[PATCH] D20289: [InstCombine] check vector elements before trying to transform LE/GE vector icmp (PR27756)

[David Majnemer via llvm-commits]

majnemer added inline comments.

================
Comment at: lib/Transforms/InstCombine/InstCombineCompares.cpp:3165-3185
@@ +3164,23 @@
+  Constant *OneOrNegOne = nullptr;
+  switch (I.getPredicate()) {
+  case ICmpInst::ICMP_ULE:
+    if (!allElementsValid(Op1C, true, false))
+      return nullptr;
+    NewPred = ICmpInst::ICMP_ULT;
+    OneOrNegOne = ConstantInt::get(Op1Type, 1);
+    break;
+  case ICmpInst::ICMP_SLE:
+    if (!allElementsValid(Op1C, true, true))
+      return nullptr;
+    NewPred = ICmpInst::ICMP_SLT;
+    OneOrNegOne = ConstantInt::get(Op1Type, 1);
+    break;
+  case ICmpInst::ICMP_UGE:
+    if (!allElementsValid(Op1C, false, false))
+      return nullptr;
+    NewPred = ICmpInst::ICMP_UGT;
+    OneOrNegOne = ConstantInt::get(Op1Type, -1);
+    break;
+  case ICmpInst::ICMP_SGE:
+    if (!allElementsValid(Op1C, false, true))
+      return nullptr;
----------------
I'd recommend passing `I.isSigned()` in instead of hard-coding true/false.  Makes it harder to make a mistake when updating this switch/case.


http://reviews.llvm.org/D20289