[PATCH] IBM Z: Emit vector alignment hints for strlen

[Stefan Schulze Frielinghaus via Gcc-patches]

In case the vectorized version of strlen is used, then each memory
access inside the loop is 16-byte aligned.  Thus add this kind of
information so that vector alignment hints can later on be emitted.
Bootstrapped and regtested on IBM Z.  Ok for master?

gcc/ChangeLog:

        * config/s390/s390.c (s390_expand_vec_strlen): Add alignment
        for memory access inside loop.
---
 gcc/config/s390/s390.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index dbb541bbea7..f9b27f96fd7 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -5955,6 +5955,7 @@ s390_expand_vec_strlen (rtx target, rtx string, rtx 
alignment)
   rtx temp;
   rtx len = gen_reg_rtx (QImode);
   rtx cond;
+  rtx mem;
 
   s390_load_address (str_addr_base_reg, XEXP (string, 0));
   emit_move_insn (str_idx_reg, const0_rtx);
@@ -5996,10 +5997,10 @@ s390_expand_vec_strlen (rtx target, rtx string, rtx 
alignment)
   LABEL_NUSES (loop_start_label) = 1;
 
   /* Load 16 bytes of the string into VR.  */
-  emit_move_insn (str_reg,
-                 gen_rtx_MEM (V16QImode,
-                              gen_rtx_PLUS (Pmode, str_idx_reg,
-                                            str_addr_base_reg)));
+  mem = gen_rtx_MEM (V16QImode,
+                    gen_rtx_PLUS (Pmode, str_idx_reg, str_addr_base_reg));
+  set_mem_align (mem, 128);
+  emit_move_insn (str_reg, mem);
   if (into_loop_label != NULL_RTX)
     {
       emit_label (into_loop_label);
-- 
2.25.3