/* { dg-do compile } */
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/* { dg-do compile } */
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/* { dg-options "-O2 -ftree-loop-distribution -fdump-tree-ldist-all" } */
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/* { dg-options "-O2 -ftree-loop-distribution -fdump-tree-ldist-all" } */
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int loop1 (int k)
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int loop1 (int k)
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{
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{
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unsigned int i;
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unsigned int i;
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int a[1000], b[1000], c[1000], d[1000];
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int a[1000], b[1000], c[1000], d[1000];
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for (i = 2; i < (1000-1); i ++) {
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for (i = 2; i < (1000-1); i ++) {
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a[i] = k * i; /* S1 */
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a[i] = k * i; /* S1 */
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b[i] = a[i-2] + k; /* S2 */
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b[i] = a[i-2] + k; /* S2 */
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c[i] = b[i-1] + a[i+1]; /* S3 */
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c[i] = b[i-1] + a[i+1]; /* S3 */
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d[i] = c[i-1] + k + i; /* S4 */
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d[i] = c[i-1] + k + i; /* S4 */
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}
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}
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/* Dependences:
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/* Dependences:
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S1->S2 (flow, level 1)
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S1->S2 (flow, level 1)
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S2->S3 (flow, level 1)
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S2->S3 (flow, level 1)
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S3->S1 (anti, level 1)
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S3->S1 (anti, level 1)
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S3->S4 (flow, level 1)
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S3->S4 (flow, level 1)
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There are two partitions: {S1, S2, S3} and {S4}.
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There are two partitions: {S1, S2, S3} and {S4}.
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{S1, S2, S3} have to be in the same partition because:
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{S1, S2, S3} have to be in the same partition because:
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- S1 (i) has to be executed before S2 (i+2), as S1 produces a[i] that is then consumed 2 iterations later by S2.
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- S1 (i) has to be executed before S2 (i+2), as S1 produces a[i] that is then consumed 2 iterations later by S2.
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- S2 (i) has to be executed before S3 (i+1), as S2 produces b[i] that is then consumed one iteration later by S3,
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- S2 (i) has to be executed before S3 (i+1), as S2 produces b[i] that is then consumed one iteration later by S3,
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- S3 (i) has to be executed before S1 (i+1), as a[i+1] has to execute before the update to a[i],
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- S3 (i) has to be executed before S1 (i+1), as a[i+1] has to execute before the update to a[i],
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{S4} is the consumer partition: it consumes the values from array "c" produced in S3.
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{S4} is the consumer partition: it consumes the values from array "c" produced in S3.
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The cost model should fuse all the tasks together as the cost of
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The cost model should fuse all the tasks together as the cost of
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fetching data from caches is too high.
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fetching data from caches is too high.
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*/
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*/
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return a[1000-2] + b[1000-1] + c[1000-2] + d[1000-2];
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return a[1000-2] + b[1000-1] + c[1000-2] + d[1000-2];
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}
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}
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/* { dg-final { scan-tree-dump-times "distributed: split to 2 loops" 0 "ldist" } } */
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/* { dg-final { scan-tree-dump-times "distributed: split to 2 loops" 0 "ldist" } } */
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/* { dg-final { cleanup-tree-dump "ldist" } } */
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/* { dg-final { cleanup-tree-dump "ldist" } } */
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