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| author | jbeulich <jbeulich@138bc75d-0d04-0410-961f-82ee72b054a4> | 2015-12-11 15:53:24 +0000 |
|---|---|---|
| committer | jbeulich <jbeulich@138bc75d-0d04-0410-961f-82ee72b054a4> | 2015-12-11 15:53:24 +0000 |
| commit | 7c5f556750802b91d68cb7f5e548eb35a82eb224 (patch) | |
| tree | d77f563c2a5cfa28caccef30637717356cd82991 /gcc/cfgexpand.c | |
| parent | 51b47129f3d83426249266b9e254fec4086fa67f (diff) | |
| download | gcc-7c5f556750802b91d68cb7f5e548eb35a82eb224.tar.gz | |
avoid alignment of static variables affecting stack's
Function (or more narrow) scope static variables (as well as others not
placed on the stack) should also not have any effect on the stack
alignment. I noticed the issue first with Linux'es dynamic_pr_debug()
construct using an 8-byte aligned sub-file-scope local variable.
According to my checking bad behavior started with 4.6.x (4.5.3 was
still okay), but generated code got quite a bit worse as of 4.9.0.
gcc/
2015-12-11 Jan Beulich <jbeulich@suse.com>
* cfgexpand.c (expand_one_var): Exit early for static and
external variables when adjusting stack alignment related.
gcc/testsuite/
2015-12-11 Jan Beulich <jbeulich@suse.com>
* gcc.c-torture/execute/stkalign.c: New.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@231569 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/cfgexpand.c')
| -rw-r--r-- | gcc/cfgexpand.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c index 7fe02a900bc..7f4eba2c226 100644 --- a/gcc/cfgexpand.c +++ b/gcc/cfgexpand.c @@ -1550,6 +1550,9 @@ expand_one_var (tree var, bool toplevel, bool really_expand) if (TREE_TYPE (var) != error_mark_node && TREE_CODE (var) == VAR_DECL) { + if (is_global_var (var)) + return 0; + /* Because we don't know if VAR will be in register or on stack, we conservatively assume it will be on stack even if VAR is eventually put into register after RA pass. For non-automatic |