RISC-V: Fix calculation of max live vregs

For the stmt _1 = _2 + _3, assume that _2 or _3 not used after this stmt.
_1 can use same register with _2 or _3 if without early clobber.
Two registers are needed, but current calculation is three.

This patch preserves point 0 for bb entry and excludes its def when
calculates live regs of certain point.

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

gcc/ChangeLog:

	* config/riscv/riscv-vector-costs.cc (max_number_of_live_regs): Fix
	max live vregs calc
	(preferred_new_lmul_p): Ditto

gcc/testsuite/ChangeLog:

	* gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul2-7.c: Moved to...
	* gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul4-10.c: ...here.
	* gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul4-4.c: Moved to...
	* gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul8-11.c: ...here.
Signed-off-by: demin.han <demin.han@starfivetech.com>

3 files changed, 11 insertions, 11 deletions

diff --git a/gcc/config/riscv/riscv-vector-costs.cc b/gcc/config/riscv/riscv-vector-costs.cc
index e7bc9ed..a316603 100644
--- a/gcc/config/riscv/riscv-vector-costs.cc
+++ b/gcc/config/riscv/riscv-vector-costs.cc
@@ -123,7 +123,7 @@ compute_local_program_points (
       /* Collect the stmts that is vectorized and mark their program point.  */
       for (i = 0; i < nbbs; i++)
 	{
-	  int point = 0;
+	  int point = 1;
 	  basic_block bb = bbs[i];
 	  vec<stmt_point> program_points = vNULL;
 	  if (dump_enabled_p ())
@@ -300,13 +300,13 @@ max_number_of_live_regs (const basic_block bb,
   unsigned int i;
   unsigned int live_point = 0;
   auto_vec<unsigned int> live_vars_vec;
-  live_vars_vec.safe_grow_cleared (max_point + 1, true);
+  live_vars_vec.safe_grow_cleared (max_point, true);
   for (hash_map<tree, pair>::iterator iter = live_ranges.begin ();
        iter != live_ranges.end (); ++iter)
     {
       tree var = (*iter).first;
       pair live_range = (*iter).second;
-      for (i = live_range.first; i <= live_range.second; i++)
+      for (i = live_range.first + 1; i <= live_range.second; i++)
 	{
 	  machine_mode mode = TYPE_MODE (TREE_TYPE (var));
 	  unsigned int nregs
@@ -485,7 +485,7 @@ update_local_live_ranges (
 	      if (!program_points_per_bb.get (e->src))
 		continue;
 	      unsigned int max_point
-		= (*program_points_per_bb.get (e->src)).length () - 1;
+		= (*program_points_per_bb.get (e->src)).length ();
 	      live_range = live_ranges->get (def);
 	      if (!live_range)
 		continue;
@@ -571,7 +571,7 @@ preferred_new_lmul_p (loop_vec_info other_loop_vinfo)
 	{
 	  basic_block bb = (*iter).first;
 	  unsigned int max_point
-	    = (*program_points_per_bb.get (bb)).length () - 1;
+	    = (*program_points_per_bb.get (bb)).length () + 1;
 	  if ((*iter).second.is_empty ())
 	    continue;
 	  /* We prefer larger LMUL unless it causes register spillings.  */
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul2-7.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul4-10.c
index 636332d..74e6291 100644
--- a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul2-7.c
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul4-10.c
@@ -17,10 +17,10 @@ bar (int *x, int a, int b, int n)
   return sum1 + sum2;
 }
 
-/* { dg-final { scan-assembler {e32,m2} } } */
+/* { dg-final { scan-assembler {e32,m4} } } */
 /* { dg-final { scan-assembler-not {jr} } } */
 /* { dg-final { scan-assembler-times {ret} 2 } } *
 /* { dg-final { scan-tree-dump-times "Maximum lmul = 8" 1 "vect" } } */
-/* { dg-final { scan-tree-dump-times "Maximum lmul = 4" 1 "vect" } } */
-/* { dg-final { scan-tree-dump "Maximum lmul = 2" "vect" } } */
+/* { dg-final { scan-tree-dump "Maximum lmul = 4" "vect" } } */
+/* { dg-final { scan-tree-dump-not "Maximum lmul = 2" "vect" } } */
 /* { dg-final { scan-tree-dump-not "Maximum lmul = 1" "vect" } } */
diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul4-4.c b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul8-11.c
index 01a359b..01c976d 100644
--- a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul4-4.c
+++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/dynamic-lmul8-11.c
@@ -39,9 +39,9 @@ void foo2 (int64_t *__restrict a,
     }
 }
 
-/* { dg-final { scan-assembler {e64,m4} } } */
+/* { dg-final { scan-assembler {e64,m8} } } */
 /* { dg-final { scan-assembler-not {csrr} } } */
-/* { dg-final { scan-tree-dump-times "Maximum lmul = 8" 1 "vect" } } */
-/* { dg-final { scan-tree-dump "Maximum lmul = 4" "vect" } } */
+/* { dg-final { scan-tree-dump "Maximum lmul = 8" "vect" } } */
+/* { dg-final { scan-tree-dump-not "Maximum lmul = 4" "vect" } } */
 /* { dg-final { scan-tree-dump-not "Maximum lmul = 2" "vect" } } */
 /* { dg-final { scan-tree-dump-not "Maximum lmul = 1" "vect" } } */