From patchwork Thu Nov 11 15:32:28 2010
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Subject: Fix var-tracking ICE (PR debug/46387)
Date: Thu, 11 Nov 2010 05:32:28 -0000
From: Alexander Monakov <amonakov@ispras.ru>
X-Patchwork-Id: 70825
Message-Id: <alpine.LNX.2.00.1011111822410.6883@monoid.intra.ispras.ru>
To: Richard Guenther <richard.guenther@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>, gcc-patches@gcc.gnu.org

Jakub, Richard,

This is what we need from the selective scheduler side (the part of the
sel-sched.c patch actually needs to be more complicated to work properly, but
the alias.c change is what we have in mind to fix PR45652).

Thanks for your help.


diff --git a/gcc/alias.c b/gcc/alias.c
index 2e0ac06..0e65d66 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -1291,6 +1291,27 @@ record_set (rtx dest, const_rtx set, void *data ATTRIBUTE_UNUSED)
   reg_seen[regno] = 1;
 }

+/* Set REG_BASE_VALUE of DEST to that of SRC if unset,
+   or set it to NULL if DEST and SRC have conflicting REG_BASE_VALUEs.  */
+void
+inherit_reg_base_value (rtx dest, rtx src)
+{
+  unsigned dest_regno = REGNO (dest), src_regno = REGNO (src);
+
+  if (! VEC_index (rtx, reg_base_value, dest_regno))
+    {
+      if (!reg_seen[dest_regno]
+         && (dest_regno >= FIRST_PSEUDO_REGISTER || !fixed_regs[dest_regno]))
+       VEC_replace (rtx, reg_base_value, dest_regno,
+                    VEC_index (rtx, reg_base_value, src_regno));
+    }
+  else if (VEC_index (rtx, reg_base_value, src_regno)
+          != VEC_index (rtx, reg_base_value, dest_regno))
+    VEC_replace (rtx, reg_base_value, dest_regno, NULL_RTX);
+
+  reg_seen[dest_regno] = 1;
+}
+
 /* If a value is known for REGNO, return it.  */

 rtx
@@ -2901,14 +2922,14 @@ init_alias_analysis (void)
   /* Clean up.  */
   free (new_reg_base_value);
   new_reg_base_value = 0;
-  free (reg_seen);
-  reg_seen = 0;
   timevar_pop (TV_ALIAS_ANALYSIS);
 }

 void
 end_alias_analysis (void)
 {
+  free (reg_seen);
+  reg_seen = 0;
   old_reg_base_value = reg_base_value;
   ggc_free (reg_known_value);
   reg_known_value = 0;
diff --git a/gcc/rtl.h b/gcc/rtl.h
index 3e1df2c..8cc6c5c 100644
--- a/gcc/rtl.h
+++ b/gcc/rtl.h
@@ -2508,6 +2508,7 @@ extern rtx find_base_term (rtx);
 extern rtx gen_hard_reg_clobber (enum machine_mode, unsigned int);
 extern rtx get_reg_known_value (unsigned int);
 extern bool get_reg_known_equiv_p (unsigned int);
+extern void inherit_reg_base_value (rtx, rtx);

 #ifdef STACK_REGS
 extern int stack_regs_mentioned (const_rtx insn);
diff --git a/gcc/sel-sched.c b/gcc/sel-sched.c
index 70e831d..ab7c708 100644
--- a/gcc/sel-sched.c
+++ b/gcc/sel-sched.c
@@ -5856,6 +5856,7 @@ maybe_emit_renaming_copy (rtx insn,
                                                    insn);
       EXPR_SPEC_DONE_DS (INSN_EXPR (reg_move_insn)) = 0;
       replace_dest_with_reg_in_expr (params->c_expr, params->dest);
+      inherit_reg_base_value (params->dest, cur_reg);

       insn_emitted = true;
       params->was_renamed = true;