[sql] Import SQLite 3.17.0.

third_party/sqlite/src/tool/mkopcodeh.tcl

Index: third_party/sqlite/src/tool/mkopcodeh.tcl
diff --git a/third_party/sqlite/src/tool/mkopcodeh.tcl b/third_party/sqlite/src/tool/mkopcodeh.tcl
index 4c36f24ba47398e98f8f7efd668bcb877ecf7e26..3c2a59789c1e7de4cfaab60702bfb8d8803afa7d 100644
--- a/third_party/sqlite/src/tool/mkopcodeh.tcl
+++ b/third_party/sqlite/src/tool/mkopcodeh.tcl
@@ -20,8 +20,7 @@
 # during code generation, we need to generate corresponding opcodes like
 # OP_Add and OP_Divide.  By making TK_ADD==OP_Add and TK_DIVIDE==OP_Divide,
 # code to translate from one to the other is avoided.  This makes the
-# code generator run (infinitesimally) faster and more importantly it makes
-# the library footprint smaller.
+# code generator smaller and faster.
 #
 # This script also scans for lines of the form:
 #
@@ -81,8 +80,8 @@ while {![eof $in]} {
     set in1($name) 0
     set in2($name) 0
     set in3($name) 0
-    set out1($name) 0
     set out2($name) 0
+    set out3($name) 0
     for {set i 3} {$i<[llength $line]-1} {incr i} {
        switch [string trim [lindex $line $i] ,] {
          same {
@@ -112,16 +111,19 @@ while {![eof $in]} {
 
 # Assign numbers to all opcodes and output the result.
 #
-set cnt 0
-set max 0
 puts "/* Automatically generated.  Do not edit */"
 puts "/* See the tool/mkopcodeh.tcl script for details */"
-set op(OP_Noop) -1
-set order($nOp) OP_Noop
-incr nOp
-set op(OP_Explain) -1
-set order($nOp) OP_Explain
-incr nOp
+foreach name {OP_Noop OP_Explain} {
+  set jump($name) 0
+  set in1($name) 0
+  set in2($name) 0
+  set in3($name) 0
+  set out2($name) 0
+  set out3($name) 0
+  set op($name) -1
+  set order($nOp) $name
+  incr nOp
+}
 
 # The following are the opcodes that are processed by resolveP2Values()
 #
@@ -144,7 +146,7 @@ set rp2v_ops {
 # Assign small values to opcodes that are processed by resolveP2Values()
 # to make code generation for the switch() statement smaller and faster.
 #
-set cnt 0
+set cnt -1
 for {set i 0} {$i<$nOp} {incr i} {
   set name $order($i)
   if {[lsearch $rp2v_ops $name]>=0} {
@@ -156,7 +158,29 @@ for {set i 0} {$i<$nOp} {incr i} {
   }
 }
 
-# Generate the numeric values for remaining opcodes
+# Assign the next group of values to JUMP opcodes
+#
+for {set i 0} {$i<$nOp} {incr i} {
+  set name $order($i)
+  if {$op($name)>=0} continue
+  if {!$jump($name)} continue
+  incr cnt
+  while {[info exists used($cnt)]} {incr cnt}
+  set op($name) $cnt
+  set used($cnt) 1
+  set def($cnt) $name
+}
+
+# Find the numeric value for the largest JUMP opcode
+#
+set mxJump -1
+for {set i 0} {$i<$nOp} {incr i} {
+  set name $order($i)
+  if {$jump($name) && $op($name)>$mxJump} {set mxJump $op($name)}
+}
+
+
+# Generate the numeric values for all remaining opcodes
 #
 for {set i 0} {$i<$nOp} {incr i} {
   set name $order($i)
@@ -169,7 +193,7 @@ for {set i 0} {$i<$nOp} {incr i} {
   }
 }
 set max $cnt
-for {set i 1} {$i<=$nOp} {incr i} {
+for {set i 0} {$i<$nOp} {incr i} {
   if {![info exists used($i)]} {
     set def($i) "OP_NotUsed_$i"
   }
@@ -196,27 +220,28 @@ for {set i 1} {$i<=$nOp} {incr i} {
 # Generate the bitvectors:
 #
 set bv(0) 0
-for {set i 1} {$i<=$max} {incr i} {
+for {set i 0} {$i<=$max} {incr i} {
   set name $def($i)
-  if {[info exists jump($name)] && $jump($name)} {set a0 1}  {set a0 0}
-  if {[info exists in1($name)] && $in1($name)}   {set a1 2}  {set a1 0}
-  if {[info exists in2($name)] && $in2($name)}   {set a2 4}  {set a2 0}
-  if {[info exists in3($name)] && $in3($name)}   {set a3 8}  {set a3 0}
-  if {[info exists out2($name)] && $out2($name)} {set a4 16} {set a4 0}
-  if {[info exists out3($name)] && $out3($name)} {set a5 32} {set a5 0}
-  set bv($i) [expr {$a0+$a1+$a2+$a3+$a4+$a5}]
+  set x 0
+  if {$jump($name)}  {incr x 1}
+  if {$in1($name)}   {incr x 2}
+  if {$in2($name)}   {incr x 4}
+  if {$in3($name)}   {incr x 8}
+  if {$out2($name)}  {incr x 16}
+  if {$out3($name)}  {incr x 32}
+  set bv($i) $x
 }
 puts ""
 puts "/* Properties such as \"out2\" or \"jump\" that are specified in"
 puts "** comments following the \"case\" for each opcode in the vdbe.c"
 puts "** are encoded into bitvectors as follows:"
 puts "*/"
-puts "#define OPFLG_JUMP            0x0001  /* jump:  P2 holds jmp target */"
-puts "#define OPFLG_IN1             0x0002  /* in1:   P1 is an input */"
-puts "#define OPFLG_IN2             0x0004  /* in2:   P2 is an input */"
-puts "#define OPFLG_IN3             0x0008  /* in3:   P3 is an input */"
-puts "#define OPFLG_OUT2            0x0010  /* out2:  P2 is an output */"
-puts "#define OPFLG_OUT3            0x0020  /* out3:  P3 is an output */"
+puts "#define OPFLG_JUMP        0x01  /* jump:  P2 holds jmp target */"
+puts "#define OPFLG_IN1         0x02  /* in1:   P1 is an input */"
+puts "#define OPFLG_IN2         0x04  /* in2:   P2 is an input */"
+puts "#define OPFLG_IN3         0x08  /* in3:   P3 is an input */"
+puts "#define OPFLG_OUT2        0x10  /* out2:  P2 is an output */"
+puts "#define OPFLG_OUT3        0x20  /* out3:  P3 is an output */"
 puts "#define OPFLG_INITIALIZER \173\\"
 for {set i 0} {$i<=$max} {incr i} {
   if {$i%8==0} {
@@ -228,3 +253,11 @@ for {set i 0} {$i<=$max} {incr i} {
   }
 }
 puts "\175"
+puts ""
+puts "/* The sqlite3P2Values() routine is able to run faster if it knows"
+puts "** the value of the largest JUMP opcode.  The smaller the maximum"
+puts "** JUMP opcode the better, so the mkopcodeh.tcl script that"
+puts "** generated this include file strives to group all JUMP opcodes"
+puts "** together near the beginning of the list."
+puts "*/"
+puts "#define SQLITE_MX_JUMP_OPCODE  $mxJump  /* Maximum JUMP opcode */"