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The UWIDTH() macro provides the correct width for an unsigned integer type , and is defined in INT19-C. Correctly compute integer widths...; see that rule for more information.

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#include <limits.h>
 
unsigned int ui_a;
unsigned int ui_b;
unsigned int uresult;

void func(void) {
  /* Initialize ui_a and ui_b */
  if (ui_b >= UWIDTH( unsigned int, UINT_MAX)) {
    /* Handle error condition */
  } else {
    uresult = ui_a >> ui_b;
  }
  /* ... */
}

 The UWIDTH() macro provides the correct width for an unsigned integer type , and is defined in INT19-C. Correctly compute integer widths...; see that rule for more information.

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GCC has no options to handle shifts by negative amounts or by amounts outside the width of the type predictably or to trap on them; they are always treated as undefined. Processors may reduce the shift amount modulo the width of the type. For example, 32-bit shifts are implemented using the following instructions on IA-32:

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Automated Detection

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