[PATCH] D116574: Materializing constants with 'rori'

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


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Comment at: llvm/lib/Target/RISCV/MCTargetDesc/RISCVMatInt.cpp:146
+  bool Ret = false;
+  int LeadingOnes = countLeadingOnes((uint64_t)Val);
+  int TrailingOnes = countTrailingOnes((uint64_t)Val);
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Use `unsigned` instead of `int`


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Comment at: llvm/lib/Target/RISCV/MCTargetDesc/RISCVMatInt.cpp:149
+  // for case: 0xffffff77ffffffff
+  if (LeadingOnes < 32 && ((64 - LeadingOnes - TrailingOnes) < 12)) {
+    NegImm12 = ((uint64_t)Val >> TrailingOnes) | (Val << (64 - TrailingOnes));
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Can we do this for LeadingOnes == 32 too? For example 0xffffffff77ffffff. That can't use LUI+ADDIW.


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Comment at: llvm/lib/Target/RISCV/MCTargetDesc/RISCVMatInt.cpp:154
+  } else {
+    int UpperTrailingOnes = countTrailingOnes((uint64_t)(Val >> 32));
+    int LowerLeadingOnes = countLeadingOnes((uint64_t)(Val << 32));
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Can this use Lo_32 and Hi_32 from MathExtras.h? Or is the signed right shift important?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D116574/new/

https://reviews.llvm.org/D116574