[Bug c/113469] New: RISC-V: Illegal Insn for test case 920501-8.c when make linux for rv32

[Bug c/113469] New: RISC-V: Illegal Insn for test case 920501-8.c when make linux for rv32

[pan2.li at intel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113469

            Bug ID: 113469
           Summary: RISC-V: Illegal Insn for test case 920501-8.c when
                    make linux for rv32
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pan2.li at intel dot com
  Target Milestone: ---

The test case will have illegal instruction when `make linux` build of the repo
riscv-gnu-toolchain for rv32.

1. Build.
../__RISC-V_INSTALL___RV32/bin/riscv32-unknown-linux-gnu-gcc
gcc/testsuite/gcc.c-torture/execute/920501-8.c -march=rv32gcv -mabi=ilp32d
-mtune=rocket -mcmodel=medlow -fdiagnostics-plain-output -O2 -w -lm -o
./920501-8.elf -static

2. Run with qemu
../build-qemu/qemu-riscv32 -cpu rv32,vlen=512,v=true,vext_spec=v1.0
920501-8.elf
Illegal instruction (core dumped)

3. When enter function __printf_buffer (comes from libc.a), it will go to insn
like below for the first insn
  __printf_buffer:
    auipc a5,0x5f  => directly jump to the vmv insn and then illegal insn met.
    ...
    vmv.v.i.v1,0

4. After some investigation, the function __printf_buffer should be the
   function Xprintf_buffer in glibc/stdio-common/vfprintf-internal.c. You can
   use the below command to compile it.

   cd glibc/stdio-common/
    ../../__RISC-V_INSTALL___RV32/bin/riscv32-unknown-linux-gnu-gcc
vfprintf-internal.c  \
 -c -std=gnu11 -fgnu89-inline  -mcmodel=medlow -O2 -Wall -Wwrite-strings
-Wundef \
 -fmerge-all-constants -frounding-math -fno-stack-protector -fno-common
-Wstrict-prototypes -Wold-style-definition  \
 -fmath-errno -fPIE   -ftls-model=initial-exec -I../include \

-I/home/pli/gcc/444/riscv-gnu-toolchain/build-glibc-linux-rv32gcv-ilp32d/stdio-common
 \
 -I/home/pli/gcc/444/riscv-gnu-toolchain/build-glibc-linux-rv32gcv-ilp32d 
-I../sysdeps/unix/sysv/linux/riscv/rv32 \
 -I../sysdeps/unix/sysv/linux/riscv  -I../sysdeps/riscv/nptl 
-I../sysdeps/unix/sysv/linux/generic/wordsize-32   \
 -I../sysdeps/unix/sysv/linux/generic  -I../sysdeps/unix/sysv/linux/include
-I../sysdeps/unix/sysv/linux  \
 -I../sysdeps/nptl  -I../sysdeps/pthread  -I../sysdeps/gnu 
-I../sysdeps/unix/inet  -I../sysdeps/unix/sysv  \
 -I../sysdeps/unix  -I../sysdeps/posix  \
 -I../sysdeps/riscv/rv32/rvd  -I../sysdeps/riscv/rv32/rvf  
-I../sysdeps/riscv/rvf \
 -I../sysdeps/riscv/rvd  -I../sysdeps/riscv/rv32  -I../sysdeps/riscv  \
 -I../sysdeps/ieee754/ldbl-128  -I../sysdeps/ieee754/dbl-64 
-I../sysdeps/ieee754/flt-32  \
 -I../sysdeps/wordsize-32   -I../sysdeps/ieee754  -I../sysdeps/generic \
 -I.. -I../libio -I. -nostdinc -isystem
/home/pli/gcc/444/riscv-gnu-toolchain/__RISC-V_INSTALL___RV32/lib/gcc/riscv32-unknown-linux-gnu/14.0.1/include
\
 -isystem
/home/pli/gcc/444/riscv-gnu-toolchain/__RISC-V_INSTALL___RV32/lib/gcc/riscv32-unknown-linux-gnu/14.0.1/include-fixed
  \
 -isystem /home/pli/gcc/444/riscv-gnu-toolchain/linux-headers/include \
 -D_LIBC_REENTRANT -include
/home/pli/gcc/444/riscv-gnu-toolchain/build-glibc-linux-rv32gcv-ilp32d/libc-modules.h
\
 -DMODULE_NAME=libc -include ../include/libc-symbols.h  -DPIC  \
 -DTOP_NAMESPACE=glibc -D_IO_MTSAFE_IO -o test.o

[Bug target/113469] RISC-V: Illegal Insn for test case 920501-8.c when make linux for rv32

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113469

--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Pan Li <panli@gcc.gnu.org>:

https://gcc.gnu.org/g:d40b3c1e439db05c835b6bd4fd5bba58fda71dd6

commit r14-8442-gd40b3c1e439db05c835b6bd4fd5bba58fda71dd6
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Fri Jan 26 14:46:21 2024 +0800

    RISC-V: Fix incorrect LCM delete bug [VSETVL PASS]

    This patch fixes the recent noticed bug in RV32 glibc.

    We incorrectly deleted a vsetvl:

            ...
            and     a4,a4,a3
            vmv.v.i v1,0                 ---> Missed vsetvl cause illegal
instruction report.
            vse8.v  v1,0(a5)

    The root cause the laterin in LCM is incorrect.

          BB 358:
            avloc: n_bits = 2, set = {}
            kill: n_bits = 2, set = {}
            antloc: n_bits = 2, set = {}
            transp: n_bits = 2, set = {}
            avin: n_bits = 2, set = {}
            avout: n_bits = 2, set = {}
            del: n_bits = 2, set = {}

    cause LCM let BB 360 delete the vsetvl:

          BB 360:
            avloc: n_bits = 2, set = {}
            kill: n_bits = 2, set = {}
            antloc: n_bits = 2, set = {}
            transp: n_bits = 2, set = {0 1 }
            avin: n_bits = 2, set = {}
            avout: n_bits = 2, set = {}
            del: n_bits = 2, set = {1}

    Also, remove unknown vsetvl info into local computation since it is
unnecessary.

    Tested on both RV32/RV64 no regression.

            PR target/113469

    gcc/ChangeLog:

            * config/riscv/riscv-vsetvl.cc
(pre_vsetvl::compute_lcm_local_properties): Fix bug.

    gcc/testsuite/ChangeLog:

            * gcc.target/riscv/rvv/autovec/pr113469.c: New test.

[Bug target/113469] RISC-V: Illegal Insn for test case 920501-8.c when make linux for rv32

[pan2.li at intel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113469

Li Pan <pan2.li at intel dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #2 from Li Pan <pan2.li at intel dot com> ---
Fixed.