C++: fix join order in hasMemoryOperandDefinition

Robert Marsh · Robert Marsh · commit bbf191e8576b · 2020-01-17T08:05:40.000-08:00
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/SSAConstruction.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/SSAConstruction.qll
@@ -75,19 +75,23 @@ private module Cached {
     )
   }
 
-  private predicate hasMemoryOperandDefinition (OldInstruction oldInstruction, OldIR::NonPhiMemoryOperand oldOperand,
-    Overlap overlap, Instruction instr) {
-      oldOperand = oldInstruction.getAnOperand() and
+  pragma[noopt]
+  private predicate hasMemoryOperandDefinition(
+    OldInstruction oldInstruction, OldIR::NonPhiMemoryOperand oldOperand, Overlap overlap,
+    Instruction instr
+  ) {
+    oldOperand = oldInstruction.getAnOperand() and
+    oldOperand instanceof OldIR::NonPhiMemoryOperand and
     exists(
       OldBlock useBlock, int useRank, Alias::MemoryLocation useLocation,
       Alias::MemoryLocation defLocation, OldBlock defBlock, int defRank, int defOffset
     |
       useLocation = Alias::getOperandMemoryLocation(oldOperand) and
-      hasDefinitionAtRank(useLocation, defLocation, defBlock, defRank, defOffset) and
       hasUseAtRank(useLocation, useBlock, useRank, oldInstruction) and
       definitionReachesUse(useLocation, defBlock, defRank, useBlock, useRank) and
-      overlap = Alias::getOverlap(defLocation, useLocation) and
-      instr = getDefinitionOrChiInstruction(defBlock, defOffset, defLocation, _)
+      hasDefinitionAtRank(useLocation, defLocation, defBlock, defRank, defOffset) and
+      instr = getDefinitionOrChiInstruction(defBlock, defOffset, defLocation, _) and
+      overlap = Alias::getOverlap(defLocation, useLocation)
     )
   }
 
@@ -102,8 +106,7 @@ private module Cached {
       (
         (
           if exists(Alias::getOperandMemoryLocation(oldOperand))
-          then
-          hasMemoryOperandDefinition(oldInstruction, oldOperand, overlap, result)
+          then hasMemoryOperandDefinition(oldInstruction, oldOperand, overlap, result)
           else (
             result = instruction.getEnclosingIRFunction().getUnmodeledDefinitionInstruction() and
             overlap instanceof MustTotallyOverlap

Original file line number	Diff line number	Diff line change
`@@ -75,19 +75,23 @@ private module Cached {`
`75`	`75`	`)`
`76`	`76`	`}`
`77`	`77`
`78`		`- private predicate hasMemoryOperandDefinition (OldInstruction oldInstruction, OldIR::NonPhiMemoryOperand oldOperand,`
`79`		`- Overlap overlap, Instruction instr) {`
`80`		`- oldOperand = oldInstruction.getAnOperand() and`
	`78`	`+ pragma[noopt]`
	`79`	`+ private predicate hasMemoryOperandDefinition(`
	`80`	`+ OldInstruction oldInstruction, OldIR::NonPhiMemoryOperand oldOperand, Overlap overlap,`
	`81`	`+ Instruction instr`
	`82`	`+ ) {`
	`83`	`+ oldOperand = oldInstruction.getAnOperand() and`
	`84`	`+ oldOperand instanceof OldIR::NonPhiMemoryOperand and`
`81`	`85`	`exists(`
`82`	`86`	`OldBlock useBlock, int useRank, Alias::MemoryLocation useLocation,`
`83`	`87`	`Alias::MemoryLocation defLocation, OldBlock defBlock, int defRank, int defOffset`
`84`	`88`	`\|`
`85`	`89`	`useLocation = Alias::getOperandMemoryLocation(oldOperand) and`
`86`		`- hasDefinitionAtRank(useLocation, defLocation, defBlock, defRank, defOffset) and`
`87`	`90`	`hasUseAtRank(useLocation, useBlock, useRank, oldInstruction) and`
`88`	`91`	`definitionReachesUse(useLocation, defBlock, defRank, useBlock, useRank) and`
`89`		`- overlap = Alias::getOverlap(defLocation, useLocation) and`
`90`		`- instr = getDefinitionOrChiInstruction(defBlock, defOffset, defLocation, _)`
	`92`	`+ hasDefinitionAtRank(useLocation, defLocation, defBlock, defRank, defOffset) and`
	`93`	`+ instr = getDefinitionOrChiInstruction(defBlock, defOffset, defLocation, _) and`
	`94`	`+ overlap = Alias::getOverlap(defLocation, useLocation)`
`91`	`95`	`)`
`92`	`96`	`}`
`93`	`97`
`@@ -102,8 +106,7 @@ private module Cached {`
`102`	`106`	`(`
`103`	`107`	`(`
`104`	`108`	`if exists(Alias::getOperandMemoryLocation(oldOperand))`
`105`		`- then`
`106`		`- hasMemoryOperandDefinition(oldInstruction, oldOperand, overlap, result)`
	`109`	`+ then hasMemoryOperandDefinition(oldInstruction, oldOperand, overlap, result)`
`107`	`110`	`else (`
`108`	`111`	`result = instruction.getEnclosingIRFunction().getUnmodeledDefinitionInstruction() and`
`109`	`112`	`overlap instanceof MustTotallyOverlap`