Allow libcalls for complex memcpy when optimizing for size.

The RISC-V backend wants to use a libcall when optimizing for size if
more than 6 instructions are needed.  Emit_move_complex asks for no
libcalls.  This case requires 8 insns for rv64 and 16 insns for rv32,
so we get fallback code that emits a loop.  Commit_one_edge_insertion
doesn't allow code inserted for a phi node on an edge to end with a
branch, and so this triggers an assertion.  This problem goes away if
we allow libcalls when optimizing for size, which gives the code the
RISC-V backend wants, and avoids triggering the assert.

	gcc/
	PR middle-end/92263
	* expr.c (emit_move_complex): Only use BLOCK_OP_NO_LIBCALL when
	optimize_insn_for_speed_p is true.

	gcc/testsuite/
	PR middle-end/92263
	* gcc.dg/pr92263.c: New.

From-SVN: r277861

1 files changed, 4 insertions, 2 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index 06e934e..0fd5890f 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -3571,11 +3571,13 @@ emit_move_complex (machine_mode mode, rtx x, rtx y)
       rtx_insn *ret;
 
       /* For memory to memory moves, optimal behavior can be had with the
-	 existing block move logic.  */
+	 existing block move logic.  But use normal expansion if optimizing
+	 for size.  */
       if (MEM_P (x) && MEM_P (y))
 	{
 	  emit_block_move (x, y, gen_int_mode (GET_MODE_SIZE (mode), Pmode),
-			   BLOCK_OP_NO_LIBCALL);
+			   (optimize_insn_for_speed_p()
+			    ? BLOCK_OP_NO_LIBCALL : BLOCK_OP_NORMAL));
 	  return get_last_insn ();
 	}