[InstCombine] remove dead cases from icmp pair switches; NFCI

"PredicatesFoldable" returns false for signed/unsigned mismatched pairs,
so these cases should never exist. We'll default to 'unreachable' on those 
predicate combos instead.

Most of what's left in these switches belongs in InstSimplify (and may 
already be there), so there's probably more that can be done to reduce
this code.

llvm-svn: 299829

1 files changed, 0 insertions, 32 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index 0bc85e4b6e4..4be64d1a46f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -897,26 +897,18 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
     case ICmpInst::ICMP_EQ:  // (X u< 13 & X == 15) -> false
     case ICmpInst::ICMP_UGT: // (X u< 13 & X u> 15) -> false
       return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
-    case ICmpInst::ICMP_SGT: // (X u< 13 & X s> 15) -> no change
-      break;
     case ICmpInst::ICMP_NE:  // (X u< 13 & X != 15) -> X u< 13
     case ICmpInst::ICMP_ULT: // (X u< 13 & X u< 15) -> X u< 13
       return LHS;
-    case ICmpInst::ICMP_SLT: // (X u< 13 & X s< 15) -> no change
-      break;
     }
     break;
   case ICmpInst::ICMP_SLT:
     switch (PredR) {
     default:
       llvm_unreachable("Unknown integer condition code!");
-    case ICmpInst::ICMP_UGT: // (X s< 13 & X u> 15) -> no change
-      break;
     case ICmpInst::ICMP_NE:  // (X s< 13 & X != 15) -> X < 13
     case ICmpInst::ICMP_SLT: // (X s< 13 & X s< 15) -> X < 13
       return LHS;
-    case ICmpInst::ICMP_ULT: // (X s< 13 & X u< 15) -> no change
-      break;
     }
     break;
   case ICmpInst::ICMP_UGT:
@@ -926,8 +918,6 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
     case ICmpInst::ICMP_EQ:  // (X u> 13 & X == 15) -> X == 15
     case ICmpInst::ICMP_UGT: // (X u> 13 & X u> 15) -> X u> 15
       return RHS;
-    case ICmpInst::ICMP_SGT: // (X u> 13 & X s> 15) -> no change
-      break;
     case ICmpInst::ICMP_NE:
       if (RHSC == AddOne(LHSC)) // (X u> 13 & X != 14) -> X u> 14
         return Builder->CreateICmp(PredL, Val, RHSC);
@@ -935,8 +925,6 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
     case ICmpInst::ICMP_ULT: // (X u> 13 & X u< 15) -> (X-14) <u 1
       return insertRangeTest(Val, LHSC->getValue() + 1, RHSC->getValue(), false,
                              true);
-    case ICmpInst::ICMP_SLT: // (X u> 13 & X s< 15) -> no change
-      break;
     }
     break;
   case ICmpInst::ICMP_SGT:
@@ -946,8 +934,6 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
     case ICmpInst::ICMP_EQ:  // (X s> 13 & X == 15) -> X == 15
     case ICmpInst::ICMP_SGT: // (X s> 13 & X s> 15) -> X s> 15
       return RHS;
-    case ICmpInst::ICMP_UGT: // (X s> 13 & X u> 15) -> no change
-      break;
     case ICmpInst::ICMP_NE:
       if (RHSC == AddOne(LHSC)) // (X s> 13 & X != 14) -> X s> 14
         return Builder->CreateICmp(PredL, Val, RHSC);
@@ -955,8 +941,6 @@ Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
     case ICmpInst::ICMP_SLT: // (X s> 13 & X s< 15) -> (X-14) s< 1
       return insertRangeTest(Val, LHSC->getValue() + 1, RHSC->getValue(), true,
                              true);
-    case ICmpInst::ICMP_ULT: // (X s> 13 & X u< 15) -> no change
-      break;
     }
     break;
   }
@@ -1846,13 +1830,9 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
         return LHS;
       return insertRangeTest(Val, LHSC->getValue(), RHSC->getValue() + 1, false,
                              false);
-    case ICmpInst::ICMP_SGT: // (X u< 13 | X s> 15) -> no change
-      break;
     case ICmpInst::ICMP_NE:  // (X u< 13 | X != 15) -> X != 15
     case ICmpInst::ICMP_ULT: // (X u< 13 | X u< 15) -> X u< 15
       return RHS;
-    case ICmpInst::ICMP_SLT: // (X u< 13 | X s< 15) -> no change
-      break;
     }
     break;
   case ICmpInst::ICMP_SLT:
@@ -1868,13 +1848,9 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
         return LHS;
       return insertRangeTest(Val, LHSC->getValue(), RHSC->getValue() + 1, true,
                              false);
-    case ICmpInst::ICMP_UGT: // (X s< 13 | X u> 15) -> no change
-      break;
     case ICmpInst::ICMP_NE:  // (X s< 13 | X != 15) -> X != 15
     case ICmpInst::ICMP_SLT: // (X s< 13 | X s< 15) -> X s< 15
       return RHS;
-    case ICmpInst::ICMP_ULT: // (X s< 13 | X u< 15) -> no change
-      break;
     }
     break;
   case ICmpInst::ICMP_UGT:
@@ -1884,13 +1860,9 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
     case ICmpInst::ICMP_EQ:  // (X u> 13 | X == 15) -> X u> 13
     case ICmpInst::ICMP_UGT: // (X u> 13 | X u> 15) -> X u> 13
       return LHS;
-    case ICmpInst::ICMP_SGT: // (X u> 13 | X s> 15) -> no change
-      break;
     case ICmpInst::ICMP_NE:  // (X u> 13 | X != 15) -> true
     case ICmpInst::ICMP_ULT: // (X u> 13 | X u< 15) -> true
       return Builder->getTrue();
-    case ICmpInst::ICMP_SLT: // (X u> 13 | X s< 15) -> no change
-      break;
     }
     break;
   case ICmpInst::ICMP_SGT:
@@ -1900,13 +1872,9 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
     case ICmpInst::ICMP_EQ:  // (X s> 13 | X == 15) -> X > 13
     case ICmpInst::ICMP_SGT: // (X s> 13 | X s> 15) -> X > 13
       return LHS;
-    case ICmpInst::ICMP_UGT: // (X s> 13 | X u> 15) -> no change
-      break;
     case ICmpInst::ICMP_NE:  // (X s> 13 | X != 15) -> true
     case ICmpInst::ICMP_SLT: // (X s> 13 | X s< 15) -> true
       return Builder->getTrue();
-    case ICmpInst::ICMP_ULT: // (X s> 13 | X u< 15) -> no change
-      break;
     }
     break;
   }