From: Andrew MacLeod <amacleod@redhat.com>
Date: Mon, 5 May 2025 16:17:13 +0000 (-0400)
Subject: Allow IPA_CP to handle UNDEFINED as VARYING.
X-Git-Tag: releases/gcc-14.3.0~54
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=93b85bdf830477fec8db1d8afcaca13530776161;p=thirdparty%2Fgcc.git

Allow IPA_CP to handle UNDEFINED as VARYING.

When applying a bitmask to reflect ranges, it is sometimes deferred and
this can result in an UNDEFINED result.  IPA is not expecting this, and
add a check for it, and convert to VARYING if encountered.

	PR tree-optimization/120048
	gcc/
	* ipa-cp.cc (ipcp_store_vr_results): Check for UNDEFINED.

	gcc/testsuite/
	* gcc.dg/pr120048.c: New.
---

diff --git a/gcc/ipa-cp.cc b/gcc/ipa-cp.cc
index 6b772fae88f..222ba01c576 100644
--- a/gcc/ipa-cp.cc
+++ b/gcc/ipa-cp.cc
@@ -6355,6 +6355,11 @@ ipcp_store_vr_results (void)
 						     TYPE_PRECISION (type),
 						     TYPE_SIGN (type)));
 		  r.update_bitmask (bm);
+		  // Reflecting the bitmask on the ranges can sometime
+		  // produce an UNDEFINED value if the the bitmask update
+		  // was previously deferred.  See PR 120048.
+		  if (tmp.undefined_p ())
+		    tmp.set_varying (type);
 		  ipa_vr vr (tmp);
 		  ts->m_vr->quick_push (vr);
 		}
@@ -6377,6 +6382,11 @@ ipcp_store_vr_results (void)
 						 TYPE_PRECISION (type),
 						 TYPE_SIGN (type)));
 	      r.update_bitmask (bm);
+	      // Reflecting the bitmask on the ranges can sometime
+	      // produce an UNDEFINED value if the the bitmask update
+	      // was previously deferred.  See PR 120048.
+	      if (tmp.undefined_p ())
+		tmp.set_varying (type);
 	      ipa_vr vr (tmp);
 	      ts->m_vr->quick_push (vr);
 	    }
diff --git a/gcc/testsuite/gcc.dg/pr120048.c b/gcc/testsuite/gcc.dg/pr120048.c
new file mode 100644
index 00000000000..6bb34b0e168
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr120048.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-vrp -fno-tree-fre" } */
+
+int a, b, c;
+static int d(short e) { return e || (a && e) ? 0 : a; }
+static void f(int e) {
+  if (!e) {
+    d(0);
+    b = d(e);
+  }
+}
+int main() { f(c | 1); }