diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 11 | ||||
| -rw-r--r-- | llvm/test/CodeGen/AArch64/combine-and-like.ll | 13 |
2 files changed, 20 insertions, 4 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index d2b06ec0a4b..1119a36849c 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -3642,15 +3642,18 @@ SDValue DAGCombiner::visitANDLike(SDValue N0, SDValue N1, SDNode *N) { if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL && VT.getSizeInBits() <= 64) { if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) { - APInt ADDC = ADDI->getAPIntValue(); - if (!TLI.isLegalAddImmediate(ADDC.getSExtValue())) { + if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) { // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal // immediate for an add, but it is legal if its top c2 bits are set, // transform the ADD so the immediate doesn't need to be materialized // in a register. - if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) { + APInt ADDC = ADDI->getAPIntValue(); + APInt SRLC = SRLI->getAPIntValue(); + if (ADDC.getMinSignedBits() <= 64 && + SRLC.ult(VT.getSizeInBits()) && + !TLI.isLegalAddImmediate(ADDC.getSExtValue())) { APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(), - SRLI->getZExtValue()); + SRLC.getZExtValue()); if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) { ADDC |= Mask; if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) { diff --git a/llvm/test/CodeGen/AArch64/combine-and-like.ll b/llvm/test/CodeGen/AArch64/combine-and-like.ll new file mode 100644 index 00000000000..15770c2e02f --- /dev/null +++ b/llvm/test/CodeGen/AArch64/combine-and-like.ll @@ -0,0 +1,13 @@ +; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py +; RUN: llc < %s -mtriple=aarch64-unknown-unknown | FileCheck %s + +define i32 @f(i32 %a0) { +; CHECK-LABEL: f: +; CHECK: // %bb.0: +; CHECK-NEXT: mov w0, wzr +; CHECK-NEXT: ret + %1 = lshr i32 %a0, 2147483647 + %2 = add i32 %1, 2147483647 + %3 = and i32 %2, %1 + ret i32 %3 +} |
