[asan] Don't skip instrumentation of masked load/store unless we've seen a full load/store on that pointer.

[RKSimon]

lib/Transforms/Instrumentation/AddressSanitizer.cpp

2074

Remove the braces. Any reason why you don't want to merge the if conditions?

[filcab]

lib/Transforms/Instrumentation/AddressSanitizer.cpp

2074

Mostly to avoid touching much code. I'll upload a new version.
But I'll keep the braces so we don't have ambiguity with the nested if (after the code change).

[filcab]

Merge ifs.

[filcab]

Ping!

[kcc]

lib/Transforms/Instrumentation/AddressSanitizer.cpp

2072

I'd expect this to be inside if (ClOpt && ClOptSameTemp)
No?

[filcab]

lib/Transforms/Instrumentation/AddressSanitizer.cpp

2072

Ah! Right. Will submit new version.

[filcab]

Fixed test

[kcc]

LGTM

lib/Transforms/Instrumentation/AddressSanitizer.cpp

bool AddressSanitizer::runOnFunction(Function &F) {
 
   // Fill the set of memory operations to instrument.
   for (auto &BB : F) {
     AllBlocks.push_back(&BB);
     TempsToInstrument.clear();
     int NumInsnsPerBB = 0;
     for (auto &Inst : BB) {
       if (LooksLikeCodeInBug11395(&Inst)) return false;
+      Value *MaybeMask = nullptr;
       if (Value *Addr = isInterestingMemoryAccess(&Inst, &IsWrite, &TypeSize,
-                                                  &Alignment)) {
-        if (ClOpt && ClOptSameTemp) {
+                                                  &Alignment, &MaybeMask)) {
+        // If we have a mask, skip instrumentation if we've already instrumented
+        // the full object. But don't add to TempsToInstrument because we might
+        // get another load/store with a different mask.
+        if (MaybeMask) {
+          if (TempsToInstrument.count(Addr))
+            continue;  // We've seen this (whole) temp in the current BB.
+        } else if (ClOpt && ClOptSameTemp) {
           if (!TempsToInstrument.insert(Addr).second)
             continue;  // We've seen this temp in the current BB.
         }
       } else if (ClInvalidPointerPairs &&
                  isInterestingPointerComparisonOrSubtraction(&Inst)) {
         PointerComparisonsOrSubtracts.push_back(&Inst);
         continue;
       } else if (isa<MemIntrinsic>(Inst)) {

test/Instrumentation/AddressSanitizer/asan-masked-load-store.ll

 define void @store.v4f32.variable(<4 x float> %arg, <4 x i1> %mask) sanitize_address {
 ; BOTH-LABEL: @store.v4f32.variable
   %p = load <4 x float>*, <4 x float>** @v4f32, align 8
 ; BOTH-NOT: call void @__asan_store
   tail call void @llvm.masked.store.v4f32.p0v4f32(<4 x float> %arg, <4 x float>* %p, i32 4, <4 x i1> %mask)
   ret void
 }
 
+;; Store using two masked.stores, which should instrument them both.
+define void @store.v4f32.1010.split(<4 x float> %arg) sanitize_address {
+; BOTH-LABEL: @store.v4f32.1010.split
+  %p = load <4 x float>*, <4 x float>** @v4f32, align 8
+; STORE: [[GEP0:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 0
+; STORE: [[PGEP0:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP0]] to i64
+; STORE: call void @__asan_store4(i64 [[PGEP0]])
+; STORE: tail call void @llvm.masked.store.v4f32.p0v4f32(<4 x float> %arg, <4 x float>* %p, i32 4, <4 x i1> <i1 true, i1 false, i1 false, i1 false>)
+  tail call void @llvm.masked.store.v4f32.p0v4f32(<4 x float> %arg, <4 x float>* %p, i32 4, <4 x i1> <i1 true, i1 false, i1 false, i1 false>)
+; STORE: [[GEP1:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 2
+; STORE: [[PGEP1:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP1]] to i64
+; STORE: call void @__asan_store4(i64 [[PGEP1]])
+; STORE: tail call void @llvm.masked.store.v4f32.p0v4f32(<4 x float> %arg, <4 x float>* %p, i32 4, <4 x i1> <i1 false, i1 false, i1 true, i1 false>)
+  tail call void @llvm.masked.store.v4f32.p0v4f32(<4 x float> %arg, <4 x float>* %p, i32 4, <4 x i1> <i1 false, i1 false, i1 true, i1 false>)
+  ret void
+}
+
+;; Store using a masked.store after a full store. Shouldn't instrument the second one.
+define void @store.v4f32.0010.after.full.store(<4 x float> %arg) sanitize_address {
+; BOTH-LABEL: @store.v4f32.0010.after.full.store
+  %p = load <4 x float>*, <4 x float>** @v4f32, align 8
+; STORE: [[PTRTOINT:%[0-9A-Za-z]+]] = ptrtoint <4 x float>* %p to i64
+; STORE: call void @__asan_store16(i64 [[PTRTOINT]])
+; STORE: store <4 x float> %arg, <4 x float>* %p
+  store <4 x float> %arg, <4 x float>* %p
+; STORE-NOT: call void @__asan_store
+; STORE: tail call void @llvm.masked.store.v4f32.p0v4f32(<4 x float> %arg, <4 x float>* %p, i32 4, <4 x i1> <i1 false, i1 false, i1 true, i1 false>)
+  tail call void @llvm.masked.store.v4f32.p0v4f32(<4 x float> %arg, <4 x float>* %p, i32 4, <4 x i1> <i1 false, i1 false, i1 true, i1 false>)
+  ret void
+}
+
 ;;;;;;;;;;;;;;;; LOAD
 declare <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>*, i32, <4 x i1>, <4 x float>) argmemonly nounwind
 declare <8 x i32> @llvm.masked.load.v8i32.p0v8i32(<8 x i32>*, i32, <8 x i1>, <8 x i32>) argmemonly nounwind
 declare <4 x i32*> @llvm.masked.load.v4p0i32.p0v4p0i32(<4 x i32*>*, i32, <4 x i1>, <4 x i32*>) argmemonly nounwind
 
 define <8 x i32> @load.v8i32.11100001(<8 x i32> %arg) sanitize_address {
 ; BOTH-LABEL: @load.v8i32.11100001
   %p = load <8 x i32>*, <8 x i32>** @v8i32, align 8

 
 define <4 x float> @load.v4f32.variable(<4 x float> %arg, <4 x i1> %mask) sanitize_address {
 ; BOTH-LABEL: @load.v4f32.variable
   %p = load <4 x float>*, <4 x float>** @v4f32, align 8
 ; BOTH-NOT: call void @__asan_load
   %res = tail call <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>* %p, i32 4, <4 x i1> %mask, <4 x float> %arg)
   ret <4 x float> %res
 }
+
+;; Load using two masked.loads, which should instrument them both.
+define <4 x float> @load.v4f32.1001.split(<4 x float> %arg) sanitize_address {
+; BOTH-LABEL: @load.v4f32.1001
+  %p = load <4 x float>*, <4 x float>** @v4f32, align 8
+; LOAD: [[GEP0:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 0
+; LOAD: [[PGEP0:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP0]] to i64
+; LOAD: call void @__asan_load4(i64 [[PGEP0]])
+; LOAD: %res = tail call <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>* %p, i32 4, <4 x i1> <i1 true, i1 false, i1 false, i1 false>, <4 x float> %arg)
+  %res = tail call <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>* %p, i32 4, <4 x i1> <i1 true, i1 false, i1 false, i1 false>, <4 x float> %arg)
+; LOAD: [[GEP3:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 3
+; LOAD: [[PGEP3:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP3]] to i64
+; LOAD: call void @__asan_load4(i64 [[PGEP3]])
+; LOAD: tail call <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>* %p, i32 4, <4 x i1> <i1 false, i1 false, i1 false, i1 true>, <4 x float> %res)
+  %res2 = tail call <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>* %p, i32 4, <4 x i1> <i1 false, i1 false, i1 false, i1 true>, <4 x float> %res)
+  ret <4 x float> %res2
+}
+
+;; Load using a masked.load after a full load. Shouldn't instrument the second one.
+define <4 x float> @load.v4f32.1001.after.full.load(<4 x float> %arg) sanitize_address {
+; BOTH-LABEL: @load.v4f32.1001.after.full.load
+  %p = load <4 x float>*, <4 x float>** @v4f32, align 8
+; LOAD: [[PTRTOINT:%[0-9A-Za-z]+]] = ptrtoint <4 x float>* %p to i64
+; LOAD: call void @__asan_load16(i64 [[PTRTOINT]])
+; LOAD: %res = load <4 x float>, <4 x float>* %p
+  %res = load <4 x float>, <4 x float>* %p
+; LOAD-NOT: call void @__asan_load
+; LOAD: tail call <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>* %p, i32 4, <4 x i1> <i1 false, i1 false, i1 false, i1 true>, <4 x float> %arg)
+  %res2 = tail call <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>* %p, i32 4, <4 x i1> <i1 false, i1 false, i1 false, i1 true>, <4 x float> %arg)
+  ret <4 x float> %res2
+}