target/arm: Convert B, BL, BLX (immediate)

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-33-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2019-09-04 12:30:22 -07:00 committed by Peter Maydell
parent b0e382b8cf
commit 360144f3b9
4 changed files with 123 additions and 107 deletions

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@ -21,3 +21,11 @@
# All insns that have 0xf in insn[31:28] are decoded here.
# All of those that have a COND field in insn[31:28] are in a32.decode
#
&i !extern imm
# Branch with Link and Exchange
%imm24h 0:s24 24:1 !function=times_2
BLX_i 1111 101 . ........................ &i imm=%imm24h

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@ -520,3 +520,11 @@ SMMLSR .... 0111 0101 .... .... .... 1111 .... @rdamn
STM ---- 100 b:1 i:1 u:1 w:1 0 rn:4 list:16 &ldst_block
LDM_a32 ---- 100 b:1 i:1 u:1 w:1 1 rn:4 list:16 &ldst_block
# Branch, branch with link
%imm26 0:s24 !function=times_4
@branch ---- .... ........................ &i imm=%imm26
B .... 1010 ........................ @branch
BL .... 1011 ........................ @branch

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@ -284,47 +284,55 @@ CLZ 1111 1010 1011 ---- 1111 .... 1000 .... @rdm
%msr_sysm 4:1 8:4
%mrs_sysm 4:1 16:4
%imm16_16_0 16:4 0:12
%imm21 26:s1 11:1 13:1 16:6 0:11 !function=times_2
&ci cond imm
{
# Group insn[25:23] = 111, which is cond=111x for the branch below,
# or unconditional, which would be illegal for the branch.
{
YIELD 1111 0011 1010 1111 1000 0000 0000 0001
WFE 1111 0011 1010 1111 1000 0000 0000 0010
WFI 1111 0011 1010 1111 1000 0000 0000 0011
# Hints
{
YIELD 1111 0011 1010 1111 1000 0000 0000 0001
WFE 1111 0011 1010 1111 1000 0000 0000 0010
WFI 1111 0011 1010 1111 1000 0000 0000 0011
# TODO: Implement SEV, SEVL; may help SMP performance.
# SEV 1111 0011 1010 1111 1000 0000 0000 0100
# SEVL 1111 0011 1010 1111 1000 0000 0000 0101
# TODO: Implement SEV, SEVL; may help SMP performance.
# SEV 1111 0011 1010 1111 1000 0000 0000 0100
# SEVL 1111 0011 1010 1111 1000 0000 0000 0101
# The canonical nop ends in 0000 0000, but the whole rest
# of the space is "reserved hint, behaves as nop".
NOP 1111 0011 1010 1111 1000 0000 ---- ----
}
# Note that the v7m insn overlaps both the normal and banked insn.
{
MRS_bank 1111 0011 111 r:1 .... 1000 rd:4 001. 0000 \
# The canonical nop ends in 0000 0000, but the whole rest
# of the space is "reserved hint, behaves as nop".
NOP 1111 0011 1010 1111 1000 0000 ---- ----
}
# Note that the v7m insn overlaps both the normal and banked insn.
{
MRS_bank 1111 0011 111 r:1 .... 1000 rd:4 001. 0000 \
&mrs_bank sysm=%mrs_sysm
MRS_reg 1111 0011 111 r:1 1111 1000 rd:4 0000 0000 &mrs_reg
MRS_v7m 1111 0011 111 0 1111 1000 rd:4 sysm:8
}
{
MSR_bank 1111 0011 100 r:1 rn:4 1000 .... 001. 0000 \
MRS_reg 1111 0011 111 r:1 1111 1000 rd:4 0000 0000 &mrs_reg
MRS_v7m 1111 0011 111 0 1111 1000 rd:4 sysm:8
}
{
MSR_bank 1111 0011 100 r:1 rn:4 1000 .... 001. 0000 \
&msr_bank sysm=%msr_sysm
MSR_reg 1111 0011 100 r:1 rn:4 1000 mask:4 0000 0000 &msr_reg
MSR_v7m 1111 0011 100 0 rn:4 1000 mask:2 00 sysm:8
}
BXJ 1111 0011 1100 rm:4 1000 1111 0000 0000 &r
{
# At v6T2, this is the T5 encoding of SUBS PC, LR, #IMM, and works as for
# every other encoding of SUBS. With v7VE, IMM=0 is redefined as ERET.
# The distinction between the two only matters for Hyp mode.
ERET 1111 0011 1101 1110 1000 1111 0000 0000
SUB_rri 1111 0011 1101 1110 1000 1111 imm:8 \
MSR_reg 1111 0011 100 r:1 rn:4 1000 mask:4 0000 0000 &msr_reg
MSR_v7m 1111 0011 100 0 rn:4 1000 mask:2 00 sysm:8
}
BXJ 1111 0011 1100 rm:4 1000 1111 0000 0000 &r
{
# At v6T2, this is the T5 encoding of SUBS PC, LR, #IMM, and works as for
# every other encoding of SUBS. With v7VE, IMM=0 is redefined as ERET.
# The distinction between the two only matters for Hyp mode.
ERET 1111 0011 1101 1110 1000 1111 0000 0000
SUB_rri 1111 0011 1101 1110 1000 1111 imm:8 \
&s_rri_rot rot=0 s=1 rd=15 rn=14
}
SMC 1111 0111 1111 imm:4 1000 0000 0000 0000 &i
HVC 1111 0111 1110 .... 1000 .... .... .... \
}
SMC 1111 0111 1111 imm:4 1000 0000 0000 0000 &i
HVC 1111 0111 1110 .... 1000 .... .... .... \
&i imm=%imm16_16_0
UDF 1111 0111 1111 ---- 1010 ---- ---- ----
UDF 1111 0111 1111 ---- 1010 ---- ---- ----
}
B_cond_thumb 1111 0. cond:4 ...... 10.0 ............ &ci imm=%imm21
}
# Load/store (register, immediate, literal)
@ -573,3 +581,12 @@ STM_t32 1110 1000 10.0 .... ................ @ldstm i=1 b=0
STM_t32 1110 1001 00.0 .... ................ @ldstm i=0 b=1
LDM_t32 1110 1000 10.1 .... ................ @ldstm i=1 b=0
LDM_t32 1110 1001 00.1 .... ................ @ldstm i=0 b=1
# Branches
%imm24 26:s1 13:1 11:1 16:10 0:11 !function=t32_branch24
@branch24 ................................ &i imm=%imm24
B 1111 0. .......... 10.1 ............ @branch24
BL 1111 0. .......... 11.1 ............ @branch24
BLX_i 1111 0. .......... 11.0 ............ @branch24

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@ -7545,6 +7545,14 @@ static int t32_expandimm_imm(DisasContext *s, int x)
return imm;
}
static int t32_branch24(DisasContext *s, int x)
{
/* Convert J1:J2 at x[22:21] to I2:I1, which involves I=J^~S. */
x ^= !(x < 0) * (3 << 21);
/* Append the final zero. */
return x << 1;
}
/*
* Include the generated decoders.
*/
@ -10030,13 +10038,56 @@ static bool trans_LDM_t32(DisasContext *s, arg_ldst_block *a)
return do_ldm(s, a, 2);
}
/*
* Branch, branch with link
*/
static bool trans_B(DisasContext *s, arg_i *a)
{
gen_jmp(s, read_pc(s) + a->imm);
return true;
}
static bool trans_B_cond_thumb(DisasContext *s, arg_ci *a)
{
/* This has cond from encoding, required to be outside IT block. */
if (a->cond >= 0xe) {
return false;
}
if (s->condexec_mask) {
unallocated_encoding(s);
return true;
}
arm_skip_unless(s, a->cond);
gen_jmp(s, read_pc(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);
return true;
}
static bool trans_BLX_i(DisasContext *s, arg_BLX_i *a)
{
/* For A32, ARCH(5) is checked near the start of the uncond block. */
if (s->thumb && (a->imm & 2)) {
return false;
}
tcg_gen_movi_i32(cpu_R[14], s->base.pc_next | s->thumb);
gen_bx_im(s, (read_pc(s) & ~3) + a->imm + !s->thumb);
return true;
}
/*
* Legacy decoder.
*/
static void disas_arm_insn(DisasContext *s, unsigned int insn)
{
unsigned int cond, val, op1, i, rn;
unsigned int cond, op1, i, rn;
TCGv_i32 tmp;
TCGv_i32 tmp2;
TCGv_i32 addr;
@ -10204,21 +10255,6 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn)
}
gen_rfe(s, tmp, tmp2);
return;
} else if ((insn & 0x0e000000) == 0x0a000000) {
/* branch link and change to thumb (blx <offset>) */
int32_t offset;
tmp = tcg_temp_new_i32();
tcg_gen_movi_i32(tmp, s->base.pc_next);
store_reg(s, 14, tmp);
/* Sign-extend the 24-bit offset */
offset = (((int32_t)insn) << 8) >> 8;
val = read_pc(s);
/* offset * 4 + bit24 * 2 + (thumb bit) */
val += (offset << 2) | ((insn >> 23) & 2) | 1;
/* protected by ARCH(5); above, near the start of uncond block */
gen_bx_im(s, val);
return;
} else if ((insn & 0x0e000f00) == 0x0c000100) {
if (arm_dc_feature(s, ARM_FEATURE_IWMMXT)) {
/* iWMMXt register transfer. */
@ -10310,23 +10346,10 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn)
case 0x7:
case 0x08:
case 0x09:
/* All done in decodetree. Reach here for illegal ops. */
goto illegal_op;
case 0xa:
case 0xb:
{
int32_t offset;
/* branch (and link) */
if (insn & (1 << 24)) {
tmp = tcg_temp_new_i32();
tcg_gen_movi_i32(tmp, s->base.pc_next);
store_reg(s, 14, tmp);
}
offset = sextract32(insn << 2, 0, 26);
gen_jmp(s, read_pc(s) + offset);
}
break;
/* All done in decodetree. Reach here for illegal ops. */
goto illegal_op;
case 0xc:
case 0xd:
case 0xe:
@ -10693,32 +10716,8 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
if (insn & (1 << 15)) {
/* Branches, misc control. */
if (insn & 0x5000) {
/* Unconditional branch. */
/* signextend(hw1[10:0]) -> offset[:12]. */
offset = ((int32_t)insn << 5) >> 9 & ~(int32_t)0xfff;
/* hw1[10:0] -> offset[11:1]. */
offset |= (insn & 0x7ff) << 1;
/* (~hw2[13, 11] ^ offset[24]) -> offset[23,22]
offset[24:22] already have the same value because of the
sign extension above. */
offset ^= ((~insn) & (1 << 13)) << 10;
offset ^= ((~insn) & (1 << 11)) << 11;
if (insn & (1 << 14)) {
/* Branch and link. */
tcg_gen_movi_i32(cpu_R[14], s->base.pc_next | 1);
}
offset += read_pc(s);
if (insn & (1 << 12)) {
/* b/bl */
gen_jmp(s, offset);
} else {
/* blx */
offset &= ~(uint32_t)2;
/* thumb2 bx, no need to check */
gen_bx_im(s, offset);
}
/* Unconditional branch, in decodetree */
goto illegal_op;
} else if (((insn >> 23) & 7) == 7) {
/* Misc control */
if (insn & (1 << 13))
@ -10804,24 +10803,8 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t insn)
}
}
} else {
/* Conditional branch. */
op = (insn >> 22) & 0xf;
/* Generate a conditional jump to next instruction. */
arm_skip_unless(s, op);
/* offset[11:1] = insn[10:0] */
offset = (insn & 0x7ff) << 1;
/* offset[17:12] = insn[21:16]. */
offset |= (insn & 0x003f0000) >> 4;
/* offset[31:20] = insn[26]. */
offset |= ((int32_t)((insn << 5) & 0x80000000)) >> 11;
/* offset[18] = insn[13]. */
offset |= (insn & (1 << 13)) << 5;
/* offset[19] = insn[11]. */
offset |= (insn & (1 << 11)) << 8;
/* jump to the offset */
gen_jmp(s, read_pc(s) + offset);
/* Conditional branch, in decodetree */
goto illegal_op;
}
} else {
/*