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| author | Marc Glisse <marc.glisse@inria.fr> | 2014-11-03 11:47:04 +0100 |
|---|---|---|
| committer | Marc Glisse <glisse@gcc.gnu.org> | 2014-11-03 10:47:04 +0000 |
| commit | 956623c1378de3c48e77b23c2f2fa275f183e270 (patch) | |
| tree | b8fffd826c781877806bce6555060851ee0637bd /gcc/tree-ssa-live.c | |
| parent | b25b35c4ca7edf62118660048d5a7672653644f4 (diff) | |
| download | gcc-956623c1378de3c48e77b23c2f2fa275f183e270.zip gcc-956623c1378de3c48e77b23c2f2fa275f183e270.tar.gz gcc-956623c1378de3c48e77b23c2f2fa275f183e270.tar.bz2 | |
re PR tree-optimization/60770 (disappearing clobbers)
2014-11-03 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/60770
gcc/
* tree-into-ssa.c (rewrite_update_stmt): Return whether the
statement should be removed.
(maybe_register_def): Likewise. Replace clobbers with default
definitions.
(rewrite_dom_walker::before_dom_children): Remove statement if
rewrite_update_stmt says so.
* tree-ssa-live.c: Include tree-ssa.h.
(set_var_live_on_entry): Do not mark undefined variables as live.
(verify_live_on_entry): Do not check undefined variables.
* tree-ssa.h (ssa_undefined_value_p): New parameter for the case
of partially undefined variables.
* tree-ssa.c (ssa_undefined_value_p): Likewise.
(execute_update_addresses_taken): Do not drop clobbers.
gcc/testsuite/
* gcc.dg/tree-ssa/pr60770-1.c: New file.
From-SVN: r217034
Diffstat (limited to 'gcc/tree-ssa-live.c')
| -rw-r--r-- | gcc/tree-ssa-live.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c index 1effb43..22013e0 100644 --- a/gcc/tree-ssa-live.c +++ b/gcc/tree-ssa-live.c @@ -57,6 +57,7 @@ along with GCC; see the file COPYING3. If not see #include "diagnostic-core.h" #include "debug.h" #include "flags.h" +#include "tree-ssa.h" #ifdef ENABLE_CHECKING static void verify_live_on_entry (tree_live_info_p); @@ -1103,6 +1104,10 @@ set_var_live_on_entry (tree ssa_name, tree_live_info_p live) else def_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun); + /* An undefined local variable does not need to be very alive. */ + if (ssa_undefined_value_p (ssa_name, false)) + return; + /* Visit each use of SSA_NAME and if it isn't in the same block as the def, add it to the list of live on entry blocks. */ FOR_EACH_IMM_USE_FAST (use, imm_iter, ssa_name) @@ -1439,6 +1444,11 @@ verify_live_on_entry (tree_live_info_p live) else if (d == var) { + /* An undefined local variable does not need to be very + alive. */ + if (ssa_undefined_value_p (var, false)) + continue; + /* The only way this var shouldn't be marked live on entry is if it occurs in a PHI argument of the block. */ size_t z; |