Files
clang-p2996/llvm/test/CodeGen/RISCV
Alex Richardson 2259ce8c91 [RISC-V] ADDI/ORI/XORI x, 0 should be as cheap as a move
The isTriviallyRematerializable hook is only called for instructions that are
tagged as isAsCheapAsAMove. Since ADDI 0 is used for "mv" it should definitely
be marked with "isAsCheapAsAMove". This change avoids one stack spill in most of
the atomic-rmw.ll tests functions. It also avoids stack spills in two of our
out-of-tree CHERI tests.
ORI/XORI with zero may or may not be the same as a move micro-architecturally,
but since we are already doing it for register == x0, we might as well
do the same if the immediate is zero.

Reviewed By: luismarques

Differential Revision: https://reviews.llvm.org/D86480
2020-08-27 10:32:22 +01:00
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