Update comments and unit tests

Author: haopliu

llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp

@@ -2279,11 +2279,11 @@ DSEState::getInitializesArgMemLoc(const Instruction *I) {
 
     Value *CurArg = CB->getArgOperand(Idx);
     // We don't perform incorrect DSE on unwind edges in the current function,
-    // and use the "initialize" attribute to kill dead stores if :
+    // and use the "initializes" attribute to kill dead stores if:
     // - The call does not throw exceptions, "CB->doesNotThrow()".
-    // - Or the argument has "dead_on_unwind" attribute.
-    // - Or the argument is invisble to caller on unwind, and CB isa<CallInst>
-    // which means no unwind edges.
+    // - Or the callee parameter has "dead_on_unwind" attribute.
+    // - Or the argument is invisible to caller on unwind, and CB isa<CallInst>
+    // which means no unwind edges from this call in the current function.
     bool IsDeadOnUnwind =
         CB->paramHasAttr(Idx, Attribute::DeadOnUnwind) ||
         (isInvisibleToCallerOnUnwind(CurArg) && isa<CallInst>(CB));
@@ -2389,6 +2389,10 @@ DSEState::eliminateDeadDefs(const MemoryLocationWrapper &KillingLocWrapper) {
         cast<MemoryDef>(DeadAccess),
         getLocForInst(cast<MemoryDef>(DeadAccess)->getMemoryInst(),
                       /*ConsiderInitializesAttr=*/false));
+    // Note that we don't consider the initializes attribute for DeadAccess.
+    // The dead access would be just a regular write access, like Store
+    // instruction, and its MemoryDefWrapper would only contain one
+    // MemoryLocationWrapper.
     assert(DeadDefWrapper.DefinedLocations.size() == 1);
     MemoryLocationWrapper &DeadLocWrapper =
         DeadDefWrapper.DefinedLocations.front();

llvm/test/Transforms/DeadStoreElimination/inter-procedural.ll

@@ -57,6 +57,35 @@ define i16 @p1_write_then_read_caller_with_clobber() {
   ret i16 %l
 }
 
+declare void @p1_write_then_read_raw(ptr nocapture noundef initializes((0, 2)))
+define i16 @p1_initializes_invoke() personality ptr undef {
+; CHECK-LABEL: @p1_initializes_invoke(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[PTR:%.*]] = alloca i16, align 2
+; CHECK-NEXT:    store i16 0, ptr [[PTR]], align 2
+; CHECK-NEXT:    invoke void @p1_write_then_read_raw(ptr [[PTR]])
+; CHECK-NEXT:            to label [[BB1:%.*]] unwind label [[BB2:%.*]]
+; CHECK:       bb1:
+; CHECK-NEXT:    ret i16 0
+; CHECK:       bb2:
+; CHECK-NEXT:    [[TMP:%.*]] = landingpad { ptr, i32 }
+; CHECK-NEXT:            cleanup
+; CHECK-NEXT:    [[L:%.*]] = load i16, ptr [[PTR]], align 2
+; CHECK-NEXT:    ret i16 [[L]]
+;
+entry:
+  %ptr = alloca i16
+  store i16 0, ptr %ptr
+  invoke void @p1_write_then_read_raw(ptr %ptr) to label %bb1 unwind label %bb2
+bb1:
+  ret i16 0
+bb2:
+  %tmp = landingpad { ptr, i32 }
+  cleanup
+  %l = load i16, ptr %ptr
+  ret i16 %l
+}
+
 ; Function Attrs: mustprogress nounwind uwtable
 define i16 @p2_same_range_noalias_caller() {
 ; CHECK-LABEL: @p2_same_range_noalias_caller(
@@ -142,8 +171,8 @@ define i16 @p2_no_init_alias_caller() {
 ; the 'dead_on_unwind' attribute, it's invisble to caller on unwind.
 ; DSE still uses the 'initializes' attribute and kill the dead store.
 ; Function Attrs: mustprogress nounwind uwtable
-define i16 @p2_no_dead_on_unwind_but_invisble_to_caller_alias_caller() {
-; CHECK-LABEL: @p2_no_dead_on_unwind_but_invisble_to_caller_alias_caller(
+define i16 @p2_no_dead_on_unwind_but_invisible_to_caller_alias_caller() {
+; CHECK-LABEL: @p2_no_dead_on_unwind_but_invisible_to_caller_alias_caller(
 ; CHECK-NEXT:    [[PTR:%.*]] = alloca i16, align 2
 ; CHECK-NEXT:    call void @p2_no_dead_on_unwind(ptr [[PTR]], ptr [[PTR]])
 ; CHECK-NEXT:    [[L:%.*]] = load i16, ptr [[PTR]], align 2