diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp index dc8e7c84f5e2c..05fa9f60758b4 100644 --- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp +++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp @@ -26192,10 +26192,22 @@ static SDValue performFlagSettingCombine(SDNode *N, return DCI.CombineTo(N, Res, SDValue(N, 1)); } - // Combine identical generic nodes into this node, re-using the result. - if (SDNode *Generic = DCI.DAG.getNodeIfExists( - GenericOpcode, DCI.DAG.getVTList(VT), {LHS, RHS})) - DCI.CombineTo(Generic, SDValue(N, 0)); + // Combine equivalent generic nodes into this node, re-using the result. + auto CombineToExistingGeneric = [&](SDValue Op0, SDValue Op1) { + if (SDNode *Generic = DCI.DAG.getNodeIfExists( + GenericOpcode, DCI.DAG.getVTList(VT), {Op0, Op1})) { + DCI.CombineTo(Generic, SDValue(N, 0)); + return true; + } + return false; + }; + + if (CombineToExistingGeneric(LHS, RHS)) + return SDValue(); + + if (DCI.DAG.getTargetLoweringInfo().isCommutativeBinOp(GenericOpcode) && + CombineToExistingGeneric(RHS, LHS)) + return SDValue(); return SDValue(); } diff --git a/llvm/test/CodeGen/AArch64/adds_cmn.ll b/llvm/test/CodeGen/AArch64/adds_cmn.ll index aa070b7886ba5..9b456a5419d61 100644 --- a/llvm/test/CodeGen/AArch64/adds_cmn.ll +++ b/llvm/test/CodeGen/AArch64/adds_cmn.ll @@ -22,10 +22,8 @@ entry: define { i32, i32 } @adds_cmn_c(i32 noundef %x, i32 noundef %y) { ; CHECK-LABEL: adds_cmn_c: ; CHECK: // %bb.0: // %entry -; CHECK-NEXT: cmn w0, w1 -; CHECK-NEXT: add w1, w1, w0 -; CHECK-NEXT: cset w8, lo -; CHECK-NEXT: mov w0, w8 +; CHECK-NEXT: adds w1, w0, w1 +; CHECK-NEXT: cset w0, lo ; CHECK-NEXT: ret entry: %0 = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 %x, i32 %y) diff --git a/llvm/test/CodeGen/AArch64/sat-add.ll b/llvm/test/CodeGen/AArch64/sat-add.ll index ecd48d6b7c65b..149b4c4fd26c9 100644 --- a/llvm/test/CodeGen/AArch64/sat-add.ll +++ b/llvm/test/CodeGen/AArch64/sat-add.ll @@ -290,8 +290,7 @@ define i32 @unsigned_sat_variable_i32_using_cmp_sum(i32 %x, i32 %y) { define i32 @unsigned_sat_variable_i32_using_cmp_notval(i32 %x, i32 %y) { ; CHECK-LABEL: unsigned_sat_variable_i32_using_cmp_notval: ; CHECK: // %bb.0: -; CHECK-NEXT: add w8, w0, w1 -; CHECK-NEXT: cmn w1, w0 +; CHECK-NEXT: adds w8, w1, w0 ; CHECK-NEXT: csinv w0, w8, wzr, lo ; CHECK-NEXT: ret %noty = xor i32 %y, -1 @@ -331,8 +330,7 @@ define i64 @unsigned_sat_variable_i64_using_cmp_sum(i64 %x, i64 %y) { define i64 @unsigned_sat_variable_i64_using_cmp_notval(i64 %x, i64 %y) { ; CHECK-LABEL: unsigned_sat_variable_i64_using_cmp_notval: ; CHECK: // %bb.0: -; CHECK-NEXT: add x8, x0, x1 -; CHECK-NEXT: cmn x1, x0 +; CHECK-NEXT: adds x8, x1, x0 ; CHECK-NEXT: csinv x0, x8, xzr, lo ; CHECK-NEXT: ret %noty = xor i64 %y, -1