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| author | Craig Topper <craig.topper@intel.com> | 2017-09-22 21:47:22 +0000 |
|---|---|---|
| committer | Craig Topper <craig.topper@intel.com> | 2017-09-22 21:47:22 +0000 |
| commit | ea927baee2ab71dde4b4c8f4df5c565ea2ff9f2b (patch) | |
| tree | 193a956bef78c32fd9686f999dcba588caa673db /llvm/lib | |
| parent | 73a998908f9ef62a5d899820310c211e3a700a43 (diff) | |
| download | bcm5719-llvm-ea927baee2ab71dde4b4c8f4df5c565ea2ff9f2b.tar.gz bcm5719-llvm-ea927baee2ab71dde4b4c8f4df5c565ea2ff9f2b.zip | |
[InstCombine] Teach foldICmpUsingKnownBits to simplify SLE/SGE/ULE/UGE to equality comparisons when the min/max ranges intersect in a single value.
This is the inverse of what we do for SGT/SLT/UGT/ULT.
llvm-svn: 314032
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index a9911f42cba..f38618e85e8 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -4272,6 +4272,8 @@ Instruction *InstCombiner::foldICmpUsingKnownBits(ICmpInst &I) { return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Max.slt(Op1Min)) // A >=s B -> false if max(A) < min(B) return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + if (Op1Min == Op0Max) // A >=s B -> A == B if max(A) == min(B) + return new ICmpInst(ICmpInst::ICMP_EQ, Op0, Op1); break; case ICmpInst::ICMP_SLE: assert(!isa<ConstantInt>(Op1) && "ICMP_SLE with ConstantInt not folded!"); @@ -4279,6 +4281,8 @@ Instruction *InstCombiner::foldICmpUsingKnownBits(ICmpInst &I) { return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Min.sgt(Op1Max)) // A <=s B -> false if min(A) > max(B) return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + if (Op1Max == Op0Min) // A <=s B -> A == B if min(A) == max(B) + return new ICmpInst(ICmpInst::ICMP_EQ, Op0, Op1); break; case ICmpInst::ICMP_UGE: assert(!isa<ConstantInt>(Op1) && "ICMP_UGE with ConstantInt not folded!"); @@ -4286,6 +4290,8 @@ Instruction *InstCombiner::foldICmpUsingKnownBits(ICmpInst &I) { return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Max.ult(Op1Min)) // A >=u B -> false if max(A) < min(B) return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + if (Op1Min == Op0Max) // A >=u B -> A == B if max(A) == min(B) + return new ICmpInst(ICmpInst::ICMP_EQ, Op0, Op1); break; case ICmpInst::ICMP_ULE: assert(!isa<ConstantInt>(Op1) && "ICMP_ULE with ConstantInt not folded!"); @@ -4293,6 +4299,8 @@ Instruction *InstCombiner::foldICmpUsingKnownBits(ICmpInst &I) { return replaceInstUsesWith(I, ConstantInt::getTrue(I.getType())); if (Op0Min.ugt(Op1Max)) // A <=u B -> false if min(A) > max(B) return replaceInstUsesWith(I, ConstantInt::getFalse(I.getType())); + if (Op1Max == Op0Min) // A <=u B -> A == B if min(A) == max(B) + return new ICmpInst(ICmpInst::ICMP_EQ, Op0, Op1); break; } |
