1.1 --- a/jitcraft/Interpreter.cpp	Tue Jul 17 00:49:24 2012 -0700
     1.2 +++ b/jitcraft/Interpreter.cpp	Tue Jul 17 03:18:32 2012 -0700
     1.3 @@ -55,6 +55,18 @@
     1.4      return value;
     1.5  }
     1.6  
     1.7 +// Pawn's original semantics specify some kind of floor operation, so
     1.8 +// (8 / -3 == -3) and (-8 / 3 == -1). The SourcePawn 1 compiler (spcomp) uses
     1.9 +// the upstream algorithm when constant folding. However the SourcePawn 1 JIT
    1.10 +// does not. My guess is that Borja freaked out seeing the 13-instruction x86
    1.11 +// sequence necessary to get this functionality (I vaguely recall a thread
    1.12 +// where we discussed this with Mark Peter? But the ITB forums are gone...),
    1.13 +// and we just decided to break the damn thing. So SP1 was inconsistent, but
    1.14 +// we are not. And for completeness, we assert that the C compiler does the
    1.15 +// right thing, since C89 leaves it unspecified.
    1.16 +STATIC_ASSERT(8 / -3 == -2);
    1.17 +STATIC_ASSERT(-8 / 3 == -2);
    1.18 +
    1.19  static inline bool
    1.20  PushNewRef(Zone *zone, Top &top, void *location, Heap::Tenure tenure)
    1.21  {
    1.22 @@ -331,41 +343,33 @@
    1.23  
    1.24  case OP_ADD:
    1.25  {
    1.26 -    int right = POP_I32(top);
    1.27 -    int left = POP_I32(top);
    1.28 -    int result = left + right;
    1.29 -    PUSH_I32(top, result);
    1.30 +    top.sp[-2].i32 = top.sp[-2].i32 + top.sp[-1].i32;
    1.31 +    top.sp--;
    1.32      break;
    1.33  }
    1.34  
    1.35  case OP_SUB:
    1.36  {
    1.37 -    int right = POP_I32(top);
    1.38 -    int left = POP_I32(top);
    1.39 -    int result = left - right;
    1.40 -    PUSH_I32(top, result);
    1.41 +    top.sp[-2].i32 = top.sp[-2].i32 - top.sp[-1].i32;
    1.42 +    top.sp--;
    1.43      break;
    1.44  }
    1.45  
    1.46  case OP_MUL:
    1.47  {
    1.48 -    int right = POP_I32(top);
    1.49 -    int left = POP_I32(top);
    1.50 -    int result = left * right;
    1.51 -    PUSH_I32(top, result);
    1.52 +    top.sp[-2].i32 = top.sp[-2].i32 * top.sp[-1].i32;
    1.53 +    top.sp--;
    1.54      break;
    1.55  }
    1.56  
    1.57  case OP_DIV:
    1.58  {
    1.59 -    int right = POP_I32(top);
    1.60 -    int left = POP_I32(top);
    1.61 -    if (!right) {
    1.62 +    if (top.sp[-1].i32 == 0) {
    1.63          zone->reportError(Message_IntegerDivideByZero);
    1.64          goto error;
    1.65      }
    1.66 -    int result = left / right;
    1.67 -    PUSH_I32(top, result);
    1.68 +    top.sp[-2].i32 = top.sp[-2].i32 / top.sp[-1].i32;
    1.69 +    top.sp--;
    1.70      break;
    1.71  }
    1.72  
    1.73 @@ -413,37 +417,29 @@
    1.74  
    1.75  case OP_ADD_F:
    1.76  {
    1.77 -    float right = POP_F(top);
    1.78 -    float left = POP_F(top);
    1.79 -    float result = left + right;
    1.80 -    PUSH_F(top, result);
    1.81 +    top.sp[-2].f = top.sp[-2].f + top.sp[-1].f;
    1.82 +    top.sp--;
    1.83      break;
    1.84  }
    1.85  
    1.86  case OP_SUB_F:
    1.87  {
    1.88 -    float right = POP_F(top);
    1.89 -    float left = POP_F(top);
    1.90 -    float result = left - right;
    1.91 -    PUSH_F(top, result);
    1.92 +    top.sp[-2].f = top.sp[-2].f - top.sp[-1].f;
    1.93 +    top.sp--;
    1.94      break;
    1.95  }
    1.96  
    1.97  case OP_MUL_F:
    1.98  {
    1.99 -    float right = POP_F(top);
   1.100 -    float left = POP_F(top);
   1.101 -    float result = left * right;
   1.102 -    PUSH_F(top, result);
   1.103 +    top.sp[-2].f = top.sp[-2].f * top.sp[-1].f;
   1.104 +    top.sp--;
   1.105      break;
   1.106  }
   1.107  
   1.108  case OP_DIV_F:
   1.109  {
   1.110 -    float right = POP_F(top);
   1.111 -    float left = POP_F(top);
   1.112 -    float result = left / right;
   1.113 -    PUSH_F(top, result);
   1.114 +    top.sp[-2].f = top.sp[-2].f / top.sp[-1].f;
   1.115 +    top.sp--;
   1.116      break;
   1.117  }
   1.118  
   1.119 @@ -491,55 +487,43 @@
   1.120  
   1.121  case OP_SHL:
   1.122  {
   1.123 -    int right = POP_I32(top);
   1.124 -    int left = POP_I32(top);
   1.125 -    int result = left << right;
   1.126 -    PUSH_I32(top, result);
   1.127 +    top.sp[-2].i32 = top.sp[-2].i32 << top.sp[-1].i32;
   1.128 +    top.sp--;
   1.129      break;
   1.130  }
   1.131  
   1.132  case OP_SHR:
   1.133  {
   1.134 -    int right = POP_I32(top);
   1.135 -    int left = POP_I32(top);
   1.136 -    int result = left >> right;
   1.137 -    PUSH_I32(top, result);
   1.138 +    top.sp[-2].i32 = top.sp[-2].i32 >> top.sp[-1].i32;
   1.139 +    top.sp--;
   1.140      break;
   1.141  }
   1.142  
   1.143  case OP_USHR:
   1.144  {
   1.145 -    int right = POP_I32(top);
   1.146 -    int left = POP_I32(top);
   1.147 -    int result = unsigned(left) >> unsigned(right);
   1.148 -    PUSH_I32(top, result);
   1.149 +    top.sp[-2].i32 = unsigned(top.sp[-2].i32) << unsigned(top.sp[-1].i32);
   1.150 +    top.sp--;
   1.151      break;
   1.152  }
   1.153  
   1.154  case OP_BITAND:
   1.155  {
   1.156 -    int right = POP_I32(top);
   1.157 -    int left = POP_I32(top);
   1.158 -    int result = left & right;
   1.159 -    PUSH_I32(top, result);
   1.160 +    top.sp[-2].i32 = top.sp[-2].i32 & top.sp[-1].i32;
   1.161 +    top.sp--;
   1.162      break;
   1.163  }
   1.164  
   1.165  case OP_BITOR:
   1.166  {
   1.167 -    int right = POP_I32(top);
   1.168 -    int left = POP_I32(top);
   1.169 -    int result = left | right;
   1.170 -    PUSH_I32(top, result);
   1.171 +    top.sp[-2].i32 = top.sp[-2].i32 | top.sp[-1].i32;
   1.172 +    top.sp--;
   1.173      break;
   1.174  }
   1.175  
   1.176  case OP_BITXOR:
   1.177  {
   1.178 -    int right = POP_I32(top);
   1.179 -    int left = POP_I32(top);
   1.180 -    int result = left ^ right;
   1.181 -    PUSH_I32(top, result);
   1.182 +    top.sp[-2].i32 = top.sp[-2].i32 ^ top.sp[-1].i32;
   1.183 +    top.sp--;
   1.184      break;
   1.185  }
   1.186