Optimizing fast_forward_start_bits in JIT.

git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1244 2f5784b3-3f2a-0410-8824-cb99058d5e15

2 files changed, 28 insertions, 11 deletions

diff --git a/ChangeLog b/ChangeLog
index a6bb6b1..c79f79c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -34,6 +34,8 @@ Version 8.33 xx-xxxx-201x
 
 8.  Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
 
+9.  Optimizing fast_forward_start_bits in JIT.
+
 
 Version 8.32 30-November-2012
 -----------------------------
diff --git a/pcre_jit_compile.c b/pcre_jit_compile.c
index 7dfe558..1752fd5 100644
--- a/pcre_jit_compile.c
+++ b/pcre_jit_compile.c
@@ -2877,16 +2877,24 @@ if (firstline)
   OP1(SLJIT_MOV, STR_END, 0, TMP3, 0);
 }
 
+static BOOL check_class_ranges(compiler_common *common, const pcre_uint8 *bits, BOOL nclass, jump_list **backtracks);
+
 static SLJIT_INLINE void fast_forward_start_bits(compiler_common *common, sljit_uw start_bits, BOOL firstline)
 {
 DEFINE_COMPILER;
 struct sljit_label *start;
 struct sljit_jump *quit;
-struct sljit_jump *found;
+struct sljit_jump *found = NULL;
+jump_list *matches = NULL;
+pcre_uint8 inverted_start_bits[32];
+int i;
 #ifndef COMPILE_PCRE8
 struct sljit_jump *jump;
 #endif
 
+for (i = 0; i < 32; ++i)
+  inverted_start_bits[i] = ~(((pcre_uint8*)start_bits)[i]);
+
 if (firstline)
   {
   SLJIT_ASSERT(common->first_line_end != 0);
@@ -2901,17 +2909,21 @@ OP1(MOV_UCHAR, TMP1, 0, SLJIT_MEM1(STR_PTR), 0);
 if (common->utf)
   OP1(SLJIT_MOV, TMP3, 0, TMP1, 0);
 #endif
+
+if (!check_class_ranges(common, inverted_start_bits, (inverted_start_bits[31] & 0x80) != 0, &matches))
+  {
 #ifndef COMPILE_PCRE8
-jump = CMP(SLJIT_C_LESS, TMP1, 0, SLJIT_IMM, 255);
-OP1(SLJIT_MOV, TMP1, 0, SLJIT_IMM, 255);
-JUMPHERE(jump);
+  jump = CMP(SLJIT_C_LESS, TMP1, 0, SLJIT_IMM, 255);
+  OP1(SLJIT_MOV, TMP1, 0, SLJIT_IMM, 255);
+  JUMPHERE(jump);
 #endif
-OP2(SLJIT_AND, TMP2, 0, TMP1, 0, SLJIT_IMM, 0x7);
-OP2(SLJIT_LSHR, TMP1, 0, TMP1, 0, SLJIT_IMM, 3);
-OP1(SLJIT_MOV_UB, TMP1, 0, SLJIT_MEM1(TMP1), start_bits);
-OP2(SLJIT_SHL, TMP2, 0, SLJIT_IMM, 1, TMP2, 0);
-OP2(SLJIT_AND | SLJIT_SET_E, SLJIT_UNUSED, 0, TMP1, 0, TMP2, 0);
-found = JUMP(SLJIT_C_NOT_ZERO);
+  OP2(SLJIT_AND, TMP2, 0, TMP1, 0, SLJIT_IMM, 0x7);
+  OP2(SLJIT_LSHR, TMP1, 0, TMP1, 0, SLJIT_IMM, 3);
+  OP1(SLJIT_MOV_UB, TMP1, 0, SLJIT_MEM1(TMP1), start_bits);
+  OP2(SLJIT_SHL, TMP2, 0, SLJIT_IMM, 1, TMP2, 0);
+  OP2(SLJIT_AND | SLJIT_SET_E, SLJIT_UNUSED, 0, TMP1, 0, TMP2, 0);
+  found = JUMP(SLJIT_C_NOT_ZERO);
+  }
 
 #ifdef SUPPORT_UTF
 if (common->utf)
@@ -2939,7 +2951,10 @@ if (common->utf)
 #endif /* COMPILE_PCRE[8|16] */
 #endif /* SUPPORT_UTF */
 JUMPTO(SLJIT_JUMP, start);
-JUMPHERE(found);
+if (found != NULL)
+  JUMPHERE(found);
+if (matches != NULL)
+  set_jumps(matches, LABEL());
 JUMPHERE(quit);
 
 if (firstline)