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[InstCombine] Don't use AddOne/SubOne to see if two APInts are 1 apart. Use APInt operations instead. NFCI 

AddOne/SubOne create new Constant objects. That seems heavy for
comparing ConstantInts which wrap APInts. Just do the math on
on the APInts and compare them.

llvm-svn: 366648
This commit is contained in:
Craig Topper 2019-07-21 05:26:05 +00:00
parent b4e06328fc
commit 8fabdfe9fc
1 changed files with 9 additions and 5 deletions
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14
llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
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@ -1196,14 +1196,16 @@ Value *InstCombiner::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS,
default:
llvm_unreachable("Unknown integer condition code!");
case ICmpInst::ICMP_ULT:
if (LHSC == SubOne(RHSC)) // (X != 13 & X u< 14) -> X < 13
// (X != 13 & X u< 14) -> X < 13
if (LHSC->getValue() == (RHSC->getValue() - 1))
return Builder.CreateICmpULT(LHS0, LHSC);
if (LHSC->isZero()) // (X != 0 & X u< 14) -> X-1 u< 13
if (LHSC->isZero()) // (X != 0 & X u< 14) -> X-1 u< 13
return insertRangeTest(LHS0, LHSC->getValue() + 1, RHSC->getValue(),
false, true);
break; // (X != 13 & X u< 15) -> no change
case ICmpInst::ICMP_SLT:
if (LHSC == SubOne(RHSC)) // (X != 13 & X s< 14) -> X < 13
// (X != 13 & X s< 14) -> X < 13
if (LHSC->getValue() == (RHSC->getValue() - 1))
return Builder.CreateICmpSLT(LHS0, LHSC);
break; // (X != 13 & X s< 15) -> no change
case ICmpInst::ICMP_NE:
@ -1216,7 +1218,8 @@ Value *InstCombiner::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS,
default:
llvm_unreachable("Unknown integer condition code!");
case ICmpInst::ICMP_NE:
if (RHSC == AddOne(LHSC)) // (X u> 13 & X != 14) -> X u> 14
// (X u> 13 & X != 14) -> X u> 14
if (RHSC->getValue() == (LHSC->getValue() + 1))
return Builder.CreateICmp(PredL, LHS0, RHSC);
break; // (X u> 13 & X != 15) -> no change
case ICmpInst::ICMP_ULT: // (X u> 13 & X u< 15) -> (X-14) <u 1
@ -1229,7 +1232,8 @@ Value *InstCombiner::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS,
default:
llvm_unreachable("Unknown integer condition code!");
case ICmpInst::ICMP_NE:
if (RHSC == AddOne(LHSC)) // (X s> 13 & X != 14) -> X s> 14
// (X s> 13 & X != 14) -> X s> 14
if (RHSC->getValue() == (LHSC->getValue() + 1))
return Builder.CreateICmp(PredL, LHS0, RHSC);
break; // (X s> 13 & X != 15) -> no change
case ICmpInst::ICMP_SLT: // (X s> 13 & X s< 15) -> (X-14) s< 1