search for: seh_stackalloc

...nwind funclet that destroys ‘x’ is just two lines of asm: lea rcx, QWORD PTR x$[rdx] jmp ??1MyClass@@QEAA at XZ However when compiling with clang-cl, it seems like it sets up an entire function frame just for the destructor call: mov qword ptr [rsp + 16], rdx push rbp .seh_pushreg 5 sub rsp, 32 .seh_stackalloc 32 Lea rbp, [rdx + 48] .seh_endprologue Lea rcx, [rbp - 16] call "??1MyClass@@QEAA at XZ” nop add rsp, 32 pop rbp ret Both were compiled with “/c /O2 /MD /EHsc” Is LLVM missing a major optimisation here? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http...

...JAE_1 <BB#1>, %EFLAGS<imp-use>; flags: FrameSetup Successors according to CFG: BB#2 BB#1 BB#2: derived from LLVM BB %0 Predecessors according to CFG: BB#1 %RSP<def,tied1> = SUB64rr %RSP<tied0>, %RAX, %EFLAGS<imp-def>; flags: FrameSetup SEH_StackAlloc 40040; flags: FrameSetup SEH_EndPrologue; flags: FrameSetup %RCX<def> = LEA64r %RSP, 1, %noreg, 40, %noreg %EDX<def> = MOV32r0 %EFLAGS<imp-def,dead> CALL64pcrel32 <ga:@dummy_use>, <regmask>, %RSP<imp-use>, %RCX<imp-use>, %EDX...

Hi, My understanding of a "dead" register is a def that is never used. However, when I dump the MI after reg alloc on a simple program I see the following sequence: ADJCALLSTACKDOWN64 0, 0, 0, *implicit-def dead %rsp*, implicit-def dead %eflags, implicit-def dead %ssp, implicit %rsp, implicit %ssp CALL64pcrel32 @foo, <regmask %bh %bl %bp %bpl %bx %ebp %ebx %rbp %rbx %r12 %r13 %r14

I would like to create something like this (x86_64) .section __DATA,__data .align 4 _a: .long 18 .globl _b _b: .long 48 If you like to notice, there is no alignment between _a and _b. _b is basically offseting into a record structure. ---- When I use two discrete structs, I get .aligns and I also don't trust the tools to keep the two globals together. %struct.a = type { i32 }

...# -- Begin function call .p2align 4, 0x90 call: # @call .seh_proc call # BB#0: # %entry .p2align 1, 0x90 .Lxray_sled_0: .ascii "\353\t" nop word ptr [rax + rax + 512] sub rsp, 16 .seh_stackalloc 16 .seh_endprologue mov dword ptr [rsp + 12], ecx mov dword ptr [rsp + 8], 0 mov dword ptr [rsp + 4], 0 .LBB0_1: # %for.cond # =>This Inner Loop Header: Depth=1 mov eax, dword ptr [rsp + 4]...

On Tue, Jul 28, 2015 at 6:34 PM, Reid Kleckner <rnk at google.com> wrote: > On Tue, Jul 28, 2015 at 2:25 AM, John Kåre Alsaker > <john.mailinglists at gmail.com> wrote: >> >> On Tue, Jul 28, 2015 at 12:44 AM, Reid Kleckner <rnk at google.com> wrote: >> > Yeah, the function attributes section of LangRef is a reasonable place >> > to >>

I'm learning the xray library and try if it can be built on windows, in xray_fdr_logging_impl.h line 152 , comment written as // Using pthread_once(...) to initialize the thread-local data structures but at line 175, 183, code written as thread_local pthread_key_t key; // Ensure that we only actually ever do the pthread initialization once. thread_local bool UNUSED Unused = [] {