root / target-m68k / op_helper.c @ 2966b390
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/*
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* M68K helper routines
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*
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* Copyright (c) 2007 CodeSourcery
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "exec.h" |
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#include "helpers.h" |
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#if defined(CONFIG_USER_ONLY)
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void do_interrupt(int is_hw) |
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{ |
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env->exception_index = -1;
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} |
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#else
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extern int semihosting_enabled; |
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#define MMUSUFFIX _mmu
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#define SHIFT 0 |
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#include "softmmu_template.h" |
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#define SHIFT 1 |
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#include "softmmu_template.h" |
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#define SHIFT 2 |
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#include "softmmu_template.h" |
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#define SHIFT 3 |
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#include "softmmu_template.h" |
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/* Try to fill the TLB and return an exception if error. If retaddr is
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NULL, it means that the function was called in C code (i.e. not
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from generated code or from helper.c) */
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/* XXX: fix it to restore all registers */
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void tlb_fill (target_ulong addr, int is_write, int mmu_idx, void *retaddr) |
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{ |
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TranslationBlock *tb; |
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CPUState *saved_env; |
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unsigned long pc; |
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int ret;
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/* XXX: hack to restore env in all cases, even if not called from
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generated code */
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saved_env = env; |
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env = cpu_single_env; |
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ret = cpu_m68k_handle_mmu_fault(env, addr, is_write, mmu_idx, 1);
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if (unlikely(ret)) {
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if (retaddr) {
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/* now we have a real cpu fault */
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pc = (unsigned long)retaddr; |
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tb = tb_find_pc(pc); |
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if (tb) {
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/* the PC is inside the translated code. It means that we have
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a virtual CPU fault */
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cpu_restore_state(tb, env, pc, NULL);
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} |
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} |
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cpu_loop_exit(); |
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} |
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env = saved_env; |
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} |
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static void do_rte(void) |
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{ |
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uint32_t sp; |
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uint32_t fmt; |
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sp = env->aregs[7];
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fmt = ldl_kernel(sp); |
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env->pc = ldl_kernel(sp + 4);
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sp |= (fmt >> 28) & 3; |
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env->sr = fmt & 0xffff;
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m68k_switch_sp(env); |
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env->aregs[7] = sp + 8; |
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} |
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void do_interrupt(int is_hw) |
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{ |
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uint32_t sp; |
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uint32_t fmt; |
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uint32_t retaddr; |
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uint32_t vector; |
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fmt = 0;
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retaddr = env->pc; |
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if (!is_hw) {
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switch (env->exception_index) {
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case EXCP_RTE:
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/* Return from an exception. */
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do_rte(); |
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return;
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case EXCP_HALT_INSN:
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if (semihosting_enabled
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&& (env->sr & SR_S) != 0
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&& (env->pc & 3) == 0 |
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&& lduw_code(env->pc - 4) == 0x4e71 |
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&& ldl_code(env->pc) == 0x4e7bf000) {
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env->pc += 4;
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do_m68k_semihosting(env, env->dregs[0]);
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return;
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} |
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env->halted = 1;
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env->exception_index = EXCP_HLT; |
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cpu_loop_exit(); |
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return;
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} |
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if (env->exception_index >= EXCP_TRAP0
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&& env->exception_index <= EXCP_TRAP15) { |
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/* Move the PC after the trap instruction. */
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retaddr += 2;
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} |
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} |
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vector = env->exception_index << 2;
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sp = env->aregs[7];
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fmt |= 0x40000000;
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fmt |= (sp & 3) << 28; |
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fmt |= vector << 16;
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fmt |= env->sr; |
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env->sr |= SR_S; |
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if (is_hw) {
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env->sr = (env->sr & ~SR_I) | (env->pending_level << SR_I_SHIFT); |
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env->sr &= ~SR_M; |
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} |
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m68k_switch_sp(env); |
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/* ??? This could cause MMU faults. */
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sp &= ~3;
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sp -= 4;
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stl_kernel(sp, retaddr); |
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sp -= 4;
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stl_kernel(sp, fmt); |
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env->aregs[7] = sp;
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/* Jump to vector. */
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env->pc = ldl_kernel(env->vbr + vector); |
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} |
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#endif
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static void raise_exception(int tt) |
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{ |
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env->exception_index = tt; |
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cpu_loop_exit(); |
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} |
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void HELPER(raise_exception)(uint32_t tt)
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{ |
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raise_exception(tt); |
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} |
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void HELPER(divu)(CPUState *env, uint32_t word)
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{ |
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uint32_t num; |
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uint32_t den; |
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uint32_t quot; |
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uint32_t rem; |
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uint32_t flags; |
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num = env->div1; |
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den = env->div2; |
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/* ??? This needs to make sure the throwing location is accurate. */
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if (den == 0) |
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raise_exception(EXCP_DIV0); |
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quot = num / den; |
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rem = num % den; |
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flags = 0;
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/* Avoid using a PARAM1 of zero. This breaks dyngen because it uses
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the address of a symbol, and gcc knows symbols can't have address
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zero. */
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if (word && quot > 0xffff) |
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flags |= CCF_V; |
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if (quot == 0) |
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flags |= CCF_Z; |
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else if ((int32_t)quot < 0) |
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flags |= CCF_N; |
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env->div1 = quot; |
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env->div2 = rem; |
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env->cc_dest = flags; |
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} |
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void HELPER(divs)(CPUState *env, uint32_t word)
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{ |
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int32_t num; |
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int32_t den; |
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int32_t quot; |
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int32_t rem; |
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int32_t flags; |
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num = env->div1; |
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den = env->div2; |
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if (den == 0) |
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raise_exception(EXCP_DIV0); |
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quot = num / den; |
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rem = num % den; |
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flags = 0;
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if (word && quot != (int16_t)quot)
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flags |= CCF_V; |
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if (quot == 0) |
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flags |= CCF_Z; |
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else if (quot < 0) |
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flags |= CCF_N; |
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env->div1 = quot; |
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env->div2 = rem; |
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env->cc_dest = flags; |
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} |