Merge pull request #1550 from jbj/array-aggregate-perf

C++ IR: Fix performance of large value-initialized arrays

cpp/ql/test/library-tests/ir/ir/PrintAST.expected

@@ -6,6 +6,10 @@
 #-----|   params: 
 #-----|     0: [Parameter] p#0
 #-----|         Type = [RValueReferenceType] __va_list_tag &&
+#-----| [Operator,TopLevelFunction] void operator delete(void*)
+#-----|   params: 
+#-----|     0: [Parameter] p#0
+#-----|         Type = [VoidPointerType] void *
 #-----| [Operator,TopLevelFunction] void operator delete(void*, unsigned long)
 #-----|   params: 
 #-----|     0: [Parameter] p#0
@@ -8001,3 +8005,49 @@ ir.cpp:
 # 1147|       2: [Handler] <handler>
 # 1147|         0: [CatchBlock] { ... }
 # 1149|     1: [ReturnStmt] return ...
+perf-regression.cpp:
+#    4| [CopyAssignmentOperator] Big& Big::operator=(Big const&)
+#    4|   params: 
+#-----|     0: [Parameter] p#0
+#-----|         Type = [LValueReferenceType] const Big &
+#    4| [MoveAssignmentOperator] Big& Big::operator=(Big&&)
+#    4|   params: 
+#-----|     0: [Parameter] p#0
+#-----|         Type = [RValueReferenceType] Big &&
+#    4| [CopyConstructor] void Big::Big(Big const&)
+#    4|   params: 
+#-----|     0: [Parameter] p#0
+#-----|         Type = [LValueReferenceType] const Big &
+#    4| [MoveConstructor] void Big::Big(Big&&)
+#    4|   params: 
+#-----|     0: [Parameter] p#0
+#-----|         Type = [RValueReferenceType] Big &&
+#    6| [Constructor] void Big::Big()
+#    6|   params: 
+#    6|   initializations: 
+#    6|     0: [ConstructorFieldInit] constructor init of field buffer
+#    6|         Type = [ArrayType] char[1073741824]
+#    6|         ValueCategory = prvalue
+#    6|       0: [ArrayAggregateLiteral] {...}
+#    6|           Type = [ArrayType] char[1073741824]
+#    6|           ValueCategory = prvalue
+#    6|   body: [Block] { ... }
+#    6|     0: [ReturnStmt] return ...
+#    9| [TopLevelFunction] int main()
+#    9|   params: 
+#    9|   body: [Block] { ... }
+#   10|     0: [DeclStmt] declaration
+#   10|       0: [VariableDeclarationEntry] definition of big
+#   10|           Type = [PointerType] Big *
+#   10|         init: [Initializer] initializer for big
+#   10|           expr: [NewExpr] new
+#   10|               Type = [PointerType] Big *
+#   10|               ValueCategory = prvalue
+#   10|             1: [ConstructorCall] call to Big
+#   10|                 Type = [VoidType] void
+#   10|                 ValueCategory = prvalue
+#   12|     1: [ReturnStmt] return ...
+#   12|       0: [Literal,Zero] 0
+#   12|           Type = [IntType] int
+#   12|           Value = [Literal,Zero] 0
+#   12|           ValueCategory = prvalue

cpp/ql/test/library-tests/ir/ir/perf-regression.cpp

@@ -0,0 +1,13 @@
+// This test ensures that we can efficiently generate IR for a large
+// value-initialized array.
+
+struct Big {
+  char buffer[1 << 30]; // 1 GiB
+  Big() : buffer() {} // This explicit init of `buffer` makes it value-initialized
+};
+
+int main() {
+  Big *big = new Big;
+
+  return 0;
+}

cpp/ql/test/library-tests/ir/ir/raw_ir.expected

@@ -5269,3 +5269,43 @@ ir.cpp:
 # 1149|     v13_0(void) = NoOp       : 
 # 1133|     v13_1(void) = ReturnVoid : 
 #-----|   Goto -> Block 1
+
+perf-regression.cpp:
+#    6| void Big::Big()
+#    6|   Block 0
+#    6|     v0_0(void)                    = EnterFunction        : 
+#    6|     mu0_1(unknown)                = AliasedDefinition    : 
+#    6|     mu0_2(unknown)                = UnmodeledDefinition  : 
+#    6|     r0_3(glval<Big>)              = InitializeThis       : 
+#    6|     r0_4(glval<char[1073741824]>) = FieldAddress[buffer] : r0_3
+#    6|     r0_5(int)                     = Constant[0]          : 
+#    6|     r0_6(glval<char>)             = PointerAdd           : r0_4, r0_5
+#    6|     r0_7(unknown[1073741824])     = Constant[0]          : 
+#    6|     mu0_8(unknown[1073741824])    = Store                : &:r0_6, r0_7
+#    6|     v0_9(void)                    = NoOp                 : 
+#    6|     v0_10(void)                   = ReturnVoid           : 
+#    6|     v0_11(void)                   = UnmodeledUse         : mu*
+#    6|     v0_12(void)                   = ExitFunction         : 
+
+#    9| int main()
+#    9|   Block 0
+#    9|     v0_0(void)           = EnterFunction                 : 
+#    9|     mu0_1(unknown)       = AliasedDefinition             : 
+#    9|     mu0_2(unknown)       = UnmodeledDefinition           : 
+#   10|     r0_3(glval<Big *>)   = VariableAddress[big]          : 
+#   10|     r0_4(glval<unknown>) = FunctionAddress[operator new] : 
+#   10|     r0_5(unsigned long)  = Constant[1073741824]          : 
+#   10|     r0_6(void *)         = Call                          : func:r0_4, 0:r0_5
+#   10|     mu0_7(unknown)       = ^CallSideEffect               : ~mu0_2
+#   10|     r0_8(Big *)          = Convert                       : r0_6
+#   10|     r0_9(glval<unknown>) = FunctionAddress[Big]          : 
+#   10|     v0_10(void)          = Call                          : func:r0_9, this:r0_8
+#   10|     mu0_11(unknown)      = ^CallSideEffect               : ~mu0_2
+#   10|     mu0_12(Big *)        = Store                         : &:r0_3, r0_8
+#   12|     r0_13(glval<int>)    = VariableAddress[#return]      : 
+#   12|     r0_14(int)           = Constant[0]                   : 
+#   12|     mu0_15(int)          = Store                         : &:r0_13, r0_14
+#    9|     r0_16(glval<int>)    = VariableAddress[#return]      : 
+#    9|     v0_17(void)          = ReturnValue                   : &:r0_16, ~mu0_2
+#    9|     v0_18(void)          = UnmodeledUse                  : mu*
+#    9|     v0_19(void)          = ExitFunction                  : 

cpp/ql/test/library-tests/literals/aggregate_literals/arrays_value_init.ql

@@ -2,5 +2,6 @@ import cpp
 
 from ArrayType a, ArrayAggregateLiteral al, int i
 where a = al.getType()
+  and i = [0 .. al.getUnspecifiedType().(ArrayType).getArraySize()]
   and al.isValueInitialized(i)
 select al, a, i