Re: [vta, graphite?] propagate degenerate phi nodes into debug stmts

[Alexandre Oliva <aoliva@redhat.com>]

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On Jun  6, 2011, Richard Guenther <richard.guenther@gmail.com> wrote:

>> You meant 4.6 stage1, but I missed it.  How's it for 4.7 stage1?
>> Regstrapped on x86_64-linux-gnu and i686-linux-gnu.

> Isn't exactly ICEing for num_ssa_operands/delink_stmt_imm_use.

Uhh.  Looks like I didn't update the patch per your comments before
putting it aside for stage1, after all.  Sorry.

> So, the op_iter_init change is ok, the other two not - they should
> either ICE or work for PHIs (by using FOR_EACH_PHI_OR_STMT_USE
> in them).

The latter is legitimately called for GIMPLE_PHI, so I changed it to use
FOR_EACH_PHI_OR_STMT_USE.  The former was never called for GIMPLE_PHIs,
so I put in an assert there.

Regstrapped on x86_64-linux-gnu and i686-linux-gnu.  Ok?


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for  gcc/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	* tree-flow-inline.h (op_iter_init): Reject GIMPLE_PHI stmts.
	(num_ssa_operands): Likewise.
	(op_iter_init_phiuse): Forward-declare.
	(delink_stmt_imm_use): Iterate with FOR_EACH_PHI_OR_STMT_USE.

Index: gcc/tree-flow-inline.h
===================================================================
--- gcc/tree-flow-inline.h.orig	2011-06-03 11:56:24.619482744 -0300
+++ gcc/tree-flow-inline.h	2011-06-07 04:15:18.344729725 -0300
@@ -737,9 +737,11 @@ clear_and_done_ssa_iter (ssa_op_iter *pt
 static inline void
 op_iter_init (ssa_op_iter *ptr, gimple stmt, int flags)
 {
-  /* We do not support iterating over virtual defs or uses without
+  /* PHI nodes require a different iterator initialization path.  We
+     do not support iterating over virtual defs or uses without
      iterating over defs or uses at the same time.  */
-  gcc_checking_assert ((!(flags & SSA_OP_VDEF) || (flags & SSA_OP_DEF))
+  gcc_checking_assert (gimple_code (stmt) != GIMPLE_PHI
+		       && (!(flags & SSA_OP_VDEF) || (flags & SSA_OP_DEF))
 		       && (!(flags & SSA_OP_VUSE) || (flags & SSA_OP_USE)));
   ptr->defs = (flags & (SSA_OP_DEF|SSA_OP_VDEF)) ? gimple_def_ops (stmt) : NULL;
   if (!(flags & SSA_OP_VDEF)
@@ -868,11 +870,14 @@ num_ssa_operands (gimple stmt, int flags
   tree t;
   int num = 0;
 
+  gcc_checking_assert (gimple_code (stmt) != GIMPLE_PHI);
   FOR_EACH_SSA_TREE_OPERAND (t, stmt, iter, flags)
     num++;
   return num;
 }
 
+static inline use_operand_p
+op_iter_init_phiuse (ssa_op_iter *ptr, gimple phi, int flags);
 
 /* Delink all immediate_use information for STMT.  */
 static inline void
@@ -882,7 +887,7 @@ delink_stmt_imm_use (gimple stmt)
    use_operand_p use_p;
 
    if (ssa_operands_active ())
-     FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES)
+     FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_ALL_USES)
        delink_imm_use (use_p);
 }
 

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-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
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Free Software Evangelist      Red Hat Brazil Compiler Engineer