[gcc r14-8418] RISC-V: Remove redundant full available computation [NFC]

[Pan Li]

https://gcc.gnu.org/g:5ee45f5e2838caf9180af1702349daa017a032f5

commit r14-8418-g5ee45f5e2838caf9180af1702349daa017a032f5
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Thu Jan 25 16:24:26 2024 +0800

    RISC-V: Remove redundant full available computation [NFC]
    
    Notice full available is computed evey round of earliest fusion which is redundant.
    Actually we only need to compute it once in phase 3.
    
    It's NFC patch and tested no regression. Committed.
    
    gcc/ChangeLog:
    
            * config/riscv/riscv-vsetvl.cc (pre_vsetvl::compute_vsetvl_def_data): Remove
            redundant full available computation.
            (pre_vsetvl::pre_global_vsetvl_info): Ditto.

Diff:
---
 gcc/config/riscv/riscv-vsetvl.cc | 57 ++++++++++++++++------------------------
 1 file changed, 23 insertions(+), 34 deletions(-)

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index 53d954e1dff..72c5a127d9e 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -1256,9 +1256,7 @@ public:
   vsetvl_info global_info;
   bb_info *bb;
 
-  bool full_available;
-
-  vsetvl_block_info () : bb (nullptr), full_available (false)
+  vsetvl_block_info () : bb (nullptr)
   {
     local_infos.safe_grow_cleared (0);
     global_info.set_empty ();
@@ -2489,34 +2487,6 @@ pre_vsetvl::compute_vsetvl_def_data ()
 	}
     }
 
-  for (const bb_info *bb : crtl->ssa->bbs ())
-    {
-      vsetvl_block_info &block_info = get_block_info (bb);
-      if (block_info.empty_p ())
-	continue;
-      vsetvl_info &curr_info = block_info.get_entry_info ();
-      if (!curr_info.valid_p ())
-	continue;
-
-      unsigned int expr_index;
-      sbitmap_iterator sbi;
-      gcc_assert (
-	!bitmap_empty_p (m_vsetvl_def_in[curr_info.get_bb ()->index ()]));
-      bool full_available = true;
-      EXECUTE_IF_SET_IN_BITMAP (m_vsetvl_def_in[bb->index ()], 0, expr_index,
-				sbi)
-	{
-	  vsetvl_info &prev_info = *m_vsetvl_def_exprs[expr_index];
-	  if (!prev_info.valid_p ()
-	      || !m_dem.available_p (prev_info, curr_info))
-	    {
-	      full_available = false;
-	      break;
-	    }
-	}
-      block_info.full_available = full_available;
-    }
-
   sbitmap_vector_free (def_loc);
   sbitmap_vector_free (m_kill);
 }
@@ -3178,11 +3148,30 @@ pre_vsetvl::pre_global_vsetvl_info ()
   for (const bb_info *bb : crtl->ssa->bbs ())
     {
       vsetvl_block_info &block_info = get_block_info (bb);
-      if (block_info.empty_p () || !block_info.full_available)
+      if (block_info.empty_p ())
+	continue;
+      vsetvl_info &curr_info = block_info.get_entry_info ();
+      if (!curr_info.valid_p ())
 	continue;
 
-      vsetvl_info &info = block_info.get_entry_info ();
-      info.set_delete ();
+      unsigned int expr_index;
+      sbitmap_iterator sbi;
+      gcc_assert (
+	!bitmap_empty_p (m_vsetvl_def_in[curr_info.get_bb ()->index ()]));
+      bool full_available = true;
+      EXECUTE_IF_SET_IN_BITMAP (m_vsetvl_def_in[bb->index ()], 0, expr_index,
+				sbi)
+	{
+	  vsetvl_info &prev_info = *m_vsetvl_def_exprs[expr_index];
+	  if (!prev_info.valid_p ()
+	      || !m_dem.available_p (prev_info, curr_info))
+	    {
+	      full_available = false;
+	      break;
+	    }
+	}
+      if (full_available)
+	curr_info.set_delete ();
     }
 
   for (const bb_info *bb : crtl->ssa->bbs ())