On 09/22/14 04:29, Jiong Wang wrote:
On 19/09/14 21:43, Jeff Law wrote:
On 09/15/14 08:33, Jiong Wang wrote:
Jeff,
thanks, I partially understand your meaning here.
take the function "ira_implicitly_set_insn_hard_regs" in ira-lives.c
for example,
when generating address rtl, gcc will automatically generate "const"
operator to prefix
the address expression, like the following. so a simple CONSTANT_P
check is enough in
case there is no embedded register.
(insn 309 310 308 3 (set (reg:DI 44 r15 [orig:94 ivtmp.674 ] [94])
(const:DI (plus:DI (symbol_ref:DI ("recog_data") [flags 0x40]
<var_decl 0x2b2c2ff91510 recog_data>)
(const_int 480 [0x1e0])))) -1
but for architecture like aarch64, the following instruction
sequences to forming address
may be generated
(insn 73 14 74 4 (set (reg/f:DI 20 x20 [99])
(high:DI (symbol_ref:DI ("global_a") [flags 0xc0] <var_decl
0x7ff755a60900 stats>))) 35 {*movdi_aarch64}
(expr_list:REG_EQUIV (high:DI (symbol_ref:DI ("global_a") [flags
0xc0] <var_decl 0x7ff755a60900 stats>))
(nil)))
(insn 17 30 25 5 (set (reg/f:DI 4 x4 [83])
(lo_sum:DI (reg/f:DI 20 x20 [99])
(symbol_ref:DI ("global_a") [flags 0xc0] <var_decl
0x7ff755a60900 stats>))) {add_losym_di}
(expr_list:REG_EQUIV (symbol_ref:DI ("global_a") [flags 0xc0]
<var_decl 0x7ff755a60900 stats>)
(nil)))
while CONSTANT_P could not catch the latter lo_sum case, as the
RTX_CLASS of lo_sum is RTX_OBJ not RTX_CONST_OBJ,
Hmm, it's been ~15 years since I regularly worked on a target that uses
HIGH/LO_SUM, I thought we wrapped the LO_SUM expression inside a CONST
as well, but reading the docs for CONST, that clearly isn't the case.
Sorry for that. Can you (re) send your current patch for this for
review?
patch attached.
please review, thanks.
gcc/
* shrink-wrap.c (move_insn_for_shrink_wrap): Add further check when
!REG_P (src) to
release more instruction sink opportunities.
gcc/testsuite/
* gcc.target/aarch64/shrink_wrap_symbol_ref_1.c: New testcase.
Thanks. Please verify this version passes a bootstrap & regression
test. Assuming it does it is OK for the trunk.
jeff
