ARM: Add test cleanup entry to the README.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159864 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2012-07-06 21:52:04 +00:00
parent 63d10fbc89
commit db6faeb19d

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@ -710,3 +710,24 @@ targets, e.g., PPC, that share this behavior, it would be best to implement
this in a target-independent way: we should probably fold that (when using
"undefined at zero" semantics) to set the "defined at zero" bit and have
the code generator expand out the right code.
//===---------------------------------------------------------------------===//
Clean up the test/MC/ARM files to have more robust register choices.
R0 should not be used as a register operand in the assembler tests as it's then
not possible to distinguish between a correct encoding and a missing operand
encoding, as zero is the default value for the binary encoder.
e.g.,
add r0, r0 // bad
add r3, r5 // good
Register operands should be distinct. That is, when the encoding does not
require two syntactical operands to refer to the same register, two different
registers should be used in the test so as to catch errors where the
operands are swapped in the encoding.
e.g.,
subs.w r1, r1, r1 // bad
subs.w r1, r2, r3 // good