[llvm] VPlan: use worklist in simplifyRecipes (PR #93998)

[Florian Hahn via llvm-commits]

================
@@ -1046,23 +1048,73 @@ static void simplifyRecipe(VPRecipeBase &R, VPTypeAnalysis &TypeInfo) {
         assert(TypeInfo.inferScalarType(VPV) == TypeInfo2.inferScalarType(VPV));
     }
 #endif
+    if (VPC)
+      return {VPC};
+    return {};
+  }
+
+  VPValue *X, *X1, *Y, *Z;
+
+  // (X || !X) -> true.
+  if (match(&R, m_c_BinaryOr(m_VPValue(X), m_Not(m_VPValue(X1)))) && X == X1) {
+    auto *VPV = new VPValue(ConstantInt::getTrue(Ctx));
+    R.getVPSingleValue()->replaceAllUsesWith(VPV);
+    return {};
+  }
+
+  // (X || true) -> true.
+  if (match(&R, m_c_BinaryOr(m_VPValue(X), m_True()))) {
+    auto *VPV = new VPValue(ConstantInt::getTrue(Ctx));
+    R.getVPSingleValue()->replaceAllUsesWith(VPV);
+    return {};
   }
 
-  // Simplify (X && Y) || (X && !Y) -> X.
-  // TODO: Split up into simpler, modular combines: (X && Y) || (X && Z) into X
-  // && (Y || Z) and (X || !X) into true. This requires queuing newly created
-  // recipes to be visited during simplification.
-  VPValue *X, *Y, *X1, *Y1;
-  if (match(&R,
-            m_c_BinaryOr(m_LogicalAnd(m_VPValue(X), m_VPValue(Y)),
-                         m_LogicalAnd(m_VPValue(X1), m_Not(m_VPValue(Y1))))) &&
-      X == X1 && Y == Y1) {
+  // (X || false) -> X.
+  if (match(&R, m_c_BinaryOr(m_VPValue(X), m_False()))) {
     R.getVPSingleValue()->replaceAllUsesWith(X);
-    return;
+    return {};
+  }
+
+  // (X && !X) -> false.
+  if (match(&R, m_LogicalAnd(m_VPValue(X), m_Not(m_VPValue(X1)))) && X == X1) {
+    auto *VPV = new VPValue(ConstantInt::getFalse(Ctx));
+    R.getVPSingleValue()->replaceAllUsesWith(VPV);
+    return {};
+  }
+
+  // (X && true) -> X.
+  if (match(&R, m_LogicalAnd(m_VPValue(X), m_True()))) {
+    R.getVPSingleValue()->replaceAllUsesWith(X);
+    return {};
+  }
+
+  // (X && false) -> false.
+  if (match(&R, m_LogicalAnd(m_VPValue(X), m_False()))) {
+    auto *VPV = new VPValue(ConstantInt::getFalse(Ctx));
+    R.getVPSingleValue()->replaceAllUsesWith(VPV);
+    return {};
+  }
+
+  // (X * 1) -> X.
+  if (match(&R, m_c_Mul(m_VPValue(X), m_SpecificInt(1)))) {
+    R.getVPSingleValue()->replaceAllUsesWith(X);
+    return {};
   }
 
-  if (match(&R, m_c_Mul(m_VPValue(A), m_SpecificInt(1))))
-    return R.getVPSingleValue()->replaceAllUsesWith(A);
+  // (X && Y) || (X && Z) -> X && (Y || Z).
+  if (match(&R, m_BinaryOr(m_LogicalAnd(m_VPValue(X), m_VPValue(Y)),
+                           m_LogicalAnd(m_VPValue(X1), m_VPValue(Z)))) &&
+      X == X1) {
+    auto *YorZ = new VPInstruction(Instruction::Or, {Y, Z}, R.getDebugLoc());
----------------
fhahn wrote:

Better to use VPBuilder to construct & Insert the new instructions?

https://github.com/llvm/llvm-project/pull/93998