Looks good. Feel free to commit yourself or lmk if you want me to commit it for you.

Thanks for fixing this! I have a few comments on the test style, but otherwise LGTM.

• Remove hanging metadata tag in test

DAGTypeLegalizer calls ReplaceNodeResults whenever CustomLowerNode is called and its parameter LegalizeResult is true or when CustomWidenLowerNode is called. So basically it is the same as LowerOperation except that it is meant to focus on legalizing the result type rather than simply transforming the operation. There is even a TODO on LowerOperationWrapper, /// TODO: Consider merging with ReplaceNodeResults..

This CL should not be merged until Chrome 75 releases to stable on June 4.

Looks good!

• Address comments

ping, I think this should be ready to go.

Might be nice to have a test, but understandable if that doesn't seem worth the effort.

• address comments

• Switch to using SyntheticSection

• Rebase on top of D60637 and add data.drop

In D60623#1465002, @dschuff wrote:

I assume the linker doesn't need to do anything with this, it can just regenerate it after linking?

Yes, ThreadModel is no longer used anywhere in the WebAssembly backend.

@dschuff, @sbc100, @azakai we should figure out what our story is for pthreads and bulk-memory in the LLVM backend. This CL assumes that passive segments will always be available when creating multithreaded binaries, but obviously that's not true for Chrome 74. I was thinking that would be fine because using the asm2wasm path with mem files will suffice for anyone wanting to target chrome 74 with pthreads. But will we want to support mem files going forward? If so, I need to add a linker option to control that.

• rebase

@sbc100 and @aheejin, this is unblocked and ready to land whenever you have a chance to review it.

• rebase

• Address comments
• gracefully handle invalid metadata
• do not emit empty producers sections

• Switch to storing target feature information as Module metadata

LGTM!

I think there are more tests that should use -o - in wasm/target-feature-none.yaml, but otherwise the wasm changes lgtm.

• Remove unnecessary test and small cleanup

• Calculate and use union of features used in module before starting instruction selection.

@sbc100 friendly ping! It would be great to start clearing this stack.

• ATOMICS -> SHARED in test

• Add --shared-memory to avoid new errors

• Make using --shared-memory when atomics are disallowed or omitting it when atomics are used an error.

This commit breaks the following IR:

@sbc100 Any comments or concerns with these flags?