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target/arm: Change gen_jmp* to work on displacements

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In preparation for TARGET_TB_PCREL, reduce reliance on absolute values.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221020030641.2066807-7-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2022-10-20 13:06:38 +10:00 committed by Peter Maydell
parent b4f8d987f6
commit bb0356170a
1 changed files with 21 additions and 16 deletions
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37
target/arm/translate.c
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@ -266,6 +266,12 @@ static uint32_t read_pc(DisasContext *s)
return s->pc_curr + (s->thumb ? 4 : 8);
}
/* The pc_curr difference for an architectural jump. */
static target_long jmp_diff(DisasContext *s, target_long diff)
{
return diff + (s->thumb ? 4 : 8);
}
/* Set a variable to the value of a CPU register. */
void load_reg_var(DisasContext *s, TCGv_i32 var, int reg)
{
@ -2592,7 +2598,7 @@ static void gen_goto_ptr(void)
* cpu_loop_exec. Any live exit_requests will be processed as we
* enter the next TB.
*/
static void gen_goto_tb(DisasContext *s, int n, int diff)
static void gen_goto_tb(DisasContext *s, int n, target_long diff)
{
target_ulong dest = s->pc_curr + diff;
@ -2608,10 +2614,8 @@ static void gen_goto_tb(DisasContext *s, int n, int diff)
}
/* Jump, specifying which TB number to use if we gen_goto_tb() */
static inline void gen_jmp_tb(DisasContext *s, uint32_t dest, int tbno)
static void gen_jmp_tb(DisasContext *s, target_long diff, int tbno)
{
int diff = dest - s->pc_curr;
if (unlikely(s->ss_active)) {
/* An indirect jump so that we still trigger the debug exception. */
gen_update_pc(s, diff);
@ -2653,9 +2657,9 @@ static inline void gen_jmp_tb(DisasContext *s, uint32_t dest, int tbno)
}
}
static inline void gen_jmp(DisasContext *s, uint32_t dest)
static inline void gen_jmp(DisasContext *s, target_long diff)
{
gen_jmp_tb(s, dest, 0);
gen_jmp_tb(s, diff, 0);
}
static inline void gen_mulxy(TCGv_i32 t0, TCGv_i32 t1, int x, int y)
@ -8322,7 +8326,7 @@ static bool trans_CLRM(DisasContext *s, arg_CLRM *a)
static bool trans_B(DisasContext *s, arg_i *a)
{
gen_jmp(s, read_pc(s) + a->imm);
gen_jmp(s, jmp_diff(s, a->imm));
return true;
}
@ -8337,14 +8341,14 @@ static bool trans_B_cond_thumb(DisasContext *s, arg_ci *a)
return true;
}
arm_skip_unless(s, a->cond);
gen_jmp(s, read_pc(s) + a->imm);
gen_jmp(s, jmp_diff(s, a->imm));
return true;
}
static bool trans_BL(DisasContext *s, arg_i *a)
{
tcg_gen_movi_i32(cpu_R[14], s->base.pc_next | s->thumb);
gen_jmp(s, read_pc(s) + a->imm);
gen_jmp(s, jmp_diff(s, a->imm));
return true;
}
@ -8364,7 +8368,8 @@ static bool trans_BLX_i(DisasContext *s, arg_BLX_i *a)
}
tcg_gen_movi_i32(cpu_R[14], s->base.pc_next | s->thumb);
store_cpu_field_constant(!s->thumb, thumb);
gen_jmp(s, (read_pc(s) & ~3) + a->imm);
/* This jump is computed from an aligned PC: subtract off the low bits. */
gen_jmp(s, jmp_diff(s, a->imm - (s->pc_curr & 3)));
return true;
}
@ -8525,10 +8530,10 @@ static bool trans_WLS(DisasContext *s, arg_WLS *a)
* when we take this upcoming exit from this TB, so gen_jmp_tb() is OK.
*/
}
gen_jmp_tb(s, s->base.pc_next, 1);
gen_jmp_tb(s, curr_insn_len(s), 1);
gen_set_label(nextlabel);
gen_jmp(s, read_pc(s) + a->imm);
gen_jmp(s, jmp_diff(s, a->imm));
return true;
}
@ -8608,7 +8613,7 @@ static bool trans_LE(DisasContext *s, arg_LE *a)
if (a->f) {
/* Loop-forever: just jump back to the loop start */
gen_jmp(s, read_pc(s) - a->imm);
gen_jmp(s, jmp_diff(s, -a->imm));
return true;
}
@ -8639,7 +8644,7 @@ static bool trans_LE(DisasContext *s, arg_LE *a)
tcg_temp_free_i32(decr);
}
/* Jump back to the loop start */
gen_jmp(s, read_pc(s) - a->imm);
gen_jmp(s, jmp_diff(s, -a->imm));
gen_set_label(loopend);
if (a->tp) {
@ -8647,7 +8652,7 @@ static bool trans_LE(DisasContext *s, arg_LE *a)
store_cpu_field(tcg_constant_i32(4), v7m.ltpsize);
}
/* End TB, continuing to following insn */
gen_jmp_tb(s, s->base.pc_next, 1);
gen_jmp_tb(s, curr_insn_len(s), 1);
return true;
}
@ -8746,7 +8751,7 @@ static bool trans_CBZ(DisasContext *s, arg_CBZ *a)
tcg_gen_brcondi_i32(a->nz ? TCG_COND_EQ : TCG_COND_NE,
tmp, 0, s->condlabel);
tcg_temp_free_i32(tmp);
gen_jmp(s, read_pc(s) + a->imm);
gen_jmp(s, jmp_diff(s, a->imm));
return true;
}