[PATCH] D39222: [InstCombine] Pull shifts through a select plus binop with constant

[Sanjay Patel via Phabricator via llvm-commits]

spatel added inline comments.


================
Comment at: lib/Transforms/InstCombine/InstCombineShifts.cpp:318-320
+  bool isValid = true;     // Valid only for And, Or Xor,
+  bool highBitSet = false; // Transform ifhigh bit of constant set?
+
----------------
Since we're moving this, we might as well fix the formatting - capitalize variables.


================
Comment at: lib/Transforms/InstCombine/InstCombineShifts.cpp:539-544
+    if (auto *SI = dyn_cast<SelectInst>(Op0)) {
+      Value *TrueVal = SI->getTrueValue();
+      Value *FalseVal = SI->getFalseValue();
+
+      if (auto *TVI = dyn_cast<BinaryOperator>(TrueVal)) {
+        if (TVI->hasOneUse() && !isa<Constant>(FalseVal)) {
----------------
Use matchers to reduce the number of if-checks and indenting?
    CmpInst::Predicate P;
    BinaryOperator *TVI;
    Value *FalseVal;
    if (match(Op0, m_Select(P, m_OneUse(m_BinOp(TVI)), m_Value(FalseVal))) ...



https://reviews.llvm.org/D39222