Since `MD_annotation` metadata now supports having mutliple strings in the annotation node. casing Operand to string directly will cause a crash. When checking if `MDOperand` equals str you can use `equalsStr` method.
Reviewed By: serge-sans-paille
Differential Revision: https://reviews.llvm.org/D152372
Original patch (50b2a113db197a97f60ad2aace8b7382dc9b8c31) ignored the
fact that -ftrivial-auto-var-init could affect function parameters with
the sret attribute.
Just do not move instruction that don't affect alloca.
Also add missing test case for volatile instruction.
Differential Revision: https://reviews.llvm.org/D148507
This could also move initialization of sret args, causing actually
initialized parts of such return values to be uninitialized. See
discussion on the code review.
> As a result of -ftrivial-auto-var-init, clang generates instructions to
> set alloca'd memory to a given pattern, right after the allocation site.
> In some cases, this (somehow costly) operation could be delayed, leading
> to conditional execution in some cases.
>
> This is not an uncommon situation: it happens ~500 times on the cPython
> code base, and much more on the LLVM codebase. The benefit greatly
> varies on the execution path, but it should not regress on performance.
>
> This is a recommit of cca01008cc31a891d0ec70aff2201b25d05d8f1b with
> MemorySSA update fixes.
>
> Differential Revision: https://reviews.llvm.org/D137707
This reverts commit 50b2a113db197a97f60ad2aace8b7382dc9b8c31
and follow-up commit ad9ad3735c4821ff4651fab7537a75b8f0bb60f8.
As a result of -ftrivial-auto-var-init, clang generates instructions to
set alloca'd memory to a given pattern, right after the allocation site.
In some cases, this (somehow costly) operation could be delayed, leading
to conditional execution in some cases.
This is not an uncommon situation: it happens ~500 times on the cPython
code base, and much more on the LLVM codebase. The benefit greatly
varies on the execution path, but it should not regress on performance.
This is a recommit of cca01008cc31a891d0ec70aff2201b25d05d8f1b with
MemorySSA update fixes.
Differential Revision: https://reviews.llvm.org/D137707
As a result of -ftrivial-auto-var-init, clang generates instructions to
set alloca'd memory to a given pattern, right after the allocation site.
In some cases, this (somehow costly) operation could be delayed, leading
to conditional execution in some cases.
This is not an uncommon situation: it happens ~500 times on the cPython
code base, and much more on the LLVM codebase. The benefit greatly
varies on the execution path, but it should not regress on performance.
Differential Revision: https://reviews.llvm.org/D137707
