[PATCH] Allow libcalls for complex memcpy when optimizing for size.

[Jim Wilson]

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.
---
 gcc/expr.c                     |  6 ++++--
 gcc/testsuite/gcc.dg/pr92263.c | 28 ++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr92263.c

diff --git a/gcc/expr.c b/gcc/expr.c
index 476c6865f20..0c2e03dd32d 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 ();
        }
 
diff --git a/gcc/testsuite/gcc.dg/pr92263.c b/gcc/testsuite/gcc.dg/pr92263.c
new file mode 100644
index 00000000000..a79dfd1e351
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr92263.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-fno-tree-dce -fno-tree-forwprop -Os -ffloat-store" } */
+
+extern long double cabsl (_Complex long double);
+
+typedef struct {
+  int nsant, nvqd;
+  _Complex long double *vqd;
+} vsorc_t;
+vsorc_t vsorc;
+
+void foo(int next_job, int ain_num, int iped, long t) {
+  long double zpnorm;
+
+  while (!next_job)
+    if (ain_num)
+    {
+      if (iped == 1)
+        zpnorm = 0.0;
+      int indx = vsorc.nvqd-1;
+      vsorc.vqd[indx] = t*1.0fj;
+      if (cabsl(vsorc.vqd[indx]) < 1.e-20)
+        vsorc.vqd[indx] = 0.0fj;
+      zpnorm = t;
+      if (zpnorm > 0.0)
+        iped = vsorc.nsant;
+    }
+}
-- 
2.17.1