qemu/target-tilegx/helper.c
Chen Gang 5b212be632 target-tilegx: Add several helpers for instructions translation
The related instructions are exception, cntlz, cnttz, shufflebytes.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Message-Id: <BLU436-SMTP83F96FD8422BE49AFDC9DFB9660@phx.gbl>
[rth: Remove incorrect implementation of add_saturate.]
Signed-off-by: Richard Henderson <rth@twiddle.net>
2015-09-15 07:41:36 -07:00

71 lines
1.9 KiB
C

/*
* QEMU TILE-Gx helpers
*
* Copyright (c) 2015 Chen Gang
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see
* <http://www.gnu.org/licenses/lgpl-2.1.html>
*/
#include "cpu.h"
#include "qemu-common.h"
#include "exec/helper-proto.h"
void helper_exception(CPUTLGState *env, uint32_t excp)
{
CPUState *cs = CPU(tilegx_env_get_cpu(env));
cs->exception_index = excp;
cpu_loop_exit(cs);
}
uint64_t helper_cntlz(uint64_t arg)
{
return clz64(arg);
}
uint64_t helper_cnttz(uint64_t arg)
{
return ctz64(arg);
}
/*
* Functional Description
* uint64_t a = rf[SrcA];
* uint64_t b = rf[SrcB];
* uint64_t d = rf[Dest];
* uint64_t output = 0;
* unsigned int counter;
* for (counter = 0; counter < (WORD_SIZE / BYTE_SIZE); counter++)
* {
* int sel = getByte (b, counter) & 0xf;
* uint8_t byte = (sel < 8) ? getByte (d, sel) : getByte (a, (sel - 8));
* output = setByte (output, counter, byte);
* }
* rf[Dest] = output;
*/
uint64_t helper_shufflebytes(uint64_t dest, uint64_t srca, uint64_t srcb)
{
uint64_t vdst = 0;
int count;
for (count = 0; count < 64; count += 8) {
uint64_t sel = srcb >> count;
uint64_t src = (sel & 8) ? srca : dest;
vdst |= extract64(src, (sel & 7) * 8, 8) << count;
}
return vdst;
}