[PATCH] D94542: [X86] Default to -x86-pad-for-align=false to drop assembler difference with or w/o -g

[Philip Reames via Phabricator via llvm-commits]

reames added a comment.

In D94542#2494838 <https://reviews.llvm.org/D94542#2494838>, @MaskRay wrote:

> In D94542#2494774 <https://reviews.llvm.org/D94542#2494774>, @reames wrote:
>
>> I also ask that a bit more background be given to justify this change.  I found the bug (https://bugs.llvm.org/show_bug.cgi?id=42138#c13), but that gives no information about the cause of the assembly difference.  Has anyone examined the cause of the labels being emitted in debug mode to see if they're necessary/useful?
>
> I explained the cause in the description: "A -g build has more MCSymbol's and therefore may have different assembler output (e.g. a MCRelaxableFragment (jmp) may have 5 bytes with -O1 while 2 bytes with -O1 -g)."

This doesn't get at the root cause though.  Are those labels doing anything in the debug build?  Why are they emitted?  Can they be reasonably removed?


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https://reviews.llvm.org/D94542