[PATCH] D19908: [X86] Support the "ms-hotpatch" attribute.

[Sanjoy Das via llvm-commits]

sanjoy requested changes to this revision.
This revision now requires changes to proceed.

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Comment at: docs/LangRef.rst:1435
@@ +1434,3 @@
+       hotpatchable function.  Additionally, patch space will be provided
+       prior to the function's entry point of an architecturally specific
+       size.  On 32-bit x86, the patch space is 64 bytes long; on x86-64, it
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So on x86-64, the 2 byte instruction can be anything?  May be helpful to be explicit about that.

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Comment at: lib/CodeGen/PatchableFunction.cpp:43
@@ -42,3 +42,3 @@
   if (!MF.getFunction()->hasFnAttribute("patchable-function"))
     return false;
 
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I presume you're handling the x86-64 case here?  If so, how about handling both the 32bit and 64bit case here?  On 32 bits, you can just emit a `mov %edi, %edi` instead of a `PATCHABLE_OP`?  That way related bits stay together.


http://reviews.llvm.org/D19908