[Pearcolator-devel] SF.net SVN: pearcolator: [66] ext/org/jikesrvm/compilers/opt/ir

[<cap...@us...>]

Revision: 66
          http://svn.sourceforge.net/pearcolator/?rev=66&view=rev
Author:   captain5050
Date:     2007-04-18 07:27:27 -0700 (Wed, 18 Apr 2007)

Log Message:
-----------
Support for overflow from multiply

Modified Paths:
--------------
    ext/org/jikesrvm/compilers/opt/ir/OPT_ConditionOperand.java
    ext/org/jikesrvm/compilers/opt/ir/ia32/OPT_IA32ConditionOperand.java

Modified: ext/org/jikesrvm/compilers/opt/ir/OPT_ConditionOperand.java
===================================================================
--- ext/org/jikesrvm/compilers/opt/ir/OPT_ConditionOperand.java	2007-04-18 14:26:40 UTC (rev 65)
+++ ext/org/jikesrvm/compilers/opt/ir/OPT_ConditionOperand.java	2007-04-18 14:27:27 UTC (rev 66)
@@ -109,6 +109,11 @@
   /** Would is bit a not set in b? */
   public static final int NO_RBIT_TEST          = 35;
 
+  /** Would a*b cause an overflow? */
+  public static final int OVERFLOW_FROM_MUL     = 36;
+  /** Would a*b not cause an overflow? */
+  public static final int NO_OVERFLOW_FROM_MUL  = 37;
+
   /* Results from evaluations */
   /** Evaluation result is false */
   public static final int FALSE = 0;
@@ -310,6 +315,15 @@
   }
 
   /**
+   * Create the condition code operand for OVERFLOW_FROM_ADD
+   * 
+   * @return a newly created condition code operand
+   */
+  public static OPT_ConditionOperand OVERFLOW_FROM_MUL() {
+    return new OPT_ConditionOperand(OVERFLOW_FROM_MUL);
+  }
+
+  /**
    * Is x higher (unsigned >) than y?
    */
   private static boolean higher(int x, int y) {
@@ -373,6 +387,15 @@
   }
 
   /**
+   * Would x*y overflow a register?
+   */
+  private static boolean overflow_from_mul(int x, int y) {
+    int z = x * y;
+    long z2 = ((long)x) * ((long)y);
+    return (long)z != z2;
+  }
+
+  /**
    * Would is bit y of x set?
    */
   private static boolean bit_test(int x, int y) {
@@ -507,6 +530,8 @@
     case NO_BIT_TEST:
     case RBIT_TEST:
     case NO_RBIT_TEST:
+    case OVERFLOW_FROM_MUL:
+    case NO_OVERFLOW_FROM_MUL:
       return true;
     default:
       return false;
@@ -845,6 +870,8 @@
       case NO_BIT_TEST:
       case RBIT_TEST:
       case NO_RBIT_TEST:
+      case OVERFLOW_FROM_MUL:
+      case NO_OVERFLOW_FROM_MUL:
         return UNKNOWN;
       default:
         throw new OPT_OptimizingCompilerException("invalid condition " + this);
@@ -891,6 +918,8 @@
     case NO_BIT_TEST:           return bit_test(v1, v2) ? FALSE : TRUE;
     case RBIT_TEST:             return bit_test(v2, v1) ? TRUE : FALSE;
     case NO_RBIT_TEST:          return bit_test(v2, v1) ? FALSE : TRUE;
+    case OVERFLOW_FROM_MUL:     return overflow_from_mul(v1, v2) ? TRUE : FALSE;
+    case NO_OVERFLOW_FROM_MUL:  return overflow_from_mul(v1, v2) ? FALSE : TRUE;
     }
     throw new OPT_OptimizingCompilerException("invalid condition " + this);
   }
@@ -1055,6 +1084,10 @@
     case NO_BIT_TEST:           value = BIT_TEST; break;
     case RBIT_TEST:             value = NO_RBIT_TEST; break;
     case NO_RBIT_TEST:          value = RBIT_TEST; break;
+
+    case OVERFLOW_FROM_MUL:     value = NO_OVERFLOW_FROM_MUL; break;
+    case NO_OVERFLOW_FROM_MUL:  value = OVERFLOW_FROM_MUL; break;
+
     default:
       OPT_OptimizingCompilerException.UNREACHABLE();
     }
@@ -1118,6 +1151,10 @@
     case NO_BIT_TEST:           value = NO_RBIT_TEST; break;
     case RBIT_TEST:             value = BIT_TEST; break;
     case NO_RBIT_TEST:          value = NO_BIT_TEST; break;
+
+    case OVERFLOW_FROM_MUL:     break; // mul is commutative
+    case NO_OVERFLOW_FROM_MUL:  break;
+
     default:
       OPT_OptimizingCompilerException.UNREACHABLE();
     }
@@ -1183,6 +1220,9 @@
     case RBIT_TEST:             return "rbt";
     case NO_RBIT_TEST:          return "!rbt";
 
+    case OVERFLOW_FROM_MUL:     return "overflow(*)";
+    case NO_OVERFLOW_FROM_MUL:  return "nooverflow(*)";
+
     default:                 return "UNKNOWN";
     }
   }

Modified: ext/org/jikesrvm/compilers/opt/ir/ia32/OPT_IA32ConditionOperand.java
===================================================================
--- ext/org/jikesrvm/compilers/opt/ir/ia32/OPT_IA32ConditionOperand.java	2007-04-18 14:26:40 UTC (rev 65)
+++ ext/org/jikesrvm/compilers/opt/ir/ia32/OPT_IA32ConditionOperand.java	2007-04-18 14:27:27 UTC (rev 66)
@@ -171,14 +171,36 @@
       value = LGT;
       break;
     case OPT_ConditionOperand.LOWER:
+    case OPT_ConditionOperand.CARRY_FROM_ADD:
+    case OPT_ConditionOperand.BORROW_FROM_SUB:
+    case OPT_ConditionOperand.BORROW_FROM_RSUB:
+    case OPT_ConditionOperand.BIT_TEST:
+    case OPT_ConditionOperand.RBIT_TEST:
       value = LLT;
       break;
     case OPT_ConditionOperand.HIGHER_EQUAL:
+    case OPT_ConditionOperand.NO_CARRY_FROM_ADD:
+    case OPT_ConditionOperand.NO_BORROW_FROM_SUB:
+    case OPT_ConditionOperand.NO_BORROW_FROM_RSUB:
+    case OPT_ConditionOperand.NO_BIT_TEST:
+    case OPT_ConditionOperand.NO_RBIT_TEST:
       value = LGE;
       break;
     case OPT_ConditionOperand.LOWER_EQUAL:
       value = LLE;
       break;
+    case OPT_ConditionOperand.OVERFLOW_FROM_ADD:
+    case OPT_ConditionOperand.OVERFLOW_FROM_SUB:
+    case OPT_ConditionOperand.OVERFLOW_FROM_RSUB:
+    case OPT_ConditionOperand.OVERFLOW_FROM_MUL:
+      value =   O;
+      break;
+    case OPT_ConditionOperand.NO_OVERFLOW_FROM_ADD:
+    case OPT_ConditionOperand.NO_OVERFLOW_FROM_SUB:
+    case OPT_ConditionOperand.NO_OVERFLOW_FROM_RSUB:
+    case OPT_ConditionOperand.NO_OVERFLOW_FROM_MUL:
+      value =  NO;
+      break;
     case OPT_ConditionOperand.CMPL_EQUAL:
     case OPT_ConditionOperand.CMPL_GREATER:
     case OPT_ConditionOperand.CMPG_LESS:


This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.