diff options
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 31 | ||||
| -rw-r--r-- | llvm/test/CodeGen/AArch64/ldst-paired-aliasing.ll | 6 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/pr40631_deadstore_elision.ll | 1 |
3 files changed, 20 insertions, 18 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 993ab4ae551..e46cda729f3 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -15414,25 +15414,28 @@ SDValue DAGCombiner::visitSTORE(SDNode *N) { if (StoreSDNode *ST1 = dyn_cast<StoreSDNode>(Chain)) { if (ST->isUnindexed() && !ST->isVolatile() && ST1->isUnindexed() && - !ST1->isVolatile() && ST1->getBasePtr() == Ptr && - ST->getMemoryVT() == ST1->getMemoryVT()) { - // If this is a store followed by a store with the same value to the same - // location, then the store is dead/noop. - if (ST1->getValue() == Value) { - // The store is dead, remove it. + !ST1->isVolatile()) { + if (ST1->getBasePtr() == Ptr && ST1->getValue() == Value && + ST->getMemoryVT() == ST1->getMemoryVT()) { + // If this is a store followed by a store with the same value to the + // same location, then the store is dead/noop. return Chain; } - // If this is a store who's preceeding store to the same location - // and no one other node is chained to that store we can effectively - // drop the store. Do not remove stores to undef as they may be used as - // data sinks. if (OptLevel != CodeGenOpt::None && ST1->hasOneUse() && !ST1->getBasePtr().isUndef()) { - // ST1 is fully overwritten and can be elided. Combine with it's chain - // value. - CombineTo(ST1, ST1->getChain()); - return SDValue(); + const BaseIndexOffset STBase = BaseIndexOffset::match(ST, DAG); + const BaseIndexOffset ChainBase = BaseIndexOffset::match(ST1, DAG); + unsigned STByteSize = ST->getMemoryVT().getSizeInBits() / 8; + unsigned ChainByteSize = ST1->getMemoryVT().getSizeInBits() / 8; + // If this is a store who's preceeding store to a subset of the current + // location and no one other node is chained to that store we can + // effectively drop the store. Do not remove stores to undef as they may + // be used as data sinks. + if (STBase.contains(STByteSize, ChainBase, ChainByteSize, DAG)) { + CombineTo(ST1, ST1->getChain()); + return SDValue(); + } } } } diff --git a/llvm/test/CodeGen/AArch64/ldst-paired-aliasing.ll b/llvm/test/CodeGen/AArch64/ldst-paired-aliasing.ll index 0f8ffb50c8d..ed72488f411 100644 --- a/llvm/test/CodeGen/AArch64/ldst-paired-aliasing.ll +++ b/llvm/test/CodeGen/AArch64/ldst-paired-aliasing.ll @@ -10,11 +10,11 @@ declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i1) #3 define i32 @main() local_unnamed_addr #1 { ; Make sure the stores happen in the correct order (the exact instructions could change). ; CHECK-LABEL: main: -; CHECK: stp xzr, xzr, [sp, #72] + +; CHECK: str xzr, [sp, #80] ; CHECK: str w9, [sp, #80] -; CHECK: str q0, [sp, #48] +; CHECK: stp q0, q0, [sp, #48] ; CHECK: ldr w8, [sp, #48] -; CHECK: str q0, [sp, #64] for.body.lr.ph.i.i.i.i.i.i63: %b1 = alloca [10 x i32], align 16 diff --git a/llvm/test/CodeGen/X86/pr40631_deadstore_elision.ll b/llvm/test/CodeGen/X86/pr40631_deadstore_elision.ll index a77bed9009a..c742ce4bd94 100644 --- a/llvm/test/CodeGen/X86/pr40631_deadstore_elision.ll +++ b/llvm/test/CodeGen/X86/pr40631_deadstore_elision.ll @@ -11,7 +11,6 @@ define i32 @ipt_do_table(%struct.sk_buff* noalias nocapture readonly) { ; CHECK-NEXT: .cfi_def_cfa_offset 48 ; CHECK-NEXT: movq (%rdi), %rax ; CHECK-NEXT: xorps %xmm0, %xmm0 -; CHECK-NEXT: movaps %xmm0, (%rsp) ; CHECK-NEXT: movaps %xmm0, {{[0-9]+}}(%rsp) ; CHECK-NEXT: movq $0, {{[0-9]+}}(%rsp) ; CHECK-NEXT: movaps {{.*#+}} xmm0 = [12297829382473034410,12297829382473034410] |
