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| author | Jeff Law <law@redhat.com> | 2019-02-26 10:08:06 -0700 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2019-02-26 10:08:06 -0700 |
| commit | f73675e3c7503d6d48ea5ac29cd9b5e9d007668f (patch) | |
| tree | 27dca3a9798238978aeb505c5e6945a926edb54e /gcc/regcprop.c | |
| parent | 067aef033f3a9ad971fc75ce0631c500de0f0423 (diff) | |
re PR rtl-optimization/87761 ([MIPS] New FAIL: gcc.target/mips/fix-r4000-10.c -O1 start with r265398)
PR rtl-optimization/87761
* regcprop.c (copyprop_hardreg_forward_1): Use REG_UNUSED notes to
detect obviously dead insns and delete them.
From-SVN: r269218
Diffstat (limited to 'gcc/regcprop.c')
| -rw-r--r-- | gcc/regcprop.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/gcc/regcprop.c b/gcc/regcprop.c index e6bdeb07d8f..926df40f954 100644 --- a/gcc/regcprop.c +++ b/gcc/regcprop.c @@ -798,6 +798,22 @@ copyprop_hardreg_forward_1 (basic_block bb, struct value_data *vd) } } + /* Detect obviously dead sets (via REG_UNUSED notes) and remove them. */ + if (set + && INSN_P (insn) + && !may_trap_p (insn) + && find_reg_note (insn, REG_UNUSED, SET_DEST (set)) + && !side_effects_p (SET_SRC (set)) + && !side_effects_p (SET_DEST (set))) + { + bool last = insn == BB_END (bb); + delete_insn (insn); + if (last) + break; + continue; + } + + extract_constrain_insn (insn); preprocess_constraints (insn); const operand_alternative *op_alt = which_op_alt (); |