rs6000: Fix ELFv2 r12 use in epilogue

We cannot use r12 here, it is already in use as the GEP (for sibling
calls).

2021-09-08  Segher Boessenkool  <segher@kernel.crashing.org>
	PR target/102107
	* config/rs6000/rs6000-logue.c (rs6000_emit_epilogue): For ELFv2 use
	r11 instead of r12 for restoring CR.

diff --git a/gcc/config/rs6000/rs6000-logue.c b/gcc/config/rs6000/rs6000-logue.c
index e363d56..9965a8a 100644 (file)
--- a/gcc/config/rs6000/rs6000-logue.c
+++ b/gcc/config/rs6000/rs6000-logue.c
@@ -4815,6 +4815,10 @@ rs6000_emit_epilogue (enum epilogue_type epilogue_type)
       else if (REGNO (frame_reg_rtx) == 12)
        cr_save_regno = 11;
 
+      /* For ELFv2 r12 is already in use as the GEP.  */
+      if (DEFAULT_ABI == ABI_ELFv2)
+       cr_save_regno = 11;
+
       cr_save_reg = load_cr_save (cr_save_regno, frame_reg_rtx,
                                  info->cr_save_offset + frame_off,
                                  exit_func);