[PATCH] D87034: [KnownBits] Implement accurate unsigned and signed max and min

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added inline comments.


================
Comment at: llvm/unittests/Support/KnownBitsTest.cpp:103
 TEST(KnownBitsTest, BinaryExhaustive) {
   unsigned Bits = 4;
   ForeachKnownBits(Bits, [&](const KnownBits &Known1) {
----------------
>>! In D87034#2252330, @foad wrote:
> I have only exhaustively tested it up to 7 bits.

For one-time testing you could bump this all the way to `16`,
but i think `7` was plenty enough to catch any correctness issues.


================
Comment at: llvm/unittests/Support/KnownBitsTest.cpp:111-114
+      KnownBits KnownUMax(KnownAnd);
+      KnownBits KnownUMin(KnownAnd);
+      KnownBits KnownSMax(KnownAnd);
+      KnownBits KnownSMin(KnownAnd);
----------------
i would think this should start from
```
      KnownBits KnownUMax(KnownAnd) = 0;
      KnownBits KnownUMin(KnownAnd) = -1;
      KnownBits KnownSMax(KnownAnd) = INT_MIN;
      KnownBits KnownSMin(KnownAnd) = INT_MAX;
```


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87034/new/

https://reviews.llvm.org/D87034