From: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Fri, 2 Dec 2016 12:22:54 +0000 (+0000)
Subject: [ree] PR rtl-optimization/78038: Handle global register dataflow definitions in ree
X-Git-Tag: releases/gcc-5.5.0~668
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d11c8f105634b09a3363ee612599a7ed36044108;p=thirdparty%2Fgcc.git

[ree] PR rtl-optimization/78038: Handle global register dataflow definitions in ree

2016-12-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	Backport from mainline
	2016-10-21  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	PR rtl-optimization/78038
	* ree.c (get_defs): Return NULL if a defining insn for REG cannot
	be deduced to set REG through the RTL structure.
	(make_defs_and_copies_lists): Return false on a failing get_defs call.

	* gcc.target/aarch64/pr78038.c: New test.

From-SVN: r243175
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3e86e38aadc9..382004e3e253 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2016-12-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	Backport from mainline
+	2016-10-21  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	PR rtl-optimization/78038
+	* ree.c (get_defs): Return NULL if a defining insn for REG cannot
+	be deduced to set REG through the RTL structure.
+	(make_defs_and_copies_lists): Return false on a failing get_defs call.
+
 2016-12-02  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
 	Backport from mainline
diff --git a/gcc/ree.c b/gcc/ree.c
index 48765b6aaabb..69dfe90af154 100644
--- a/gcc/ree.c
+++ b/gcc/ree.c
@@ -529,6 +529,14 @@ get_defs (rtx_insn *insn, rtx reg, vec<rtx_insn *> *dest)
         return NULL;
       if (DF_REF_INSN_INFO (ref_link->ref) == NULL)
         return NULL;
+      /* As global regs are assumed to be defined at each function call
+	 dataflow can report a call_insn as being a definition of REG.
+	 But we can't do anything with that in this pass so proceed only
+	 if the instruction really sets REG in a way that can be deduced
+	 from the RTL structure.  */
+      if (global_regs[REGNO (reg)]
+	  && !set_of (reg, DF_REF_INSN (ref_link->ref)))
+	return NULL;
     }
 
   if (dest)
@@ -627,7 +635,7 @@ make_defs_and_copies_lists (rtx_insn *extend_insn, const_rtx set_pat,
 
   /* Initialize the work list.  */
   if (!get_defs (extend_insn, src_reg, &state->work_list))
-    gcc_unreachable ();
+    return false;
 
   is_insn_visited = XCNEWVEC (bool, max_insn_uid);
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index cb846e6d9b93..ab1f24dbca59 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2016-12-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	Backport from mainline
+	2016-10-21  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	PR rtl-optimization/78038
+	* gcc.target/aarch64/pr78038.c: New test.
+
 2016-12-02  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
 	Backport from mainline
diff --git a/gcc/testsuite/gcc.target/aarch64/pr78038.c b/gcc/testsuite/gcc.target/aarch64/pr78038.c
new file mode 100644
index 000000000000..76d97d3b0ad4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr78038.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+/* PR rtl-optimization/78038.
+   Make sure ree can gracefully handle extensions of the global
+   variable register after a call.  */
+
+typedef void (*test_fptr_t) (void);
+void
+test_f (void)
+{
+}
+test_fptr_t test_fptr = test_f;
+
+struct test2_s
+{
+  int f;
+};
+
+register struct test2_s *g __asm__("x28");
+
+void
+do_something ()
+{
+  test_fptr ();
+  struct test2_s *p1 = 0;
+  *p1 = *g;
+}