From: Tejas Belagod <tejas.belagod@arm.com>
Date: Thu, 5 Sep 2024 09:05:59 +0000 (+0530)
Subject: c: Range-check indexing of SVE ACLE vectors
X-Git-Tag: basepoints/gcc-16~3775
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=47fa008ad880c115bce4007fe9808e48b0dcf859;p=thirdparty%2Fgcc.git

c: Range-check indexing of SVE ACLE vectors

This patch adds a check for non-GNU vectors to warn that the index is outside
the range of a fixed vector size.  For VLA vectors, we don't diagnose.

gcc/c-family/ChangeLog:

	* c-common.cc (convert_vector_to_array_for_subscript): Add
	range-check for target vector types.
---

diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc
index a8f25d6cb944..d21f2f9909c4 100644
--- a/gcc/c-family/c-common.cc
+++ b/gcc/c-family/c-common.cc
@@ -9075,10 +9075,12 @@ convert_vector_to_array_for_subscript (location_t loc,
       ret = !lvalue_p (*vecp);
 
       index = fold_for_warn (index);
-      if (TREE_CODE (index) == INTEGER_CST)
-        if (!tree_fits_uhwi_p (index)
-	    || maybe_ge (tree_to_uhwi (index), TYPE_VECTOR_SUBPARTS (type)))
-	  warning_at (loc, OPT_Warray_bounds_, "index value is out of bound");
+      /* Warn out-of-bounds index for vectors only if known.  */
+      if (poly_int_tree_p (index))
+	if (!tree_fits_poly_uint64_p (index)
+	    || known_ge (tree_to_poly_uint64 (index),
+			  TYPE_VECTOR_SUBPARTS (type)))
+	    warning_at (loc, OPT_Warray_bounds_, "index value is out of bound");
 
       /* We are building an ARRAY_REF so mark the vector as addressable
          to not run into the gimplifiers premature setting of DECL_GIMPLE_REG_P