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tcg/i386: Use host/cpuinfo.h 
Use the CPUINFO_* bits instead of the individual boolean
variables that we had been using.  Remove all of the init
code that was moved over to cpuinfo-i386.c.

Note that have_avx512* check both AVX512{F,VL}, as we had
previously done during tcg_target_init.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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@rth7680
rth7680 committed May 23, 2023
1 parent a48b6af commit dbedadb
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Showing 2 changed files with 22 additions and 129 deletions.
123 changes: 4 additions & 119 deletions tcg/i386/tcg-target.c.inc
View file
Expand Up @@ -158,42 +158,14 @@ static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
# define SOFTMMU_RESERVE_REGS 0
#endif

/* The host compiler should supply <cpuid.h> to enable runtime features
detection, as we're not going to go so far as our own inline assembly.
If not available, default values will be assumed. */
#if defined(CONFIG_CPUID_H)
#include "qemu/cpuid.h"
#endif

/* For 64-bit, we always know that CMOV is available. */
#if TCG_TARGET_REG_BITS == 64
# define have_cmov 1
#elif defined(CONFIG_CPUID_H)
static bool have_cmov;
#else
# define have_cmov 0
#endif

/* We need these symbols in tcg-target.h, and we can't properly conditionalize
it there. Therefore we always define the variable. */
bool have_bmi1;
bool have_popcnt;
bool have_avx1;
bool have_avx2;
bool have_avx512bw;
bool have_avx512dq;
bool have_avx512vbmi2;
bool have_avx512vl;
bool have_movbe;
bool have_atomic16;

#ifdef CONFIG_CPUID_H
static bool have_bmi2;
static bool have_lzcnt;
# define have_cmov true
#else
# define have_bmi2 0
# define have_lzcnt 0
# define have_cmov (cpuinfo & CPUINFO_CMOV)
#endif
#define have_bmi2 (cpuinfo & CPUINFO_BMI2)
#define have_lzcnt (cpuinfo & CPUINFO_LZCNT)

static const tcg_insn_unit *tb_ret_addr;

Expand Down Expand Up @@ -3961,93 +3933,6 @@ static void tcg_out_nop_fill(tcg_insn_unit *p, int count)

static void tcg_target_init(TCGContext *s)
{
#ifdef CONFIG_CPUID_H
unsigned a, b, c, d, b7 = 0, c7 = 0;
unsigned max = __get_cpuid_max(0, 0);

if (max >= 7) {
/* BMI1 is available on AMD Piledriver and Intel Haswell CPUs. */
__cpuid_count(7, 0, a, b7, c7, d);
have_bmi1 = (b7 & bit_BMI) != 0;
have_bmi2 = (b7 & bit_BMI2) != 0;
}

if (max >= 1) {
__cpuid(1, a, b, c, d);
#ifndef have_cmov
/* For 32-bit, 99% certainty that we're running on hardware that
supports cmov, but we still need to check. In case cmov is not
available, we'll use a small forward branch. */
have_cmov = (d & bit_CMOV) != 0;
#endif

/* MOVBE is only available on Intel Atom and Haswell CPUs, so we
need to probe for it. */
have_movbe = (c & bit_MOVBE) != 0;
have_popcnt = (c & bit_POPCNT) != 0;

/* There are a number of things we must check before we can be
sure of not hitting invalid opcode. */
if (c & bit_OSXSAVE) {
unsigned bv = xgetbv_low(0);

if ((bv & 6) == 6) {
have_avx1 = (c & bit_AVX) != 0;
have_avx2 = (b7 & bit_AVX2) != 0;

/*
* There are interesting instructions in AVX512, so long
* as we have AVX512VL, which indicates support for EVEX
* on sizes smaller than 512 bits. We are required to
* check that OPMASK and all extended ZMM state are enabled
* even if we're not using them -- the insns will fault.
*/
if ((bv & 0xe0) == 0xe0
&& (b7 & bit_AVX512F)
&& (b7 & bit_AVX512VL)) {
have_avx512vl = true;
have_avx512bw = (b7 & bit_AVX512BW) != 0;
have_avx512dq = (b7 & bit_AVX512DQ) != 0;
have_avx512vbmi2 = (c7 & bit_AVX512VBMI2) != 0;
}

/*
* The Intel SDM has added:
* Processors that enumerate support for Intel® AVX
* (by setting the feature flag CPUID.01H:ECX.AVX[bit 28])
* guarantee that the 16-byte memory operations performed
* by the following instructions will always be carried
* out atomically:
* - MOVAPD, MOVAPS, and MOVDQA.
* - VMOVAPD, VMOVAPS, and VMOVDQA when encoded with VEX.128.
* - VMOVAPD, VMOVAPS, VMOVDQA32, and VMOVDQA64 when encoded
* with EVEX.128 and k0 (masking disabled).
* Note that these instructions require the linear addresses
* of their memory operands to be 16-byte aligned.
*
* AMD has provided an even stronger guarantee that processors
* with AVX provide 16-byte atomicity for all cachable,
* naturally aligned single loads and stores, e.g. MOVDQU.
*
* See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104688
*/
if (have_avx1) {
__cpuid(0, a, b, c, d);
have_atomic16 = (c == signature_INTEL_ecx ||
c == signature_AMD_ecx);
}
}
}
}

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 /* CONFIG_CPUID_H */

tcg_target_available_regs[TCG_TYPE_I32] = ALL_GENERAL_REGS;
if (TCG_TARGET_REG_BITS == 64) {
tcg_target_available_regs[TCG_TYPE_I64] = ALL_GENERAL_REGS;
Expand Down
28 changes: 18 additions & 10 deletions tcg/i386/tcg-target.h
View file
Expand Up @@ -25,6 +25,8 @@
#ifndef I386_TCG_TARGET_H
#define I386_TCG_TARGET_H

#include "host/cpuinfo.h"

#define TCG_TARGET_INSN_UNIT_SIZE 1
#define TCG_TARGET_TLB_DISPLACEMENT_BITS 31

Expand Down Expand Up @@ -111,16 +113,22 @@ typedef enum {
# define TCG_TARGET_CALL_RET_I128 TCG_CALL_RET_BY_REF
#endif

extern bool have_bmi1;
extern bool have_popcnt;
extern bool have_avx1;
extern bool have_avx2;
extern bool have_avx512bw;
extern bool have_avx512dq;
extern bool have_avx512vbmi2;
extern bool have_avx512vl;
extern bool have_movbe;
extern bool have_atomic16;
#define have_bmi1 (cpuinfo & CPUINFO_BMI1)
#define have_popcnt (cpuinfo & CPUINFO_POPCNT)
#define have_avx1 (cpuinfo & CPUINFO_AVX1)
#define have_avx2 (cpuinfo & CPUINFO_AVX2)
#define have_movbe (cpuinfo & CPUINFO_MOVBE)
#define have_atomic16 (cpuinfo & CPUINFO_ATOMIC_VMOVDQA)

/*
* There are interesting instructions in AVX512, so long as we have AVX512VL,
* which indicates support for EVEX on sizes smaller than 512 bits.
*/
#define have_avx512vl ((cpuinfo & CPUINFO_AVX512VL) && \
(cpuinfo & CPUINFO_AVX512F))
#define have_avx512bw ((cpuinfo & CPUINFO_AVX512BW) && have_avx512vl)
#define have_avx512dq ((cpuinfo & CPUINFO_AVX512DQ) && have_avx512vl)
#define have_avx512vbmi2 ((cpuinfo & CPUINFO_AVX512VBMI2) && have_avx512vl)

/* optional instructions */
#define TCG_TARGET_HAS_div2_i32 1
Expand Down

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