On Wed, 2024-01-17 at 17:38 +0800, chenglulu wrote:
>
> 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
I've seen some "guality" test failures in GCC test suite as well.
Normally I just ignore the guality failures but this time they look very
suspicious. I'll investigate these issues...
--
Xi Ruoyao <xry...@xry111.site>
School of Aerospace Science and Technology, Xidian University
