[PATCH] D111532: [RISCV] Optimize immediate materialisation with BCLRI

[Ben Shi via Phabricator via llvm-commits]

benshi001 marked an inline comment as done.
benshi001 added inline comments.


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Comment at: llvm/lib/Target/RISCV/MCTargetDesc/RISCVMatInt.cpp:191
+           "Expected RV32 to only need 2 instructions");
+    int64_t NewVal = Val + 0x80000000;
+    if (NewVal < 0 && isInt<32>(NewVal)) {
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craig.topper wrote:
> Can this be Val | 0x80000000? That makes more sense to me since BCLRI only affects 1 bit.
If we change to `Val | 0x80000000` instead of `Val + 0x80000000`,

we still need not to check `NewVal != Val`, and checking `NewVal < 0 && isInt<32>(NewVal)` is enough.

Since Val is not int32 while NewVal is.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D111532/new/

https://reviews.llvm.org/D111532