[gcc r14-9885] Revert "combine: Don't combine if I2 does not change"

[gcc r14-9885] Revert "combine: Don't combine if I2 does not change"

[Richard Biener]

https://gcc.gnu.org/g:109f1b28fc94c93096506e3df0c25e331cef19d0

commit r14-9885-g109f1b28fc94c93096506e3df0c25e331cef19d0
Author: Richard Biener <rguenther@suse.de>
Date:   Wed Apr 10 07:57:03 2024 +0200

    Revert "combine: Don't combine if I2 does not change"
    
    This reverts commit 839bc42772ba7af66af3bd16efed4a69511312ae.

Diff:
---
 gcc/combine.cc | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/gcc/combine.cc b/gcc/combine.cc
index 71c9abc145c..92b8d98e6c1 100644
--- a/gcc/combine.cc
+++ b/gcc/combine.cc
@@ -4196,17 +4196,6 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
       adjust_for_new_dest (i3);
     }
 
-  /* If I2 didn't change, this is not a combination (but a simplification or
-     canonicalisation with context), which should not be done here.  Doing
-     it here explodes the algorithm.  Don't.  */
-  if (rtx_equal_p (newi2pat, PATTERN (i2)))
-    {
-      if (dump_file)
-	fprintf (dump_file, "i2 didn't change, not doing this\n");
-      undo_all ();
-      return 0;
-    }
-
   /* We now know that we can do this combination.  Merge the insns and
      update the status of registers and LOG_LINKS.  */