Hi! On Thu, 5 Sep 2013 18:11:05 +0200, Jakub Jelinek <ja...@redhat.com> wrote: > 4) the reference testcase showed a problem with fold_stmt calls > we do very early, during gimplification, because for TREE_READONLY > vars with DECL_INITIAL fold_stmt can replace the uses of the var with > its initializer, but as the gimplifier isn't aware of it, we wouldn't remap > that, or worse there could be explicit remapping of it via array section, > but one that the compiler doesn't see, and if that is smaller than > the whole array size, that would result in runtime error. So, after > some talk with richi on IRC, I've decided to just not fold_stmt > inside of target constructs during gimplification and defer it until > omplower.
> * gimplify.c (gimplify_call_expr): Don't call fold_stmt
> inside of #pragma omp target construct.
> (gimplify_modify_expr): Likewise.
> * omp-low.c
> (lower_omp): Call fold_stmt on all stmts inside of
> #pragma omp target construct.
> --- gcc/gimplify.c.jj 2013-09-05 09:19:03.000000000 +0200
> +++ gcc/gimplify.c 2013-09-05 14:45:48.632720617 +0200
> @@ -2704,7 +2704,14 @@ gimplify_call_expr (tree *expr_p, gimple
> notice_special_calls (call);
> gimplify_seq_add_stmt (pre_p, call);
> gsi = gsi_last (*pre_p);
> - fold_stmt (&gsi);
> + /* Don't fold stmts inside of target construct. We'll do it
> + during omplower pass instead. */
> + struct gimplify_omp_ctx *ctx;
> + for (ctx = gimplify_omp_ctxp; ctx; ctx = ctx->outer_context)
> + if (ctx->region_type == ORT_TARGET)
> + break;
> + if (ctx == NULL)
> + fold_stmt (&gsi);
> *expr_p = NULL_TREE;
> }
> else
> @@ -4961,7 +4968,14 @@ gimplify_modify_expr (tree *expr_p, gimp
>
> gimplify_seq_add_stmt (pre_p, assign);
> gsi = gsi_last (*pre_p);
> - fold_stmt (&gsi);
> + /* Don't fold stmts inside of target construct. We'll do it
> + during omplower pass instead. */
> + struct gimplify_omp_ctx *ctx;
> + for (ctx = gimplify_omp_ctxp; ctx; ctx = ctx->outer_context)
> + if (ctx->region_type == ORT_TARGET)
> + break;
> + if (ctx == NULL)
> + fold_stmt (&gsi);
>
> if (want_value)
> {
> --- gcc/omp-low.c.jj 2013-09-05 09:19:03.000000000 +0200
> +++ gcc/omp-low.c 2013-09-05 17:11:14.693638660 +0200
> @@ -9673,6 +9685,12 @@ lower_omp (gimple_seq *body, omp_context
> gimple_stmt_iterator gsi;
> for (gsi = gsi_start (*body); !gsi_end_p (gsi); gsi_next (&gsi))
> lower_omp_1 (&gsi, ctx);
> + /* Inside target region we haven't called fold_stmt during gimplification,
> + because it can break code by adding decl references that weren't in the
> + source. Call fold_stmt now. */
> + if (target_nesting_level)
> + for (gsi = gsi_start (*body); !gsi_end_p (gsi); gsi_next (&gsi))
> + fold_stmt (&gsi);
> input_location = saved_location;
> }
OK to commit to trunk the following patch?
commit 6ff10eb51ea39a25e53e0369626559be208bb16e
Author: Thomas Schwinge <tho...@codesourcery.com>
Date: Mon Oct 21 16:37:41 2013 +0200
Refactor common code into new maybe_fold_stmt function.
gcc/
* gimplify.c (gimplify_call_expr, gimplify_modify_expr): Move
common code...
(maybe_fold_stmt): ... into this new function.
* omp-low.c (lower_omp): Update comment.
diff --git gcc/gimplify.c gcc/gimplify.c
index 1ca847a..7203456 100644
--- gcc/gimplify.c
+++ gcc/gimplify.c
@@ -2184,6 +2184,23 @@ gimplify_arg (tree *arg_p, gimple_seq *pre_p, location_t
call_location)
return gimplify_expr (arg_p, pre_p, NULL, test, fb);
}
+/* Don't fold STMT inside ORT_TARGET, because it can break code by adding decl
+ references that weren't in the source. We'll do it during omplower pass
+ instead. */
+
+static bool
+maybe_fold_stmt (gimple_stmt_iterator *gsi)
+{
+ bool changed = false;
+ struct gimplify_omp_ctx *ctx;
+ for (ctx = gimplify_omp_ctxp; ctx; ctx = ctx->outer_context)
+ if (ctx->region_type == ORT_TARGET)
+ break;
+ if (ctx == NULL)
+ changed = fold_stmt (gsi);
+ return changed;
+}
+
/* Gimplify the CALL_EXPR node *EXPR_P into the GIMPLE sequence PRE_P.
WANT_VALUE is true if the result of the call is desired. */
@@ -2417,14 +2434,7 @@ gimplify_call_expr (tree *expr_p, gimple_seq *pre_p,
bool want_value)
notice_special_calls (call);
gimplify_seq_add_stmt (pre_p, call);
gsi = gsi_last (*pre_p);
- /* Don't fold stmts inside of target construct. We'll do it
- during omplower pass instead. */
- struct gimplify_omp_ctx *ctx;
- for (ctx = gimplify_omp_ctxp; ctx; ctx = ctx->outer_context)
- if (ctx->region_type == ORT_TARGET)
- break;
- if (ctx == NULL)
- fold_stmt (&gsi);
+ maybe_fold_stmt (&gsi);
*expr_p = NULL_TREE;
}
else
@@ -4572,14 +4582,7 @@ gimplify_modify_expr (tree *expr_p, gimple_seq *pre_p,
gimple_seq *post_p,
gimplify_seq_add_stmt (pre_p, assign);
gsi = gsi_last (*pre_p);
- /* Don't fold stmts inside of target construct. We'll do it
- during omplower pass instead. */
- struct gimplify_omp_ctx *ctx;
- for (ctx = gimplify_omp_ctxp; ctx; ctx = ctx->outer_context)
- if (ctx->region_type == ORT_TARGET)
- break;
- if (ctx == NULL)
- fold_stmt (&gsi);
+ maybe_fold_stmt (&gsi);
if (want_value)
{
diff --git gcc/omp-low.c gcc/omp-low.c
index 05fca40..1222df6 100644
--- gcc/omp-low.c
+++ gcc/omp-low.c
@@ -10110,9 +10110,8 @@ lower_omp (gimple_seq *body, omp_context *ctx)
gimple_stmt_iterator gsi;
for (gsi = gsi_start (*body); !gsi_end_p (gsi); gsi_next (&gsi))
lower_omp_1 (&gsi, ctx);
- /* Inside target region we haven't called fold_stmt during gimplification,
- because it can break code by adding decl references that weren't in the
- source. Call fold_stmt now. */
+ /* During gimplification, we haven't called fold_stmt inside ORT_TARGET
+ (gimplify.c:maybe_fold_stmt); call it now. */
if (target_nesting_level)
for (gsi = gsi_start (*body); !gsi_end_p (gsi); gsi_next (&gsi))
fold_stmt (&gsi);
Grüße,
Thomas
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