Patchwork fix pr 46515

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Submitter Richard Henderson
Date Nov. 18, 2010, 9:11 p.m.
Message ID <4CE5969B.5010900@redhat.com>
Download mbox | patch
Permalink /patch/72149/
State New
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Comments

Richard Henderson - Nov. 18, 2010, 9:11 p.m.
This PR has to do with replacing an insn that is FRAME_RELATED_P, and
the replacement not being a member of epilogue_insn_hash.  Which meant
that we didn't re-position the EPILOGUE_BEG note properly, which meant
that we emitted a DW_CFA_remember_state opcode at the wrong place.

In theory something similar could happen with prologue insns, particularly
with non-dwarf2 unwind info, such as ia64 or seh that have special 
directives that mark the end of the prologue.

Tested on x86_64-linux.  Committed.


r~
PR middle-end/46515
        * function.c (maybe_copy_prologue_epilogue_insn): Rename from
        maybe_copy_epilogue_insn; handle prologue insns as well.  
        * rtl.h, cfglayout.c: Update for rename.
        * recog.c (peep2_attempt): Copy prologue/epilogue data for
        RTX_FRAME_RELATED_P insns.

Patch

diff --git a/gcc/cfglayout.c b/gcc/cfglayout.c
index be99991..e883af4 100644
--- a/gcc/cfglayout.c
+++ b/gcc/cfglayout.c
@@ -1179,7 +1179,7 @@  duplicate_insn_chain (rtx from, rtx to)
 	      || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)
 	    break;
 	  copy = emit_copy_of_insn_after (insn, get_last_insn ());
-          maybe_copy_epilogue_insn (insn, copy);
+          maybe_copy_prologue_epilogue_insn (insn, copy);
 	  break;
 
 	case CODE_LABEL:
diff --git a/gcc/function.c b/gcc/function.c
index b9805dc..0ed674d 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -5140,19 +5140,25 @@  record_insns (rtx insns, rtx end, htab_t *hashp)
     }
 }
 
-/* INSN has been duplicated as COPY, as part of duping a basic block.
-   If INSN is an epilogue insn, then record COPY as epilogue as well.  */
+/* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
+   basic block, splitting or peepholes.  If INSN is a prologue or epilogue
+   insn, then record COPY as well.  */
 
 void
-maybe_copy_epilogue_insn (rtx insn, rtx copy)
+maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
 {
+  htab_t hash;
   void **slot;
 
-  if (epilogue_insn_hash == NULL
-      || htab_find (epilogue_insn_hash, insn) == NULL)
-    return;
+  hash = epilogue_insn_hash;
+  if (!hash || !htab_find (hash, insn))
+    {
+      hash = prologue_insn_hash;
+      if (!hash || !htab_find (hash, insn))
+	return;
+    }
 
-  slot = htab_find_slot (epilogue_insn_hash, copy, INSERT);
+  slot = htab_find_slot (hash, copy, INSERT);
   gcc_assert (*slot == NULL);
   *slot = copy;
 }
diff --git a/gcc/recog.c b/gcc/recog.c
index b140c0e..edbf82b 100644
--- a/gcc/recog.c
+++ b/gcc/recog.c
@@ -3219,6 +3219,10 @@  peep2_attempt (basic_block bb, rtx insn, int match_len, rtx attempt)
 	  if (!new_set || !rtx_equal_p (new_set, old_set))
 	    add_reg_note (new_insn, REG_FRAME_RELATED_EXPR, old_set);
 	}
+
+      /* Copy prologue/epilogue status.  This is required in order to keep
+	 proper placement of EPILOGUE_BEG and the DW_CFA_remember_state.  */
+      maybe_copy_prologue_epilogue_insn (old_insn, new_insn);
     }
 
   /* If we are splitting a CALL_INSN, look for the CALL_INSN
diff --git a/gcc/rtl.h b/gcc/rtl.h
index 745d6f4..ab215d6 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -2411,7 +2411,7 @@  extern int prologue_epilogue_contains (const_rtx);
 extern int sibcall_epilogue_contains (const_rtx);
 extern void mark_temp_addr_taken (rtx);
 extern void update_temp_slot_address (rtx, rtx);
-extern void maybe_copy_epilogue_insn (rtx, rtx);
+extern void maybe_copy_prologue_epilogue_insn (rtx, rtx);
 
 /* In stmt.c */
 extern void expand_null_return (void);