[PATCH] Allow USE in PARALLELs in store_data_bypass_p

[Jakub Jelinek]

Hi!

When looking at the rs6000_store_data_bypass_p stuff, I've noticed that
it accepts PARALLELs containing not just SETs and CLOBBERs like
store_data_bypass_p, but also USEs.  Given that it is something that
single_set also ignores, I think fixing store_data_bypass_p is the
right fix here.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

Note, the patch is larger due to the formatting fixes, the actual changes
are just 3x
-             if (GET_CODE (xxx) == CLOBBER)
+             if (GET_CODE (xxx) == CLOBBER || GET_CODE (xxx) == USE)

2017-12-06  Jakub Jelinek  <ja...@redhat.com>

        * recog.c (store_data_bypass_p): Handle USE in a PARALLEL
        like CLOBBER.  Formatting fixes.

--- gcc/recog.c.jj      2017-10-24 12:07:06.000000000 +0200
+++ gcc/recog.c 2017-12-06 12:20:37.256654794 +0100
@@ -3677,30 +3677,30 @@ store_data_bypass_p (rtx_insn *out_insn,
 
       out_set = single_set (out_insn);
       if (out_set)
-        {
-          if (reg_mentioned_p (SET_DEST (out_set), SET_DEST (in_set)))
-            return false;
-        }
+       {
+         if (reg_mentioned_p (SET_DEST (out_set), SET_DEST (in_set)))
+           return false;
+       }
       else
-        {
-          out_pat = PATTERN (out_insn);
+       {
+         out_pat = PATTERN (out_insn);
 
          if (GET_CODE (out_pat) != PARALLEL)
            return false;
 
-          for (i = 0; i < XVECLEN (out_pat, 0); i++)
-          {
-            out_exp = XVECEXP (out_pat, 0, i);
-
-            if (GET_CODE (out_exp) == CLOBBER)
-              continue;
-
-            gcc_assert (GET_CODE (out_exp) == SET);
-
-            if (reg_mentioned_p (SET_DEST (out_exp), SET_DEST (in_set)))
-              return false;
-          }
-      }
+         for (i = 0; i < XVECLEN (out_pat, 0); i++)
+           {
+             out_exp = XVECEXP (out_pat, 0, i);
+
+             if (GET_CODE (out_exp) == CLOBBER || GET_CODE (out_exp) == USE)
+               continue;
+
+             gcc_assert (GET_CODE (out_exp) == SET);
+
+             if (reg_mentioned_p (SET_DEST (out_exp), SET_DEST (in_set)))
+               return false;
+           }
+       }
     }
   else
     {
@@ -3711,7 +3711,7 @@ store_data_bypass_p (rtx_insn *out_insn,
        {
          in_exp = XVECEXP (in_pat, 0, i);
 
-         if (GET_CODE (in_exp) == CLOBBER)
+         if (GET_CODE (in_exp) == CLOBBER || GET_CODE (in_exp) == USE)
            continue;
 
          gcc_assert (GET_CODE (in_exp) == SET);
@@ -3719,31 +3719,32 @@ store_data_bypass_p (rtx_insn *out_insn,
          if (!MEM_P (SET_DEST (in_exp)))
            return false;
 
-          out_set = single_set (out_insn);
-          if (out_set)
-            {
-              if (reg_mentioned_p (SET_DEST (out_set), SET_DEST (in_exp)))
-                return false;
-            }
-          else
-            {
-              out_pat = PATTERN (out_insn);
-              gcc_assert (GET_CODE (out_pat) == PARALLEL);
-
-              for (j = 0; j < XVECLEN (out_pat, 0); j++)
-                {
-                  out_exp = XVECEXP (out_pat, 0, j);
-
-                  if (GET_CODE (out_exp) == CLOBBER)
-                    continue;
-
-                  gcc_assert (GET_CODE (out_exp) == SET);
-
-                  if (reg_mentioned_p (SET_DEST (out_exp), SET_DEST (in_exp)))
-                    return false;
-                }
-            }
-        }
+         out_set = single_set (out_insn);
+         if (out_set)
+           {
+             if (reg_mentioned_p (SET_DEST (out_set), SET_DEST (in_exp)))
+               return false;
+           }
+         else
+           {
+             out_pat = PATTERN (out_insn);
+             gcc_assert (GET_CODE (out_pat) == PARALLEL);
+
+             for (j = 0; j < XVECLEN (out_pat, 0); j++)
+               {
+                 out_exp = XVECEXP (out_pat, 0, j);
+
+                 if (GET_CODE (out_exp) == CLOBBER
+                     || GET_CODE (out_exp) == USE)
+                   continue;
+
+                 gcc_assert (GET_CODE (out_exp) == SET);
+
+                 if (reg_mentioned_p (SET_DEST (out_exp), SET_DEST (in_exp)))
+                   return false;
+               }
+           }
+       }
     }
 
   return true;

        Jakub