[IRGen] Add back temporary allocation very large allocation codegen test

Author: xwu

test/IRGen/temporary_allocation/codegen_very_large_allocation.swift

@@ -0,0 +1,29 @@
+// RUN: %target-swift-frontend -primary-file %s -O -emit-ir | %FileCheck %s --check-prefixes=CHECK-LARGE-ALLOC,CHECK-LARGE-ALLOC-%target-vendor -DWORD=i%target-ptrsize
+// RUN: %target-swift-frontend -primary-file %s -O -emit-ir | %FileCheck %s --check-prefix=CHECK-LARGE-STACK-ALLOC -DWORD=i%target-ptrsize
+// RUN: %target-swift-frontend -primary-file %s -O -emit-ir | %FileCheck %s --check-prefix=CHECK-LARGE-HEAP-ALLOC -DWORD=i%target-ptrsize
+// REQUIRES: rdar104435186
+
+@_silgen_name("blackHole")
+func blackHole(_ value: UnsafeMutableRawPointer?) -> Void
+
+// MARK: Very large allocation
+
+// A large allocation size should produce an OS version check, call to
+// swift_stdlib_isStackAllocationSafe(), and then a branch based on the result
+// to either stack-allocate or heap-allocate.
+withUnsafeTemporaryAllocation(byteCount: 0x0FFF_FFFF, alignment: 1) { buffer in
+  blackHole(buffer.baseAddress)
+}
+// CHECK-LARGE-HEAP-ALLOC: [[HEAP_PTR_RAW:%[0-9]+]] = {{(tail )?}}call noalias i8* @swift_slowAlloc([[WORD]] 268435455, [[WORD]] -1)
+// CHECK-LARGE-HEAP-ALLOC-NEXT: [[HEAP_PTR:%[0-9]+]] = ptrtoint i8* [[HEAP_PTR_RAW]] to [[WORD]]
+// CHECK-LARGE-HEAP-ALLOC-NEXT: {{(tail )?}}call swiftcc void @blackHole([[WORD]] [[HEAP_PTR]])
+// CHECK-LARGE-HEAP-ALLOC-NEXT: {{(tail )?}}call void @swift_slowDealloc(i8* [[HEAP_PTR_RAW]], [[WORD]] -1, [[WORD]] -1)
+
+// CHECK-LARGE-STACK-ALLOC: [[STACK_PTR_RAW:%temp_alloc[0-9]*]] = alloca [268435455 x i8], align 1
+// CHECK-LARGE-STACK-ALLOC-NEXT: [[STACK_PTR:%[0-9]+]] = ptrtoint [268435455 x i8]* [[STACK_PTR_RAW]] to [[WORD]]
+// CHECK-LARGE-STACK-ALLOC-NEXT: call swiftcc void @blackHole([[WORD]] [[STACK_PTR]])
+
+// CHECK-LARGE-ALLOC-DAG: [[IS_SAFE:%[0-9]+]] = {{(tail )?}}call {{(zeroext )?}}i1 @swift_stdlib_isStackAllocationSafe([[WORD]] 268435455, [[WORD]] 1)
+// CHECK-LARGE-ALLOC-DAG: br i1 [[IS_SAFE]], label %{{[0-9]+}}, label %{{[0-9]+}}
+// CHECK-LARGE-ALLOC-apple-DAG: [[IS_OS_OK:%[0-9]+]] = {{(tail )?}}call swiftcc i1 @"$ss26_stdlib_isOSVersionAtLeastyBi1_Bw_BwBwtF"
+// CHECK-LARGE-ALLOC-apple-DAG: br i1 [[IS_OS_OK]], label %{{[0-9]+}}, label %{{[0-9]+}}