[PATCH] [Instcombine] Recognize test for overflow in integer multiplication.

[Benjamin Kramer]

  Some more review comments. I think you're good to commit when those are fixed.


================
Comment at: lib/Transforms/InstCombine/InstCombineCompares.cpp:2129
@@ +2128,3 @@
+    if (ConstantInt *CI = dyn_cast<ConstantInt>(OtherVal)) {
+      APInt MaxVal(CI->getBitWidth(), 1ULL << MulWidth);
+      if (MaxVal.eq(CI->getValue()))
----------------
MulWidth can be >= 64. would be better to use APInt arithmetic.

================
Comment at: lib/Transforms/InstCombine/InstCombineCompares.cpp:2070
@@ +2069,3 @@
+        if (ConstantInt *CI = dyn_cast<ConstantInt>(BO->getOperand(1))) {
+          APInt CVal = CI->getValue();
+          if (CVal.getBitWidth() - CVal.countLeadingZeros() > MulWidth)
----------------
"const APInt &" would save a copy.


http://reviews.llvm.org/D2814