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GlobalISel: Add a note to G_BITCAST documentation
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Authored by arsenm on Jun 8 2020, 4:45 AM.

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Summary

This is currently different from the IR rules.

ping

This revision is now accepted and ready to land.Jun 15 2020, 2:26 PM

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GlobalISel/

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	.. code-block:: none			.. code-block:: none

	%1:_(s32) = G_PTRTOINT %0:_(p0)			%1:_(s32) = G_PTRTOINT %0:_(p0)

	G_BITCAST			G_BITCAST
	^^^^^^^^^			^^^^^^^^^

	Reinterpret a value as a new type. This is usually done without changing any			Reinterpret a value as a new type. This is usually done without
	bits but this is not always the case due a sublety in the definition of the			changing any bits but this is not always the case due a sublety in the
	:ref:`LLVM-IR Bitcast Instruction <i_bitcast>`.			definition of the :ref:`LLVM-IR Bitcast Instruction <i_bitcast>`. It
				is allowed to bitcast between pointers with the same size, but
				different address spaces.

	.. code-block:: none			.. code-block:: none

	%1:_(s64) = G_BITCAST %0:_(<2 x s32>)			%1:_(s64) = G_BITCAST %0:_(<2 x s32>)

	G_ADDRSPACE_CAST			G_ADDRSPACE_CAST
	^^^^^^^^^^^^^^^^			^^^^^^^^^^^^^^^^

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