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| Rev 149 |
Rev 154 |
/* Problem originally visible on ia64.
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/* Problem originally visible on ia64.
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There is a partial redundancy of "in + 1" that makes GCSE want to
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There is a partial redundancy of "in + 1" that makes GCSE want to
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transform the final while loop to
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transform the final while loop to
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p = in + 1;
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p = in + 1;
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tmp = p;
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tmp = p;
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...
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...
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goto start;
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goto start;
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top:
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top:
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tmp = tmp + 1;
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tmp = tmp + 1;
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start:
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start:
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in = tmp;
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in = tmp;
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if (in < p) goto top;
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if (in < p) goto top;
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We miscalculate the number of loop iterations as (p - tmp) = 0
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We miscalculate the number of loop iterations as (p - tmp) = 0
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instead of (p - in) = 1, which results in overflow in the doloop
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instead of (p - in) = 1, which results in overflow in the doloop
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optimization. */
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optimization. */
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static const char *
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static const char *
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test (const char *in, char *out)
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test (const char *in, char *out)
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{
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{
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while (1)
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while (1)
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{
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{
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if (*in == 'a')
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if (*in == 'a')
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{
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{
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const char *p = in + 1;
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const char *p = in + 1;
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while (*p == 'x')
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while (*p == 'x')
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++p;
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++p;
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if (*p == 'b')
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if (*p == 'b')
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return p;
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return p;
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while (in < p)
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while (in < p)
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*out++ = *in++;
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*out++ = *in++;
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}
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}
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}
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}
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}
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}
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int main ()
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int main ()
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{
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{
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char out[4];
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char out[4];
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test ("aab", out);
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test ("aab", out);
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return 0;
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return 0;
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}
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}
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