From: Richard Henderson <rth@twiddle.net>
To: qemu-devel@nongnu.org
Cc: pbonzini@redhat.com
Subject: [Qemu-devel] [PATCH 08/16] target-i386: Split up gen_lea_modrm
Date: Wed, 10 Feb 2016 04:43:44 +1100 [thread overview]
Message-ID: <1455039832-9133-9-git-send-email-rth@twiddle.net> (raw)
In-Reply-To: <1455039832-9133-1-git-send-email-rth@twiddle.net>
This is immediately usable by lea and multi-byte nop,
and will be required to implement parts of the mpx spec.
Signed-off-by: Richard Henderson <rth@twiddle.net>
---
target-i386/translate.c | 199 +++++++++++++++++++++---------------------------
1 file changed, 85 insertions(+), 114 deletions(-)
diff --git a/target-i386/translate.c b/target-i386/translate.c
index 3971541..5e7403f 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -1807,37 +1807,52 @@ static void gen_shifti(DisasContext *s1, int op, TCGMemOp ot, int d, int c)
}
}
-static void gen_lea_modrm(CPUX86State *env, DisasContext *s, int modrm)
+/* Decompose an address. */
+
+typedef struct AddressParts {
+ int def_seg;
+ int base;
+ int index;
+ int scale;
+ target_long disp;
+} AddressParts;
+
+static AddressParts gen_lea_modrm_0(CPUX86State *env, DisasContext *s,
+ int modrm)
{
+ int def_seg, base, index, scale, mod, rm;
target_long disp;
- int havesib, base, index, scale;
- int mod, rm, code, def_seg, ovr_seg;
- TCGv sum;
+ bool havesib;
def_seg = R_DS;
- ovr_seg = s->override;
+ index = -1;
+ scale = 0;
+ disp = 0;
+
mod = (modrm >> 6) & 3;
rm = modrm & 7;
+ base = rm | REX_B(s);
+
+ if (mod == 3) {
+ /* Normally filtered out earlier, but including this path
+ simplifies multi-byte nop, as well as bndcl, bndcu, bndcn. */
+ goto done;
+ }
switch (s->aflag) {
case MO_64:
case MO_32:
havesib = 0;
- base = rm;
- index = -1;
- scale = 0;
-
- if (base == 4) {
- havesib = 1;
- code = cpu_ldub_code(env, s->pc++);
+ if (rm == 4) {
+ int code = cpu_ldub_code(env, s->pc++);
scale = (code >> 6) & 3;
index = ((code >> 3) & 7) | REX_X(s);
if (index == 4) {
index = -1; /* no index */
}
- base = (code & 7);
+ base = (code & 7) | REX_B(s);
+ havesib = 1;
}
- base |= REX_B(s);
switch (mod) {
case 0:
@@ -1846,10 +1861,9 @@ static void gen_lea_modrm(CPUX86State *env, DisasContext *s, int modrm)
disp = (int32_t)cpu_ldl_code(env, s->pc);
s->pc += 4;
if (CODE64(s) && !havesib) {
+ base = -2;
disp += s->pc + s->rip_offset;
}
- } else {
- disp = 0;
}
break;
case 1:
@@ -1866,46 +1880,19 @@ static void gen_lea_modrm(CPUX86State *env, DisasContext *s, int modrm)
if (base == R_ESP && s->popl_esp_hack) {
disp += s->popl_esp_hack;
}
-
- /* Compute the address, with a minimum number of TCG ops. */
- TCGV_UNUSED(sum);
- if (index >= 0) {
- if (scale == 0) {
- sum = cpu_regs[index];
- } else {
- tcg_gen_shli_tl(cpu_A0, cpu_regs[index], scale);
- sum = cpu_A0;
- }
- if (base >= 0) {
- tcg_gen_add_tl(cpu_A0, sum, cpu_regs[base]);
- sum = cpu_A0;
- }
- } else if (base >= 0) {
- sum = cpu_regs[base];
- }
- if (TCGV_IS_UNUSED(sum)) {
- tcg_gen_movi_tl(cpu_A0, disp);
- sum = cpu_A0;
- } else if (disp != 0) {
- tcg_gen_addi_tl(cpu_A0, sum, disp);
- sum = cpu_A0;
- }
-
if (base == R_EBP || base == R_ESP) {
def_seg = R_SS;
}
break;
case MO_16:
- sum = cpu_A0;
if (mod == 0) {
if (rm == 6) {
+ base = -1;
disp = cpu_lduw_code(env, s->pc);
s->pc += 2;
- tcg_gen_movi_tl(cpu_A0, disp);
break;
}
- disp = 0;
} else if (mod == 1) {
disp = (int8_t)cpu_ldub_code(env, s->pc++);
} else {
@@ -1915,102 +1902,89 @@ static void gen_lea_modrm(CPUX86State *env, DisasContext *s, int modrm)
switch (rm) {
case 0:
- tcg_gen_add_tl(cpu_A0, cpu_regs[R_EBX], cpu_regs[R_ESI]);
+ base = R_EBX;
+ index = R_ESI;
break;
case 1:
- tcg_gen_add_tl(cpu_A0, cpu_regs[R_EBX], cpu_regs[R_EDI]);
+ base = R_EBX;
+ index = R_EDI;
break;
case 2:
- tcg_gen_add_tl(cpu_A0, cpu_regs[R_EBP], cpu_regs[R_ESI]);
+ base = R_EBP;
+ index = R_ESI;
def_seg = R_SS;
break;
case 3:
- tcg_gen_add_tl(cpu_A0, cpu_regs[R_EBP], cpu_regs[R_EDI]);
+ base = R_EBP;
+ index = R_EDI;
def_seg = R_SS;
break;
case 4:
- sum = cpu_regs[R_ESI];
+ base = R_ESI;
break;
case 5:
- sum = cpu_regs[R_EDI];
+ base = R_EDI;
break;
case 6:
- sum = cpu_regs[R_EBP];
+ base = R_EBP;
def_seg = R_SS;
break;
default:
case 7:
- sum = cpu_regs[R_EBX];
+ base = R_EBX;
break;
}
- if (disp != 0) {
- tcg_gen_addi_tl(cpu_A0, sum, disp);
- sum = cpu_A0;
- }
break;
default:
tcg_abort();
}
- gen_lea_v_seg(s, s->aflag, sum, def_seg, ovr_seg);
+ done:
+ return (AddressParts){ def_seg, base, index, scale, disp };
}
-static void gen_nop_modrm(CPUX86State *env, DisasContext *s, int modrm)
+/* Compute the address, with a minimum number of TCG ops. */
+static TCGv gen_lea_modrm_1(AddressParts a)
{
- int mod, rm, base, code;
-
- mod = (modrm >> 6) & 3;
- if (mod == 3)
- return;
- rm = modrm & 7;
-
- switch (s->aflag) {
- case MO_64:
- case MO_32:
- base = rm;
+ TCGv ea;
- if (base == 4) {
- code = cpu_ldub_code(env, s->pc++);
- base = (code & 7);
+ TCGV_UNUSED(ea);
+ if (a.index >= 0) {
+ if (a.scale == 0) {
+ ea = cpu_regs[a.index];
+ } else {
+ tcg_gen_shli_tl(cpu_A0, cpu_regs[a.index], a.scale);
+ ea = cpu_A0;
}
-
- switch (mod) {
- case 0:
- if (base == 5) {
- s->pc += 4;
- }
- break;
- case 1:
- s->pc++;
- break;
- default:
- case 2:
- s->pc += 4;
- break;
+ if (a.base >= 0) {
+ tcg_gen_add_tl(cpu_A0, ea, cpu_regs[a.base]);
+ ea = cpu_A0;
}
- break;
+ } else if (a.base >= 0) {
+ ea = cpu_regs[a.base];
+ }
+ if (TCGV_IS_UNUSED(ea)) {
+ tcg_gen_movi_tl(cpu_A0, a.disp);
+ ea = cpu_A0;
+ } else if (a.disp != 0) {
+ tcg_gen_addi_tl(cpu_A0, ea, a.disp);
+ ea = cpu_A0;
+ }
- case MO_16:
- switch (mod) {
- case 0:
- if (rm == 6) {
- s->pc += 2;
- }
- break;
- case 1:
- s->pc++;
- break;
- default:
- case 2:
- s->pc += 2;
- break;
- }
- break;
+ return ea;
+}
- default:
- tcg_abort();
- }
+static void gen_lea_modrm(CPUX86State *env, DisasContext *s, int modrm)
+{
+ AddressParts a = gen_lea_modrm_0(env, s, modrm);
+ TCGv ea = gen_lea_modrm_1(a);
+ gen_lea_v_seg(s, s->aflag, ea, a.def_seg, s->override);
+}
+
+static void gen_nop_modrm(CPUX86State *env, DisasContext *s, int modrm)
+{
+ (void)gen_lea_modrm_0(env, s, modrm);
}
/* used for LEA and MOV AX, mem */
@@ -5301,19 +5275,16 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
break;
case 0x8d: /* lea */
- ot = dflag;
modrm = cpu_ldub_code(env, s->pc++);
mod = (modrm >> 6) & 3;
if (mod == 3)
goto illegal_op;
reg = ((modrm >> 3) & 7) | rex_r;
- /* we must ensure that no segment is added */
- s->override = -1;
- val = s->addseg;
- s->addseg = 0;
- gen_lea_modrm(env, s, modrm);
- s->addseg = val;
- gen_op_mov_reg_v(ot, reg, cpu_A0);
+ {
+ AddressParts a = gen_lea_modrm_0(env, s, modrm);
+ TCGv ea = gen_lea_modrm_1(a);
+ gen_op_mov_reg_v(dflag, reg, ea);
+ }
break;
case 0xa0: /* mov EAX, Ov */
--
2.5.0
next prev parent reply other threads:[~2016-02-09 17:44 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-09 17:43 [Qemu-devel] [PATCH 00/16] TCG support for XSAVE, MPX, FSGSBASE Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 01/16] target-i386: Split fxsave/fxrstor implementation Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 02/16] target-i386: Rearrange processing of 0F 01 Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 03/16] target-i386: Rearrange processing of 0F AE Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 04/16] target-i386: Add XSAVE extension Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 05/16] target-i386: Implement XSAVEOPT Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 06/16] target-i386: Enable control registers for MPX Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 07/16] target-i386: Perform set/reset_inhibit_irq inline Richard Henderson
2016-02-09 17:43 ` Richard Henderson [this message]
2016-02-09 17:43 ` [Qemu-devel] [PATCH 09/16] target-i386: Implement BNDMK Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 10/16] target-i386: Implement BNDMOV Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 11/16] target-i386: Implement BNDCL, BNDCU, BNDCN Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 12/16] target-i386: Update BNDSTATUS for exceptions raised by BOUND Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 13/16] target-i386: Implement BNDLDX, BNDSTX Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 14/16] target-i386: Clear bndregs during legacy near jumps Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 15/16] target-i386: Enable CR4/XCR0 features for user-mode Richard Henderson
2016-02-09 17:43 ` [Qemu-devel] [PATCH 16/16] target-i386: Implement FSGSBASE Richard Henderson
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