[llvm] [ValueTracking] Handle not cond to assume. (PR #127140)

[Andreas Jonson via llvm-commits]

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@@ -441,16 +441,28 @@ void llvm::computeKnownBitsFromRangeMetadata(const MDNode &Ranges,
 }
 
 static bool isEphemeralValueOf(const Instruction *I, const Value *E) {
-  SmallVector<const Value *, 16> WorkSet(1, I);
-  SmallPtrSet<const Value *, 32> Visited;
-  SmallPtrSet<const Value *, 16> EphValues;
 
   // The instruction defining an assumption's condition itself is always
   // considered ephemeral to that assumption (even if it has other
   // non-ephemeral users). See r246696's test case for an example.
   if (is_contained(I->operands(), E))
     return true;
 
+  SmallPtrSet<const Value *, 32> Visited{I};
+  SmallPtrSet<const Value *, 16> EphValues{I};
+
+  Value *X;
+  if (match(I, m_Intrinsic<Intrinsic::assume>(m_Not(m_Value(X))))) {
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andjo403 wrote:

the `!IsAssume &&` for the trunc check is only to avoid to add the same value twice to the `AssumptionCache` as it is added by the https://github.com/llvm/llvm-project/blob/70b95ca6dbee7036dcfa5995ff804471fd7e8c2a/llvm/lib/Analysis/ValueTracking.cpp#L10229-L10232
via https://github.com/llvm/llvm-project/blob/70b95ca6dbee7036dcfa5995ff804471fd7e8c2a/llvm/lib/Analysis/ValueTracking.cpp#L10261-L10262

This was the only way that I was able to think of how to solve.

https://github.com/llvm/llvm-project/pull/127140