[PATCH] D93619: [RISCV] Optimize multiplication with constant

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


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Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:3829
+      // Omit 64-bit multiplication on riscv32.
+      if (!Subtarget.is64Bit() && VT.getSizeInBits() > 32)
+        return false;
----------------
What about 128-bit on riscv64?


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Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:3834
+        int64_t Tmp = Imm;
+        while (Tmp != 0 && (Tmp & 1) == 0)
+          Tmp >>= 1;
----------------
Can we just use countTrailingZeros here?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D93619/new/

https://reviews.llvm.org/D93619