qemu/include/exec/gen-icount.h
Paolo Bonzini 1aab16c28a cpu-exec: unify icount_decr and tcg_exit_req
The icount interrupt flag and tcg_exit_req serve almost the same
purpose, let's make them completely the same.

The former TB_EXIT_REQUESTED and TB_EXIT_ICOUNT_EXPIRED cases are
unified, since we can distinguish them from the value of the
interrupt flag.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-02-22 14:56:34 +01:00

77 lines
2.1 KiB
C

#ifndef GEN_ICOUNT_H
#define GEN_ICOUNT_H
#include "qemu/timer.h"
/* Helpers for instruction counting code generation. */
static int icount_start_insn_idx;
static TCGLabel *exitreq_label;
static inline void gen_tb_start(TranslationBlock *tb)
{
TCGv_i32 count, imm;
exitreq_label = gen_new_label();
if (tb->cflags & CF_USE_ICOUNT) {
count = tcg_temp_local_new_i32();
} else {
count = tcg_temp_new_i32();
}
tcg_gen_ld_i32(count, cpu_env,
-ENV_OFFSET + offsetof(CPUState, icount_decr.u32));
if (tb->cflags & CF_USE_ICOUNT) {
imm = tcg_temp_new_i32();
/* We emit a movi with a dummy immediate argument. Keep the insn index
* of the movi so that we later (when we know the actual insn count)
* can update the immediate argument with the actual insn count. */
icount_start_insn_idx = tcg_op_buf_count();
tcg_gen_movi_i32(imm, 0xdeadbeef);
tcg_gen_sub_i32(count, count, imm);
tcg_temp_free_i32(imm);
}
tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, exitreq_label);
if (tb->cflags & CF_USE_ICOUNT) {
tcg_gen_st16_i32(count, cpu_env,
-ENV_OFFSET + offsetof(CPUState, icount_decr.u16.low));
}
tcg_temp_free_i32(count);
}
static void gen_tb_end(TranslationBlock *tb, int num_insns)
{
if (tb->cflags & CF_USE_ICOUNT) {
/* Update the num_insn immediate parameter now that we know
* the actual insn count. */
tcg_set_insn_param(icount_start_insn_idx, 1, num_insns);
}
gen_set_label(exitreq_label);
tcg_gen_exit_tb((uintptr_t)tb + TB_EXIT_REQUESTED);
/* Terminate the linked list. */
tcg_ctx.gen_op_buf[tcg_ctx.gen_op_buf[0].prev].next = 0;
}
static inline void gen_io_start(void)
{
TCGv_i32 tmp = tcg_const_i32(1);
tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
tcg_temp_free_i32(tmp);
}
static inline void gen_io_end(void)
{
TCGv_i32 tmp = tcg_const_i32(0);
tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
tcg_temp_free_i32(tmp);
}
#endif