[gcc r13-4101] middle-end/107679 - fix SSA rewrite of clobber of parameter

[gcc r13-4101] middle-end/107679 - fix SSA rewrite of clobber of parameter

[Richard Biener]

https://gcc.gnu.org/g:8a5f3663f8de45b7030dfe7ce962783dc1a19885

commit r13-4101-g8a5f3663f8de45b7030dfe7ce962783dc1a19885
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Nov 16 13:57:14 2022 +0100

    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:
---
 gcc/testsuite/gfortran.dg/pr107679.f90 | 9 +++++++++
 gcc/tree-into-ssa.cc                   | 8 ++++++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/gcc/testsuite/gfortran.dg/pr107679.f90 b/gcc/testsuite/gfortran.dg/pr107679.f90
new file mode 100644
index 00000000000..33a52fb5ef2
--- /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 d13fb720b37..f21ed2bea3f 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
 	    {