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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>I noticed that c code below failed with -O3 : <o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>#include <setjmp.h><o:p></o:p></p><p class=MsoNormal>#include <stdio.h><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>static int cnt;<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>int main(){<o:p></o:p></p><p class=MsoNormal> int var;<o:p></o:p></p><p class=MsoNormal> jmp_buf buffer;<o:p></o:p></p><p class=MsoNormal> cnt = 0;<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> if ((var = setjmp(buffer)) == 0) {<o:p></o:p></p><p class=MsoNormal> printf(" if true, var: %d, .count:%d , increase count !\n",var, cnt);<o:p></o:p></p><p class=MsoNormal> cnt++;<o:p></o:p></p><p class=MsoNormal> longjmp(buffer, 2);<o:p></o:p></p><p class=MsoNormal> } else {<o:p></o:p></p><p class=MsoNormal> if (cnt == 1)<o:p></o:p></p><p class=MsoNormal> printf(" Pass var: %d, .count:%d \n",var, cnt);<o:p></o:p></p><p class=MsoNormal> else<o:p></o:p></p><p class=MsoNormal> printf(" Fail !!! var: %d, .count:%d \n",var, cnt);<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><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div><div><p class=MsoNormal>The documentation of setjmp/longjmp says that the values of objects of automatic storage duration which are local to the function containing the invocation of the corresponding setjmp() which do not have volatile-qualified type and which are changed between the setjmp() invocation and longjmp() call are indeterminate.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Even though “cnt” is a global variable, above c code failed because the globalopt pass localizes the global value (cnt) in main(), causing that the value of the global variable becomes indeterminate between setjmp() and longjmp. I believe the globalopt pass need to check this case before localizing global variables. Is there any better solution about it?<o:p></o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal>Thanks,<o:p></o:p></p><p class=MsoNormal>Balaram<o:p></o:p></p></div></div></body></html>