Revert "partial revert of the commit 4ad186c5ef61"

There seems nothing wrong.  With

    int t1 = 176401255;
    float f = 0.25;
    int t2 = t1 * f; // 176401255 * 0.25 = 44100313.75

according to the arithmetic conversion rules, the number
176401255 needs to be converted to float, and the compiler
can choose either the nearest higher or nearest lower
representable number "in an implementation-defined manner".

Which may be 176401248 or 176401264.  So as result both
44100312 and 44100313 are correct.

This reverts commit 664c19ad5e.
This commit is contained in:
grischka 2016-10-14 11:23:48 +02:00
parent 85fca9e924
commit 3b84e61ead
3 changed files with 0 additions and 23 deletions

View File

@ -1037,15 +1037,6 @@ ST_FUNC void gen_cvt_itof(int t)
/* convert fp to int 't' type */
ST_FUNC void gen_cvt_ftoi(int t)
{
#if 1
gv(RC_FLOAT);
save_reg(TREG_EAX);
save_reg(TREG_EDX);
gen_static_call(TOK___tcc_cvt_ftol);
vtop->r = TREG_EAX; /* mark reg as used */
if (t == VT_LLONG)
vtop->r2 = TREG_EDX;
#else
int bt = vtop->type.t & VT_BTYPE;
if (bt == VT_FLOAT)
vpush_global_sym(&func_old_type, TOK___fixsfdi);
@ -1058,7 +1049,6 @@ ST_FUNC void gen_cvt_ftoi(int t)
vpushi(0);
vtop->r = REG_IRET;
vtop->r2 = REG_LRET;
#endif
}
/* convert from one floating point type to another */

View File

@ -478,18 +478,6 @@ long long __ashldi3(long long a, int b)
#endif
}
long long __tcc_cvt_ftol(long double x)
{
unsigned c0, c1;
long long ret;
__asm__ __volatile__ ("fnstcw %0" : "=m" (c0));
c1 = c0 | 0x0C00;
__asm__ __volatile__ ("fldcw %0" : : "m" (c1));
__asm__ __volatile__ ("fistpll %0" : "=m" (ret));
__asm__ __volatile__ ("fldcw %0" : : "m" (c0));
return ret;
}
#endif /* !__x86_64__ */
/* XXX: fix tcc's code generator to do this instead */

View File

@ -243,7 +243,6 @@
DEF(TOK___fixsfdi, "__fixsfdi")
DEF(TOK___fixdfdi, "__fixdfdi")
DEF(TOK___fixxfdi, "__fixxfdi")
DEF(TOK___tcc_cvt_ftol, "__tcc_cvt_ftol")
#endif
#if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64