[llvm] [InstCombine] Canonicalize `smax(smin(X, MinC), MaxC) -> smin(smax(X, MaxC), MinC)` (PR #136665)

[Yingwei Zheng via llvm-commits]

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@@ -1924,6 +1924,26 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
       }
     }
 
+    // Canonicalize smax(smin(X, MinC), MaxC) to smin(smax(X, MaxC), MinC)
+    if (IID == Intrinsic::smax) {
+      Constant *MinC, *MaxC;
+      if ((match(I1, m_Constant(MaxC)) &&
+           (match(I0, m_OneUse(m_Intrinsic<Intrinsic::smin>(
+                          m_Value(X), m_Constant(MinC)))) ||
+            match(I0, m_OneUse(m_Intrinsic<Intrinsic::smin>(m_Constant(MinC),
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dtcxzyw wrote:

We always put the constant on the RHS.


https://github.com/llvm/llvm-project/pull/136665