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tcg/i386: Handle ctz and clz opcodes
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Signed-off-by: Richard Henderson <rth@twiddle.net>
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@rth7680
rth7680 committed Jan 10, 2017
1 parent 6a5aed4 commit bbf25f9
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Showing 2 changed files with 120 additions and 13 deletions.
8 changes: 4 additions & 4 deletions tcg/i386/tcg-target.h
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Expand Up @@ -93,8 +93,8 @@ extern bool have_bmi1;
#define TCG_TARGET_HAS_eqv_i32 0
#define TCG_TARGET_HAS_nand_i32 0
#define TCG_TARGET_HAS_nor_i32 0
#define TCG_TARGET_HAS_clz_i32 0
#define TCG_TARGET_HAS_ctz_i32 0
#define TCG_TARGET_HAS_clz_i32 1
#define TCG_TARGET_HAS_ctz_i32 1
#define TCG_TARGET_HAS_deposit_i32 1
#define TCG_TARGET_HAS_extract_i32 1
#define TCG_TARGET_HAS_sextract_i32 1
Expand Down Expand Up @@ -127,8 +127,8 @@ extern bool have_bmi1;
#define TCG_TARGET_HAS_eqv_i64 0
#define TCG_TARGET_HAS_nand_i64 0
#define TCG_TARGET_HAS_nor_i64 0
#define TCG_TARGET_HAS_clz_i64 0
#define TCG_TARGET_HAS_ctz_i64 0
#define TCG_TARGET_HAS_clz_i64 1
#define TCG_TARGET_HAS_ctz_i64 1
#define TCG_TARGET_HAS_deposit_i64 1
#define TCG_TARGET_HAS_extract_i64 1
#define TCG_TARGET_HAS_sextract_i64 0
Expand Down
125 changes: 116 additions & 9 deletions tcg/i386/tcg-target.inc.c
View file
Expand Up @@ -92,6 +92,7 @@ static const int tcg_target_call_oarg_regs[] = {
#define TCG_CT_CONST_S32 0x100
#define TCG_CT_CONST_U32 0x200
#define TCG_CT_CONST_I32 0x400
#define TCG_CT_CONST_WSZ 0x800

/* Registers used with L constraint, which are the first argument
registers on x86_64, and two random call clobbered registers on
Expand Down Expand Up @@ -138,6 +139,11 @@ static bool have_bmi2;
#else
# define have_bmi2 0
#endif
#if defined(CONFIG_CPUID_H) && defined(bit_LZCNT)
static bool have_lzcnt;
#else
# define have_lzcnt 0
#endif

static tcg_insn_unit *tb_ret_addr;

Expand Down Expand Up @@ -214,6 +220,10 @@ static const char *target_parse_constraint(TCGArgConstraint *ct,
tcg_regset_set32(ct->u.regs, 0, 0xff);
}
break;
case 'W':
/* With TZCNT/LZCNT, we can have operand-size as an input. */
ct->ct |= TCG_CT_CONST_WSZ;
break;

/* qemu_ld/st address constraint */
case 'L':
Expand Down Expand Up @@ -260,6 +270,9 @@ static inline int tcg_target_const_match(tcg_target_long val, TCGType type,
if ((ct & TCG_CT_CONST_I32) && ~val == (int32_t)~val) {
return 1;
}
if ((ct & TCG_CT_CONST_WSZ) && val == (type == TCG_TYPE_I32 ? 32 : 64)) {
return 1;
}
return 0;
}

Expand Down Expand Up @@ -293,6 +306,8 @@ static inline int tcg_target_const_match(tcg_target_long val, TCGType type,
#define OPC_ARITH_GvEv (0x03) /* ... plus (ARITH_FOO << 3) */
#define OPC_ANDN (0xf2 | P_EXT38)
#define OPC_ADD_GvEv (OPC_ARITH_GvEv | (ARITH_ADD << 3))
#define OPC_BSF (0xbc | P_EXT)
#define OPC_BSR (0xbd | P_EXT)
#define OPC_BSWAP (0xc8 | P_EXT)
#define OPC_CALL_Jz (0xe8)
#define OPC_CMOVCC (0x40 | P_EXT) /* ... plus condition code */
Expand All @@ -307,6 +322,7 @@ static inline int tcg_target_const_match(tcg_target_long val, TCGType type,
#define OPC_JMP_long (0xe9)
#define OPC_JMP_short (0xeb)
#define OPC_LEA (0x8d)
#define OPC_LZCNT (0xbd | P_EXT | P_SIMDF3)
#define OPC_MOVB_EvGv (0x88) /* stores, more or less */
#define OPC_MOVL_EvGv (0x89) /* stores, more or less */
#define OPC_MOVL_GvEv (0x8b) /* loads, more or less */
Expand All @@ -333,6 +349,7 @@ static inline int tcg_target_const_match(tcg_target_long val, TCGType type,
#define OPC_SHLX (0xf7 | P_EXT38 | P_DATA16)
#define OPC_SHRX (0xf7 | P_EXT38 | P_SIMDF2)
#define OPC_TESTL (0x85)
#define OPC_TZCNT (0xbc | P_EXT | P_SIMDF3)
#define OPC_XCHG_ax_r32 (0x90)

#define OPC_GRP3_Ev (0xf7)
Expand Down Expand Up @@ -418,6 +435,11 @@ static void tcg_out_opc(TCGContext *s, int opc, int r, int rm, int x)
if (opc & P_ADDR32) {
tcg_out8(s, 0x67);
}
if (opc & P_SIMDF3) {
tcg_out8(s, 0xf3);
} else if (opc & P_SIMDF2) {
tcg_out8(s, 0xf2);
}

rex = 0;
rex |= (opc & P_REXW) ? 0x8 : 0x0; /* REX.W */
Expand Down Expand Up @@ -452,6 +474,11 @@ static void tcg_out_opc(TCGContext *s, int opc)
if (opc & P_DATA16) {
tcg_out8(s, 0x66);
}
if (opc & P_SIMDF3) {
tcg_out8(s, 0xf3);
} else if (opc & P_SIMDF2) {
tcg_out8(s, 0xf2);
}
if (opc & (P_EXT | P_EXT38)) {
tcg_out8(s, 0x0f);
if (opc & P_EXT38) {
Expand Down Expand Up @@ -1080,13 +1107,11 @@ static void tcg_out_setcond2(TCGContext *s, const TCGArg *args,
}
#endif

static void tcg_out_movcond32(TCGContext *s, TCGCond cond, TCGArg dest,
TCGArg c1, TCGArg c2, int const_c2,
TCGArg v1)
static void tcg_out_cmov(TCGContext *s, TCGCond cond, int rexw,
TCGReg dest, TCGReg v1)
{
tcg_out_cmp(s, c1, c2, const_c2, 0);
if (have_cmov) {
tcg_out_modrm(s, OPC_CMOVCC | tcg_cond_to_jcc[cond], dest, v1);
tcg_out_modrm(s, OPC_CMOVCC | tcg_cond_to_jcc[cond] | rexw, dest, v1);
} else {
TCGLabel *over = gen_new_label();
tcg_out_jxx(s, tcg_cond_to_jcc[tcg_invert_cond(cond)], over, 1);
Expand All @@ -1095,16 +1120,64 @@ static void tcg_out_movcond32(TCGContext *s, TCGCond cond, TCGArg dest,
}
}

static void tcg_out_movcond32(TCGContext *s, TCGCond cond, TCGReg dest,
TCGReg c1, TCGArg c2, int const_c2,
TCGReg v1)
{
tcg_out_cmp(s, c1, c2, const_c2, 0);
tcg_out_cmov(s, cond, 0, dest, v1);
}

#if TCG_TARGET_REG_BITS == 64
static void tcg_out_movcond64(TCGContext *s, TCGCond cond, TCGArg dest,
TCGArg c1, TCGArg c2, int const_c2,
TCGArg v1)
static void tcg_out_movcond64(TCGContext *s, TCGCond cond, TCGReg dest,
TCGReg c1, TCGArg c2, int const_c2,
TCGReg v1)
{
tcg_out_cmp(s, c1, c2, const_c2, P_REXW);
tcg_out_modrm(s, OPC_CMOVCC | tcg_cond_to_jcc[cond] | P_REXW, dest, v1);
tcg_out_cmov(s, cond, P_REXW, dest, v1);
}
#endif

static void tcg_out_ctz(TCGContext *s, int rexw, TCGReg dest, TCGReg arg1,
TCGArg arg2, bool const_a2)
{
if (const_a2) {
tcg_debug_assert(have_bmi1);
tcg_debug_assert(arg2 == (rexw ? 64 : 32));
tcg_out_modrm(s, OPC_TZCNT + rexw, dest, arg1);
} else {
tcg_debug_assert(dest != arg2);
tcg_out_modrm(s, OPC_BSF + rexw, dest, arg1);
tcg_out_cmov(s, TCG_COND_EQ, rexw, dest, arg2);
}
}

static void tcg_out_clz(TCGContext *s, int rexw, TCGReg dest, TCGReg arg1,
TCGArg arg2, bool const_a2)
{
if (have_lzcnt) {
tcg_out_modrm(s, OPC_LZCNT + rexw, dest, arg1);
if (const_a2) {
tcg_debug_assert(arg2 == (rexw ? 64 : 32));
} else {
tcg_debug_assert(dest != arg2);
tcg_out_cmov(s, TCG_COND_LTU, rexw, dest, arg2);
}
} else {
tcg_debug_assert(!const_a2);
tcg_debug_assert(dest != arg1);
tcg_debug_assert(dest != arg2);

/* Recall that the output of BSR is the index not the count. */
tcg_out_modrm(s, OPC_BSR + rexw, dest, arg1);
tgen_arithi(s, ARITH_XOR + rexw, dest, rexw ? 63 : 31, 0);

/* Since we have destroyed the flags from BSR, we have to re-test. */
tcg_out_cmp(s, arg1, 0, 1, rexw);
tcg_out_cmov(s, TCG_COND_EQ, rexw, dest, arg2);
}
}

static void tcg_out_branch(TCGContext *s, int call, tcg_insn_unit *dest)
{
intptr_t disp = tcg_pcrel_diff(s, dest) - 5;
Expand Down Expand Up @@ -1995,6 +2068,13 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
}
break;

OP_32_64(ctz):
tcg_out_ctz(s, rexw, args[0], args[1], args[2], const_args[2]);
break;
OP_32_64(clz):
tcg_out_clz(s, rexw, args[0], args[1], args[2], const_args[2]);
break;

case INDEX_op_brcond_i32:
tcg_out_brcond32(s, a2, a0, a1, const_args[1], arg_label(args[3]), 0);
break;
Expand Down Expand Up @@ -2359,6 +2439,24 @@ static const TCGTargetOpDef *tcg_target_op_def(TCGOpcode op)
= { .args_ct_str = { "r", "r", "0", "1", "re", "re" } };
return &arith2;
}
case INDEX_op_ctz_i32:
case INDEX_op_ctz_i64:
{
static const TCGTargetOpDef ctz[2] = {
{ .args_ct_str = { "&r", "r", "r" } },
{ .args_ct_str = { "&r", "r", "rW" } },
};
return &ctz[have_bmi1];
}
case INDEX_op_clz_i32:
case INDEX_op_clz_i64:
{
static const TCGTargetOpDef clz[2] = {
{ .args_ct_str = { "&r", "r", "r" } },
{ .args_ct_str = { "&r", "r", "rW" } },
};
return &clz[have_lzcnt];
}

case INDEX_op_qemu_ld_i32:
return TARGET_LONG_BITS <= TCG_TARGET_REG_BITS ? &r_L : &r_L_L;
Expand Down Expand Up @@ -2509,6 +2607,15 @@ static void tcg_target_init(TCGContext *s)
}
#endif

#ifndef have_lzcnt
max = __get_cpuid_max(0x8000000, 0);
if (max >= 1) {
__cpuid(0x80000001, a, b, c, d);
/* LZCNT was introduced with AMD Barcelona and Intel Haswell CPUs. */
have_lzcnt = (c & bit_LZCNT) != 0;
}
#endif

if (TCG_TARGET_REG_BITS == 64) {
tcg_regset_set32(tcg_target_available_regs[TCG_TYPE_I32], 0, 0xffff);
tcg_regset_set32(tcg_target_available_regs[TCG_TYPE_I64], 0, 0xffff);
Expand Down

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