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[PATCH] Avoid compile-time overhead of GIMPLE FE in CFG construction
- From: Richard Biener <rguenther at suse dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Tue, 29 Nov 2016 14:59:59 +0100 (CET)
- Subject: [PATCH] Avoid compile-time overhead of GIMPLE FE in CFG construction
- Authentication-results: sourceware.org; auth=none
$subject
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2016-11-29 Richard Biener <rguenther@suse.de>
* tree-cfg.c (lower_phi_internal_fn): Do not look for further
PHIs after a regular stmt.
(stmt_starts_bb_p): PHIs not preceeded by a PHI or a label
start a new BB.
Index: gcc/tree-cfg.c
===================================================================
--- gcc/tree-cfg.c (revision 242953)
+++ gcc/tree-cfg.c (working copy)
@@ -361,14 +361,11 @@ lower_phi_internal_fn ()
/* After edge creation, handle __PHI function from GIMPLE FE. */
FOR_EACH_BB_FN (bb, cfun)
{
- for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi);)
+ for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi);)
{
stmt = gsi_stmt (gsi);
if (! gimple_call_internal_p (stmt, IFN_PHI))
- {
- gsi_next (&gsi);
- continue;
- }
+ break;
lhs = gimple_call_lhs (stmt);
phi_node = create_phi_node (lhs, bb);
@@ -2604,11 +2601,21 @@ stmt_starts_bb_p (gimple *stmt, gimple *
else
return true;
}
- else if (gimple_code (stmt) == GIMPLE_CALL
- && gimple_call_flags (stmt) & ECF_RETURNS_TWICE)
- /* setjmp acts similar to a nonlocal GOTO target and thus should
- start a new block. */
- return true;
+ else if (gimple_code (stmt) == GIMPLE_CALL)
+ {
+ if (gimple_call_flags (stmt) & ECF_RETURNS_TWICE)
+ /* setjmp acts similar to a nonlocal GOTO target and thus should
+ start a new block. */
+ return true;
+ if (gimple_call_internal_p (stmt, IFN_PHI)
+ && prev_stmt
+ && gimple_code (prev_stmt) != GIMPLE_LABEL
+ && (gimple_code (prev_stmt) != GIMPLE_CALL
+ || ! gimple_call_internal_p (prev_stmt, IFN_PHI)))
+ /* PHI nodes start a new block unless preceeded by a label
+ or another PHI. */
+ return true;
+ }
return false;
}