[PATCH][v2] middle-end/110495 - avoid associating constants with (VL) vectors

[PATCH][v2] middle-end/110495 - avoid associating constants with (VL) vectors

[Richard Biener]

When trying to associate (v + INT_MAX) + INT_MAX we are using
the TREE_OVERFLOW bit to check for correctness.  That isn't
working for VECTOR_CSTs and it can't in general when one considers
VL vectors.  It looks like it should work for COMPLEX_CSTs but
I didn't try to single out _Complex int in this change.

The following makes sure that for vectors we use the fallback of
using unsigned arithmetic when associating the above to
v + (INT_MAX + INT_MAX).

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

	PR middle-end/110495
	* tree.h (TREE_OVERFLOW): Do not mention VECTOR_CSTs
	since we do not set TREE_OVERFLOW on those since the
	introduction of VL vectors.
	* match.pd (x +- CST +- CST): For VECTOR_CST do not look
	at TREE_OVERFLOW to determine validity of association.

	* gcc.dg/tree-ssa/addadd-2.c: Amend.
	* gcc.dg/tree-ssa/forwprop-27.c: Adjust.
---
 gcc/match.pd                                | 28 +++++++++++----------
 gcc/testsuite/gcc.dg/tree-ssa/addadd-2.c    |  1 +
 gcc/testsuite/gcc.dg/tree-ssa/forwprop-27.c |  4 ++-
 gcc/tree.h                                  |  2 +-
 4 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/gcc/match.pd b/gcc/match.pd
index f09583bbcac..861b7dfcddd 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3025,19 +3025,21 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	(with { tree cst = const_binop (outer_op == inner_op
 					? PLUS_EXPR : MINUS_EXPR,
 					type, @1, @2); }
-	 (if (cst && !TREE_OVERFLOW (cst))
-	  (inner_op @0 { cst; } )
-	  /* X+INT_MAX+1 is X-INT_MIN.  */
-	  (if (INTEGRAL_TYPE_P (type) && cst
-	       && wi::to_wide (cst) == wi::min_value (type))
-	   (neg_inner_op @0 { wide_int_to_tree (type, wi::to_wide (cst)); })
-	   /* Last resort, use some unsigned type.  */
-	   (with { tree utype = unsigned_type_for (type); }
-	    (if (utype)
-	     (view_convert (inner_op
-			    (view_convert:utype @0)
-			    (view_convert:utype
-			     { drop_tree_overflow (cst); }))))))))))))))
+	 (if (cst)
+	  (if (INTEGRAL_TYPE_P (type) && !TREE_OVERFLOW (cst))
+	   (inner_op @0 { cst; } )
+	   /* X+INT_MAX+1 is X-INT_MIN.  */
+	   (if (INTEGRAL_TYPE_P (type)
+	        && wi::to_wide (cst) == wi::min_value (type))
+	    (neg_inner_op @0 { wide_int_to_tree (type, wi::to_wide (cst)); })
+	    /* Last resort, use some unsigned type.  */
+	    (with { tree utype = unsigned_type_for (type); }
+	     (if (utype)
+	      (view_convert (inner_op
+			     (view_convert:utype @0)
+			     (view_convert:utype
+			      { TREE_OVERFLOW (cst)
+			        ? drop_tree_overflow (cst) : cst; })))))))))))))))
 
   /* (CST1 - A) +- CST2 -> CST3 - A  */
   (for outer_op (plus minus)
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/addadd-2.c b/gcc/testsuite/gcc.dg/tree-ssa/addadd-2.c
index 39aa032c9b1..8c05911f473 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/addadd-2.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/addadd-2.c
@@ -12,4 +12,5 @@ void k(S*x){
   *x = (S)(y + __INT_MAX__);
 }
 
+/* { dg-final { scan-tree-dump "4294967294" "optimized" { target int32plus } } } */
 /* { dg-final { scan-tree-dump-not "2147483647" "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/forwprop-27.c b/gcc/testsuite/gcc.dg/tree-ssa/forwprop-27.c
index 9775a4c6367..6c71a4fc81c 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/forwprop-27.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/forwprop-27.c
@@ -33,7 +33,9 @@ void i (V *v1, V *v2){
   *v2 = (c1-*v2)+c2;
 }
 
-/* { dg-final { scan-tree-dump-not "\\\+" "forwprop1"} } */
+/* { dg-final { scan-tree-dump-times "\\\+" 1 "forwprop1"} } */
 /* { dg-final { scan-tree-dump "{ 0, 4 }" "forwprop1"} } */
 /* { dg-final { scan-tree-dump "{ 37, -5 }" "forwprop1"} } */
+/* { dg-final { scan-tree-dump "{ 27, 23 }" "forwprop1"} } */
+/* { dg-final { scan-tree-dump "{ 37, 3 }" "forwprop1"} } */
 
diff --git a/gcc/tree.h b/gcc/tree.h
index f11c758afb9..bedbbb0bcc0 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -824,7 +824,7 @@ extern void omp_clause_range_check_failed (const_tree, const char *, int,
 #define TYPE_REF_CAN_ALIAS_ALL(NODE) \
   (PTR_OR_REF_CHECK (NODE)->base.static_flag)
 
-/* In an INTEGER_CST, REAL_CST, COMPLEX_CST, or VECTOR_CST, this means
+/* In an INTEGER_CST, REAL_CST, or COMPLEX_CST, this means
    there was an overflow in folding.  */
 
 #define TREE_OVERFLOW(NODE) (CST_CHECK (NODE)->base.public_flag)
-- 
2.35.3