From f96b6328fa7162111e4440c5901ef313ed3e6c9a Mon Sep 17 00:00:00 2001
From: Tom de Vries <tdevries@suse.de>
Date: Thu, 10 Sep 2020 12:44:20 +0200
Subject: [tree-optimization] Don't clear ctrl-altering flag for IFN_UNIQUE
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There's an invariant for IFN_UNIQUE, listed here in
gimple_call_initialize_ctrl_altering:
...
/* IFN_UNIQUE should be the last insn, to make checking for it
as cheap as possible. */
|| (gimple_call_internal_p (stmt)
&& gimple_call_internal_unique_p (stmt)))
gimple_call_set_ctrl_altering (stmt, true);
...
Recent commit fab77644842 "tree-optimization/96931 - clear ctrl-altering flag
more aggressively" breaks this invariant, causing an ICE triggered during
libgomp testing for x86_64 with nvptx accelerator:
...
during RTL pass: mach
asyncwait-1.f90: In function ‘MAIN__._omp_fn.0’:
asyncwait-1.f90:19: internal compiler error: in nvptx_find_par, at \
config/nvptx/nvptx.c:3293
...
Fix this by listing IFN_UNIQUE as exception in
cleanup_call_ctrl_altering_flag.
Build for x86_64 with nvptx accelerator, tested libgomp.
gcc/ChangeLog:
PR tree-optimization/97000
* tree-cfgcleanup.c (cleanup_call_ctrl_altering_flag): Don't clear
flag for IFN_UNIQUE.
---
gcc/tree-cfgcleanup.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c
index f8169ee..f2edd3f 100644
--- a/gcc/tree-cfgcleanup.c
+++ b/gcc/tree-cfgcleanup.c
@@ -212,7 +212,11 @@ static void
cleanup_call_ctrl_altering_flag (basic_block bb, gimple *bb_end)
{
if (!is_gimple_call (bb_end)
- || !gimple_call_ctrl_altering_p (bb_end))
+ || !gimple_call_ctrl_altering_p (bb_end)
+ || (/* IFN_UNIQUE should be the last insn, to make checking for it
+ as cheap as possible. */
+ gimple_call_internal_p (bb_end)
+ && gimple_call_internal_unique_p (bb_end)))
return;
int flags = gimple_call_flags (bb_end);
--
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