qemu/target-s390x/int_helper.c
Richard Henderson 4e4bb43899 target-s390: Convert ADD LOGICAL CARRY and SUBTRACT LOGICAL BORROW
I'm resonably certain that the carry/borrow-out condition for both
helpers was incorrect, failing to take into account the carry-in.
Adding the new CC_OP codes also allows removing the awkward interface
we used for the slb helpers.

Signed-off-by: Richard Henderson <rth@twiddle.net>
2013-01-05 12:00:29 -08:00

152 lines
3.5 KiB
C

/*
* S/390 integer helper routines
*
* Copyright (c) 2009 Ulrich Hecht
* Copyright (c) 2009 Alexander Graf
*
* 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 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/>.
*/
#include "cpu.h"
#include "qemu/host-utils.h"
#include "helper.h"
/* #define DEBUG_HELPER */
#ifdef DEBUG_HELPER
#define HELPER_LOG(x...) qemu_log(x)
#else
#define HELPER_LOG(x...)
#endif
/* 64/64 -> 128 unsigned multiplication */
uint64_t HELPER(mul128)(CPUS390XState *env, uint64_t v1, uint64_t v2)
{
uint64_t reth;
mulu64(&env->retxl, &reth, v1, v2);
return reth;
}
/* 128 -> 64/64 unsigned division */
void HELPER(dlg)(CPUS390XState *env, uint32_t r1, uint64_t v2)
{
uint64_t divisor = v2;
if (!env->regs[r1]) {
/* 64 -> 64/64 case */
env->regs[r1] = env->regs[r1 + 1] % divisor;
env->regs[r1 + 1] = env->regs[r1 + 1] / divisor;
return;
} else {
#if HOST_LONG_BITS == 64 && defined(__GNUC__)
/* assuming 64-bit hosts have __uint128_t */
__uint128_t dividend = (((__uint128_t)env->regs[r1]) << 64) |
(env->regs[r1 + 1]);
__uint128_t quotient = dividend / divisor;
__uint128_t remainder = dividend % divisor;
env->regs[r1 + 1] = quotient;
env->regs[r1] = remainder;
#else
/* 32-bit hosts would need special wrapper functionality - just abort if
we encounter such a case; it's very unlikely anyways. */
cpu_abort(env, "128 -> 64/64 division not implemented\n");
#endif
}
}
/* absolute value 32-bit */
uint32_t HELPER(abs_i32)(int32_t val)
{
if (val < 0) {
return -val;
} else {
return val;
}
}
/* negative absolute value 32-bit */
int32_t HELPER(nabs_i32)(int32_t val)
{
if (val < 0) {
return val;
} else {
return -val;
}
}
/* absolute value 64-bit */
uint64_t HELPER(abs_i64)(int64_t val)
{
HELPER_LOG("%s: val 0x%" PRIx64 "\n", __func__, val);
if (val < 0) {
return -val;
} else {
return val;
}
}
/* negative absolute value 64-bit */
int64_t HELPER(nabs_i64)(int64_t val)
{
if (val < 0) {
return val;
} else {
return -val;
}
}
/* find leftmost one */
uint32_t HELPER(flogr)(CPUS390XState *env, uint32_t r1, uint64_t v2)
{
uint64_t res = 0;
uint64_t ov2 = v2;
while (!(v2 & 0x8000000000000000ULL) && v2) {
v2 <<= 1;
res++;
}
if (!v2) {
env->regs[r1] = 64;
env->regs[r1 + 1] = 0;
return 0;
} else {
env->regs[r1] = res;
env->regs[r1 + 1] = ov2 & ~(0x8000000000000000ULL >> res);
return 2;
}
}
uint64_t HELPER(cvd)(int32_t bin)
{
/* positive 0 */
uint64_t dec = 0x0c;
int shift = 4;
if (bin < 0) {
bin = -bin;
dec = 0x0d;
}
for (shift = 4; (shift < 64) && bin; shift += 4) {
int current_number = bin % 10;
dec |= (current_number) << shift;
bin /= 10;
}
return dec;
}