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tcg: Remove CONFIG_VECTOR16

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The comment in tcg-runtime-gvec.c about CONFIG_VECTOR16 says that
tcg-op-gvec.c has eliminated size 8 vectors, and only passes on
multiples of 16.  This may have been true of the first few operations,
but is not true of all operations.

In particular, multiply, shift by scalar, and compare of 8- and 16-bit
elements are not expanded inline if host vector operations are not
supported.

For an x86_64 host that does not support AVX, this means that we will
fall back to the helper, which will attempt to use SSE instructions,
which will SEGV on an invalid 8-byte aligned memory operation.

This patch simply removes the CONFIG_VECTOR16 code and configuration
without further simplification.

Buglink: https://bugs.launchpad.net/bugs/1863508
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2020-02-16 17:43:11 -08:00
parent 312b426fea
commit 43d1ccd2a0
2 changed files with 1 additions and 90 deletions
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56
configure vendored
View file

@ -5711,58 +5711,6 @@ if test "$plugins" = "yes" &&
"for this purpose. You can't build with --static."
fi
########################################
# See if 16-byte vector operations are supported.
# Even without a vector unit the compiler may expand these.
# There is a bug in old GCC for PPC that crashes here.
# Unfortunately it's the system compiler for Centos 7.
cat > $TMPC << EOF
typedef unsigned char U1 __attribute__((vector_size(16)));
typedef unsigned short U2 __attribute__((vector_size(16)));
typedef unsigned int U4 __attribute__((vector_size(16)));
typedef unsigned long long U8 __attribute__((vector_size(16)));
typedef signed char S1 __attribute__((vector_size(16)));
typedef signed short S2 __attribute__((vector_size(16)));
typedef signed int S4 __attribute__((vector_size(16)));
typedef signed long long S8 __attribute__((vector_size(16)));
static U1 a1, b1;
static U2 a2, b2;
static U4 a4, b4;
static U8 a8, b8;
static S1 c1;
static S2 c2;
static S4 c4;
static S8 c8;
static int i;
void helper(void *d, void *a, int shift, int i);
void helper(void *d, void *a, int shift, int i)
{
*(U1 *)(d + i) = *(U1 *)(a + i) << shift;
*(U2 *)(d + i) = *(U2 *)(a + i) << shift;
*(U4 *)(d + i) = *(U4 *)(a + i) << shift;
*(U8 *)(d + i) = *(U8 *)(a + i) << shift;
}
int main(void)
{
a1 += b1; a2 += b2; a4 += b4; a8 += b8;
a1 -= b1; a2 -= b2; a4 -= b4; a8 -= b8;
a1 *= b1; a2 *= b2; a4 *= b4; a8 *= b8;
a1 &= b1; a2 &= b2; a4 &= b4; a8 &= b8;
a1 |= b1; a2 |= b2; a4 |= b4; a8 |= b8;
a1 ^= b1; a2 ^= b2; a4 ^= b4; a8 ^= b8;
a1 <<= i; a2 <<= i; a4 <<= i; a8 <<= i;
a1 >>= i; a2 >>= i; a4 >>= i; a8 >>= i;
c1 >>= i; c2 >>= i; c4 >>= i; c8 >>= i;
return 0;
}
EOF
vector16=no
if compile_prog "" "" ; then
vector16=yes
fi
########################################
# See if __attribute__((alias)) is supported.
# This false for Xcode 9, but has been remedied for Xcode 10.
@ -7383,10 +7331,6 @@ if test "$atomic64" = "yes" ; then
echo "CONFIG_ATOMIC64=y" >> $config_host_mak
fi
if test "$vector16" = "yes" ; then
echo "CONFIG_VECTOR16=y" >> $config_host_mak
fi
if test "$attralias" = "yes" ; then
echo "CONFIG_ATTRIBUTE_ALIAS=y" >> $config_host_mak
fi