[Bug target/109092] [13 Regression] ICE: RTL check: expected code 'reg', have 'subreg' in rhs_regno, at rtl.h:1932 when building libgcc on riscv64

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109092

--- Comment #9 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Lehua Ding <lhtin@gcc.gnu.org>:

https://gcc.gnu.org/g:f625c017e60b6e05675b7d6280f2c7677ce691c3

commit r14-8333-gf625c017e60b6e05675b7d6280f2c7677ce691c3
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Mon Jan 22 17:05:07 2024 +0800

    RISC-V: Fix regressions due to 86de9b66480b710202a2898cf513db105d8c432f

    This patch fixes the recent regression:

    FAIL: gcc.dg/torture/float32-tg-2.c   -O1  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg-2.c   -O1  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg-2.c   -O2  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg-2.c   -O2  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg-2.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (internal compiler error: in reg_or_subregno, at
jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg-2.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg-2.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (internal compiler error: in reg_or_subregno, at
jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg-2.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg-2.c   -O3 -g  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg-2.c   -O3 -g  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg-2.c   -Os  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg-2.c   -Os  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg.c   -O1  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg.c   -O1  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg.c   -O2  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg.c   -O2  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (internal compiler error: in reg_or_subregno, at
jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (internal compiler error: in reg_or_subregno, at
jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg.c   -O3 -g  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg.c   -O3 -g  (test for excess errors)
    FAIL: gcc.dg/torture/float32-tg.c   -Os  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/float32-tg.c   -Os  (test for excess errors)
    FAIL: gcc.dg/torture/pr48124-4.c   -O1  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/pr48124-4.c   -O1  (test for excess errors)
    FAIL: gcc.dg/torture/pr48124-4.c   -O2  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/pr48124-4.c   -O2  (test for excess errors)
    FAIL: gcc.dg/torture/pr48124-4.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (internal compiler error: in reg_or_subregno, at
jump.cc:1895)
    FAIL: gcc.dg/torture/pr48124-4.c   -O2 -flto -fno-use-linker-plugin
-flto-partition=none  (test for excess errors)
    FAIL: gcc.dg/torture/pr48124-4.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (internal compiler error: in reg_or_subregno, at
jump.cc:1895)
    FAIL: gcc.dg/torture/pr48124-4.c   -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects  (test for excess errors)
    FAIL: gcc.dg/torture/pr48124-4.c   -O3 -fomit-frame-pointer -funroll-loops
-fpeel-loops -ftracer -finline-functions  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/pr48124-4.c   -O3 -fomit-frame-pointer -funroll-loops
-fpeel-loops -ftracer -finline-functions  (test for excess errors)
    FAIL: gcc.dg/torture/pr48124-4.c   -O3 -g  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/pr48124-4.c   -O3 -g  (test for excess errors)
    FAIL: gcc.dg/torture/pr48124-4.c   -Os  (internal compiler error: in
reg_or_subregno, at jump.cc:1895)
    FAIL: gcc.dg/torture/pr48124-4.c   -Os  (test for excess errors)

    due to commit 86de9b66480b710202a2898cf513db105d8c432f.

    The root cause is register_operand and reg_or_subregno are consistent so we
reach the assertion fail.

    We shouldn't worry about subreg:...VL_REGNUM since it's impossible that we
can have such situation,
    that is, we only have (set (reg) (reg:VL_REGNUM)) which generate "csrr vl"
ASM for first fault load instructions (vleff).
    So, using REG_P and REGNO must be totally solid and robostic.

    Since we don't allow VL_RENUM involved into register allocation and we
don't have such constraint, we always use this
    following pattern to generate "csrr vl" ASM:

    (define_insn "read_vlsi"
      [(set (match_operand:SI 0 "register_operand" "=r")
            (reg:SI VL_REGNUM))]
      "TARGET_VECTOR"
      "csrr\t%0,vl"
      [(set_attr "type" "rdvl")
       (set_attr "mode" "SI")])

    So the check in riscv.md is to disallow such situation fall into move
pattern in riscv.md

    Tested on both RV32/RV64 no regression.

            PR target/109092

    gcc/ChangeLog:

            * config/riscv/riscv.md: Use reg instead of subreg.

    gcc/testsuite/ChangeLog:

            * gcc.target/riscv/rvv/base/pr109092.c: New test.