The following patch improves the constant_after_peeling estimate of
the GIMPLE unroller by not requiring a strictly "simple-iv" but
an evolution w/o symbols. It also avoids computing any of this for
ops defined in a subloop of the loop we unroll (that only yields
garbage). So it makes constant_after_peeling cheaper as well.
It also adjusts the simple-minded CCP to propagate all constants
(esp. float and vector constants).
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress, queued for
GCC 8.
Richard.
2016-02-14 Richard Biener <rguent...@suse.de>
* tree-ssa-loop-ivcanon.c (constant_after_peeling): Do not require
sth as strict as a simple_iv but a chrec without symbols and an
operand defined in the loop we are peeling (and not some subloop).
(propagate_constants_for_unrolling): Propagate all constants.
* gcc.dg/vect/no-scevccp-outer-13.c: Adjust to prevent unrolling
of inner loops.
* gcc.dg/vect/no-scevccp-outer-7.c: Likewise.
* gcc.dg/vect/vect-104.c: Likewise.
Index: gcc/tree-ssa-loop-ivcanon.c
===================================================================
--- gcc/tree-ssa-loop-ivcanon.c (revision 245417)
+++ gcc/tree-ssa-loop-ivcanon.c (working copy)
@@ -157,8 +157,6 @@ struct loop_size
static bool
constant_after_peeling (tree op, gimple *stmt, struct loop *loop)
{
- affine_iv iv;
-
if (is_gimple_min_invariant (op))
return true;
@@ -188,12 +186,12 @@ constant_after_peeling (tree op, gimple
return false;
}
- /* Induction variables are constants. */
- if (!simple_iv (loop, loop_containing_stmt (stmt), op, &iv, false))
- return false;
- if (!is_gimple_min_invariant (iv.base))
+ /* Induction variables are constants when defined in loop. */
+ if (loop_containing_stmt (stmt) != loop)
return false;
- if (!is_gimple_min_invariant (iv.step))
+ tree ev = analyze_scalar_evolution (loop, op);
+ if (chrec_contains_undetermined (ev)
+ || chrec_contains_symbols (ev))
return false;
return true;
}
@@ -1259,7 +1257,7 @@ propagate_constants_for_unrolling (basic
if (! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (result)
&& gimple_phi_num_args (phi) == 1
- && TREE_CODE (arg) == INTEGER_CST)
+ && CONSTANT_CLASS_P (arg))
{
replace_uses_by (result, arg);
gsi_remove (&gsi, true);
@@ -1276,7 +1274,7 @@ propagate_constants_for_unrolling (basic
tree lhs;
if (is_gimple_assign (stmt)
- && gimple_assign_rhs_code (stmt) == INTEGER_CST
+ && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) == tcc_constant
&& (lhs = gimple_assign_lhs (stmt), TREE_CODE (lhs) == SSA_NAME)
&& !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
{
Index: gcc/testsuite/gcc.dg/vect/no-scevccp-outer-13.c
===================================================================
--- gcc/testsuite/gcc.dg/vect/no-scevccp-outer-13.c (revision 245417)
+++ gcc/testsuite/gcc.dg/vect/no-scevccp-outer-13.c (working copy)
@@ -1,4 +1,5 @@
/* { dg-require-effective-target vect_int } */
+/* { dg-additional-options "--param max-completely-peel-times=1" } */
#include <stdarg.h>
#include "tree-vect.h"
Index: gcc/testsuite/gcc.dg/vect/no-scevccp-outer-7.c
===================================================================
--- gcc/testsuite/gcc.dg/vect/no-scevccp-outer-7.c (revision 245417)
+++ gcc/testsuite/gcc.dg/vect/no-scevccp-outer-7.c (working copy)
@@ -1,4 +1,5 @@
/* { dg-require-effective-target vect_int } */
+/* { dg-additional-options "--param max-completely-peel-times=1" } */
#include <stdarg.h>
#include "tree-vect.h"
Index: gcc/testsuite/gcc.dg/vect/vect-104.c
===================================================================
--- gcc/testsuite/gcc.dg/vect/vect-104.c (revision 245417)
+++ gcc/testsuite/gcc.dg/vect/vect-104.c (working copy)
@@ -1,4 +1,5 @@
/* { dg-require-effective-target vect_int } */
+/* { dg-additional-options "--param max-completely-peel-times=1" } */
#include <stdlib.h>
#include <stdarg.h>
