From: Richard Biener <rguenther@suse.de>
Date: Thu, 24 Oct 2019 09:38:56 +0000 (+0000)
Subject: backport: [multiple changes]
X-Git-Tag: releases/gcc-7.5.0~49
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d23b9ce71519880d0dc73dfea464ac288498e3c0;p=thirdparty%2Fgcc.git

backport: [multiple changes]

2019-10-24  Richard Biener  <rguenther@suse.de>

	Backport from mainline
	2019-10-17  Richard Biener  <rguenther@suse.de>

	PR debug/91887
	* dwarf2out.c (gen_formal_parameter_die): Also try to match
	context_die against a DW_TAG_GNU_formal_parameter_pack parent.

	* g++.dg/debug/dwarf2/pr91887.C: New testcase.

	2019-09-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91812
	* tree-ssa-phiprop.c (propagate_with_phi): Do not replace
	volatile loads.

	* gcc.dg/torture/pr91812.c: New testcase.

From-SVN: r277370
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index fe43786a8e12..33024b992507 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2019-10-24  Richard Biener  <rguenther@suse.de>
+
+	Backport from mainline
+	2019-10-17  Richard Biener  <rguenther@suse.de>
+
+	PR debug/91887
+	* dwarf2out.c (gen_formal_parameter_die): Also try to match
+	context_die against a DW_TAG_GNU_formal_parameter_pack parent.
+
+	2019-09-19  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/91812
+	* tree-ssa-phiprop.c (propagate_with_phi): Do not replace
+	volatile loads.
+
 2019-10-23  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR tree-optimization/92131
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index a7f560872c0b..5590845d2a43 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -21212,7 +21212,10 @@ gen_formal_parameter_die (tree node, tree origin, bool emit_name_p,
 
       /* If the contexts differ, we may not be talking about the same
 	 thing.  */
-      if (parm_die && parm_die->die_parent != context_die)
+      if (parm_die
+	  && parm_die->die_parent != context_die
+	  && (parm_die->die_parent->die_tag != DW_TAG_GNU_formal_parameter_pack
+	      || parm_die->die_parent->die_parent != context_die))
 	{
 	  if (!DECL_ABSTRACT_P (node))
 	    {
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9dfad63b9ab3..25a0ac91a958 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,16 @@
+2019-10-24  Richard Biener  <rguenther@suse.de>
+
+	Backport from mainline
+	2019-10-17  Richard Biener  <rguenther@suse.de>
+
+	PR debug/91887
+	* g++.dg/debug/dwarf2/pr91887.C: New testcase.
+
+	2019-09-19  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/91812
+	* gcc.dg/torture/pr91812.c: New testcase.
+
 2019-10-23  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc.c-torture/execute/20191023-1.c: New test.
diff --git a/gcc/testsuite/g++.dg/debug/dwarf2/pr91887.C b/gcc/testsuite/g++.dg/debug/dwarf2/pr91887.C
new file mode 100644
index 000000000000..6cd99cc9bb86
--- /dev/null
+++ b/gcc/testsuite/g++.dg/debug/dwarf2/pr91887.C
@@ -0,0 +1,12 @@
+// { dg-do compile }
+// { dg-require-effective-target c++11 }
+// { dg-options "-g -fdebug-types-section" }
+class A {
+public:
+  A();
+  template <typename U> A(U);
+};
+template <class> struct B { typedef A type; };
+template <class R, typename... Args>
+int Bind(R(Args...), typename B<Args>::type...) { return 0; }
+void KeepBufferRefs(A, A) { A a, b(Bind(KeepBufferRefs, a, b)); }
diff --git a/gcc/testsuite/gcc.dg/torture/pr91812.c b/gcc/testsuite/gcc.dg/torture/pr91812.c
new file mode 100644
index 000000000000..ebc67a01e33f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr91812.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-fno-fat-lto-objects" } { "" } } */
+/* { dg-options "-fdump-tree-optimized-blocks" } */
+
+unsigned register1;
+unsigned register2;
+
+void busy_wait_for_register (int x)
+{
+  volatile unsigned* ptr;
+  switch(x) {
+    case 0x1111:
+    ptr = &register1;
+    break;
+
+    case 0x2222:
+    ptr = &register2;
+    break;
+
+    default:
+    return;
+  }
+  while (*ptr) {}
+}
+
+/* { dg-final { scan-tree-dump "loop depth 1" "optimized" } } */
diff --git a/gcc/tree-ssa-phiprop.c b/gcc/tree-ssa-phiprop.c
index 4f5f95df4f1b..9cb474114457 100644
--- a/gcc/tree-ssa-phiprop.c
+++ b/gcc/tree-ssa-phiprop.c
@@ -338,8 +338,15 @@ propagate_with_phi (basic_block bb, gphi *phi, struct phiprop_d *phivn,
 	    && (!type
 		|| types_compatible_p
 		     (TREE_TYPE (gimple_assign_lhs (use_stmt)), type))
-	    /* We cannot replace a load that may throw or is volatile.  */
-	    && !stmt_can_throw_internal (use_stmt)))
+	    /* We cannot replace a load that may throw or is volatile.
+	       For volatiles the transform can change the number of
+	       executions if the load is inside a loop but the address
+	       computations outside (PR91812).  We could relax this
+	       if we guard against that appropriately.  For loads that can
+	       throw we could relax things if the moved loads all are
+	       known to not throw.  */
+	    && !stmt_can_throw_internal (use_stmt)
+	    && !gimple_has_volatile_ops (use_stmt)))
 	continue;
 
       /* Check if we can move the loads.  The def stmt of the virtual use