This removes redundant "folding" code from reference phi-translation
and it avoids allocating the "translated" operands vector if it is
identical to the original one.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2014-09-01 Richard Biener <rguent...@suse.de>
* tree-ssa-pre.c (phi_translate_1): Avoid re-allocating the
operands vector in most cases. Remove redundant code.
Index: trunk/gcc/tree-ssa-pre.c
===================================================================
--- trunk.orig/gcc/tree-ssa-pre.c 2014-09-01 13:32:10.305710553 +0200
+++ trunk/gcc/tree-ssa-pre.c 2014-09-01 13:25:48.774736821 +0200
@@ -1536,12 +1536,11 @@ phi_translate_1 (pre_expr expr, bitmap_s
tree newvuse = vuse;
vec<vn_reference_op_s> newoperands = vNULL;
bool changed = false, same_valid = true;
- unsigned int i, j, n;
+ unsigned int i, n;
vn_reference_op_t operand;
vn_reference_t newref;
- for (i = 0, j = 0;
- operands.iterate (i, &operand); i++, j++)
+ for (i = 0; operands.iterate (i, &operand); i++)
{
pre_expr opresult;
pre_expr leader;
@@ -1585,6 +1584,8 @@ phi_translate_1 (pre_expr expr, bitmap_s
newoperands.release ();
return NULL;
}
+ if (!changed)
+ continue;
if (!newoperands.exists ())
newoperands = operands.copy ();
/* We may have changed from an SSA_NAME to a constant */
@@ -1594,36 +1595,14 @@ phi_translate_1 (pre_expr expr, bitmap_s
newop.op0 = op[0];
newop.op1 = op[1];
newop.op2 = op[2];
- /* If it transforms a non-constant ARRAY_REF into a constant
- one, adjust the constant offset. */
- if (newop.opcode == ARRAY_REF
- && newop.off == -1
- && TREE_CODE (op[0]) == INTEGER_CST
- && TREE_CODE (op[1]) == INTEGER_CST
- && TREE_CODE (op[2]) == INTEGER_CST)
- {
- offset_int off = ((wi::to_offset (op[0])
- - wi::to_offset (op[1]))
- * wi::to_offset (op[2]));
- if (wi::fits_shwi_p (off))
- newop.off = off.to_shwi ();
- }
- newoperands[j] = newop;
- /* If it transforms from an SSA_NAME to an address, fold with
- a preceding indirect reference. */
- if (j > 0 && op[0] && TREE_CODE (op[0]) == ADDR_EXPR
- && newoperands[j - 1].opcode == MEM_REF)
- vn_reference_fold_indirect (&newoperands, &j);
- }
- if (i != operands.length ())
- {
- newoperands.release ();
- return NULL;
+ newoperands[i] = newop;
}
+ gcc_checking_assert (i == operands.length ());
if (vuse)
{
- newvuse = translate_vuse_through_block (newoperands,
+ newvuse = translate_vuse_through_block (newoperands.exists ()
+ ? newoperands : operands,
ref->set, ref->type,
vuse, phiblock, pred,
&same_valid);
@@ -1641,7 +1620,8 @@ phi_translate_1 (pre_expr expr, bitmap_s
tree result = vn_reference_lookup_pieces (newvuse, ref->set,
ref->type,
- newoperands,
+ newoperands.exists ()
+ ? newoperands : operands,
&newref, VN_WALK);
if (result)
newoperands.release ();
@@ -1700,11 +1680,13 @@ phi_translate_1 (pre_expr expr, bitmap_s
}
else
new_val_id = ref->value_id;
+ if (!newoperands.exists ())
+ newoperands = operands.copy ();
newref = vn_reference_insert_pieces (newvuse, ref->set,
ref->type,
newoperands,
result, new_val_id);
- newoperands.create (0);
+ newoperands = vNULL;
PRE_EXPR_REFERENCE (expr) = newref;
constant = fully_constant_expression (expr);
if (constant != expr)
