在 2024/1/13 下午9:05, Xi Ruoyao 写道:
> 在 2024-01-13星期六的 15:01 +0800，chenglulu写道：
>> 在 2024/1/12 下午7:42, Xi Ruoyao 写道:
>>> 在 2024-01-12星期五的 09:46 +0800，chenglulu写道：
>>>
>>>>> I found an issue bootstrapping GCC with -mcmodel=extreme in BOOT_CFLAGS:
>>>>> we need a target hook to tell the generic code
>>>>> UNSPEC_LA_PCREL_64_PART{1,2} are just a wrapper around symbols, or we'll
>>>>> see millions lines of messages like
>>>>>
>>>>> ../../gcc/gcc/tree.h:4171:1: note: non-delegitimized UNSPEC
>>>>> UNSPEC_LA_PCREL_64_PART1 (42) found in variable location
>>>> I build GCC with -mcmodel=extreme in BOOT_CFLAGS, but I haven't reproduced the problem you mentioned.
>>>>
>>>>       $ ../configure --host=loongarch64-linux-gnu --target=loongarch64-linux-gnu --build=loongarch64-linux-gnu \
>>>>           --with-arch=loongarch64 --with-abi=lp64d --enable-tls --enable-languages=c,c++,fortran,lto --enable-plugin \
>>>>           --disable-multilib --disable-host-shared --enable-bootstrap --enable-checking=release
>>>>       $ make BOOT_FLAGS="-mcmodel=extreme"
>>>>
>>>> What did I do wrong?:-(
>>> BOOT_CFLAGS, not BOOT_FLAGS :).
>>>
>> This is so strange. My compilation here stopped due to syntax problems,
>>
>> and I still haven't reproduced the information you mentioned about
>> UNSPEC_LA_PCREL_64_PART1.
> I used:
>
> ../gcc/configure --with-system-zlib --disable-fixincludes \
>                   --enable-default-ssp --enable-default-pie \
>                   --disable-werror --disable-multilib \
>                   --prefix=/home/xry111/gcc-dev
>
> and then
>
> make STAGE1_{C,CXX}FLAGS="-O2 -g" -j8 \
>       BOOT_{C,CXX}FLAGS="-O2 -g -mcmodel=extreme" &| tee gcc-build.log
>
> I guess "-g" is needed to reproduce the issue as well as the messages
> were produced in dwarf generation.
>
I have reproduced this problem, and it can be solved by adding a hook.

But unfortunately, when using '-mcmodel=extreme -mexplicit-relocs=always'

to test spec2006 403.gcc, an error will occur. Others have not been 
tested yet.

I roughly debugged it, and the problem should be this:

The problem is that the address of the instruction ‘ldx.d $r12, $r25, 
$r6’ is wrong.

Wrong assembly:

    5826         pcalau12i       $r13,%got_pc_hi20(recog_data)
  5827         addi.d  $r12,$r0,%got_pc_lo12(recog_data)
  5828         lu32i.d $r12,%got64_pc_lo20(recog_data)
  5829         lu52i.d $r12,$r12,%got64_pc_hi12(recog_data)
  5830         ldx.d   $r12,$r13,$r12
  5831         ld.b    $r8,$r12,997
  5832         .loc 1 829 18 discriminator 1 view .LVU1527
  5833         ble     $r8,$r0,.L476
  5834         ld.d    $r6,$r3,16
  5835         ld.d    $r9,$r3,88
  5836 .LBB189 = .
  5837         .loc 1 839 24 view .LVU1528
  5838         alsl.d  $r7,$r19,$r19,2
  5839         ldx.d   $r12,$r25,$r6
  5840         addi.d  $r17,$r3,120
  5841 .LBE189 = .
  5842         .loc 1 829 18 discriminator 1 view .LVU1529
  5843         or      $r13,$r0,$r0
  5844         addi.d  $r4,$r12,992

Assembly that works fine using macros:

3040         la.global       $r12,$r13,recog_data
3041         ld.b    $r9,$r12,997
3042         ble     $r9,$r0,.L475
3043         alsl.d  $r5,$r16,$r16,2
3044         la.global       $r15,$r17,recog_data
3045         addi.d  $r4,$r12,992
3046         addi.d  $r18,$r3,48
3047         or      $r13,$r0,$r0

Comparing the assembly, we can see that lines 5844 and 3045 have the 
same function,

but there is a problem with the base address register optimization at 
line 5844.

regrename.c.283r.loop2_init:

(insn 6 497 2741 34 (set (reg:DI 180 [ ivtmp.713D.15724 ])
         (const_int 0 [0])) "regrename.c":829:18 discrim 1 156 
{*movdi_64bit}
(nil))
(insn 2741 6 2744 34 (parallel [
             (set (reg:DI 1502)
                 (unspec:DI [
                         (symbol_ref:DI ("recog_data") [flags 0xc0]  
<var_decl 0x7f8c5ffd66c0 recog_data>)
                     ] UNSPEC_LA_PCREL_64_PART1))
             (set (reg/f:DI 1479)
                 (unspec:DI [
                         (symbol_ref:DI ("recog_data") [flags 0xc0]  
<var_decl 0x7f8c5ffd66c0 recog_data>)
                     ] UNSPEC_LA_PCREL_64_PART2))
         ]) -1
      (expr_list:REG_UNUSED (reg/f:DI 1479)
(nil)))
(insn 2744 2741 2745 34 (set (reg/f:DI 1503)
         (mem:DI (plus:DI (reg/f:DI 1479)
                 (reg:DI 1502)) [0  S8 A8])) 156 {*movdi_64bit}
      (expr_list:REG_EQUAL (symbol_ref:DI ("recog_data") [flags 0xc0]  
<var_decl 0x7f8c5ffd66c0 recog_data>)
(nil)))


Virtual register 1479 will be used in insn 2744, but register 1479 was 
assigned the REG_UNUSED attribute in the previous instruction.

The attached file is the wrong file.
The compilation command is as follows:

$ ./gcc/cc1 -fpreprocessed regrename.i -quiet -dp -dumpbase regrename.c 
-dumpbase-ext .c -mno-relax -mabi=lp64d -march=loongarch64 -mfpu=64 
-msimd=lasx -mcmodel=extreme -mtune=loongarch64 -g3 -O2 
-Wno-int-conversion -Wno-implicit-int -Wno-implicit-function-declaration 
-Wno-incompatible-pointer-types -version -o regrename.s 
-mexplicit-relocs=always -fdump-rtl-all-all