Xiangling_L marked an inline comment as done.
Xiangling_L added inline comments.
================
Comment at: clang/test/Layout/aix-double-struct-member.cpp:1
+// RUN: %clang_cc1 -emit-llvm-only -triple powerpc-ibm-aix-xcoff \
+// RUN: -fdump-record-layouts -fsyntax-only %s 2>/dev/null | \
----------------
hubert.reinterpretcast wrote:
> I am concerned that none of the tests actually create an instance of the
> classes under test and check the alignment (or related adjustments) in the
> IR. That is, we set up the preferred alignment value but don't check that we
> use it where we should.
>
> As it is, it seems array new/delete has problems:
> ```
> #include <assert.h>
> extern "C" void *calloc(decltype(sizeof 0), decltype(sizeof 0));
> extern "C" void free(void *);
> extern "C" int printf(const char *, ...);
>
> extern void *allocated_ptr;
> extern decltype(sizeof 0) allocated_size;
> struct B {
> double d;
> ~B() {}
> static void *operator new[](decltype(sizeof 0) sz);
> static void operator delete[](void *p, decltype(sizeof 0) sz);
> };
> B *allocBp();
>
> #ifdef ALLOCBP
> void *allocated_ptr;
> decltype(sizeof 0) allocated_size;
> void *B::operator new[](decltype(sizeof 0) sz) {
> void *alloc = calloc(1u, allocated_size = sz);
> printf("%p: %s\n", alloc, __PRETTY_FUNCTION__);
> printf("%zu\n", sz);
> return allocated_ptr = alloc;
> }
> void B::operator delete[](void *p, decltype(sizeof 0) sz) {
> printf("%p: %s\n", p, __PRETTY_FUNCTION__);
> printf("%zu\n", sz);
> assert(sz == allocated_size);
> assert(p == allocated_ptr);
> free(p);
> }
> B *allocBp() { return new B[2]; }
> #endif
>
> #ifdef MAIN
> int main(void) { delete[] allocBp(); }
> #endif
> ```
>
> The `xlclang++` invocation from XL C/C++ generates padding before the 32-bit
> `new[]` cookie. I'm not seeing that padding with this patch.
Thank. I will create more practical testcases as you mentioned in your concern.
And regarding to `padding before the 32-bit new[] cookie` issue, I am wondering
is that part of `power` alignment rule or what rules do we follow to generate
this kind of padding?
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D79719/new/
https://reviews.llvm.org/D79719
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