diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index c5c38661f1d71..6ca73403a5ede 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -5042,7 +5042,6 @@ static SDValue simplifyDivRem(SDNode *N, SelectionDAG &DAG) { unsigned Opc = N->getOpcode(); bool IsDiv = (ISD::SDIV == Opc) || (ISD::UDIV == Opc); - ConstantSDNode *N1C = isConstOrConstSplat(N1); // X / undef -> undef // X % undef -> undef @@ -5074,7 +5073,7 @@ static SDValue simplifyDivRem(SDNode *N, SelectionDAG &DAG) { // division-by-zero or remainder-by-zero, so assume the divisor is 1. // TODO: Similarly, if we're zero-extending a boolean divisor, then assume // it's a 1. - if ((N1C && N1C->isOne()) || (VT.getScalarType() == MVT::i1)) + if (isOneOrOneSplat(N1) || (VT.getScalarType() == MVT::i1)) return IsDiv ? N0 : DAG.getConstant(0, DL, VT); return SDValue(); diff --git a/llvm/test/CodeGen/AArch64/combine-sdiv.ll b/llvm/test/CodeGen/AArch64/combine-sdiv.ll index dc88f9414b866..cca190f08df2b 100644 --- a/llvm/test/CodeGen/AArch64/combine-sdiv.ll +++ b/llvm/test/CodeGen/AArch64/combine-sdiv.ll @@ -1774,3 +1774,88 @@ define i128 @combine_i128_sdiv_const100(i128 %x) { %1 = sdiv i128 %x, 100 ret i128 %1 } + +; The following only becomes an sdiv_by_one after type legalisation, after which +; the splatted scalar constant has a different type to the splat vector. This +; test verifies DAGCombiner does not care about this type difference. +define <16 x i16> @combine_vec_sdiv_by_one_obfuscated(<16 x i16> %x) "target-features"="+sve" { +; CHECK-SD-LABEL: combine_vec_sdiv_by_one_obfuscated: +; CHECK-SD: // %bb.0: +; CHECK-SD-NEXT: ret +; +; CHECK-GI-LABEL: combine_vec_sdiv_by_one_obfuscated: +; CHECK-GI: // %bb.0: +; CHECK-GI-NEXT: movi v2.2d, #0000000000000000 +; CHECK-GI-NEXT: movi v3.8h, #1 +; CHECK-GI-NEXT: smov w8, v0.h[0] +; CHECK-GI-NEXT: mov v3.h[0], v2.h[0] +; CHECK-GI-NEXT: smov w9, v3.h[0] +; CHECK-GI-NEXT: smov w16, v3.h[7] +; CHECK-GI-NEXT: sdiv w14, w8, w9 +; CHECK-GI-NEXT: smov w8, v0.h[1] +; CHECK-GI-NEXT: smov w9, v3.h[1] +; CHECK-GI-NEXT: sdiv w15, w8, w9 +; CHECK-GI-NEXT: smov w8, v0.h[2] +; CHECK-GI-NEXT: smov w9, v3.h[2] +; CHECK-GI-NEXT: sdiv w13, w8, w9 +; CHECK-GI-NEXT: smov w8, v0.h[3] +; CHECK-GI-NEXT: smov w9, v3.h[3] +; CHECK-GI-NEXT: sdiv w12, w8, w9 +; CHECK-GI-NEXT: smov w8, v0.h[4] +; CHECK-GI-NEXT: smov w9, v3.h[4] +; CHECK-GI-NEXT: sdiv w11, w8, w9 +; CHECK-GI-NEXT: smov w8, v0.h[5] +; CHECK-GI-NEXT: smov w9, v3.h[5] +; CHECK-GI-NEXT: sdiv w10, w8, w9 +; CHECK-GI-NEXT: smov w8, v0.h[6] +; CHECK-GI-NEXT: smov w9, v3.h[6] +; CHECK-GI-NEXT: movi v3.8h, #1 +; CHECK-GI-NEXT: smov w17, v3.h[0] +; CHECK-GI-NEXT: smov w18, v3.h[1] +; CHECK-GI-NEXT: smov w0, v3.h[2] +; CHECK-GI-NEXT: smov w1, v3.h[3] +; CHECK-GI-NEXT: smov w2, v3.h[4] +; CHECK-GI-NEXT: smov w3, v3.h[5] +; CHECK-GI-NEXT: sdiv w8, w8, w9 +; CHECK-GI-NEXT: smov w9, v0.h[7] +; CHECK-GI-NEXT: fmov s0, w14 +; CHECK-GI-NEXT: mov v0.h[1], w15 +; CHECK-GI-NEXT: smov w15, v1.h[6] +; CHECK-GI-NEXT: mov v0.h[2], w13 +; CHECK-GI-NEXT: sdiv w9, w9, w16 +; CHECK-GI-NEXT: smov w16, v1.h[0] +; CHECK-GI-NEXT: mov v0.h[3], w12 +; CHECK-GI-NEXT: smov w12, v1.h[7] +; CHECK-GI-NEXT: mov v0.h[4], w11 +; CHECK-GI-NEXT: sdiv w16, w16, w17 +; CHECK-GI-NEXT: smov w17, v1.h[1] +; CHECK-GI-NEXT: mov v0.h[5], w10 +; CHECK-GI-NEXT: mov v0.h[6], w8 +; CHECK-GI-NEXT: sdiv w17, w17, w18 +; CHECK-GI-NEXT: smov w18, v1.h[2] +; CHECK-GI-NEXT: fmov s2, w16 +; CHECK-GI-NEXT: smov w16, v3.h[6] +; CHECK-GI-NEXT: mov v0.h[7], w9 +; CHECK-GI-NEXT: sdiv w18, w18, w0 +; CHECK-GI-NEXT: smov w0, v1.h[3] +; CHECK-GI-NEXT: mov v2.h[1], w17 +; CHECK-GI-NEXT: sdiv w0, w0, w1 +; CHECK-GI-NEXT: smov w1, v1.h[4] +; CHECK-GI-NEXT: mov v2.h[2], w18 +; CHECK-GI-NEXT: sdiv w1, w1, w2 +; CHECK-GI-NEXT: smov w2, v1.h[5] +; CHECK-GI-NEXT: mov v2.h[3], w0 +; CHECK-GI-NEXT: sdiv w14, w2, w3 +; CHECK-GI-NEXT: mov v2.h[4], w1 +; CHECK-GI-NEXT: sdiv w13, w15, w16 +; CHECK-GI-NEXT: smov w15, v3.h[7] +; CHECK-GI-NEXT: mov v2.h[5], w14 +; CHECK-GI-NEXT: sdiv w10, w12, w15 +; CHECK-GI-NEXT: mov v2.h[6], w13 +; CHECK-GI-NEXT: mov v2.h[7], w10 +; CHECK-GI-NEXT: mov v1.16b, v2.16b +; CHECK-GI-NEXT: ret + %zero_and_ones = shufflevector <16 x i16> zeroinitializer, <16 x i16> splat (i16 1), <16 x i32> + %div = sdiv <16 x i16> %x, %zero_and_ones + ret <16 x i16> %div +}