diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp | 20 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/select.ll | 20 |
2 files changed, 30 insertions, 10 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp index b24f0eafd5d..0f796fee56a 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp @@ -474,18 +474,18 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) { } // load (select (cond, null, P)) -> load P - if (Constant *C = dyn_cast<Constant>(SI->getOperand(1))) - if (C->isNullValue()) { - LI.setOperand(0, SI->getOperand(2)); - return &LI; - } + if (isa<ConstantPointerNull>(SI->getOperand(1)) && + LI.getPointerAddressSpace() == 0) { + LI.setOperand(0, SI->getOperand(2)); + return &LI; + } // load (select (cond, P, null)) -> load P - if (Constant *C = dyn_cast<Constant>(SI->getOperand(2))) - if (C->isNullValue()) { - LI.setOperand(0, SI->getOperand(1)); - return &LI; - } + if (isa<ConstantPointerNull>(SI->getOperand(2)) && + LI.getPointerAddressSpace() == 0) { + LI.setOperand(0, SI->getOperand(1)); + return &LI; + } } } return nullptr; diff --git a/llvm/test/Transforms/InstCombine/select.ll b/llvm/test/Transforms/InstCombine/select.ll index 765b42dfbe2..054f00a0de4 100644 --- a/llvm/test/Transforms/InstCombine/select.ll +++ b/llvm/test/Transforms/InstCombine/select.ll @@ -308,6 +308,26 @@ define i32 @test16(i1 %C, i32* %P) { ; CHECK: ret i32 %V } +;; It may be legal to load from a null address in a non-zero address space +define i32 @test16_neg(i1 %C, i32 addrspace(1)* %P) { + %P2 = select i1 %C, i32 addrspace(1)* %P, i32 addrspace(1)* null + %V = load i32 addrspace(1)* %P2 + ret i32 %V +; CHECK-LABEL: @test16_neg +; CHECK-NEXT: %P2 = select i1 %C, i32 addrspace(1)* %P, i32 addrspace(1)* null +; CHECK-NEXT: %V = load i32 addrspace(1)* %P2 +; CHECK: ret i32 %V +} +define i32 @test16_neg2(i1 %C, i32 addrspace(1)* %P) { + %P2 = select i1 %C, i32 addrspace(1)* null, i32 addrspace(1)* %P + %V = load i32 addrspace(1)* %P2 + ret i32 %V +; CHECK-LABEL: @test16_neg2 +; CHECK-NEXT: %P2 = select i1 %C, i32 addrspace(1)* null, i32 addrspace(1)* %P +; CHECK-NEXT: %V = load i32 addrspace(1)* %P2 +; CHECK: ret i32 %V +} + define i1 @test17(i32* %X, i1 %C) { %R = select i1 %C, i32* %X, i32* null %RV = icmp eq i32* %R, null |
