoundUp(tbSize)) part of the condition controlling the loop. But not the i < arrSize part.

      Build it ...

      % cl6x -@options.txt file.cpp

      Inspect the compiler generated comments for the problem loop.

      ;* 128211       -----------------------    memset(&localMem, 0, 16u);
;* 128212       -----------------------    K$13 = tbSize+7u;
;* 128212       -----------------------    if ( !(C$5 = K$13>>3) ) goto g4;
;**     -----------------------    U$21 = p_corruptedPdu;
;* 128213       -----------------------    L$1 = C$5;
;**     -----------------------    U$23 = &localMem[0];
;**     -----------------------    #pragma MUST_ITERATE(1, 16, 1)
;**     -----------------------    #pragma LOOP_FLAGS(4096u)
;**     -----------------------g3:
;* 128213       -----------------------    *U$23++ = *U$21++;
;* 128212       -----------------------    if ( L$1 = L$1-1 ) goto g3;
;**     -----------------------g4:

      L$1 controls this loop. It down counts from CByteAligner::bitsToOctetsRoundUp(tbSize)) to 0. But this ignores the i < 16 part of the loop condition.

            syncuser TI User
            syncuser TI User
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              Created:
              Updated:
              Resolved: