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target/arm: Convert T16, long branches 

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-68-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2019-09-04 12:30:57 -07:00 committed by Peter Maydell
parent 8d4a4dc849
commit 67b54c554b
2 changed files with 43 additions and 49 deletions
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7
target/arm/t16.decode
View File

@ -272,3 +272,10 @@ LDM_t16 1011 110 ......... \
%imm11_0x2 0:s11 !function=times_2
B 11100 ........... &i imm=%imm11_0x2
# thumb_insn_is_16bit() ensures we won't be decoding these as
# T16 instructions for a Thumb2 CPU, so these patterns must be
# a Thumb1 split BL/BLX.
BLX_suffix 11101 imm:11 &i
BL_BLX_prefix 11110 imm:s11 &i
BL_suffix 11111 imm:11 &i

85
target/arm/translate.c
View File

@ -10147,6 +10147,40 @@ static bool trans_BLX_i(DisasContext *s, arg_BLX_i *a)
return true;
}
static bool trans_BL_BLX_prefix(DisasContext *s, arg_BL_BLX_prefix *a)
{
assert(!arm_dc_feature(s, ARM_FEATURE_THUMB2));
tcg_gen_movi_i32(cpu_R[14], read_pc(s) + (a->imm << 12));
return true;
}
static bool trans_BL_suffix(DisasContext *s, arg_BL_suffix *a)
{
TCGv_i32 tmp = tcg_temp_new_i32();
assert(!arm_dc_feature(s, ARM_FEATURE_THUMB2));
tcg_gen_addi_i32(tmp, cpu_R[14], (a->imm << 1) | 1);
tcg_gen_movi_i32(cpu_R[14], s->base.pc_next | 1);
gen_bx(s, tmp);
return true;
}
static bool trans_BLX_suffix(DisasContext *s, arg_BLX_suffix *a)
{
TCGv_i32 tmp;
assert(!arm_dc_feature(s, ARM_FEATURE_THUMB2));
if (!ENABLE_ARCH_5) {
return false;
}
tmp = tcg_temp_new_i32();
tcg_gen_addi_i32(tmp, cpu_R[14], a->imm << 1);
tcg_gen_andi_i32(tmp, tmp, 0xfffffffc);
tcg_gen_movi_i32(cpu_R[14], s->base.pc_next | 1);
gen_bx(s, tmp);
return true;
}
static bool op_tbranch(DisasContext *s, arg_tbranch *a, bool half)
{
TCGv_i32 addr, tmp;
@ -10736,10 +10770,6 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
static void disas_thumb_insn(DisasContext *s, uint32_t insn)
{
int32_t offset;
TCGv_i32 tmp;
TCGv_i32 tmp2;
if (disas_t16(s, insn)) {
return;
}
@ -10758,53 +10788,10 @@ static void disas_thumb_insn(DisasContext *s, uint32_t insn)
case 11: /* misc, in decodetree */
case 12: /* load/store multiple, in decodetree */
case 13: /* conditional branch or swi, in decodetree */
goto illegal_op;
case 14:
if (insn & (1 << 11)) {
/* thumb_insn_is_16bit() ensures we can't get here for
* a Thumb2 CPU, so this must be a thumb1 split BL/BLX:
* 0b1110_1xxx_xxxx_xxxx : BLX suffix (or UNDEF)
*/
assert(!arm_dc_feature(s, ARM_FEATURE_THUMB2));
ARCH(5);
offset = ((insn & 0x7ff) << 1);
tmp = load_reg(s, 14);
tcg_gen_addi_i32(tmp, tmp, offset);
tcg_gen_andi_i32(tmp, tmp, 0xfffffffc);
tmp2 = tcg_temp_new_i32();
tcg_gen_movi_i32(tmp2, s->base.pc_next | 1);
store_reg(s, 14, tmp2);
gen_bx(s, tmp);
break;
}
/* unconditional branch, in decodetree */
goto illegal_op;
case 15:
/* thumb_insn_is_16bit() ensures we can't get here for
* a Thumb2 CPU, so this must be a thumb1 split BL/BLX.
*/
assert(!arm_dc_feature(s, ARM_FEATURE_THUMB2));
if (insn & (1 << 11)) {
/* 0b1111_1xxx_xxxx_xxxx : BL suffix */
offset = ((insn & 0x7ff) << 1) | 1;
tmp = load_reg(s, 14);
tcg_gen_addi_i32(tmp, tmp, offset);
tmp2 = tcg_temp_new_i32();
tcg_gen_movi_i32(tmp2, s->base.pc_next | 1);
store_reg(s, 14, tmp2);
gen_bx(s, tmp);
} else {
/* 0b1111_0xxx_xxxx_xxxx : BL/BLX prefix */
uint32_t uoffset = ((int32_t)insn << 21) >> 9;
tcg_gen_movi_i32(cpu_R[14], read_pc(s) + uoffset);
}
break;
/* branches, in decodetree */
goto illegal_op;
}
return;
illegal_op: