reload.c (subst_reloads): Take INSN argument.

* reload.c (subst_reloads): Take INSN argument.  When
replacing a LABEL_REF in a JUMP_INSN, add a REG_LABEL note.
* reload.h (subst_reloads): Adjust prototype.
* reload1.c (reload_as_needed): Pass INSN to subst_reloads.
* jump.c (mark_all_labels): Canonicalize any REG_LABEL notes
present in JUMP_INSNs and copy them to JUMP_LABEL.
* flow.c (find_label_refs, find_basic_blocks_1): Skip
JUMP_INSNs and insns with REG_LABELs that are followed by
JUMP_INSNs with the same REG_LABEL.
* sched-rgn.c (is_cfg_nonregular): Likewise.
* rtlanal.c (computed_jump_p): Make it false if a REG_LABEL
note is available.
* unroll.c (unroll_loop): Look for REG_LABEL notes in
JUMP_INSNs too.
* rtl.texi (REG_LABEL): Document usage in JUMP_INSNs.

From-SVN: r38755

1 files changed, 18 insertions, 0 deletions

diff --git a/gcc/jump.c b/gcc/jump.c
index 1c6c3a6..032172d 100644
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -863,6 +863,24 @@ mark_all_labels (f, cross_jump)
 	mark_jump_label (PATTERN (insn), insn, cross_jump, 0);
 	if (! INSN_DELETED_P (insn) && GET_CODE (insn) == JUMP_INSN)
 	  {
+	    /* When we know the LABEL_REF contained in a REG used in
+	       an indirect jump, we'll have a REG_LABEL note so that
+	       flow can tell where it's going.  */
+	    if (JUMP_LABEL (insn) == 0)
+	      {
+		rtx label_note = find_reg_note (insn, REG_LABEL, NULL_RTX);
+		if (label_note)
+		  {
+		    /* But a LABEL_REF around the REG_LABEL note, so
+		       that we can canonicalize it.  */
+		    rtx label_ref = gen_rtx_LABEL_REF (VOIDmode,
+						       XEXP (label_note, 0));
+
+		    mark_jump_label (label_ref, insn, cross_jump, 0);
+		    XEXP (label_note, 0) = XEXP (label_ref, 0);
+		    JUMP_LABEL (insn) = XEXP (label_note, 0);
+		  }
+	      }
 	    if (JUMP_LABEL (insn) != 0 && simplejump_p (insn))
 	      {
 		jump_chain[INSN_UID (insn)]