Don't let pointer randomization change the order in which we process
store chains. This may cause SSA_NAMEs to be released in different
order, and if they're reused later, they may cause differences in SSA
partitioning, leading to differences in expand, and ultimately to
different code.
bootstrap-debug-lean (-fcompare-debug) on i686-linux-gnu has failed in
haifa-sched.c since r245196 exposed the latent ordering problem in
store merging. In this case, the IR differences (different SSA names
selected for copies in out-of-SSA, resulting in some off-by-one
differences in pseudos) were not significant enough to be visible in
the compiler output.
for gcc/ChangeLog
* gimple-ssa-store-merging.c (struct imm_store_chain_info):
Add linked-list forward and backlinks. Insert on
construction, remove on destruction.
(class pass_store_merging): Add m_stores_head field.
(pass_store_merging::terminate_and_process_all_chains):
Iterate over m_stores_head list.
(pass_store_merging::terminate_all_aliasing_chains):
Likewise.
(pass_store_merging::execute): Check for debug stmts first.
Push new chains onto the m_stores_head stack.
From-SVN: r246213
PR tree-optimization/79737
* gimple-ssa-store-merging.c (encode_tree_to_bitpos): If bitlen is
a multiple of BITS_PER_UNIT and !BYTES_BIG_ENDIAN, clear
tmpbuf[byte_size - 1]. Call natice_encode_expr with byte_size - 1
instead of byte_size. Formatting fix.
(shift_bytes_in_array_right): Formatting fix.
* gcc.c-torture/execute/pr79737-1.c: New test.
* gcc.c-torture/execute/pr79737-2.c: New test.
From-SVN: r245795
PR tree-optimization/78436
* gimple-ssa-store-merging.c (zero_char_buf): Removed.
(shift_bytes_in_array, shift_bytes_in_array_right,
merged_store_group::apply_stores): Formatting fixes.
(clear_bit_region): Likewise. Use memset.
(encode_tree_to_bitpos): Formatting fixes. Fix comment typos - EPXR
instead of EXPR and inerted instead of inserted. Use memset instead
of zero_char_buf. For !BYTES_BIG_ENDIAN decrease byte_size by 1
if shift_amnt is 0.
* gcc.c-torture/execute/pr78436.c: New test.
From-SVN: r242691
2016-11-07 Richard Biener <rguenther@suse.de>
PR tree-optimization/78218
* gimple-ssa-store-merging.c
(pass_store_merging::terminate_all_aliasing_chains):
Drop unused argument, fix alias check to also consider uses.
(pass_store_merging::execute): Adjust.
* gcc.dg/torture/pr78218.c: New testcase.
From-SVN: r241900
2016-11-02 Richard Biener <rguenther@suse.de>
* gimple-ssa-store-merging.c: Include gimplify-me.h.
(imm_store_chain_info::output_merged_stores): Force base_addr
to be proper GIMPLE for a MEM_REF address.
(pass_store_merging::execute): Restrict negative bitpos
handling to non-MEM_REF bases. Remove TREE_THIS_VOLATILE
check. Take into account non-NULL_TREE offset if the base
is already addressable.
* gcc.dg/store_merging_8.c: New testcase.
From-SVN: r241796
2016-11-02 Richard Biener <rguenther@suse.de>
* gimple-ssa-store-merging.c (struct store_immediate_info): Remove
redundant val and dest members.
(store_immediate_info::store_immediate_info): Adjust.
(merged_store_group::merged_store_group): Adjust.
(merged_store_group::apply_stores): Likewise.
(struct imm_store_chain_info): Add base_addr field.
(imm_store_chain_info::imm_store_chain_info): New constructor.
(imm_store_chain_info::terminate_and_process_chain): Do not pass base.
(imm_store_chain_info::output_merged_store): Likewise. Use
addr_base which is already the address.
(imm_store_chain_info::output_merged_stores): Likewise.
(pass_tree_store_merging::terminate_all_aliasing_chains): Take
imm_store_chain_info instead of base. Fix alias check.
(pass_tree_store_merging::terminate_and_release_chain): Likewise.
(imm_store_chain_info::coalesce_immediate_stores): Adjust.
(pass_store_merging::execute): Refuse to operate on TARGET_MEM_REF.
use the address of the base and adjust for other changes.
From-SVN: r241789
PR tree-optimization/78170
* gimple-ssa-store-merging.c (encode_tree_to_bitpos): Truncate padding
introduced by native_encode_expr on little-endian as well.
* gcc.c-torture/execute/pr78170.c: New test.
From-SVN: r241779
PR tree-optimization/78162
* gimple-ssa-store-merging.c (execute): Mark stores with bitpos < 0
as invalid.
* gcc.c-torture/compile/pr78162.c: New test.
From-SVN: r241778
PR target/78148
* gimple-ssa-store-merging.c
(imm_store_chain_info::output_merged_store): Use build_aligned_type
instead of SET_TYPE_ALIGN on shared integral type.
* gcc.dg/pr78148.c: New test.
From-SVN: r241679
Marek Polacek
Alexandre Oliva
Jakub Jelinek
Jakub Jelinek
Kyrylo Tkachov
Richard Biener