From: Aldy Hernandez <aldyh@redhat.com>
Date: Mon, 27 Sep 2021 07:20:56 +0000 (+0200)
Subject: Use on-demand ranges in ssa_name_has_boolean_range before querying nonzero bits.
X-Git-Tag: upstream/12.2.0~4802
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d5f8abe1d3f718a75cbff0a453c1d961be5939b7;p=platform%2Fupstream%2Fgcc.git

Use on-demand ranges in ssa_name_has_boolean_range before querying nonzero bits.

The function ssa_name_has_boolean_range looks at the nonzero bits stored
in SSA_NAME_RANGE_INFO.  These are global in nature and are the result
of a previous evrp/VRP run (technically other passes can also set them).

However, we can do better if we use get_range_query.  Doing so will use
a ranger if enabled in a pass, or global ranges otherwise.  The call to
get_nonzero_bits remains, as there are passes that will set them
independently of the global range info.

Tested on x86-64 Linux with a regstrap as well as in a DOM environment
using an on-demand ranger instead of evrp.

gcc/ChangeLog:

	* tree-ssanames.c (ssa_name_has_boolean_range): Use
	get_range_query.
---

diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c
index 2165ad7..f427c5a 100644
--- a/gcc/tree-ssanames.c
+++ b/gcc/tree-ssanames.c
@@ -31,6 +31,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa.h"
 #include "cfgloop.h"
 #include "tree-scalar-evolution.h"
+#include "value-query.h"
 
 /* Rewriting a function into SSA form can create a huge number of SSA_NAMEs,
    many of which may be thrown away shortly after their creation if jumps
@@ -484,7 +485,7 @@ get_nonzero_bits (const_tree name)
 
    This can be because it is a boolean type, any unsigned integral
    type with a single bit of precision, or has known range of [0..1]
-   via VRP analysis.  */
+   via range analysis.  */
 
 bool
 ssa_name_has_boolean_range (tree op)
@@ -502,12 +503,20 @@ ssa_name_has_boolean_range (tree op)
     return true;
 
   /* An integral type with more precision, but the object
-     only takes on values [0..1] as determined by VRP
+     only takes on values [0..1] as determined by range
      analysis.  */
   if (INTEGRAL_TYPE_P (TREE_TYPE (op))
-      && (TYPE_PRECISION (TREE_TYPE (op)) > 1)
-      && wi::eq_p (get_nonzero_bits (op), 1))
-    return true;
+      && (TYPE_PRECISION (TREE_TYPE (op)) > 1))
+    {
+      int_range<2> onezero (build_zero_cst (TREE_TYPE (op)),
+			    build_one_cst (TREE_TYPE (op)));
+      int_range<2> r;
+      if (get_range_query (cfun)->range_of_expr (r, op) && r == onezero)
+	return true;
+
+      if (wi::eq_p (get_nonzero_bits (op), 1))
+	return true;
+    }
 
   return false;
 }