arch-gcn3: Validate if scalar sources are scalar gprs

Scalar sources can either be a general-purpose register or a constant
register that holds a single value.

If we don't check for if the register is a general-purpose register,
it's possible that we get a constant register, which then causes all of
the register mapping code to break, as the constant registers aren't
supposed to be mapped like the general-purpose registers are.

This fix adds an isScalarReg check to the instruction encodings that
were missing it.

Change-Id: I3d7d5393aa324737301c3269cc227b60e8a159e4
Tested-by: kokoro <>
Reviewed-by: Matt Sinclair <>
Reviewed-by: Bobby R. Bruce <>
Reviewed-by: Matthew Poremba <>
Maintainer: Matt Sinclair <>
1 file changed