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[Qemu-devel] [PATCH 04/11] target/arm: Introduce add_reg_for_lit
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From: |
Richard Henderson |
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Subject: |
[Qemu-devel] [PATCH 04/11] target/arm: Introduce add_reg_for_lit |
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Date: |
Tue, 6 Aug 2019 21:53:28 -0700 |
Provide a common routine for the places that require ALIGN(PC, 4)
as the base address as opposed to plain PC. The two are always
the same for A32, but the difference is meaningful for thumb mode.
Signed-off-by: Richard Henderson <address@hidden>
---
Note: This patch is easier to read with -b, as there are several
large-ish indentation changes as the if statements fold together.
---
target/arm/translate-vfp.inc.c | 38 ++------
target/arm/translate.c | 166 +++++++++++++++------------------
2 files changed, 82 insertions(+), 122 deletions(-)
diff --git a/target/arm/translate-vfp.inc.c b/target/arm/translate-vfp.inc.c
index 092eb5ec53..262d4177e5 100644
--- a/target/arm/translate-vfp.inc.c
+++ b/target/arm/translate-vfp.inc.c
@@ -941,14 +941,8 @@ static bool trans_VLDR_VSTR_sp(DisasContext *s,
arg_VLDR_VSTR_sp *a)
offset = -offset;
}
- if (s->thumb && a->rn == 15) {
- /* This is actually UNPREDICTABLE */
- addr = tcg_temp_new_i32();
- tcg_gen_movi_i32(addr, s->pc & ~2);
- } else {
- addr = load_reg(s, a->rn);
- }
- tcg_gen_addi_i32(addr, addr, offset);
+ /* For thumb, use of PC is UNPREDICTABLE. */
+ addr = add_reg_for_lit(s, a->rn, offset);
tmp = tcg_temp_new_i32();
if (a->l) {
gen_aa32_ld32u(s, tmp, addr, get_mem_index(s));
@@ -983,14 +977,8 @@ static bool trans_VLDR_VSTR_dp(DisasContext *s,
arg_VLDR_VSTR_dp *a)
offset = -offset;
}
- if (s->thumb && a->rn == 15) {
- /* This is actually UNPREDICTABLE */
- addr = tcg_temp_new_i32();
- tcg_gen_movi_i32(addr, s->pc & ~2);
- } else {
- addr = load_reg(s, a->rn);
- }
- tcg_gen_addi_i32(addr, addr, offset);
+ /* For thumb, use of PC is UNPREDICTABLE. */
+ addr = add_reg_for_lit(s, a->rn, offset);
tmp = tcg_temp_new_i64();
if (a->l) {
gen_aa32_ld64(s, tmp, addr, get_mem_index(s));
@@ -1029,13 +1017,8 @@ static bool trans_VLDM_VSTM_sp(DisasContext *s,
arg_VLDM_VSTM_sp *a)
return true;
}
- if (s->thumb && a->rn == 15) {
- /* This is actually UNPREDICTABLE */
- addr = tcg_temp_new_i32();
- tcg_gen_movi_i32(addr, s->pc & ~2);
- } else {
- addr = load_reg(s, a->rn);
- }
+ /* For thumb, use of PC is UNPREDICTABLE. */
+ addr = add_reg_for_lit(s, a->rn, 0);
if (a->p) {
/* pre-decrement */
tcg_gen_addi_i32(addr, addr, -(a->imm << 2));
@@ -1112,13 +1095,8 @@ static bool trans_VLDM_VSTM_dp(DisasContext *s,
arg_VLDM_VSTM_dp *a)
return true;
}
- if (s->thumb && a->rn == 15) {
- /* This is actually UNPREDICTABLE */
- addr = tcg_temp_new_i32();
- tcg_gen_movi_i32(addr, s->pc & ~2);
- } else {
- addr = load_reg(s, a->rn);
- }
+ /* For thumb, use of PC is UNPREDICTABLE. */
+ addr = add_reg_for_lit(s, a->rn, 0);
if (a->p) {
/* pre-decrement */
tcg_gen_addi_i32(addr, addr, -(a->imm << 2));
diff --git a/target/arm/translate.c b/target/arm/translate.c
index 61933865d5..71d94c053b 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -220,6 +220,23 @@ static inline TCGv_i32 load_reg(DisasContext *s, int reg)
return tmp;
}
+/*
+ * Create a new temp, REG + OFS, except PC is ALIGN(PC, 4).
+ * This is used for load/store for which use of PC implies (literal),
+ * or ADD that implies ADR.
+ */
+static TCGv_i32 add_reg_for_lit(DisasContext *s, int reg, int ofs)
+{
+ TCGv_i32 tmp = tcg_temp_new_i32();
+
+ if (reg == 15) {
+ tcg_gen_movi_i32(tmp, (read_pc(s) & ~3) + ofs);
+ } else {
+ tcg_gen_addi_i32(tmp, cpu_R[reg], ofs);
+ }
+ return tmp;
+}
+
/* Set a CPU register. The source must be a temporary and will be
marked as dead. */
static void store_reg(DisasContext *s, int reg, TCGv_i32 var)
@@ -9472,16 +9489,12 @@ static void disas_thumb2_insn(DisasContext *s, uint32_t
insn)
*/
bool wback = extract32(insn, 21, 1);
- if (rn == 15) {
- if (insn & (1 << 21)) {
- /* UNPREDICTABLE */
- goto illegal_op;
- }
- addr = tcg_temp_new_i32();
- tcg_gen_movi_i32(addr, s->pc & ~3);
- } else {
- addr = load_reg(s, rn);
+ if (rn == 15 && (insn & (1 << 21))) {
+ /* UNPREDICTABLE */
+ goto illegal_op;
}
+
+ addr = add_reg_for_lit(s, rn, 0);
offset = (insn & 0xff) * 4;
if ((insn & (1 << 23)) == 0) {
offset = -offset;
@@ -10682,27 +10695,15 @@ static void disas_thumb2_insn(DisasContext *s,
uint32_t insn)
store_reg(s, rd, tmp);
} else {
/* Add/sub 12-bit immediate. */
- if (rn == 15) {
- offset = s->pc & ~(uint32_t)3;
- if (insn & (1 << 23))
- offset -= imm;
- else
- offset += imm;
- tmp = tcg_temp_new_i32();
- tcg_gen_movi_i32(tmp, offset);
- store_reg(s, rd, tmp);
+ if (insn & (1 << 23)) {
+ imm = -imm;
+ }
+ tmp = add_reg_for_lit(s, rn, imm);
+ if (rn == 13 && rd == 13) {
+ /* ADD SP, SP, imm or SUB SP, SP, imm */
+ store_sp_checked(s, tmp);
} else {
- tmp = load_reg(s, rn);
- if (insn & (1 << 23))
- tcg_gen_subi_i32(tmp, tmp, imm);
- else
- tcg_gen_addi_i32(tmp, tmp, imm);
- if (rn == 13 && rd == 13) {
- /* ADD SP, SP, imm or SUB SP, SP, imm */
- store_sp_checked(s, tmp);
- } else {
- store_reg(s, rd, tmp);
- }
+ store_reg(s, rd, tmp);
}
}
}
@@ -10816,61 +10817,53 @@ static void disas_thumb2_insn(DisasContext *s,
uint32_t insn)
}
}
memidx = get_mem_index(s);
- if (rn == 15) {
- addr = tcg_temp_new_i32();
- /* PC relative. */
- /* s->pc has already been incremented by 4. */
- imm = s->pc & 0xfffffffc;
- if (insn & (1 << 23))
- imm += insn & 0xfff;
- else
- imm -= insn & 0xfff;
- tcg_gen_movi_i32(addr, imm);
+ imm = insn & 0xfff;
+ if (insn & (1 << 23)) {
+ /* PC relative or Positive offset. */
+ addr = add_reg_for_lit(s, rn, imm);
+ } else if (rn == 15) {
+ /* PC relative with negative offset. */
+ addr = add_reg_for_lit(s, rn, -imm);
} else {
addr = load_reg(s, rn);
- if (insn & (1 << 23)) {
- /* Positive offset. */
- imm = insn & 0xfff;
- tcg_gen_addi_i32(addr, addr, imm);
- } else {
- imm = insn & 0xff;
- switch ((insn >> 8) & 0xf) {
- case 0x0: /* Shifted Register. */
- shift = (insn >> 4) & 0xf;
- if (shift > 3) {
- tcg_temp_free_i32(addr);
- goto illegal_op;
- }
- tmp = load_reg(s, rm);
- if (shift)
- tcg_gen_shli_i32(tmp, tmp, shift);
- tcg_gen_add_i32(addr, addr, tmp);
- tcg_temp_free_i32(tmp);
- break;
- case 0xc: /* Negative offset. */
- tcg_gen_addi_i32(addr, addr, -imm);
- break;
- case 0xe: /* User privilege. */
- tcg_gen_addi_i32(addr, addr, imm);
- memidx = get_a32_user_mem_index(s);
- break;
- case 0x9: /* Post-decrement. */
- imm = -imm;
- /* Fall through. */
- case 0xb: /* Post-increment. */
- postinc = 1;
- writeback = 1;
- break;
- case 0xd: /* Pre-decrement. */
- imm = -imm;
- /* Fall through. */
- case 0xf: /* Pre-increment. */
- writeback = 1;
- break;
- default:
+ imm = insn & 0xff;
+ switch ((insn >> 8) & 0xf) {
+ case 0x0: /* Shifted Register. */
+ shift = (insn >> 4) & 0xf;
+ if (shift > 3) {
tcg_temp_free_i32(addr);
goto illegal_op;
}
+ tmp = load_reg(s, rm);
+ if (shift) {
+ tcg_gen_shli_i32(tmp, tmp, shift);
+ }
+ tcg_gen_add_i32(addr, addr, tmp);
+ tcg_temp_free_i32(tmp);
+ break;
+ case 0xc: /* Negative offset. */
+ tcg_gen_addi_i32(addr, addr, -imm);
+ break;
+ case 0xe: /* User privilege. */
+ tcg_gen_addi_i32(addr, addr, imm);
+ memidx = get_a32_user_mem_index(s);
+ break;
+ case 0x9: /* Post-decrement. */
+ imm = -imm;
+ /* Fall through. */
+ case 0xb: /* Post-increment. */
+ postinc = 1;
+ writeback = 1;
+ break;
+ case 0xd: /* Pre-decrement. */
+ imm = -imm;
+ /* Fall through. */
+ case 0xf: /* Pre-increment. */
+ writeback = 1;
+ break;
+ default:
+ tcg_temp_free_i32(addr);
+ goto illegal_op;
}
}
@@ -11066,10 +11059,7 @@ static void disas_thumb_insn(DisasContext *s, uint32_t
insn)
if (insn & (1 << 11)) {
rd = (insn >> 8) & 7;
/* load pc-relative. Bit 1 of PC is ignored. */
- val = read_pc(s) + ((insn & 0xff) * 4);
- val &= ~(uint32_t)2;
- addr = tcg_temp_new_i32();
- tcg_gen_movi_i32(addr, val);
+ addr = add_reg_for_lit(s, 15, (insn & 0xff) * 4);
tmp = tcg_temp_new_i32();
gen_aa32_ld32u_iss(s, tmp, addr, get_mem_index(s),
rd | ISSIs16Bit);
@@ -11447,16 +11437,8 @@ static void disas_thumb_insn(DisasContext *s, uint32_t
insn)
* - Add PC/SP (immediate)
*/
rd = (insn >> 8) & 7;
- if (insn & (1 << 11)) {
- /* SP */
- tmp = load_reg(s, 13);
- } else {
- /* PC. bit 1 is ignored. */
- tmp = tcg_temp_new_i32();
- tcg_gen_movi_i32(tmp, read_pc(s) & ~(uint32_t)2);
- }
val = (insn & 0xff) * 4;
- tcg_gen_addi_i32(tmp, tmp, val);
+ tmp = add_reg_for_lit(s, insn & (1 << 11) ? 13 : 15, val);
store_reg(s, rd, tmp);
break;
--
2.17.1
[Qemu-devel] [PATCH 05/11] target/arm: Remove redundant s->pc & ~1, Richard Henderson, 2019/08/07
[Qemu-devel] [PATCH 04/11] target/arm: Introduce add_reg_for_lit,
Richard Henderson <=
[Qemu-devel] [PATCH 07/11] target/arm: Replace offset with pc in gen_exception_insn, Richard Henderson, 2019/08/07
[Qemu-devel] [PATCH 08/11] target/arm: Replace offset with pc in gen_exception_internal_insn, Richard Henderson, 2019/08/07
[Qemu-devel] [PATCH 09/11] target/arm: Remove offset argument to gen_exception_bkpt_insn, Richard Henderson, 2019/08/07
[Qemu-devel] [PATCH 10/11] target/arm: Use unallocated_encoding for aarch32, Richard Henderson, 2019/08/07
[Qemu-devel] [PATCH 11/11] target/arm: Remove helper_double_saturate, Richard Henderson, 2019/08/07
[Qemu-devel] [PATCH 06/11] target/arm: Replace s->pc with s->base.pc_next, Richard Henderson, 2019/08/07
Re: [Qemu-devel] [PATCH 00/11] target/arm: decodetree prep patches, Peter Maydell, 2019/08/07