Re: [Tinycc-devel] asmtest problem

[grischka]

Michael Matz wrote:
> Hello grischka,
>
> On Wed, 19 Oct 2016, grischka wrote:
>
> > There seems to be a asm problem in tcctest.c with the bts
> > instruction on x86-64, which crashes it under circumstances.
> >
> >     __asm__("bts %1,%0" : "=m"(*pset) : "Ir"(_sig - 1) : "cc");
> >
> > From dump:
> >   3d:   8b 45 d0                mov    -0x30(%rbp),%eax <-- address
> >   Here it should load the addres into %rax, not %eax
>
> Ah yes, that one.  The attached patch should solve this, which also is 
> part of that mythical larger series that makes us compile the linux x86-64 
> kernel.

Ok, I added some of this.  Also support for X(%rip) addresses, currently
without any checks for usage of %rip in invalid context.

http://repo.or.cz/tinycc.git/commitdiff/4a3741bf02eb51c377312bdabc979e5ccbf5bf89

Ready for release 0.9.27 soon? ;)

--- grischka



> Ciao,
> Michael.
>
> commit 70a1dc38908b6ff679f15cf033828afda885d35f
> Author: Michael Matz <address@hidden>
> Date:   Wed Jun 29 18:06:40 2016 +0200
>
>     inline asm: Fix 'm' constraints
>     
>     See testcase.  The m constraint actually passes the address
>     and hence is of pointer type.
>
> diff --git a/i386-asm.c b/i386-asm.c
> index c0dd435..cc73320 100644
> --- a/i386-asm.c
> +++ b/i386-asm.c
> @@ -1291,7 +1291,12 @@ ST_FUNC void subst_asm_operand(CString *add_str,
>          if (reg >= VT_CONST)
>              tcc_error("internal compiler error");
>          snprintf(buf, sizeof(buf), "(%%%s)",
> -                 get_tok_str(TOK_ASM_eax + reg, NULL));
> +#ifdef TCC_TARGET_X86_64
> +                 get_tok_str(TOK_ASM_rax + reg, NULL)
> +#else
> +                 get_tok_str(TOK_ASM_eax + reg, NULL)
> +#endif
> +                );
>          cstr_cat(add_str, buf, -1);
>      } else {
>          /* register case */
> @@ -1392,7 +1397,8 @@ ST_FUNC void asm_gen_code(ASMOperand *operands, int 
> nb_operands,
>                         output cases) */
>                      SValue sv;
>                      sv = *op->vt;
> -                    sv.r = (sv.r & ~VT_VALMASK) | VT_LOCAL;
> +                    sv.r = (sv.r & ~VT_VALMASK) | VT_LOCAL | VT_LVAL;
> +                   sv.type.t = VT_PTR;
>                      load(op->reg, &sv);
>                  } else if (i >= nb_outputs || op->is_rw) {
>                      /* load value in register */
> diff --git a/tccasm.c b/tccasm.c
> index 55feecf..ad9580a 100644
> --- a/tccasm.c
> +++ b/tccasm.c
> @@ -1043,7 +1043,8 @@ static void parse_asm_operands(ASMOperand *operands, int 
> *nb_operands_ptr,
>              skip('(');
>              gexpr();
>              if (is_output) {
> -                test_lvalue();
> +               if (!(vtop->type.t & VT_ARRAY))
> +                   test_lvalue();
>              } else {
>                  /* we want to avoid LLOCAL case, except when the 'm'
>                     constraint is used. Note that it may come from
> diff --git a/tests/tcctest.c b/tests/tcctest.c
> index 28ba263..0922d77 100644
> --- a/tests/tcctest.c
> +++ b/tests/tcctest.c
> @@ -2583,12 +2583,33 @@ int fls64(unsigned long long x)
>  }
>  #endif
>  
> +struct struct123 {
> +    int a;
> +    int b;
> +};
> +struct struct1231 {
> +    unsigned long addr;
> +};
> +
> +unsigned long mconstraint_test(struct struct1231 *r)
> +{
> +    unsigned long ret;
> +    unsigned int a[2];
> +    a[0] = 0;
> +    __asm__ volatile ("leaq %2,%0; movl 4(%0),%k0; addl %2,%k0; movl $51,%2; movl 
> $52,4%2; movl $63,%1"
> +                     : "=&r" (ret), "=m" (a)
> +                     : "m" (*(struct struct123 *)r->addr));
> +    return ret + a[0];
> +}
> +
>  unsigned int set;
>  
>  void asm_test(void)
>  {
>      char buf[128];
>      unsigned int val;
> +    struct struct123 s1;
> +    struct struct1231 s2 = { (unsigned long)&s1 };
>  
>      printf("inline asm:\n");
>  
> @@ -2610,6 +2631,10 @@ void asm_test(void)
>      printf("mul64=0x%Lx\n", mul64(0x12345678, 0xabcd1234));
>      printf("inc64=0x%Lx\n", inc64(0x12345678ffffffff));
>  
> +    s1.a = 42;
> +    s1.b = 43;
> +    printf("mconstraint: %d", mconstraint_test(&s2));
> +    printf(" %d %d\n", s1.a, s1.b);
>      set = 0xff;
>      sigdelset1(&set, 2);
>      sigaddset1(&set, 16);
>
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