Hi,
This patch computes and returns separate aff_trees for invariant expression
and induction expression, so that invariant and induction parts can be handled
separately in both cost computation and code generation.
Is it OK?
Thanks,
bin
2017-04-11 Bin Cheng <bin.ch...@arm.com>
* tree-ssa-loop-ivopts.c (get_computation_aff_1): New.
(get_computation_aff): Reorder parameters. Use get_computation_aff_1.
(get_computation_at, rewrite_use_address): Update use of
get_computation_aff.From a6ffd9fc3a2f8c6e3b8764e31ae72c67f896b469 Mon Sep 17 00:00:00 2001
From: Bin Cheng <binch...@e108451-lin.cambridge.arm.com>
Date: Wed, 1 Mar 2017 11:07:11 +0000
Subject: [PATCH 09/33] compute-inv-var-affine-20170220.txt
---
gcc/tree-ssa-loop-ivopts.c | 73 ++++++++++++++++++++++++++++------------------
1 file changed, 44 insertions(+), 29 deletions(-)
diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 22c0ea5..4b6eda1 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -3684,29 +3684,26 @@ determine_common_wider_type (tree *a, tree *b)
}
/* Determines the expression by that USE is expressed from induction variable
- CAND at statement AT in LOOP. The expression is stored in a decomposed
- form into AFF. Returns false if USE cannot be expressed using CAND. */
+ CAND at statement AT in LOOP. The expression is stored in two parts in a
+ decomposed form. The invariant part is stored in AFF_INV; while variant
+ part in AFF_VAR. Store ratio of CAND.step over USE.step in PRAT if it's
+ non-null. Returns false if USE cannot be expressed using CAND. */
static bool
-get_computation_aff (struct loop *loop,
- struct iv_use *use, struct iv_cand *cand, gimple *at,
- struct aff_tree *aff)
-{
- tree ubase = use->iv->base;
- tree ustep = use->iv->step;
- tree cbase = cand->iv->base;
- tree cstep = cand->iv->step, cstep_common;
+get_computation_aff_1 (struct loop *loop, gimple *at, struct iv_use *use,
+ struct iv_cand *cand, struct aff_tree *aff_inv,
+ struct aff_tree *aff_var, widest_int *prat = NULL)
+{
+ tree ubase = use->iv->base, ustep = use->iv->step;
+ tree cbase = cand->iv->base, cstep = cand->iv->step;
+ tree common_type, uutype, var, cstep_common;
tree utype = TREE_TYPE (ubase), ctype = TREE_TYPE (cbase);
- tree common_type, var;
- tree uutype;
- aff_tree cbase_aff, var_aff;
+ aff_tree aff_cbase;
widest_int rat;
+ /* We must have a precision to express the values of use. */
if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype))
- {
- /* We do not have a precision to express the values of use. */
- return false;
- }
+ return false;
var = var_at_stmt (loop, cand, at);
uutype = unsigned_type_for (utype);
@@ -3736,8 +3733,8 @@ get_computation_aff (struct loop *loop,
cstep = inner_step;
}
}
- cstep = fold_convert (uutype, cstep);
cbase = fold_convert (uutype, cbase);
+ cstep = fold_convert (uutype, cstep);
var = fold_convert (uutype, var);
}
@@ -3756,6 +3753,9 @@ get_computation_aff (struct loop *loop,
else if (!constant_multiple_of (ustep, cstep, &rat))
return false;
+ if (prat)
+ *prat = rat;
+
/* In case both UBASE and CBASE are shortened to UUTYPE from some common
type, we achieve better folding by computing their difference in this
wider type, and cast the result to UUTYPE. We do not need to worry about
@@ -3764,9 +3764,9 @@ get_computation_aff (struct loop *loop,
common_type = determine_common_wider_type (&ubase, &cbase);
/* use = ubase - ratio * cbase + ratio * var. */
- tree_to_aff_combination (ubase, common_type, aff);
- tree_to_aff_combination (cbase, common_type, &cbase_aff);
- tree_to_aff_combination (var, uutype, &var_aff);
+ tree_to_aff_combination (ubase, common_type, aff_inv);
+ tree_to_aff_combination (cbase, common_type, &aff_cbase);
+ tree_to_aff_combination (var, uutype, aff_var);
/* We need to shift the value if we are after the increment. */
if (stmt_after_increment (loop, cand, at))
@@ -3779,17 +3779,32 @@ get_computation_aff (struct loop *loop,
cstep_common = cstep;
tree_to_aff_combination (cstep_common, common_type, &cstep_aff);
- aff_combination_add (&cbase_aff, &cstep_aff);
+ aff_combination_add (&aff_cbase, &cstep_aff);
}
- aff_combination_scale (&cbase_aff, -rat);
- aff_combination_add (aff, &cbase_aff);
+ aff_combination_scale (&aff_cbase, -rat);
+ aff_combination_add (aff_inv, &aff_cbase);
if (common_type != uutype)
- aff_combination_convert (aff, uutype);
+ aff_combination_convert (aff_inv, uutype);
- aff_combination_scale (&var_aff, rat);
- aff_combination_add (aff, &var_aff);
+ aff_combination_scale (aff_var, rat);
+ return true;
+}
+
+/* Determines the expression by that USE is expressed from induction variable
+ CAND at statement AT in LOOP. The expression is stored in a decomposed
+ form into AFF. Returns false if USE cannot be expressed using CAND. */
+
+static bool
+get_computation_aff (struct loop *loop, gimple *at, struct iv_use *use,
+ struct iv_cand *cand, struct aff_tree *aff)
+{
+ aff_tree aff_var;
+
+ if (!get_computation_aff_1 (loop, at, use, cand, aff, &aff_var))
+ return false;
+ aff_combination_add (aff, &aff_var);
return true;
}
@@ -3825,7 +3840,7 @@ get_computation_at (struct loop *loop, gimple *at,
aff_tree aff;
tree type = get_use_type (use);
- if (!get_computation_aff (loop, use, cand, at, &aff))
+ if (!get_computation_aff (loop, at, use, cand, &aff))
return NULL_TREE;
unshare_aff_combination (&aff);
return fold_convert (type, aff_combination_to_tree (&aff));
@@ -7309,7 +7324,7 @@ rewrite_use_address (struct ivopts_data *data,
bool ok;
adjust_iv_update_pos (cand, use);
- ok = get_computation_aff (data->current_loop, use, cand, use->stmt, &aff);
+ ok = get_computation_aff (data->current_loop, use->stmt, use, cand, &aff);
gcc_assert (ok);
unshare_aff_combination (&aff);
--
1.9.1
