complex: Directly emit gimple from extract_component [PR121661]HEADtrunkmaster

Currently extract_component uses force_gimple_operand_gsi to emit
gimple including loads. The problem with that decls that have
DECL_EXPR_DECL set on it will change over to use the DECL_EXPR_DECL instead.
Normally this is ok except for nested functions where the original decl
is a PARAM_DECL, there is a copy from the param decl to the new frame based
location.
Well instead we should just create the gimple ourselves.
The only special case that needs to be handled is BIT_FIELD_REF and
a VCE of SSA_NAME. BIT_FIELD_REF was already handled specially
so we can just emit the load there. VCE of SSA_NAME on the other
hand needed some extra code.

Note VCE of s SSA_NAME case could be optimized, I filed PR 123968
for that. Since that is not a regression at this point and we are
now producing the same code as before.

Bootstrapped and tested on x86_64-linux-gnu.

	PR middle-end/121661

gcc/ChangeLog:

	* tree-complex.cc (extract_component): Create gimple
	assign statements directly rather than call force_gimple_operand_gsi.

gcc/testsuite/ChangeLog:

	* gcc.dg/torture/pr121661-1.c: New test.

Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>

2 files changed, 60 insertions, 7 deletions

diff --git a/gcc/testsuite/gcc.dg/torture/pr121661-1.c b/gcc/testsuite/gcc.dg/torture/pr121661-1.c
new file mode 100644
index 0000000..3bc2a8e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr121661-1.c
@@ -0,0 +1,21 @@
+/* { dg-do run } */
+/* { dg-options "" } */
+/* PR middle-end/121661 */
+
+static void fun1(_Complex int val)
+{
+  __attribute__((unused))
+  void nfun()
+    {
+      if (__real__ val != 1)
+        __builtin_abort();
+    }
+  (void)&val;
+  if (__real__ val != 1)
+    __builtin_abort();
+}
+
+int main(int argc, char* [])
+{
+  fun1(1);
+}
diff --git a/gcc/tree-complex.cc b/gcc/tree-complex.cc
index d2a3ed3..9040192 100644
--- a/gcc/tree-complex.cc
+++ b/gcc/tree-complex.cc
@@ -652,28 +652,60 @@ extract_component (gimple_stmt_iterator *gsi, tree t, bool imagpart_p,
 	if (imagpart_p)
 	  TREE_OPERAND (t, 2) = size_binop (PLUS_EXPR, TREE_OPERAND (t, 2),
 					    TYPE_SIZE (inner_type));
+
 	if (gimple_p)
-	  t = force_gimple_operand_gsi (gsi, t, true, NULL, true,
-					GSI_SAME_STMT);
+	  {
+	    tree new_lhs = make_ssa_name (inner_type);
+	    gimple *new_load = gimple_build_assign (new_lhs, t);
+	    gsi_insert_before (gsi, new_load, GSI_SAME_STMT);
+	    t = new_lhs;
+	  }
 	return t;
       }
 
+    case VIEW_CONVERT_EXPR:
+      /* Getting the real/imag parts of a VCE of a ssa-name requires
+	 to place the complex into a ssa name before getting the
+	 2 parts.
+	 As `IMAGPART_EXPR<VIEW_CONVERT_EXPR<a_BN>>` is an invalid
+	 gimple. This will only show up when gimplifying it.
+	 Note this creates an extra copy.  The call to
+	 force_gimple_operand_gsi would create one too.  */
+      if (TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME)
+	{
+	  gcc_assert (gimple_p);
+	  tree new_cplx = make_ssa_name (TREE_TYPE (t));
+	  gimple *vce = gimple_build_assign (new_cplx, unshare_expr (t));
+	  gsi_insert_before (gsi, vce, GSI_SAME_STMT);
+
+	  tree new_lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (t)));
+	  t = build1 ((imagpart_p ? IMAGPART_EXPR : REALPART_EXPR),
+		      TREE_TYPE (TREE_TYPE (t)), new_cplx);
+	  gimple *new_ri = gimple_build_assign (new_lhs, t);
+	  gsi_insert_before (gsi, new_ri, GSI_SAME_STMT);
+	  t = new_lhs;
+	  return t;
+	}
+    /* FALLTHRU */
     case VAR_DECL:
     case RESULT_DECL:
     case PARM_DECL:
     case COMPONENT_REF:
     case ARRAY_REF:
-    case VIEW_CONVERT_EXPR:
     case MEM_REF:
       {
 	tree inner_type = TREE_TYPE (TREE_TYPE (t));
 
-	t = build1 ((imagpart_p ? IMAGPART_EXPR : REALPART_EXPR),
-		    inner_type, unshare_expr (t));
+	t = fold_build1 ((imagpart_p ? IMAGPART_EXPR : REALPART_EXPR),
+			 inner_type, unshare_expr (t));
 
 	if (gimple_p)
-	  t = force_gimple_operand_gsi (gsi, t, true, NULL, true,
-                                        GSI_SAME_STMT);
+	  {
+	    tree new_lhs = make_ssa_name (inner_type);
+	    gimple *new_load = gimple_build_assign (new_lhs, t);
+	    gsi_insert_before (gsi, new_load, GSI_SAME_STMT);
+	    t = new_lhs;
+	  }
 
 	return t;
       }