From: Juergen Christ <jchrist@linux.ibm.com>
Date: Mon, 10 Mar 2025 09:03:36 +0000 (+0100)
Subject: s390: fix delegitimization of addresses
X-Git-Tag: basepoints/gcc-16~1591
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4001281d69e9f8e01d2183f0e931e15ec4a522eb;p=thirdparty%2Fgcc.git

s390: fix delegitimization of addresses

In legitimize_pic_address we create a
(const (unspec ... UNSPEC_GOTENT))
in the GOT offset might be >= 4k.  However, the
s390_delegitimize_address does not contain a case for this scenario.

gcc/ChangeLog:

	* config/s390/s390.cc (s390_delegitimize_address): Add missing case.

gcc/testsuite/ChangeLog:

	* gcc.target/s390/delegitimize-1.c: New test.

Signed-off-by: Juergen Christ <jchrist@linux.ibm.com>
---

diff --git a/gcc/config/s390/s390.cc b/gcc/config/s390/s390.cc
index 645aedba67f..d4e849b12de 100644
--- a/gcc/config/s390/s390.cc
+++ b/gcc/config/s390/s390.cc
@@ -8238,6 +8238,21 @@ s390_delegitimize_address (rtx orig_x)
 	return plus_constant (Pmode, XVECEXP (y, 0, 0), offset);
     }
 
+  if (GET_CODE (x) == CONST)
+    {
+      /* Extract the symbol ref from:
+	 (const:DI (unspec:DI [(symbol_ref:DI ("foo"))]
+				       UNSPEC_PLT/GOTENT))  */
+
+      y = XEXP (x, 0);
+      if (GET_CODE (y) == UNSPEC
+	  && (XINT (y, 1) == UNSPEC_GOTENT
+	      || XINT (y, 1) == UNSPEC_PLT31))
+	return XVECEXP (y, 0, 0);
+      else
+	return orig_x;
+    }
+
   if (GET_CODE (x) != MEM)
     return orig_x;
 
diff --git a/gcc/testsuite/gcc.target/s390/delegitimize-1.c b/gcc/testsuite/gcc.target/s390/delegitimize-1.c
new file mode 100644
index 00000000000..5c49565db2f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/s390/delegitimize-1.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-m64 -fPIC -O2 -g -fdump-rtl-final-details" } */
+
+struct sk_buff {
+  struct {
+    struct {
+      struct {
+        int inner_ipproto;
+      };
+    };
+  };
+};
+void skb_udp_tunnel_segment(struct sk_buff *skb);
+const int *inet_offloads[42], *inet6_offloads[42];
+_Bool skb_udp_tunnel_segment_is_ipv6;
+void skb_udp_tunnel_segment(struct sk_buff *skb) {
+  const int **offloads =
+      skb_udp_tunnel_segment_is_ipv6 ? inet6_offloads : inet_offloads;
+  *(volatile typeof(_Generic(0, default : 0)) *)&offloads[skb->inner_ipproto];
+}
+
+/* { dg-final { scan-rtl-dump-not "Failed to expand as dwarf:" "final" } } */