From: Richard Biener <rguenther@suse.de>
Date: Fri, 23 Jun 2023 08:15:27 +0000 (+0200)
Subject: Bogus and missed folding on vector compares
X-Git-Tag: basepoints/gcc-15~8099
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b32400e19a702137fd11571d199f725add0daf6;p=thirdparty%2Fgcc.git

Bogus and missed folding on vector compares

fold_binary tries to transform (double)float1 CMP (double)float2
into float1 CMP float2 but ends up using TYPE_PRECISION on the
argument types.  For vector types that compares the number of
lanes which should be always equal (so it's harmless as to
not generating wrong code).  The following instead properly
uses element_precision.

The same happens in the corresponding match.pd pattern.

	* fold-const.cc (fold_binary_loc): Use element_precision
	when trying (double)float1 CMP (double)float2 to
	float1 CMP float2 simplification.
	* match.pd: Likewise.
---

diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index 3aa6851acd5e..b05b3ae16e93 100644
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -12564,10 +12564,10 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
 	tree targ1 = strip_float_extensions (arg1);
 	tree newtype = TREE_TYPE (targ0);
 
-	if (TYPE_PRECISION (TREE_TYPE (targ1)) > TYPE_PRECISION (newtype))
+	if (element_precision (TREE_TYPE (targ1)) > element_precision (newtype))
 	  newtype = TREE_TYPE (targ1);
 
-	if (TYPE_PRECISION (newtype) < TYPE_PRECISION (TREE_TYPE (arg0)))
+	if (element_precision (newtype) < element_precision (TREE_TYPE (arg0)))
 	  return fold_build2_loc (loc, code, type,
 			      fold_convert_loc (loc, newtype, targ0),
 			      fold_convert_loc (loc, newtype, targ1));
diff --git a/gcc/match.pd b/gcc/match.pd
index 2dd238260346..85d562a531d2 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -6034,10 +6034,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	     type1 = double_type_node;
 	 }
       tree newtype
-        = (TYPE_PRECISION (TREE_TYPE (@00)) > TYPE_PRECISION (type1)
+        = (element_precision (TREE_TYPE (@00)) > element_precision (type1)
 	   ? TREE_TYPE (@00) : type1);
      }
-     (if (TYPE_PRECISION (TREE_TYPE (@0)) > TYPE_PRECISION (newtype))
+     (if (element_precision (TREE_TYPE (@0)) > element_precision (newtype))
       (cmp (convert:newtype @00) (convert:newtype @10))))))))