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target/arm: Convert TBZ, TBNZ to decodetree

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Convert the test-and-branch-immediate insns TBZ and TBNZ
to decodetree.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230512144106.3608981-16-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2023-05-12 15:41:01 +01:00
parent f8977d50fc
commit e505828d30
2 changed files with 11 additions and 20 deletions
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6
target/arm/tcg/a64.decode
View File

@ -118,3 +118,9 @@ BL 1 00101 .......................... @branch
&cbz rt imm sf nz
CBZ sf:1 011010 nz:1 ................... rt:5 &cbz imm=%imm19
%imm14 5:s14 !function=times_4
%imm31_19 31:1 19:5
&tbz rt imm nz bitpos
TBZ . 011011 nz:1 ..... .............. rt:5 &tbz imm=%imm14 bitpos=%imm31_19

25
target/arm/tcg/translate-a64.c
View File

@ -1352,35 +1352,23 @@ static bool trans_CBZ(DisasContext *s, arg_cbz *a)
return true;
}
/* Test and branch (immediate)
* 31 30 25 24 23 19 18 5 4 0
* +----+-------------+----+-------+-------------+------+
* | b5 | 0 1 1 0 1 1 | op | b40 | imm14 | Rt |
* +----+-------------+----+-------+-------------+------+
*/
static void disas_test_b_imm(DisasContext *s, uint32_t insn)
static bool trans_TBZ(DisasContext *s, arg_tbz *a)
{
unsigned int bit_pos, op, rt;
int64_t diff;
DisasLabel match;
TCGv_i64 tcg_cmp;
bit_pos = (extract32(insn, 31, 1) << 5) | extract32(insn, 19, 5);
op = extract32(insn, 24, 1); /* 0: TBZ; 1: TBNZ */
diff = sextract32(insn, 5, 14) * 4;
rt = extract32(insn, 0, 5);
tcg_cmp = tcg_temp_new_i64();
tcg_gen_andi_i64(tcg_cmp, cpu_reg(s, rt), (1ULL << bit_pos));
tcg_gen_andi_i64(tcg_cmp, cpu_reg(s, a->rt), 1ULL << a->bitpos);
reset_btype(s);
match = gen_disas_label(s);
tcg_gen_brcondi_i64(op ? TCG_COND_NE : TCG_COND_EQ,
tcg_gen_brcondi_i64(a->nz ? TCG_COND_NE : TCG_COND_EQ,
tcg_cmp, 0, match.label);
gen_goto_tb(s, 0, 4);
set_disas_label(s, match);
gen_goto_tb(s, 1, diff);
gen_goto_tb(s, 1, a->imm);
return true;
}
/* Conditional branch (immediate)
@ -2397,9 +2385,6 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn)
static void disas_b_exc_sys(DisasContext *s, uint32_t insn)
{
switch (extract32(insn, 25, 7)) {
case 0x1b: case 0x5b: /* Test & branch (immediate) */
disas_test_b_imm(s, insn);
break;
case 0x2a: /* Conditional branch (immediate) */
disas_cond_b_imm(s, insn);
break;