Hi Jerin,
On 09/03/2020 16:39, Jerin Jacob wrote:
On Mon, Mar 9, 2020 at 6:14 PM Vladimir Medvedkin
<vladimir.medved...@intel.com> wrote:
New data type to manipulate 512 bit AVX values.
Signed-off-by: Vladimir Medvedkin <vladimir.medved...@intel.com>
---
lib/librte_eal/common/include/arch/x86/rte_vect.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/lib/librte_eal/common/include/arch/x86/rte_vect.h
b/lib/librte_eal/common/include/arch/x86/rte_vect.h
index df5a607..09f30e6 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_vect.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_vect.h
@@ -90,6 +90,26 @@ __extension__ ({ \
})
#endif /* (defined(__ICC) && __ICC < 1210) */
+#ifdef __AVX512F__
+
+typedef __m512i zmm_t;
+
+#define ZMM_SIZE (sizeof(zmm_t))
+#define ZMM_MASK (ZMM_SIZE - 1)
+
+typedef union rte_zmm {
+ zmm_t z;
+ ymm_t y[ZMM_SIZE / sizeof(ymm_t)];
+ xmm_t x[ZMM_SIZE / sizeof(xmm_t)];
+ uint8_t u8[ZMM_SIZE / sizeof(uint8_t)];
+ uint16_t u16[ZMM_SIZE / sizeof(uint16_t)];
+ uint32_t u32[ZMM_SIZE / sizeof(uint32_t)];
+ uint64_t u64[ZMM_SIZE / sizeof(uint64_t)];
+ double pd[ZMM_SIZE / sizeof(double)];
Are we missing __attribute__((aligned(64))) here?
Agree. While modern compilers align __m512i by default, some old could
failure to align. Please correct me if I'm wrong.
+} rte_zmm_t;
IMO, Due to legacy reason, we have selected rte_xmm_t, rte_ymm_t for
128 and 256 operations in public APIs[1]
As for me, since these functions are inlined, prototype should be
changed to uint32_t ip[4] instead of passing vector type as an argument.
# Not sure where xmm_t and ymm_t and new zmm_t come from? Is this name
x86 arch-specific?
Yes, that's why they are in arch/x86/rte_vect.h
If so,
why not give the more generic name rte_512i_t or something?
# Currently, In every arch file, we are repeating the definition for
rte_xmm_t, Why not make, this generic definition
in common file. ie. rte_zmm_t or rte_512i_t definition in common
file(./lib/librte_eal/common/include/generic/rte_vect.h)
I think there could be some arch specific thing that prevents it from
being generic.
# Currently ./lib/librte_eal/common/include/generic/rte_vect.h has
defintion for rte_vXsY_t for vector representation, would that
be enough for public API? Do we need to new type?
Definitions for rte_vXsY_tare almost the same as compiler's
__m[128,256,512]i apart from alignment.
Union types such as rte_zmm_t are very useful because of the ability to
access parts of a wide vector register with an arbitrary granularity.
For example, some old compiler don't support
_mm512_set_epi8()/_mm512_set_epi16() intrinsics, so accessing ".u8[]" of
".u16[]" solves the problem.
[1]
rte_lpm_lookupx4(const struct rte_lpm *lpm, xmm_t ip, uint32_t hop[4],
uint32_t defv)
+
+#endif /* __AVX512F__ */
+
#ifdef __cplusplus
}
#endif
--
2.7.4
--
Regards,
Vladimir
