From: Richard Biener <rguenther@suse.de>
Date: Wed, 16 Nov 2022 12:57:14 +0000 (+0100)
Subject: middle-end/107679 - fix SSA rewrite of clobber of parameter
X-Git-Tag: basepoints/gcc-14~3106
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8a5f3663f8de45b7030dfe7ce962783dc1a19885;p=thirdparty%2Fgcc.git

middle-end/107679 - fix SSA rewrite of clobber of parameter

When the frontend clobbers a parameter and that parameter gets
rewritten into SSA then we ICE because we didn't expect this.  Avoid
using the parameter decl to create a SSA default def in this case.

	PR middle-end/107679
	* tree-into-ssa.cc (maybe_register_def): Use new temporary if
	we require an uninitialized value for a parameter decl.

	* gfortran.dg/pr107679.f90: New testcase.
---

diff --git a/gcc/testsuite/gfortran.dg/pr107679.f90 b/gcc/testsuite/gfortran.dg/pr107679.f90
new file mode 100644
index 000000000000..33a52fb5ef22
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr107679.f90
@@ -0,0 +1,9 @@
+! { dg-do compile }
+
+subroutine s1(x)
+   integer, intent(out) :: x
+end
+subroutine s2(z)
+   integer, value :: z
+   call s1(z)
+end
diff --git a/gcc/tree-into-ssa.cc b/gcc/tree-into-ssa.cc
index d13fb720b37c..f21ed2bea3fb 100644
--- a/gcc/tree-into-ssa.cc
+++ b/gcc/tree-into-ssa.cc
@@ -1911,13 +1911,17 @@ maybe_register_def (def_operand_p def_p, gimple *stmt,
 	{
 	  if (gimple_clobber_p (stmt) && is_gimple_reg (sym))
 	    {
-	      gcc_checking_assert (VAR_P (sym));
+	      tree defvar;
+	      if (VAR_P (sym))
+		defvar = sym;
+	      else
+		defvar = create_tmp_reg (TREE_TYPE (sym));
 	      /* Replace clobber stmts with a default def. This new use of a
 		 default definition may make it look like SSA_NAMEs have
 		 conflicting lifetimes, so we need special code to let them
 		 coalesce properly.  */
 	      to_delete = true;
-	      def = get_or_create_ssa_default_def (cfun, sym);
+	      def = get_or_create_ssa_default_def (cfun, defvar);
 	    }
 	  else
 	    {