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Re: [PATCH] Scalar evolution and hidden casts
> Yes, that would be better.
OK, here is the (barely tested) patch. OK after a full testing cycle?
2009-05-19 Eric Botcazou <ebotcazou@adacore.com>
* tree-scalar-evolution.c (follow_ssa_edge_expr) <PLUS_EXPR>: Strip
useless type conversions instead of type nops. Propagate the type
of the first operand.
<ASSERT_EXPR>: Simplify.
(follow_ssa_edge_in_rhs): Use gimple_expr_type to get the type.
Rewrite using the RHS code as discriminant.
<PLUS_EXPR>: Propagate the type of the first operand.
2009-05-19 Eric Botcazou <ebotcazou@adacore.com>
* gnat.dg/loop_optimization6.ad[sb]: New test.
> I chickened out several times to reorganize the tree code binning
> in tcc_binary/tcc_unary vs. tcc_expression ... maybe I should
> come back to that.
Certainly having COMPLEX_EXPR as tcc_binary is a little surprising.
--
Eric Botcazou
Index: tree-scalar-evolution.c
===================================================================
--- tree-scalar-evolution.c (revision 147612)
+++ tree-scalar-evolution.c (working copy)
@@ -1141,11 +1141,10 @@ static t_bool
follow_ssa_edge_expr (struct loop *loop, gimple at_stmt, tree expr,
gimple halting_phi, tree *evolution_of_loop, int limit)
{
- t_bool res = t_false;
- tree rhs0, rhs1;
- tree type = TREE_TYPE (expr);
- enum tree_code code;
-
+ enum tree_code code = TREE_CODE (expr);
+ tree type = TREE_TYPE (expr), rhs0, rhs1;
+ t_bool res;
+
/* The EXPR is one of the following cases:
- an SSA_NAME,
- an INTEGER_CST,
@@ -1154,7 +1153,7 @@ follow_ssa_edge_expr (struct loop *loop,
- a MINUS_EXPR,
- an ASSERT_EXPR,
- other cases are not yet handled. */
- code = TREE_CODE (expr);
+
switch (code)
{
case NOP_EXPR:
@@ -1168,43 +1167,42 @@ follow_ssa_edge_expr (struct loop *loop,
/* This assignment is under the form "a_1 = 7". */
res = t_false;
break;
-
+
case SSA_NAME:
/* This assignment is under the form: "a_1 = b_2". */
res = follow_ssa_edge
(loop, SSA_NAME_DEF_STMT (expr), halting_phi, evolution_of_loop, limit);
break;
-
+
case POINTER_PLUS_EXPR:
case PLUS_EXPR:
case MINUS_EXPR:
/* This case is under the form "rhs0 +- rhs1". */
rhs0 = TREE_OPERAND (expr, 0);
rhs1 = TREE_OPERAND (expr, 1);
- STRIP_TYPE_NOPS (rhs0);
- STRIP_TYPE_NOPS (rhs1);
- return follow_ssa_edge_binary (loop, at_stmt, type, rhs0, code, rhs1,
- halting_phi, evolution_of_loop, limit);
+ type = TREE_TYPE (rhs0);
+ STRIP_USELESS_TYPE_CONVERSION (rhs0);
+ STRIP_USELESS_TYPE_CONVERSION (rhs1);
+ res = follow_ssa_edge_binary (loop, at_stmt, type, rhs0, code, rhs1,
+ halting_phi, evolution_of_loop, limit);
+ break;
case ASSERT_EXPR:
- {
- /* This assignment is of the form: "a_1 = ASSERT_EXPR <a_2, ...>"
- It must be handled as a copy assignment of the form a_1 = a_2. */
- tree op0 = ASSERT_EXPR_VAR (expr);
- if (TREE_CODE (op0) == SSA_NAME)
- res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (op0),
- halting_phi, evolution_of_loop, limit);
- else
- res = t_false;
- break;
- }
-
+ /* This assignment is of the form: "a_1 = ASSERT_EXPR <a_2, ...>"
+ It must be handled as a copy assignment of the form a_1 = a_2. */
+ rhs0 = ASSERT_EXPR_VAR (expr);
+ if (TREE_CODE (rhs0) == SSA_NAME)
+ res = follow_ssa_edge (loop, SSA_NAME_DEF_STMT (rhs0),
+ halting_phi, evolution_of_loop, limit);
+ else
+ res = t_false;
+ break;
default:
res = t_false;
break;
}
-
+
return res;
}
@@ -1215,34 +1213,38 @@ static t_bool
follow_ssa_edge_in_rhs (struct loop *loop, gimple stmt,
gimple halting_phi, tree *evolution_of_loop, int limit)
{
- tree type = TREE_TYPE (gimple_assign_lhs (stmt));
enum tree_code code = gimple_assign_rhs_code (stmt);
+ tree type = gimple_expr_type (stmt), rhs1;
+ t_bool res;
- switch (get_gimple_rhs_class (code))
+ switch (code)
{
- case GIMPLE_BINARY_RHS:
- return follow_ssa_edge_binary (loop, stmt, type,
- gimple_assign_rhs1 (stmt), code,
- gimple_assign_rhs2 (stmt),
- halting_phi, evolution_of_loop, limit);
- case GIMPLE_SINGLE_RHS:
- return follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
- halting_phi, evolution_of_loop, limit);
- case GIMPLE_UNARY_RHS:
- if (code == NOP_EXPR)
- {
- /* This assignment is under the form "a_1 = (cast) rhs. */
- t_bool res
- = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
+ case NOP_EXPR:
+ /* This assignment is under the form "a_1 = (cast) rhs. */
+ res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
+ halting_phi, evolution_of_loop, limit);
+ *evolution_of_loop = chrec_convert (type, *evolution_of_loop, stmt);
+ break;
+
+ case POINTER_PLUS_EXPR:
+ case PLUS_EXPR:
+ case MINUS_EXPR:
+ rhs1 = gimple_assign_rhs1 (stmt);
+ res = follow_ssa_edge_binary (loop, stmt, TREE_TYPE (rhs1), rhs1,
+ code, gimple_assign_rhs2 (stmt),
halting_phi, evolution_of_loop, limit);
- *evolution_of_loop = chrec_convert (type, *evolution_of_loop, stmt);
- return res;
- }
- /* FALLTHRU */
+ break;
default:
- return t_false;
+ if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
+ res = follow_ssa_edge_expr (loop, stmt, gimple_assign_rhs1 (stmt),
+ halting_phi, evolution_of_loop, limit);
+ else
+ res = t_false;
+ break;
}
+
+ return res;
}
/* Checks whether the I-th argument of a PHI comes from a backedge. */
-- { dg-do compile }
-- { dg-options "-O -gnatp" }
package body Loop_Optimization6 is
procedure Foo is
begin
for I in 1 .. 1_000_000 loop
A := A + 1;
end loop;
end Foo;
procedure Bar is
begin
for J in 1 .. 1_000 loop
Foo;
end loop;
end Bar;
procedure Main is
begin
Bar;
end;
end Loop_Optimization6;
-- { dg-final { scan-assembler "1000000000" { target i?86-*-* x86_64-*-* } } }
package Loop_Optimization6 is
A : Integer := 0;
procedure Main;
end Loop_Optimization6;