[PATCH] D29937: [RISCV 15/n] Implement lowering of ISD::SELECT

[John Russo via Phabricator via llvm-commits]

johnrusso added inline comments.


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Comment at: lib/Target/RISCV/RISCVISelLowering.cpp:173
+  // -> (riscvisd::select_cc condv, zero, setne, truev, falsev)
+  SDValue Zero = DAG.getConstant(0, DL, XLenVT);
+  SDValue SetNE = DAG.getConstant(ISD::SETNE, DL, XLenVT);
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I noticed that the select-cc.ll test didn't cover this code. 
This little snip with the correct matching pattern should cover it.
...
  %val20 = select i1 %tst10, i32 %val18, i32 %val19

  %tr3 = trunc i32 %val3 to i1
  %val21 = select i1 %tr3, i32 %val20, i32 %val19

  ret i32 %val21



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Comment at: lib/Target/RISCV/RISCVISelLowering.cpp:188
+
+  assert(MI.getOpcode() == RISCV::Select_GPR_Using_CC_GPR &&
+         "Unexpected instr type to insert");
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Could we use a 'switch(MI.getOpcode())' here and assert on an unhandled opcode if it occurs. I suspect other pseudos may require a custom inserter in the future.


https://reviews.llvm.org/D29937