C++: Remove safeFloor in simple range analysis

Author: paldepind

cpp/ql/lib/semmle/code/cpp/rangeanalysis/SimpleRangeAnalysis.qll

@@ -158,22 +158,6 @@ private class UnsignedBitwiseAndExpr extends BitwiseAndExpr {
   }
 }
 
-/**
- * Gets the floor of `v`, with additional logic to work around issues with
- * large numbers.
- */
-bindingset[v]
-float safeFloor(float v) {
-  // return the floor of v
-  v.abs() < 2.pow(31) and
-  result = v.floor()
-  or
-  // `floor()` doesn't work correctly on large numbers (since it returns an integer),
-  // so fall back to unrounded numbers at this scale.
-  not v.abs() < 2.pow(31) and
-  result = v
-}
-
 /** A `MulExpr` where exactly one operand is constant. */
 private class MulByConstantExpr extends MulExpr {
   float constant;
@@ -1266,7 +1250,7 @@ private float getLowerBoundsImpl(Expr expr) {
       rsExpr = expr and
       left = getFullyConvertedLowerBounds(rsExpr.getLeftOperand()) and
       right = getValue(rsExpr.getRightOperand().getFullyConverted()).toInt() and
-      result = safeFloor(left / 2.pow(right))
+      result = (left / 2.pow(right)).floorFloat()
     )
     // Not explicitly modeled by a SimpleRangeAnalysisExpr
   ) and
@@ -1475,7 +1459,7 @@ private float getUpperBoundsImpl(Expr expr) {
       rsExpr = expr and
       left = getFullyConvertedUpperBounds(rsExpr.getLeftOperand()) and
       right = getValue(rsExpr.getRightOperand().getFullyConverted()).toInt() and
-      result = safeFloor(left / 2.pow(right))
+      result = (left / 2.pow(right)).floorFloat()
     )
     // Not explicitly modeled by a SimpleRangeAnalysisExpr
   ) and

cpp/ql/test/library-tests/rangeanalysis/SimpleRangeAnalysis/lowerBound.expected

@@ -351,7 +351,7 @@
 | test.c:330:14:330:14 | r | -2147483648 |
 | test.c:333:10:333:14 | total | -2147483648 |
 | test.c:341:32:341:34 | odd | 9007199254740991 |
-| test.c:343:10:343:16 | shifted | 4503599627370495.5 |
+| test.c:343:10:343:16 | shifted | 4503599627370495 |
 | test.c:348:7:348:7 | x | -2147483648 |
 | test.c:352:10:352:10 | i | 0 |
 | test.c:353:5:353:5 | i | 0 |

cpp/ql/test/library-tests/rangeanalysis/SimpleRangeAnalysis/upperBound.expected

@@ -351,7 +351,7 @@
 | test.c:330:14:330:14 | r | 2147483647 |
 | test.c:333:10:333:14 | total | 2147483647 |
 | test.c:341:32:341:34 | odd | 9007199254740991 |
-| test.c:343:10:343:16 | shifted | 4503599627370495.5 |
+| test.c:343:10:343:16 | shifted | 4503599627370495 |
 | test.c:348:7:348:7 | x | 2147483647 |
 | test.c:352:10:352:10 | i | 7 |
 | test.c:353:5:353:5 | i | 2 |