util: Introduce include/qemu/cpuid.h

Clang 3.9 passes the CONFIG_AVX2_OPT configure test.  However, the
supplied <cpuid.h> does not contain the bit_AVX2 define that we use
when detecting whether the routine can be enabled.

Introduce a qemu-specific header that uses the compiler's definition
of __cpuid et al, but supplies any missing bit_* definitions needed.
This avoids introducing any extra ifdefs to util/bufferiszero.c, and
allows quite a few to be removed from tcg/i386/tcg-target.inc.c.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20170719044018.18063-1-rth@twiddle.net
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2017-07-18 18:40:18 -10:00 committed by Peter Maydell
parent df95f1a298
commit 5dd8990841
4 changed files with 92 additions and 51 deletions

43
configure vendored
View file

@ -358,6 +358,7 @@ libusb=""
usb_redir=""
opengl=""
opengl_dmabuf="no"
cpuid_h="no"
avx2_opt="no"
zlib="yes"
lzo=""
@ -1931,24 +1932,6 @@ EOF
fi
fi
##########################################
# avx2 optimization requirement check
cat > $TMPC << EOF
#pragma GCC push_options
#pragma GCC target("avx2")
#include <cpuid.h>
#include <immintrin.h>
static int bar(void *a) {
__m256i x = *(__m256i *)a;
return _mm256_testz_si256(x, x);
}
int main(int argc, char *argv[]) { return bar(argv[0]); }
EOF
if compile_object "" ; then
avx2_opt="yes"
fi
#########################################
# zlib check
@ -4646,7 +4629,6 @@ fi
########################################
# check if cpuid.h is usable.
cpuid_h=no
cat > $TMPC << EOF
#include <cpuid.h>
int main(void) {
@ -4668,6 +4650,29 @@ if compile_prog "" "" ; then
cpuid_h=yes
fi
##########################################
# avx2 optimization requirement check
#
# There is no point enabling this if cpuid.h is not usable,
# since we won't be able to select the new routines.
if test $cpuid_h = yes; then
cat > $TMPC << EOF
#pragma GCC push_options
#pragma GCC target("avx2")
#include <cpuid.h>
#include <immintrin.h>
static int bar(void *a) {
__m256i x = *(__m256i *)a;
return _mm256_testz_si256(x, x);
}
int main(int argc, char *argv[]) { return bar(argv[0]); }
EOF
if compile_object "" ; then
avx2_opt="yes"
fi
fi
########################################
# check if __[u]int128_t is usable.

57
include/qemu/cpuid.h Normal file
View file

@ -0,0 +1,57 @@
/* cpuid.h: Macros to identify the properties of an x86 host.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef QEMU_CPUID_H
#define QEMU_CPUID_H
#ifndef CONFIG_CPUID_H
# error "<cpuid.h> is unusable with this compiler"
#endif
#include <cpuid.h>
/* Cover the uses that we have within qemu. */
/* ??? Irritating that we have the same information in target/i386/. */
/* Leaf 1, %edx */
#ifndef bit_CMOV
#define bit_CMOV (1 << 15)
#endif
#ifndef bit_SSE2
#define bit_SSE2 (1 << 26)
#endif
/* Leaf 1, %ecx */
#ifndef bit_SSE4_1
#define bit_SSE4_1 (1 << 19)
#endif
#ifndef bit_MOVBE
#define bit_MOVBE (1 << 22)
#endif
#ifndef bit_OSXSAVE
#define bit_OSXSAVE (1 << 27)
#endif
#ifndef bit_AVX
#define bit_AVX (1 << 28)
#endif
/* Leaf 7, %ebx */
#ifndef bit_BMI
#define bit_BMI (1 << 3)
#endif
#ifndef bit_AVX2
#define bit_AVX2 (1 << 5)
#endif
#ifndef bit_BMI2
#define bit_BMI2 (1 << 8)
#endif
/* Leaf 0x80000001, %ecx */
#ifndef bit_LZCNT
#define bit_LZCNT (1 << 5)
#endif
#endif /* QEMU_CPUID_H */

View file

@ -109,40 +109,30 @@ static const int tcg_target_call_oarg_regs[] = {
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 <cpuid.h>
#include "qemu/cpuid.h"
#endif
/* For 32-bit, we are going to attempt to determine at runtime whether cmov
is available. */
/* 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) && defined(bit_CMOV)
#elif defined(CONFIG_CPUID_H)
static bool have_cmov;
#else
# define have_cmov 0
#endif
/* If bit_MOVBE is defined in cpuid.h (added in GCC version 4.6), we are
going to attempt to determine at runtime whether movbe is available. */
#if defined(CONFIG_CPUID_H) && defined(bit_MOVBE)
static bool have_movbe;
#else
# define have_movbe 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;
#if defined(CONFIG_CPUID_H) && defined(bit_BMI2)
#ifdef CONFIG_CPUID_H
static bool have_movbe;
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_movbe 0
# define have_bmi2 0
# define have_lzcnt 0
#endif
@ -2619,36 +2609,26 @@ static void tcg_target_init(TCGContext *s)
available, we'll use a small forward branch. */
have_cmov = (d & bit_CMOV) != 0;
#endif
#ifndef have_movbe
/* MOVBE is only available on Intel Atom and Haswell CPUs, so we
need to probe for it. */
have_movbe = (c & bit_MOVBE) != 0;
#endif
#ifdef bit_POPCNT
have_popcnt = (c & bit_POPCNT) != 0;
#endif
}
if (max >= 7) {
/* BMI1 is available on AMD Piledriver and Intel Haswell CPUs. */
__cpuid_count(7, 0, a, b, c, d);
#ifdef bit_BMI
have_bmi1 = (b & bit_BMI) != 0;
#endif
#ifndef have_bmi2
have_bmi2 = (b & bit_BMI2) != 0;
#endif
}
#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
#endif /* CONFIG_CPUID_H */
if (TCG_TARGET_REG_BITS == 64) {
tcg_regset_set32(tcg_target_available_regs[TCG_TYPE_I32], 0, 0xffff);

View file

@ -197,7 +197,7 @@ buffer_zero_avx2(const void *buf, size_t len)
/* Make sure that these variables are appropriately initialized when
* SSE2 is enabled on the compiler command-line, but the compiler is
* too old to support <cpuid.h>.
* too old to support CONFIG_AVX2_OPT.
*/
#ifdef CONFIG_AVX2_OPT
# define INIT_CACHE 0
@ -231,7 +231,8 @@ static void init_accel(unsigned cache)
}
#ifdef CONFIG_AVX2_OPT
#include <cpuid.h>
#include "qemu/cpuid.h"
static void __attribute__((constructor)) init_cpuid_cache(void)
{
int max = __get_cpuid_max(0, NULL);
@ -243,7 +244,6 @@ static void __attribute__((constructor)) init_cpuid_cache(void)
if (d & bit_SSE2) {
cache |= CACHE_SSE2;
}
#ifdef CONFIG_AVX2_OPT
if (c & bit_SSE4_1) {
cache |= CACHE_SSE4;
}
@ -257,7 +257,6 @@ static void __attribute__((constructor)) init_cpuid_cache(void)
cache |= CACHE_AVX2;
}
}
#endif
}
cpuid_cache = cache;
init_accel(cache);