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authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/testsuite/gcc.dg/tree-ssa/ldist-6.c
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Diffstat (limited to 'gcc/testsuite/gcc.dg/tree-ssa/ldist-6.c')
-rw-r--r--gcc/testsuite/gcc.dg/tree-ssa/ldist-6.c38
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diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ldist-6.c b/gcc/testsuite/gcc.dg/tree-ssa/ldist-6.c
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index 000000000..7a38c8683
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+++ b/gcc/testsuite/gcc.dg/tree-ssa/ldist-6.c
@@ -0,0 +1,38 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-loop-distribution -fdump-tree-ldist-all" } */
+
+int loop1 (int k)
+{
+ unsigned int i;
+ int a[1000], b[1000], c[1000], d[1000];
+
+ for (i = 2; i < (1000-1); i ++) {
+ a[i] = k * i; /* S1 */
+ b[i] = a[i-2] + k; /* S2 */
+ c[i] = b[i-1] + a[i+1]; /* S3 */
+ d[i] = c[i-1] + k + i; /* S4 */
+ }
+ /* Dependences:
+ S1->S2 (flow, level 1)
+ S2->S3 (flow, level 1)
+ S3->S1 (anti, level 1)
+ S3->S4 (flow, level 1)
+
+ There are two partitions: {S1, S2, S3} and {S4}.
+
+ {S1, S2, S3} have to be in the same partition because:
+ - S1 (i) has to be executed before S2 (i+2), as S1 produces a[i] that is then consumed 2 iterations later by S2.
+ - S2 (i) has to be executed before S3 (i+1), as S2 produces b[i] that is then consumed one iteration later by S3,
+ - S3 (i) has to be executed before S1 (i+1), as a[i+1] has to execute before the update to a[i],
+
+ {S4} is the consumer partition: it consumes the values from array "c" produced in S3.
+
+ The cost model should fuse all the tasks together as the cost of
+ fetching data from caches is too high.
+ */
+
+ return a[1000-2] + b[1000-1] + c[1000-2] + d[1000-2];
+}
+
+/* { dg-final { scan-tree-dump-times "distributed: split to 2 loops" 0 "ldist" } } */
+/* { dg-final { cleanup-tree-dump "ldist" } } */