arch/parisc/math-emu/sfcmp.c

Source file repositories/reference/linux-study-clean/arch/parisc/math-emu/sfcmp.c

File Facts

System
Linux kernel
Corpus path
arch/parisc/math-emu/sfcmp.c
Extension
.c
Size
3825 bytes
Lines
143
Domain
Architecture Layer
Bucket
arch/parisc
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

if( Is_invalidtrap_enabled() ) {
	    	Set_status_cbit(Unordered(cond));
		return(INVALIDEXCEPTION);
	    }
	    else Set_invalidflag();
	    Set_status_cbit(Unordered(cond));
	    return(NOEXCEPTION);
	    }
	/* All the exceptional conditions are handled, now special case
	   NaN compares */
        else if( ((Sgl_exponent(left) == SGL_INFINITY_EXPONENT)
	    && Sgl_isnotzero_mantissa(left))
	   ||
	    ((Sgl_exponent(right) == SGL_INFINITY_EXPONENT)
	    && Sgl_isnotzero_mantissa(right)) )
	    {
	    /* NaNs always compare unordered. */
	    Set_status_cbit(Unordered(cond));
	    return(NOEXCEPTION);
	    }
	/* infinities will drop down to the normal compare mechanisms */
	}
    /* First compare for unequal signs => less or greater or
     * special equal case */
    Sgl_xortointp1(left,right,xorresult);
    if( xorresult < 0 )
        {
        /* left negative => less, left positive => greater.
         * equal is possible if both operands are zeros. */
        if( Sgl_iszero_exponentmantissa(left) 
	  && Sgl_iszero_exponentmantissa(right) )
            {
	    Set_status_cbit(Equal(cond));
	    }
	else if( Sgl_isone_sign(left) )
	    {
	    Set_status_cbit(Lessthan(cond));
	    }
	else
	    {
	    Set_status_cbit(Greaterthan(cond));
	    }
        }
    /* Signs are the same.  Treat negative numbers separately
     * from the positives because of the reversed sense.  */
    else if( Sgl_all(left) == Sgl_all(right) )
        {
        Set_status_cbit(Equal(cond));
        }
    else if( Sgl_iszero_sign(left) )
        {
        /* Positive compare */
        if( Sgl_all(left) < Sgl_all(right) )
	    {
	    Set_status_cbit(Lessthan(cond));
	    }
	else
	    {
	    Set_status_cbit(Greaterthan(cond));
	    }
	}
    else
        {
        /* Negative compare.  Signed or unsigned compares
         * both work the same.  That distinction is only
         * important when the sign bits differ. */
        if( Sgl_all(left) > Sgl_all(right) )
	    {
	    Set_status_cbit(Lessthan(cond));
	    }
        else
	    {
	    Set_status_cbit(Greaterthan(cond));
	    }
        }
	return(NOEXCEPTION);
    }

Annotation

Implementation Notes