[PATCH] D59343: [WebAssembly] Use passive segments when memory is shared

Thu Mar 14 14:01:27 PDT 2019

sbc100 added inline comments.

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Comment at: lld/test/wasm/data-segment-merging.ll:12
 ; RUN: llc -filetype=obj %s -o %t.data-segment-merging.o
+; RUN: llc -filetype=obj %s -o %t.data-segment-merging.atomics.o -mattr=+atomics

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tlively wrote:
> sbc100 wrote:
> > The code looks like passive initiazlition is driver by the "--shared-memory" flag rather than atomics.   Wouldn't it make more sense to use "SHARED" over "ATOMICS" in this test?
> D59284 makes the "atomics" feature imply the use of shared memory, and in this test the flag that causes shared memory to be used is `-mattr=+atomics`, so I think the current naming accurately describes what is happening. I expect the common way to get shared memory is by using the atomics feature, so perhaps we can even deprecate the --shared-memory flag, WDYT?
I'm not sure.   Part of me likes the explicit requirment/ability to pass this kind of thing as a linker flag.   I think shared vs non-shared memory is significant enough that I'm not sure it should be driven my object file input. 

e.g. As a developer, I don't necessarily want the accidental inclusion of the bad object file to change the type of output object.  It would be like infering `-shared` if I pass objects build with `-PIC`.     I think I'd rather get a linker error (object files use atomics, did you mean to pass --shared-memory?)

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D59343/new/

https://reviews.llvm.org/D59343