coreboot-libre-fam15h-rdimm/3rdparty/chromeec/chip/it83xx/it83xx_fpu.S

146 lines
4.3 KiB
ArmAsm

/* Copyright 2017 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "config_chip.h"
/*
* DLMB register = 0x80189:
* Disable all interrupts and switching CPU's
* ALU (Arithmetic Logic Unit) to floating point operation mode.
* (IEEE standard 754 floating point)
*
* DLMB register = 0x80009:
* Restore interrupts and ALU.
*/
.text
.align 2
.global __addsf3
.type __addsf3, @function
__addsf3:
sethi $r2, 0x80 /* r2 = 0x80000 */
addi $r3, $r2, 0x189 /* r3 = 0x80189 */
addi45 $r2, 0x9 /* r2 = 0x80009 */
mtsr $r3, $dlmb /* dlmb = 0x80189 */
dsb
/* Floating-point addition single-precision */
add45 $r0, $r1
mtsr $r2, $dlmb /* dlmb = 0x80009 */
dsb
ret5 $lp
.size __addsf3, .-__addsf3
.text
.align 2
.global __subsf3
.type __subsf3, @function
__subsf3:
sethi $r2, 0x80 /* r2 = 0x80000 */
addi $r3, $r2, 0x189 /* r3 = 0x80189 */
addi45 $r2, 0x9 /* r2 = 0x80009 */
mtsr $r3, $dlmb /* dlmb = 0x80189 */
dsb
/* Floating-point subtraction single-precision */
sub45 $r0, $r1
mtsr $r2, $dlmb /* dlmb = 0x80009 */
dsb
ret5 $lp
.size __subsf3, .-__subsf3
.text
.align 2
.global __mulsf3
.type __mulsf3, @function
__mulsf3:
#ifdef IT83XX_FPU_MUL_BY_DIV
#define SIGN $r2
#define EXPOA $r3
#define MANTA $r4
#define VALUA $r5
#define EXPOB $r6
#define MANTB $r7
#define VALUB $r8
#define SPROD $r15
/* save r6-r8 */
smw.adm $r6, [$sp], $r8, #0x0
xor SPROD, $r1, $r0 /* sign(A xor B) */
move SIGN, #0x80000000
and SPROD, SPROD, SIGN /* store sign bit */
slli VALUA, $r0, 1 /* A<<1, (exponent and mantissa) */
slli VALUB, $r1, 1 /* B<<1, (exponent and mantissa) */
srli EXPOA, VALUA, 24 /* exponent(A) */
srli EXPOB, VALUB, 24 /* exponent(B) */
slli MANTA, VALUA, 7 /* A<<8, mantissa(A) with exponent's LSB */
slli MANTB, VALUB, 7 /* A<<8, mantissa(B) with exponent's LSB */
beqz VALUA, .LFzeroA /* exponent(A) and mantissa (A) are zero */
beqc EXPOA, 0xff, .LFinfnanA /* A is inf or NaN */
beqz VALUB, .LFzeroB /* exponent(B) and mantissa (B) are zero */
beqc EXPOB, 0xff, .LFinfnanB /* B is inf or NaN */
/* A*B = A/(1/B) */
sethi $r2, 0x80 /* r2 = 0x80000 */
addi $r3, $r2, 0x189 /* r3 = 0x80189 */
addi45 $r2, 0x9 /* r2 = 0x80009 */
mtsr $r3, $dlmb /* dlmb = 0x80189 */
dsb
sethi $r5, #0x3f800 /* r5 = 1.0f */
divsr $r1,$r1,$r5,$r1 /* r1 = 1.0f / r1 */
divsr $r0,$r0,$r0,$r1 /* r0 = r0 / r1 */
mtsr $r2, $dlmb /* dlmb = 0x80009 */
dsb
.LFret:
/* restore r6-r8 */
lmw.bim $r6, [$sp], $r8, #0x0
ret5 $lp
.LFzeroA: /* A is zero */
beqc EXPOB, 0xff, .LFnan/*zero * inf = zero * NaN = NaN */
.LFzero:
move $r0, SPROD /* return 0.0f or -0.0f */
b .LFret
.LFinfnanA: /* exponent(A) is 0xff */
bne MANTA, SIGN, .LFnan/* A is NaN: NaN * B = NaN */
beqz VALUB, .LFnan /* A is inf and B is zero: inf * zero = NaN */
bnec EXPOB, 0xff, .LFinf/* B is finite: inf * B = inf */
.LFinfnanB: /* exponent(B) is 0xff */
bne MANTB, SIGN, .LFnan/* B is NaN: A * NaN = NaN */
.LFinf:
move $r0, #0x7f800000
or $r0, $r0, SPROD /* return inf or -inf */
b .LFret
.LFzeroB: /* B is zero and A is finit */
b .LFzero /* B is zero */
.LFnan:
move $r0, #0xffc00000 /* return NaN */
b .LFret
#else /* !IT83XX_FPU_MUL_BY_DIV */
sethi $r2, 0x80 /* r2 = 0x80000 */
addi $r3, $r2, 0x189 /* r3 = 0x80189 */
addi45 $r2, 0x9 /* r2 = 0x80009 */
mtsr $r3, $dlmb /* dlmb = 0x80189 */
dsb
/* Floating-point multiplication single-precision */
mul33 $r0, $r1
mtsr $r2, $dlmb /* dlmb = 0x80009 */
dsb
ret5 $lp
#endif /* IT83XX_FPU_MUL_BY_DIV */
.size __mulsf3, .-__mulsf3
.text
.align 2
.global __divsf3
.type __divsf3, @function
__divsf3:
sethi $r2, 0x80 /* r2 = 0x80000 */
addi $r3, $r2, 0x189 /* r3 = 0x80189 */
addi45 $r2, 0x9 /* r2 = 0x80009 */
mtsr $r3, $dlmb /* dlmb = 0x80189 */
dsb
/* Floating-point division single-precision */
divsr $r0,$r0,$r0,$r1
mtsr $r2, $dlmb /* dlmb = 0x80009 */
dsb
ret5 $lp
.size __divsf3, .-__divsf3