29e7e9664a
clang warns about a few parts of the math-emu implementation
where a 16-bit integer becomes negative during assignment:
arch/x86/math-emu/poly_tan.c:88:35: error: implicit conversion from 'int' to 'short' changes value from 49216 to -16320 [-Werror,-Wconstant-conversion]
(0x41 + EXTENDED_Ebias) | SIGN_Negative);
~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
arch/x86/math-emu/fpu_emu.h:180:58: note: expanded from macro 'setexponent16'
#define setexponent16(x,y) { (*(short *)&((x)->exp)) = (y); }
~ ^
arch/x86/math-emu/reg_constant.c:37:32: error: implicit conversion from 'int' to 'short' changes value from 49085 to -16451 [-Werror,-Wconstant-conversion]
FPU_REG const CONST_PI2extra = MAKE_REG(NEG, -66,
^~~~~~~~~~~~~~~~~~
arch/x86/math-emu/reg_constant.c:21:25: note: expanded from macro 'MAKE_REG'
((EXTENDED_Ebias+(e)) | ((SIGN_##s != 0)*0x8000)) }
~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/math-emu/reg_constant.c:48:28: error: implicit conversion from 'int' to 'short' changes value from 65535 to -1 [-Werror,-Wconstant-conversion]
FPU_REG const CONST_QNaN = MAKE_REG(NEG, EXP_OVER, 0x00000000, 0xC0000000);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/math-emu/reg_constant.c:21:25: note: expanded from macro 'MAKE_REG'
((EXTENDED_Ebias+(e)) | ((SIGN_##s != 0)*0x8000)) }
~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
The code is correct as is, so add a typecast to shut up the warnings.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190712090816.350668-1-arnd@arndb.de
119 lines
3.8 KiB
C
119 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*---------------------------------------------------------------------------+
|
|
| 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, \
|
|
(u16)((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);
|
|
}
|