[PATCH] D156442: [RISCV][Backend] Zext flag conversion in RISC-V Backend

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


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Comment at: llvm/lib/Target/RISCV/RISCVCodeGenPrepare.cpp:92
+  // Look for a non negative zext(value) and replace it with sext.
+	if (isKnownNonNegative(Src, *DL, 0, AC, Ctxi)) {
+    auto SExt = new SExtInst(Src, ZExt.getType(), "", &ZExt);
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Could we have InstCombine call isKnownNonNegative during visitZExt and set the flag if the input is non negative? Then we only need the code here that checks the flag.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D156442/new/

https://reviews.llvm.org/D156442