Use Tilera SIMD for Signature matching ala SSE3

Makes use of 8-wide byte compare instructions in signature matching. For allocating aligned memory, _mm_malloc() is SSE only, so added check for __tile__ to use memalign() instead. Shows a 13% speed up.
ken-tilera · Aug 1, 2013 · 1e501b6 · 1e501b6
1 parent 2b71f3b
commit 1e501b6
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Showing 4 changed files with 89 additions and 27 deletions.
diff --git a/src/detect-engine-siggroup.c b/src/detect-engine-siggroup.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2010 Open Information Security Foundation
+/* Copyright (C) 2007-2013 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free
@@ -175,7 +175,7 @@ void SigGroupHeadFree(SigGroupHead *sgh)
 
     PatternMatchDestroyGroup(sgh);
 
-#if defined(__SSE3__)
+#if defined(__SSE3__) || defined(__tile__)
     if (sgh->mask_array != NULL) {
         /* mask is aligned */
         SCFreeAligned(sgh->mask_array);
@@ -1690,7 +1690,7 @@ int SigGroupHeadBuildHeadArray(DetectEngineCtx *de_ctx, SigGroupHead *sgh)
         return 0;
 
     BUG_ON(sgh->head_array != NULL);
-#if defined(__SSE3__)
+#if defined(__SSE3__) || defined(__tile__)
     BUG_ON(sgh->mask_array != NULL);
 
     /* mask array is 16 byte aligned for SIMD checking, also we always
@@ -1706,7 +1706,7 @@ int SigGroupHeadBuildHeadArray(DetectEngineCtx *de_ctx, SigGroupHead *sgh)
     }
 #endif /* __WORDSIZE */
 
-    sgh->mask_array = SCMallocAligned((cnt * sizeof(SignatureMask)), 16);
+    sgh->mask_array = (SignatureMask *)SCMallocAligned((cnt * sizeof(SignatureMask)), 16);
     if (sgh->mask_array == NULL)
         return -1;
 
@@ -1732,7 +1732,7 @@ int SigGroupHeadBuildHeadArray(DetectEngineCtx *de_ctx, SigGroupHead *sgh)
         sgh->head_array[idx].hdr_copy3 = s->hdr_copy3;
         sgh->head_array[idx].full_sig = s;
 
-#if defined(__SSE3__)
+#if defined(__SSE3__) || defined(__tile__)
         sgh->mask_array[idx] = s->mask;
 #endif
         idx++;

diff --git a/src/detect.c b/src/detect.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2011 Open Information Security Foundation
+/* Copyright (C) 2007-2013 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free
@@ -576,7 +576,7 @@ static inline int SigMatchSignaturesBuildMatchArrayAddSignature(DetectEngineThre
  *  On 64 bit systems we inspect in 64 sig batches, creating a u64 with flags.
  *  The size of a register is leading here.
  */
-static inline void SigMatchSignaturesBuildMatchArraySIMD(DetectEngineThreadCtx *det_ctx,
+static inline void SigMatchSignaturesBuildMatchArray(DetectEngineThreadCtx *det_ctx,
         Packet *p, SignatureMask mask, uint16_t alproto)
 {
     uint32_t u;
@@ -712,28 +712,70 @@ static inline void SigMatchSignaturesBuildMatchArraySIMD(DetectEngineThreadCtx *
 #error Wordsize (__WORDSIZE) neither 32 or 64.
 #endif
 }
-#endif /* defined(__SSE3__) */
+ /* end defined(__SSE3__) */
+#elif defined(__tile__)
 
-static inline void SigMatchSignaturesBuildMatchArrayNoSIMD(DetectEngineThreadCtx *det_ctx,
+/**
+ *  \brief SIMD implementation of mask prefiltering for TILE-Gx
+ *
+ *  Mass mask matching is done creating a bitmap of signatures that need
+ *  futher inspection.
+ */
+static inline void SigMatchSignaturesBuildMatchArray(DetectEngineThreadCtx *det_ctx,
         Packet *p, SignatureMask mask, uint16_t alproto)
 {
     uint32_t u;
+    register uint64_t bm; /* bit mask, 64 bits used */
 
-    /* reset previous run */
-    det_ctx->match_array_cnt = 0;
+    /* Keep local copies of variables that don't change during this function. */
+    uint64_t *mask_vector = (uint64_t*)det_ctx->sgh->mask_array;
+    uint32_t sig_cnt = det_ctx->sgh->sig_cnt;
+    SignatureHeader *head_array = det_ctx->sgh->head_array;
+
+    Signature **match_array = det_ctx->match_array;
+    uint32_t match_count = 0;
+
+    /* Replicate the packet mask into each byte of the vector. */
+    uint64_t pm = __insn_shufflebytes(mask, 0, 0);
+
+    /* u is the signature index. */
+    for (u = 0; u < sig_cnt; u += 8) {
+        /* Load 8 masks */
+        uint64_t sm = *mask_vector++;
+        /* Binary AND 8 masks with the packet's mask */
+        uint64_t r1 = pm & sm;
+        /* Compare the result with the original mask
+         * Result if equal puts a 1 in LSB of bytes that match.
+         */
+        bm = __insn_v1cmpeq(sm, r1);
+
+        /* Check the LSB bit of each byte in the bit map. Little endian is assumed,
+         * so the LSB byte is index 0. Uses count trailing zeros to find least
+         * significant bit that is set. */
+        while (bm) {
+            /* Find first bit set starting from LSB. */
+            unsigned int first_bit = __insn_ctz(bm);
+            unsigned int first_byte = first_bit >> 3;
+            unsigned int x = u + first_byte;
+            if (x >= sig_cnt)
+                break;
+            SignatureHeader *s = &head_array[x];
+
+            /* Clear the first bit set, so it is not found again. */
+            bm -= (1UL << first_bit);
 
-    for (u = 0; u < det_ctx->sgh->sig_cnt; u++) {
-        SignatureHeader *s = &det_ctx->sgh->head_array[u];
-        if ((mask & s->mask) == s->mask) {
             if (SigMatchSignaturesBuildMatchArrayAddSignature(det_ctx, p, s, alproto) == 1) {
                 /* okay, store it */
-                det_ctx->match_array[det_ctx->match_array_cnt] = s->full_sig;
-                det_ctx->match_array_cnt++;
+                *match_array++ = s->full_sig;
+                match_count++;
             }
         }
     }
+    det_ctx->match_array_cnt = match_count;
 }
-
+/* end defined(__tile__) */
+#else
+/* No SIMD implementation */
 /**
  *  \brief build an array of signatures that will be inspected
  *
@@ -745,15 +787,27 @@ static inline void SigMatchSignaturesBuildMatchArrayNoSIMD(DetectEngineThreadCtx
  *  \param mask Packets mask
  *  \param alproto application layer protocol
  */
-static void SigMatchSignaturesBuildMatchArray(DetectEngineThreadCtx *det_ctx,
-        Packet *p, SignatureMask mask, uint16_t alproto)
+static inline void SigMatchSignaturesBuildMatchArray(DetectEngineThreadCtx *det_ctx,
+                                                     Packet *p, SignatureMask mask,
+                                                     uint16_t alproto)
 {
-#if defined(__SSE3__)
-    SigMatchSignaturesBuildMatchArraySIMD(det_ctx, p, mask, alproto);
-#else
-    SigMatchSignaturesBuildMatchArrayNoSIMD(det_ctx, p, mask, alproto);
-#endif
+    uint32_t u;
+
+    /* reset previous run */
+    det_ctx->match_array_cnt = 0;
+
+    for (u = 0; u < det_ctx->sgh->sig_cnt; u++) {
+        SignatureHeader *s = &det_ctx->sgh->head_array[u];
+        if ((mask & s->mask) == s->mask) {
+            if (SigMatchSignaturesBuildMatchArrayAddSignature(det_ctx, p, s, alproto) == 1) {
+                /* okay, store it */
+                det_ctx->match_array[det_ctx->match_array_cnt] = s->full_sig;
+                det_ctx->match_array_cnt++;
+            }
+        }
+    }
 }
+#endif /* No SIMD implementation */
 
 int SigMatchSignaturesRunPostMatch(ThreadVars *tv,
                                    DetectEngineCtx *de_ctx, DetectEngineThreadCtx *det_ctx, Packet *p,

diff --git a/src/detect.h b/src/detect.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2011 Open Information Security Foundation
+/* Copyright (C) 2007-2013 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free
@@ -949,7 +949,7 @@ typedef struct SigGroupHead_ {
 
     /** array of masks, used to check multiple masks against
      *  a packet using SIMD. */
-#if defined(__SSE3__)
+#if defined(__SSE3__) || defined(__tile__)
     SignatureMask *mask_array;
 #endif
     /** chunk of memory containing the "header" part of each

diff --git a/src/util-mem.h b/src/util-mem.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2010 Open Information Security Foundation
+/* Copyright (C) 2007-2013 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free
@@ -36,6 +36,14 @@
 #include "mm_malloc.h"
 #endif
 
+#if defined(__tile__)
+/* Need to define __mm_ function alternatives, since these are SSE only.
+ */
+#include <malloc.h>
+#define _mm_malloc(a,b) memalign((b),(a))
+#define _mm_free(a) free((a))
+#endif /* defined(__tile__) */
+
 SC_ATOMIC_EXTERN(unsigned int, engine_stage);
 
 /* Use this only if you want to debug memory allocation and free()