"Bug 47046 - gcc.target/i386/sse4_1-movntdqa.c ICEs with -fgraphite-identity"

The problem here is that we are left with the following code to be
translated in the new representation following the transform that
Graphite has chosen:

        D.2709_14 = j_33 * i_32;
        D.2710_15 = D.2709_14 * i_32;
        D.2711_16 = D.2710_15 * sign_34;
        *D.2708_13 = D.2711_16;

In this particular case we have a nonlinear expression "i * i" for
which we have to generate code following the new graphite_iv variables.

The patch fixes the function that detects whether we are passing non
linear stuff to graphite: evolution_function_is_affine_p.  It seems
like for the moment evolution_function_is_affine_p is testing whether
an evolution function is affine only in the innermost loop, without
looking recursively at what happens in outer loops.

The chrec for this case is: {0, +, {0, +, {1, +, 2}_1}_1}_2 and we are
testing whether the evolution is affine only for the loop_2, which is
true as we have {0, +, blah}_2 with blah invariant in loop_2.

The patch adds the recursive call to evolution_function_is_affine_p.

Bootstrapped and tested on amd64-linux.

2011-07-23  Sebastian Pop  <[email protected]>

        PR middle-end/47046
        * tree-chrec.h (evolution_function_is_affine_p): Recursively call
        evolution_function_is_affine_p on CHREC_RIGHT.

        * gcc.dg/graphite/id-pr47046.c: New.
---
 gcc/ChangeLog                              |    6 ++++++
 gcc/testsuite/ChangeLog                    |    5 +++++
 gcc/testsuite/gcc.dg/graphite/id-pr47046.c |   13 +++++++++++++
 gcc/tree-chrec.h                           |    4 +++-
 4 files changed, 27 insertions(+), 1 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/graphite/id-pr47046.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index feffc6b..2237954 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,11 @@
 2011-07-23  Sebastian Pop  <[email protected]>
 
+       PR middle-end/47046
+       * tree-chrec.h (evolution_function_is_affine_p): Recursively call
+       evolution_function_is_affine_p on CHREC_RIGHT.
+
+2011-07-23  Sebastian Pop  <[email protected]>
+
        PR middle-end/47594
        * graphite-sese-to-poly.c (scan_tree_for_params_right_scev): Sign
        extend constants.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index af1211a..919484b 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2011-07-23  Sebastian Pop  <[email protected]>
 
+       PR middle-end/47046
+       * gcc.dg/graphite/id-pr47046.c: New.
+
+2011-07-23  Sebastian Pop  <[email protected]>
+
        PR middle-end/47594
        * gfortran.dg/graphite/run-id-pr47594.f90: New.
 
diff --git a/gcc/testsuite/gcc.dg/graphite/id-pr47046.c 
b/gcc/testsuite/gcc.dg/graphite/id-pr47046.c
new file mode 100644
index 0000000..aba38ed
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/graphite/id-pr47046.c
@@ -0,0 +1,13 @@
+void
+init_movntdqa (int *src)
+{
+  int i, j, sign = 1;
+
+  for (i = 0; i < 20; i++)
+    for (j = 0; j < 4; j++)
+      {
+       src[i * 4 + j] = j * i * i * sign;
+       sign = -sign;
+      }
+}
+
diff --git a/gcc/tree-chrec.h b/gcc/tree-chrec.h
index b9bf71e..9b971bd 100644
--- a/gcc/tree-chrec.h
+++ b/gcc/tree-chrec.h
@@ -205,7 +205,9 @@ evolution_function_is_affine_p (const_tree chrec)
   return chrec
     && TREE_CODE (chrec) == POLYNOMIAL_CHREC
     && evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
-                                         CHREC_VARIABLE (chrec));
+                                         CHREC_VARIABLE (chrec))
+    && (TREE_CODE (CHREC_RIGHT (chrec)) != POLYNOMIAL_CHREC
+       || evolution_function_is_affine_p (CHREC_RIGHT (chrec)));
 }
 
 /* Determines whether EXPR does not contains chrec expressions.  */
-- 
1.7.4.1

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