C++: Add getUpdatedInterval predicate to ChiInstructions, and getUsedInterval predicate to NonPhiMemoryOperands.

cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/Instruction.qll

@@ -1962,6 +1962,13 @@ class ChiInstruction extends Instruction {
    * Gets the operand that represents the new value written by the memory write.
    */
   final Instruction getPartial() { result = getPartialOperand().getDef() }
+
+  /**
+   * Gets the bit range `[startBit, endBit)` updated by the partial operand of this `ChiInstruction`.
+   */
+  final predicate getUpdatedInterval(int startBit, int endBit) {
+    Construction::getIntervalUpdatedByChi(this, startBit, endBit)
+  }
 }
 
 /**

cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/Operand.qll

@@ -328,6 +328,14 @@ class NonPhiMemoryOperand extends NonPhiOperand, MemoryOperand, NonPhiMemoryOper
     not Construction::isInCycle(useInstr) and
     strictcount(Construction::getMemoryOperandDefinition(useInstr, tag, _)) = 1
   }
+
+  /**
+   * Holds if the operand totally overlaps with its definition and consumes the
+   * bit range `[startBitOffset, endBitOffset)`.
+   */
+  predicate getUsedInterval(int startBitOffset, int endBitOffset) {
+    Construction::getUsedInterval(this, startBitOffset, endBitOffset)
+  }
 }
 
 /**

cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/AliasedSSA.qll

@@ -556,22 +556,6 @@ private Overlap getVariableMemoryLocationOverlap(
       use.getEndBitOffset())
 }
 
-predicate getDefInterval(Instruction defInstr, IntValue startBitDef, IntValue endBitDef) {
-  exists(VariableMemoryLocation def |
-    def = getResultMemoryLocation(defInstr) and
-    startBitDef = def.getStartBitOffset() and
-    endBitDef = def.getEndBitOffset()
-  )
-}
-
-predicate getUseInterval(Instruction useInstr, IntValue startBitUse, IntValue endBitUse) {
-  exists(VariableMemoryLocation use |
-    use = getOperandMemoryLocation(useInstr.getAnOperand()) and
-    startBitUse = use.getStartBitOffset() and
-    endBitUse = use.getEndBitOffset()
-  )
-}
-
 MemoryLocation getResultMemoryLocation(Instruction instr) {
   exists(MemoryAccessKind kind, boolean isMayAccess |
     kind = instr.getResultMemoryAccess() and
@@ -633,3 +617,9 @@ MemoryLocation getOperandMemoryLocation(MemoryOperand operand) {
     )
   )
 }
+
+/** Gets the start bit offset of a `MemoryLocation`, if any. */
+int getStartBitOffset(VariableMemoryLocation location) { result = location.getStartBitOffset() }
+
+/** Gets the end bit offset of a `MemoryLocation`, if any. */
+int getEndBitOffset(VariableMemoryLocation location) { result = location.getEndBitOffset() }

cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/SSAConstruction.qll

@@ -149,6 +149,34 @@ private module Cached {
     )
   }
 
+  /**
+   * Holds if the partial operand of this `ChiInstruction` updates the bit range
+   * `[startBitOffset, endBitOffset)` of the total operand.
+   */
+  cached
+  predicate getIntervalUpdatedByChi(ChiInstruction chi, int startBitOffset, int endBitOffset) {
+    exists(Alias::MemoryLocation location, OldInstruction oldInstruction |
+      oldInstruction = getOldInstruction(chi.getPartial()) and
+      location = Alias::getResultMemoryLocation(oldInstruction) and
+      startBitOffset = Alias::getStartBitOffset(location) and
+      endBitOffset = Alias::getEndBitOffset(location)
+    )
+  }
+
+  /**
+   * Holds if `operand` totally overlaps with its definition and consumes the bit range
+   * `[startBitOffset, endBitOffset)`.
+   */
+  cached
+  predicate getUsedInterval(NonPhiMemoryOperand operand, int startBitOffset, int endBitOffset) {
+    exists(Alias::MemoryLocation location, OldIR::NonPhiMemoryOperand oldOperand |
+      oldOperand = operand.getUse().(OldInstruction).getAnOperand() and
+      location = Alias::getOperandMemoryLocation(oldOperand) and
+      startBitOffset = Alias::getStartBitOffset(location) and
+      endBitOffset = Alias::getEndBitOffset(location)
+    )
+  }
+
   /**
    * Holds if `instr` is part of a cycle in the operand graph that doesn't go
    * through a phi instruction and therefore should be impossible.

cpp/ql/src/semmle/code/cpp/ir/implementation/raw/Instruction.qll

@@ -1962,6 +1962,13 @@ class ChiInstruction extends Instruction {
    * Gets the operand that represents the new value written by the memory write.
    */
   final Instruction getPartial() { result = getPartialOperand().getDef() }
+
+  /**
+   * Gets the bit range `[startBit, endBit)` updated by the partial operand of this `ChiInstruction`.
+   */
+  final predicate getUpdatedInterval(int startBit, int endBit) {
+    Construction::getIntervalUpdatedByChi(this, startBit, endBit)
+  }
 }
 
 /**

cpp/ql/src/semmle/code/cpp/ir/implementation/raw/Operand.qll

@@ -328,6 +328,14 @@ class NonPhiMemoryOperand extends NonPhiOperand, MemoryOperand, NonPhiMemoryOper
     not Construction::isInCycle(useInstr) and
     strictcount(Construction::getMemoryOperandDefinition(useInstr, tag, _)) = 1
   }
+
+  /**
+   * Holds if the operand totally overlaps with its definition and consumes the
+   * bit range `[startBitOffset, endBitOffset)`.
+   */
+  predicate getUsedInterval(int startBitOffset, int endBitOffset) {
+    Construction::getUsedInterval(this, startBitOffset, endBitOffset)
+  }
 }
 
 /**

cpp/ql/src/semmle/code/cpp/ir/implementation/raw/internal/IRConstruction.qll

@@ -182,6 +182,18 @@ Instruction getMemoryOperandDefinition(
   none()
 }
 
+/**
+ * Holds if the partial operand of this `ChiInstruction` updates the bit range
+ * `[startBitOffset, endBitOffset)` of the total operand.
+ */
+predicate getIntervalUpdatedByChi(ChiInstruction chi, int startBit, int endBit) { none() }
+
+/**
+ * Holds if the operand totally overlaps with its definition and consumes the
+ * bit range `[startBitOffset, endBitOffset)`.
+ */
+predicate getUsedInterval(Operand operand, int startBit, int endBit) { none() }
+
 /** Gets a non-phi instruction that defines an operand of `instr`. */
 private Instruction getNonPhiOperandDef(Instruction instr) {
   result = getRegisterOperandDefinition(instr, _)

cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/Instruction.qll

@@ -1962,6 +1962,13 @@ class ChiInstruction extends Instruction {
    * Gets the operand that represents the new value written by the memory write.
    */
   final Instruction getPartial() { result = getPartialOperand().getDef() }
+
+  /**
+   * Gets the bit range `[startBit, endBit)` updated by the partial operand of this `ChiInstruction`.
+   */
+  final predicate getUpdatedInterval(int startBit, int endBit) {
+    Construction::getIntervalUpdatedByChi(this, startBit, endBit)
+  }
 }
 
 /**

cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/Operand.qll

@@ -328,6 +328,14 @@ class NonPhiMemoryOperand extends NonPhiOperand, MemoryOperand, NonPhiMemoryOper
     not Construction::isInCycle(useInstr) and
     strictcount(Construction::getMemoryOperandDefinition(useInstr, tag, _)) = 1
   }
+
+  /**
+   * Holds if the operand totally overlaps with its definition and consumes the
+   * bit range `[startBitOffset, endBitOffset)`.
+   */
+  predicate getUsedInterval(int startBitOffset, int endBitOffset) {
+    Construction::getUsedInterval(this, startBitOffset, endBitOffset)
+  }
 }
 
 /**

cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/SSAConstruction.qll

@@ -149,6 +149,34 @@ private module Cached {
     )
   }
 
+  /**
+   * Holds if the partial operand of this `ChiInstruction` updates the bit range
+   * `[startBitOffset, endBitOffset)` of the total operand.
+   */
+  cached
+  predicate getIntervalUpdatedByChi(ChiInstruction chi, int startBitOffset, int endBitOffset) {
+    exists(Alias::MemoryLocation location, OldInstruction oldInstruction |
+      oldInstruction = getOldInstruction(chi.getPartial()) and
+      location = Alias::getResultMemoryLocation(oldInstruction) and
+      startBitOffset = Alias::getStartBitOffset(location) and
+      endBitOffset = Alias::getEndBitOffset(location)
+    )
+  }
+
+  /**
+   * Holds if `operand` totally overlaps with its definition and consumes the bit range
+   * `[startBitOffset, endBitOffset)`.
+   */
+  cached
+  predicate getUsedInterval(NonPhiMemoryOperand operand, int startBitOffset, int endBitOffset) {
+    exists(Alias::MemoryLocation location, OldIR::NonPhiMemoryOperand oldOperand |
+      oldOperand = operand.getUse().(OldInstruction).getAnOperand() and
+      location = Alias::getOperandMemoryLocation(oldOperand) and
+      startBitOffset = Alias::getStartBitOffset(location) and
+      endBitOffset = Alias::getEndBitOffset(location)
+    )
+  }
+
   /**
    * Holds if `instr` is part of a cycle in the operand graph that doesn't go
    * through a phi instruction and therefore should be impossible.

cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/SimpleSSA.qll

@@ -79,3 +79,9 @@ MemoryLocation getResultMemoryLocation(Instruction instr) {
 MemoryLocation getOperandMemoryLocation(MemoryOperand operand) {
   result = getMemoryLocation(getAddressOperandAllocation(operand.getAddressOperand()))
 }
+
+/** Gets the start bit offset of a `MemoryLocation`, if any. */
+int getStartBitOffset(MemoryLocation location) { none() }
+
+/** Gets the end bit offset of a `MemoryLocation`, if any. */
+int getEndBitOffset(MemoryLocation location) { none() }