[committed] [PR target/103722] Fix register_move_cost for the sh

[committed] [PR target/103722] Fix register_move_cost for the sh

[Jeff Law]

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As outlined in the BZ the sh is returning cost 2 for various reg->reg 
moves.  Cost 2 has special meaning to reload and prevents the insns from 
being re-recognized.  Vlad's patch bumps the cost to 7.  Other values 
might be better, but given this has been languishing for ~6 months and 
there are no signs of an SH expert stepping in to provide a better 
value, I'm going with Vlad's patch from the PR as-is.

Committed to the trunk,
Jeff

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commit 42d8fb2d4569e9930e277b01170bfd3586bf94d3
Author: Vladimir Makarov <vmakarov@gcc.gnu.org>
Date:   Sat May 28 12:08:38 2022 -0600

    Fix ICE on sh
    
    gcc/
            PR target/103722
            * config/sh/sh.c (sh_register_move_cost): Avoid cost "2" (which
            is special) for various scenarios.

diff --git a/gcc/config/sh/sh.cc b/gcc/config/sh/sh.cc
index 8d4056338a5..03e1c04ec7e 100644
--- a/gcc/config/sh/sh.cc
+++ b/gcc/config/sh/sh.cc
@@ -10762,6 +10762,12 @@ sh_register_move_cost (machine_mode mode,
       && ! REGCLASS_HAS_GENERAL_REG (dstclass))
     return 2 * ((GET_MODE_SIZE (mode) + 7) / 8U);
 
+  if (((dstclass == FP_REGS || dstclass == DF_REGS)
+       && (srcclass == PR_REGS))
+      || ((srcclass == FP_REGS || srcclass == DF_REGS)
+	  && (dstclass == PR_REGS)))
+    return 7;
+
   return 2 * ((GET_MODE_SIZE (mode) + 3) / 4U);
 }