RISC-V: Refine the condition for add additional vars in RVV cost model

The adjacent_dr_p is sufficient and unnecessary condition for contiguous access.
So unnecessary live-ranges are added and result in smaller LMUL.

This patch uses MEMORY_ACCESS_TYPE as condition and constrains segment
load/store.

Tested on RV64 and no regression.

	PR target/114506

gcc/ChangeLog:

	* config/riscv/riscv-vector-costs.cc (non_contiguous_memory_access_p): Rename
	(need_additional_vector_vars_p): Rename and refine condition

gcc/testsuite/ChangeLog:

	* gcc.dg/vect/costmodel/riscv/rvv/pr114506.c: New test.

Signed-off-by: demin.han <demin.han@starfivetech.com>

diff --git a/gcc/config/riscv/riscv-vector-costs.cc b/gcc/config/riscv/riscv-vector-costs.cc
index d27bb68a7b92ccda13e4427a2836bb7a489075de..4582b0db425069fb775d98257f3eaee6cf1b8a6d 100644 (file)
--- a/gcc/config/riscv/riscv-vector-costs.cc
+++ b/gcc/config/riscv/riscv-vector-costs.cc
@@ -563,14 +563,24 @@ get_store_value (gimple *stmt)
     return gimple_assign_rhs1 (stmt);
 }
 
-/* Return true if it is non-contiguous load/store.  */
+/* Return true if addtional vector vars needed.  */
 static bool
-non_contiguous_memory_access_p (stmt_vec_info stmt_info)
+need_additional_vector_vars_p (stmt_vec_info stmt_info)
 {
   enum stmt_vec_info_type type
     = STMT_VINFO_TYPE (vect_stmt_to_vectorize (stmt_info));
-  return ((type == load_vec_info_type || type == store_vec_info_type)
-         && !adjacent_dr_p (STMT_VINFO_DATA_REF (stmt_info)));
+  if (type == load_vec_info_type || type == store_vec_info_type)
+    {
+      if (STMT_VINFO_GATHER_SCATTER_P (stmt_info)
+         && STMT_VINFO_MEMORY_ACCESS_TYPE (stmt_info) == VMAT_GATHER_SCATTER)
+       return true;
+
+      machine_mode mode = TYPE_MODE (STMT_VINFO_VECTYPE (stmt_info));
+      int lmul = riscv_get_v_regno_alignment (mode);
+      if (DR_GROUP_SIZE (stmt_info) * lmul > RVV_M8)
+       return true;
+    }
+  return false;
 }
 
 /* Return the LMUL of the current analysis.  */
@@ -739,10 +749,7 @@ update_local_live_ranges (
          stmt_vec_info stmt_info = vinfo->lookup_stmt (gsi_stmt (si));
          enum stmt_vec_info_type type
            = STMT_VINFO_TYPE (vect_stmt_to_vectorize (stmt_info));
-         if (non_contiguous_memory_access_p (stmt_info)
-             /* LOAD_LANES/STORE_LANES doesn't need a perm indice.  */
-             && STMT_VINFO_MEMORY_ACCESS_TYPE (stmt_info)
-                  != VMAT_LOAD_STORE_LANES)
+         if (need_additional_vector_vars_p (stmt_info))
            {
              /* For non-adjacent load/store STMT, we will potentially
                 convert it into:

diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr114506.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr114506.c
new file mode 100644 (file)
index 0000000..a88d24b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr114506.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -ftree-vectorize -mrvv-max-lmul=dynamic -fdump-tree-vect-details" } */
+
+float a[32000], b[32000], c[32000], d[32000];
+float aa[256][256], bb[256][256], cc[256][256];
+
+void
+s2275 ()
+{
+  for (int i = 0; i < 256; i++)
+    {
+      for (int j = 0; j < 256; j++)
+       {
+         aa[j][i] = aa[j][i] + bb[j][i] * cc[j][i];
+       }
+      a[i] = b[i] + c[i] * d[i];
+    }
+}
+
+/* { dg-final { scan-assembler-times {e32,m8} 1 } } */
+/* { dg-final { scan-assembler-not {e32,m4} } } */
+/* { dg-final { scan-assembler-not {csrr} } } */
+/* { dg-final { scan-tree-dump-not "Preferring smaller LMUL loop because it has unexpected spills" "vect" } } */