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| author | Max Filippov <jcmvbkbc@gmail.com> | 2019-04-02 14:32:42 -0700 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2019-04-03 10:24:15 -0700 |
| commit | 403b0b61f6d4358aee8493cb1d11814e368942c9 (patch) | |
| tree | ad564c6c9f423c3a756aead6577a242c46da5e1e /gas/config/tc-xtensa.c | |
| parent | 1c6aafe894645ca1da5c0dd0661bca19caf37ad0 (diff) | |
| download | binutils-403b0b61f6d4358aee8493cb1d11814e368942c9.zip binutils-403b0b61f6d4358aee8493cb1d11814e368942c9.tar.gz binutils-403b0b61f6d4358aee8493cb1d11814e368942c9.tar.bz2 | |
gas: use literals/const16 for xtensa loop relaxation
Loop opcode relaxation that uses addi/addmi doesn't work well with other
relaxations that may cause code movement. Instead of encoding fixed loop
end offset in the relaxed sequence use l32r or a pair of const16 to load
loop end address. This way the address of the loop end gets a relocation
record and it gets updated appropriately.
gas/
2019-04-03 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (convert_frag_immed): Drop
convert_frag_immed_finish_loop invocation.
(convert_frag_immed_finish_loop): Drop declaration and
definition.
* config/xtensa-relax.c (widen_spec_list): Replace loop
widening that uses addi/addmi with widening that uses l32r
and const16.
Diffstat (limited to 'gas/config/tc-xtensa.c')
| -rw-r--r-- | gas/config/tc-xtensa.c | 120 |
1 files changed, 0 insertions, 120 deletions
diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c index 3bdbbc9..0cc0636 100644 --- a/gas/config/tc-xtensa.c +++ b/gas/config/tc-xtensa.c @@ -10668,7 +10668,6 @@ convert_frag_fill_nop (fragS *fragP) static fixS *fix_new_exp_in_seg (segT, subsegT, fragS *, int, int, expressionS *, int, bfd_reloc_code_real_type); -static void convert_frag_immed_finish_loop (segT, fragS *, TInsn *); static void convert_frag_immed (segT segP, @@ -10910,9 +10909,6 @@ convert_frag_immed (segT segP, } } - if (expanded && xtensa_opcode_is_loop (isa, orig_tinsn.opcode) == 1) - convert_frag_immed_finish_loop (segP, fragP, &orig_tinsn); - if (expanded && is_direct_call_opcode (orig_tinsn.opcode)) { /* Add an expansion note on the expanded instruction. */ @@ -10949,122 +10945,6 @@ fix_new_exp_in_seg (segT new_seg, } -/* Relax a loop instruction so that it can span loop >256 bytes. - - loop as, .L1 - .L0: - rsr as, LEND - wsr as, LBEG - addi as, as, lo8 (label-.L1) - addmi as, as, mid8 (label-.L1) - wsr as, LEND - isync - rsr as, LCOUNT - addi as, as, 1 - .L1: - <<body>> - label: -*/ - -static void -convert_frag_immed_finish_loop (segT segP, fragS *fragP, TInsn *tinsn) -{ - TInsn loop_insn; - TInsn addi_insn; - TInsn addmi_insn; - unsigned long target; - static xtensa_insnbuf insnbuf = NULL; - unsigned int loop_length, loop_length_hi, loop_length_lo; - xtensa_isa isa = xtensa_default_isa; - addressT loop_offset; - addressT addi_offset = 9; - addressT addmi_offset = 12; - fragS *next_fragP; - int target_count; - - if (!insnbuf) - insnbuf = xtensa_insnbuf_alloc (isa); - - /* Get the loop offset. */ - loop_offset = get_expanded_loop_offset (tinsn->opcode); - - /* Validate that there really is a LOOP at the loop_offset. Because - loops are not bundleable, we can assume that the instruction will be - in slot 0. */ - tinsn_from_chars (&loop_insn, fragP->fr_opcode + loop_offset, 0); - tinsn_immed_from_frag (&loop_insn, fragP, 0); - - gas_assert (xtensa_opcode_is_loop (isa, loop_insn.opcode) == 1); - addi_offset += loop_offset; - addmi_offset += loop_offset; - - gas_assert (tinsn->ntok == 2); - if (tinsn->tok[1].X_op == O_constant) - target = tinsn->tok[1].X_add_number; - else if (tinsn->tok[1].X_op == O_symbol) - { - /* Find the fragment. */ - symbolS *sym = tinsn->tok[1].X_add_symbol; - gas_assert (S_GET_SEGMENT (sym) == segP - || S_GET_SEGMENT (sym) == absolute_section); - target = (S_GET_VALUE (sym) + tinsn->tok[1].X_add_number); - } - else - { - as_bad (_("invalid expression evaluation type %d"), tinsn->tok[1].X_op); - target = 0; - } - - loop_length = target - (fragP->fr_address + fragP->fr_fix); - loop_length_hi = loop_length & ~0x0ff; - loop_length_lo = loop_length & 0x0ff; - if (loop_length_lo >= 128) - { - loop_length_lo -= 256; - loop_length_hi += 256; - } - - /* Because addmi sign-extends the immediate, 'loop_length_hi' can be at most - 32512. If the loop is larger than that, then we just fail. */ - if (loop_length_hi > 32512) - as_bad_where (fragP->fr_file, fragP->fr_line, - _("loop too long for LOOP instruction")); - - tinsn_from_chars (&addi_insn, fragP->fr_opcode + addi_offset, 0); - gas_assert (addi_insn.opcode == xtensa_addi_opcode); - - tinsn_from_chars (&addmi_insn, fragP->fr_opcode + addmi_offset, 0); - gas_assert (addmi_insn.opcode == xtensa_addmi_opcode); - - set_expr_const (&addi_insn.tok[2], loop_length_lo); - tinsn_to_insnbuf (&addi_insn, insnbuf); - - fragP->tc_frag_data.is_insn = TRUE; - xtensa_insnbuf_to_chars - (isa, insnbuf, (unsigned char *) fragP->fr_opcode + addi_offset, 0); - - set_expr_const (&addmi_insn.tok[2], loop_length_hi); - tinsn_to_insnbuf (&addmi_insn, insnbuf); - xtensa_insnbuf_to_chars - (isa, insnbuf, (unsigned char *) fragP->fr_opcode + addmi_offset, 0); - - /* Walk through all of the frags from here to the loop end - and mark them as no_transform to keep them from being modified - by the linker. If we ever have a relocation for the - addi/addmi of the difference of two symbols we can remove this. */ - - target_count = 0; - for (next_fragP = fragP; next_fragP != NULL; - next_fragP = next_fragP->fr_next) - { - next_fragP->tc_frag_data.is_no_transform = TRUE; - if (next_fragP->tc_frag_data.is_loop_target) - target_count++; - if (target_count == 2) - break; - } -} - /* A map that keeps information on a per-subsegment basis. This is maintained during initial assembly, but is invalid once the |