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linux/arch/x86/math-emu/reg_constant.c
Ingo Molnar 3d0d14f983 x86: lindent arch/i386/math-emu
lindent these files:
                                       errors   lines of code   errors/KLOC
 arch/x86/math-emu/                      2236            9424         237.2
 arch/x86/math-emu/                       128            8706          14.7

no other changes. No code changed:

   text    data     bss     dec     hex filename
   5589802  612739 3833856 10036397         9924ad vmlinux.before
   5589802  612739 3833856 10036397         9924ad vmlinux.after

the intent of this patch is to ease the automated tracking of kernel
code quality - it's just much easier for us to maintain it if every file
in arch/x86 is supposed to be clean.

NOTE: it is a known problem of lindent that it causes some style damage
of its own, but it's a safe tool (well, except for the gcc array range
initializers extension), so we did the bulk of the changes via lindent,
and did the manual fixups in a followup patch.

the resulting math-emu code has been tested by Thomas Gleixner on a real
386 DX CPU as well, and it works fine.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:11 +01:00

118 lines
3.7 KiB
C

/*---------------------------------------------------------------------------+
| reg_constant.c |
| |
| All of the constant FPU_REGs |
| |
| Copyright (C) 1992,1993,1994,1997 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
| Australia. E-mail billm@suburbia.net |
| |
| |
+---------------------------------------------------------------------------*/
#include "fpu_system.h"
#include "fpu_emu.h"
#include "status_w.h"
#include "reg_constant.h"
#include "control_w.h"
#define MAKE_REG(s,e,l,h) { l, h, \
((EXTENDED_Ebias+(e)) | ((SIGN_##s != 0)*0x8000)) }
FPU_REG const CONST_1 = MAKE_REG(POS, 0, 0x00000000, 0x80000000);
#if 0
FPU_REG const CONST_2 = MAKE_REG(POS, 1, 0x00000000, 0x80000000);
FPU_REG const CONST_HALF = MAKE_REG(POS, -1, 0x00000000, 0x80000000);
#endif /* 0 */
static FPU_REG const CONST_L2T = MAKE_REG(POS, 1, 0xcd1b8afe, 0xd49a784b);
static FPU_REG const CONST_L2E = MAKE_REG(POS, 0, 0x5c17f0bc, 0xb8aa3b29);
FPU_REG const CONST_PI = MAKE_REG(POS, 1, 0x2168c235, 0xc90fdaa2);
FPU_REG const CONST_PI2 = MAKE_REG(POS, 0, 0x2168c235, 0xc90fdaa2);
FPU_REG const CONST_PI4 = MAKE_REG(POS, -1, 0x2168c235, 0xc90fdaa2);
static FPU_REG const CONST_LG2 = MAKE_REG(POS, -2, 0xfbcff799, 0x9a209a84);
static FPU_REG const CONST_LN2 = MAKE_REG(POS, -1, 0xd1cf79ac, 0xb17217f7);
/* Extra bits to take pi/2 to more than 128 bits precision. */
FPU_REG const CONST_PI2extra = MAKE_REG(NEG, -66,
0xfc8f8cbb, 0xece675d1);
/* Only the sign (and tag) is used in internal zeroes */
FPU_REG const CONST_Z = MAKE_REG(POS, EXP_UNDER, 0x0, 0x0);
/* Only the sign and significand (and tag) are used in internal NaNs */
/* The 80486 never generates one of these
FPU_REG const CONST_SNAN = MAKE_REG(POS, EXP_OVER, 0x00000001, 0x80000000);
*/
/* This is the real indefinite QNaN */
FPU_REG const CONST_QNaN = MAKE_REG(NEG, EXP_OVER, 0x00000000, 0xC0000000);
/* Only the sign (and tag) is used in internal infinities */
FPU_REG const CONST_INF = MAKE_REG(POS, EXP_OVER, 0x00000000, 0x80000000);
static void fld_const(FPU_REG const *c, int adj, u_char tag)
{
FPU_REG *st_new_ptr;
if (STACK_OVERFLOW) {
FPU_stack_overflow();
return;
}
push();
reg_copy(c, st_new_ptr);
st_new_ptr->sigl += adj; /* For all our fldxxx constants, we don't need to
borrow or carry. */
FPU_settag0(tag);
clear_C1();
}
/* A fast way to find out whether x is one of RC_DOWN or RC_CHOP
(and not one of RC_RND or RC_UP).
*/
#define DOWN_OR_CHOP(x) (x & RC_DOWN)
static void fld1(int rc)
{
fld_const(&CONST_1, 0, TAG_Valid);
}
static void fldl2t(int rc)
{
fld_const(&CONST_L2T, (rc == RC_UP) ? 1 : 0, TAG_Valid);
}
static void fldl2e(int rc)
{
fld_const(&CONST_L2E, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
}
static void fldpi(int rc)
{
fld_const(&CONST_PI, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
}
static void fldlg2(int rc)
{
fld_const(&CONST_LG2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
}
static void fldln2(int rc)
{
fld_const(&CONST_LN2, DOWN_OR_CHOP(rc) ? -1 : 0, TAG_Valid);
}
static void fldz(int rc)
{
fld_const(&CONST_Z, 0, TAG_Zero);
}
typedef void (*FUNC_RC) (int);
static FUNC_RC constants_table[] = {
fld1, fldl2t, fldl2e, fldpi, fldlg2, fldln2, fldz, (FUNC_RC) FPU_illegal
};
void fconst(void)
{
(constants_table[FPU_rm]) (control_word & CW_RC);
}