[gcc(refs/users/meissner/heads/work067)] Revert patch.

[Michael Meissner]

https://gcc.gnu.org/g:ac87de6541cb686a9922a4f293f21ab3fff4100d

commit ac87de6541cb686a9922a4f293f21ab3fff4100d
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Wed Sep 8 12:30:49 2021 -0400

    Revert patch.
    
    2021-09-08  Michael Meissner  <meissner@linux.ibm.com>
    
    gcc/
    
            Revert patch.
            * config/rs6000/rs6000.c (rs6000_emit_move_si_sf_subreg): Deal
            with SUBREGs of TImode and DImode.

Diff:
---
 gcc/config/rs6000/rs6000.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 7bbf29a3e1c..da5abe6f7b5 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -10952,6 +10952,16 @@ rs6000_emit_move_si_sf_subreg (rtx dest, rtx source, machine_mode mode)
 	  return true;
 	}
 
+      /* In case we are given a SUBREG for a larger type, reduce it to
+	 SImode.  */
+      if (mode == SFmode && GET_MODE_SIZE (inner_mode) > 4)
+	{
+	  rtx tmp = gen_reg_rtx (SImode);
+	  emit_move_insn (tmp, gen_lowpart (SImode, source));
+	  emit_insn (gen_movsf_from_si (dest, tmp));
+	  return true;
+	}
+
       if (mode == SFmode && inner_mode == SImode)
 	{
 	  emit_insn (gen_movsf_from_si (dest, inner_source));