re PR middle-end/42181 ([graphite] -fgraphite-identity miscompiles air.f90)

Fix PR42181.

2009-12-14  Sebastian Pop  <sebastian.pop@amd.com>

	PR middle-end/42181
	* graphite-scop-detection.c (graphite_can_represent_scev): Handle more
	carefully PLUS_EXPR, MINUS_EXPR, and MULT_EXPR.

	* testsuite/gfortran.dg/graphite/pr42181.f90: New.

From-SVN: r155417

gcc/ChangeLog.graphite

+2009-12-14  Sebastian Pop  <sebastian.pop@amd.com>
+
+	PR middle-end/42181
+	* graphite-scop-detection.c (graphite_can_represent_scev): Handle more
+	carefully PLUS_EXPR, MINUS_EXPR, and MULT_EXPR.
+
+	* testsuite/gfortran.dg/graphite/pr42181.f90: New.
+
 2009-12-12  Sebastian Pop  <sebpop@gmail.com>
 
 	PR middle-end/42284

gcc/graphite-scop-detection.c

@@ -213,15 +213,33 @@ graphite_can_represent_scev (tree scev, int outermost_loop)
   if (chrec_contains_undetermined (scev))
     return false;
 
-  if (TREE_CODE (scev) == POLYNOMIAL_CHREC
+  switch (TREE_CODE (scev))
+    {
+    case PLUS_EXPR:
+    case MINUS_EXPR:
+      return graphite_can_represent_scev (TREE_OPERAND (scev, 0), outermost_loop)
+	&& graphite_can_represent_scev (TREE_OPERAND (scev, 1), outermost_loop);
+
+    case MULT_EXPR:
+      return !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 0)))
+	&& !CONVERT_EXPR_CODE_P (TREE_CODE (TREE_OPERAND (scev, 1)))
+	&& !(chrec_contains_symbols (TREE_OPERAND (scev, 0))
+	     && chrec_contains_symbols (TREE_OPERAND (scev, 1)))
+	&& graphite_can_represent_scev (TREE_OPERAND (scev, 0), outermost_loop)
+	&& graphite_can_represent_scev (TREE_OPERAND (scev, 1), outermost_loop);
 
+    case POLYNOMIAL_CHREC:
       /* Check for constant strides.  With a non constant stride of
-	 'n' we would have a value of 'iv * n'.  */
-      && (!evolution_function_right_is_integer_cst (scev)
+	 'n' we would have a value of 'iv * n'.  Also check that the
+	 initial value can represented: for example 'n * m' cannot be
+	 represented.  */
+      if (!evolution_function_right_is_integer_cst (scev)
+	  || !graphite_can_represent_init (scev))
+	return false;
 
-	  /* Check the initial value: 'n * m' cannot be represented.  */
-	  || !graphite_can_represent_init (scev)))
-    return false;
+    default:
+      break;
+    }
 
   /* Only affine functions can be represented.  */
   if (!scev_is_linear_expression (scev))

gcc/testsuite/gfortran.dg/graphite/pr42181.f90

+! { dg-options "-O1 -fgraphite" }
+
+MODULE powell
+  INTEGER, PARAMETER :: dp=8
+CONTAINS
+  SUBROUTINE newuob (n,npt,x,rhobeg,rhoend,maxfun,xbase,&
+       xopt,xnew,xpt,fval,gq,hq,pq,bmat,zmat,ndim,d,vlag,w,opt)
+    REAL(dp), DIMENSION(npt, *), &
+      INTENT(inout)                          :: xpt
+    REAL(dp), DIMENSION(*), INTENT(inout)    :: fval, gq, hq, pq
+120 IF (dsq <= 1.0e-3_dp*xoptsq) THEN
+       DO k=1,npt
+          DO i=1,n
+             gq(i)=gq(i)+temp*xpt(k,i)
+          END DO
+       END DO
+    END IF
+  END SUBROUTINE newuob
+END MODULE powell