Incorrect assembly of "xchg %eax, %eax" on x86-64

[efriedma-quic]

Bugzilla Link	10345
Resolution	FIXED
Resolved on	Oct 06, 2011 10:17
Version	unspecified
OS	All
Blocks	llvm/llvm-bugzilla-archive#10988
CC	@topperc

Extended Description

$ echo "xchg %eax, %eax" | llvm-mc -show-encoding
xchgl %eax, %eax ## encoding: [0x90]

The correct encoding is "0x87 0xc0"; the given encoding, "0x90", is a nop.

[efriedma-quic]

assigned to @topperc

[topperc]

Fixed in r141274.

[bcardosolopes]

mentioned in issue llvm/llvm-bugzilla-archive#10988