Instructions like memd(r0+##global+1) are legal as long as the entire
address is properly aligned. Assuming that "global" is aligned at an
8-byte boundary, the expression "global+1" appears to be misaligned.
Handle such cases in HexagonConstExtenders, and make sure that any non-
extended offsets generated are still aligned accordingly.
llvm-svn: 323799
This reverts r323562, since it wasn't actually necessary. Constant-
extended offsets do not need to be aligned, as long as the effective
address is aligned.
Keep the testcase, with a modification which checks that such offsets
are not unnecessarily avoided.
llvm-svn: 323798
LLVM Coding Standards:
Function names should be verb phrases (as they represent actions), and
command-like function should be imperative. The name should be camel
case, and start with a lower case letter (e.g. openFile() or isFoo()).
Differential Revision: https://reviews.llvm.org/D40416
llvm-svn: 319168
In getOffsetRange, Max can be set to 0 to force the extender replacement
to be at or below the original value. This would cause the new offset to
be non-negative, which is preferred for memory instructions (to reduce
the likelihood of it getting constant-extended due to predication). The
problem happens when the range is shifted by an offset (present in the
instruction being examined) and the offset is negative. The entire range
for the allowable deviation will then be strictly negative. This creates
a problem, since 0 is assumed to be a valid deviation.
llvm-svn: 316601
Each constant extender requires an extra instruction, which adds to the
code size and also reduces the number of available slots in an instruction
packet. In most cases, the value of a repeated constant extender could be
loaded into a register, and the instructions using the extender could be
replaced with their counterparts that use that register instead.
This patch adds a pass that tries to reduce the number of constant
extenders, including extenders which differ only in an immediate offset
known at compile time, e.g. @global and @global+12.
llvm-svn: 315735
Krzysztof Parzyszek