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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I was wondering if there is an optimization pass in LLVM or Polly that can optimize this given loop:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">int main(int argc, char* argv[]) { <o:p></o:p></p>
<p class="MsoNormal"> char s = 0;<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> // Loop is setting s = argv[1][0];<o:p></o:p></p>
<p class="MsoNormal"> for (int i=0; i<argv[1][0]; i++) {<o:p></o:p></p>
<p class="MsoNormal"> s++;<o:p></o:p></p>
<p class="MsoNormal"> }<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> printf("s = %c\n", s);<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> return 0;<o:p></o:p></p>
<p class="MsoNormal">}<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">into:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">int main(int argc, char* argv[]) { <o:p></o:p></p>
<p class="MsoNormal"> // Optimized loop<o:p></o:p></p>
<p class="MsoNormal"> char s = argv[1][0]; <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> printf("s = %c\n", s);<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> return 0;<o:p></o:p></p>
<p class="MsoNormal">}<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is there an optimization that can do this?<o:p></o:p></p>
<p class="MsoNormal">And if not, maybe someone knows what hinders the optimizer?!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Peter<o:p></o:p></p>
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