Peter Smith 41cc727b1c [ARM] Remove condition that could never be true ...

From Arm v8 Architecture Reference Manual F5.1.84 LDREXD
The ldrexd instruction in Arm state has the following conditions:

t = UInt(Rt); t2 = t + 1; n = UInt(Rn);
if Rt<0> == '1' || t2 == 15 || n == 15 then UNPREDICTABLE;

In when Rt is odd or if Rt is 14 (making t2 15).

In the implementation when the pair is the UNPREDICTABLE R14_R15 we
would ideally return SOFT_FAIL. We can't because there is no R14_R15
value for us to return so we fail early returning FAIL.

The early return for registers outside the bounds of the table means
the check for Rt == 14 (0xE) redundant which causes a static analyzer
to flag the condition as never being true.

To fix the warning I've removed the check and replaced with a comment
explaining the difference with the specification.

Fixes pr41660

Differential Revision: https://reviews.llvm.org/D77463

2020-04-07 09:50:56 +01:00

..

ARMDisassembler.cpp

[ARM] Remove condition that could never be true

2020-04-07 09:50:56 +01:00

CMakeLists.txt

[cmake] Explicitly mark libraries defined in lib/ as "Component Libraries"

2019-11-21 10:48:08 -08:00

LLVMBuild.txt

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