[PATCH] D109883: [Analysis] Add support for vscale in computeKnownBitsFromOperator

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/lib/Analysis/ValueTracking.cpp:1696
+
+        std::pair<unsigned, unsigned> VScaleRange =
+            II->getFunction()
----------------
Maybe use auto?


================
Comment at: llvm/lib/Analysis/ValueTracking.cpp:1708
+
+        unsigned FirstSetBit = findFirstSet(VScaleRange.first);
+        if (FirstSetBit <= BitWidth)
----------------
Can min ever be zero here?


================
Comment at: llvm/lib/Analysis/ValueTracking.cpp:1710
+        if (FirstSetBit <= BitWidth)
+          Known.Zero.setLowBits(FirstSetBit);
+
----------------
This assumes that vscale is a multiple of min, which is not documented in the langref.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109883/new/

https://reviews.llvm.org/D109883