[Bug rtl-optimization/105936] [10 Regression] ICE with inline-asm and TLS on x86_64 and -O2 in move_insn

[ubizjak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105936

--- Comment #4 from Uroš Bizjak <ubizjak at gmail dot com> ---
Digging a bit further with current gcc-10 branch...

Instrumenting a TLS address splitter in i386.md with some creative printfs:

(define_split
  [(match_operand 0 "tls_address_pattern")]
  "TARGET_TLS_DIRECT_SEG_REFS"
  [(match_dup 0)]
{
  debug_rtx (curr_insn);
  debug_rtx (operands[0]);
  printf ("%s\n", GET_RTX_NAME (classify_insn (operands[0])));
  operands[0] = ix86_rewrite_tls_address (operands[0]);
  debug_rtx (operands[0]);
  printf ("%s\n", GET_RTX_NAME (classify_insn (operands[0])));
})

we get:

(insn 54 51 109 9 (parallel [
            (asm_operands/v ("btrl %1,%0") ("") 0 [
                    (mem/c:BLK (plus:DI (plus:DI (unspec:DI [
                                        (const_int 0 [0])
                                    ] UNSPEC_TP)
                                (reg:DI 100))
                            (const_int 96 [0x60])) [21 MEM[(struct
revectored_struct *)&vm86u + 96B]+0 S32 A32])
                    (reg:SI 101)
                ]
                 [
                    (asm_input:BLK ("m") ../../../src/include/cpu.h:355)
                    (asm_input:SI ("r") ../../../src/include/cpu.h:355)
                ]
                 [] ../../../src/include/cpu.h:355)
            (clobber (reg:CC 17 flags))
        ]) "../../../src/include/cpu.h":355:2 -1
     (expr_list:REG_DEAD (reg:SI 101)
        (expr_list:REG_DEAD (reg:DI 100)
            (expr_list:REG_UNUSED (reg:CC 17 flags)
                (nil)))))
(parallel [
        (asm_operands/v ("btrl %1,%0") ("") 0 [
                (mem/c:BLK (plus:DI (plus:DI (unspec:DI [
                                    (const_int 0 [0])
                                ] UNSPEC_TP)
                            (reg:DI 100))
                        (const_int 96 [0x60])) [21 MEM[(struct
revectored_struct *)&vm86u + 96B]+0 S32 A32])
                (reg:SI 101)
            ]
             [
                (asm_input:BLK ("m") ../../../src/include/cpu.h:355)
                (asm_input:SI ("r") ../../../src/include/cpu.h:355)
            ]
             [] ../../../src/include/cpu.h:355)
        (clobber (reg:CC 17 flags))
    ])
jump_insn
(parallel [
        (asm_operands/v ("btrl %1,%0") ("") 0 [
                (mem/c:BLK (plus:DI (reg:DI 100)
                        (const_int 96 [0x60])) [21 MEM[(struct
revectored_struct *)&vm86u + 96B]+0 S32 A32 AS1])
                (reg:SI 101)
            ]
             [
                (asm_input:BLK ("m") ../../../src/include/cpu.h:355)
                (asm_input:SI ("r") ../../../src/include/cpu.h:355)
            ]
             [] ../../../src/include/cpu.h:355)
        (clobber (reg:CC 17 flags))
    ])
jump_insn

Please note that classify_insn declares the pattern as JUMP_INSN due to:

  if (GET_CODE (x) == ASM_OPERANDS && ASM_OPERANDS_LABEL_VEC (x))
    return JUMP_INSN;

but no label is defined in asm operands.