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SavchenkoValeriySavchenkoValeriy
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[DAGCombiner] Allow promoted constants when lowering vector SDIVs
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4 files changed

+53
-345
lines changed

4 files changed

+53
-345
lines changed

‎llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp‎

Lines changed: 4 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -5186,7 +5186,8 @@ static bool isDivisorPowerOfTwo(SDValue Divisor) {
51865186
return false;
51875187
};
51885188

5189-
return ISD::matchUnaryPredicate(Divisor, IsPowerOfTwo);
5189+
return ISD::matchUnaryPredicate(Divisor, IsPowerOfTwo, /*AllowUndefs=*/false,
5190+
/*AllowTruncation=*/true);
51905191
}
51915192

51925193
SDValue DAGCombiner::visitSDIVLike(SDValue N0, SDValue N1, SDNode *N) {
@@ -5250,7 +5251,8 @@ SDValue DAGCombiner::visitSDIVLike(SDValue N0, SDValue N1, SDNode *N) {
52505251
// alternate sequence. Targets may check function attributes for size/speed
52515252
// trade-offs.
52525253
AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes();
5253-
if (isConstantOrConstantVector(N1) &&
5254+
if (isConstantOrConstantVector(N1, /*NoOpaques=*/false,
5255+
/*AllowTruncation=*/true) &&
52545256
!TLI.isIntDivCheap(N->getValueType(0), Attr))
52555257
if (SDValue Op = BuildSDIV(N))
52565258
return Op;

‎llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp‎

Lines changed: 5 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -6562,8 +6562,9 @@ SDValue TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG,
65626562
auto BuildSDIVPattern = [&](ConstantSDNode *C) {
65636563
if (C->isZero())
65646564
return false;
6565-
6566-
const APInt &Divisor = C->getAPIntValue();
6565+
// Truncate the divisor to the target scalar type in case it was promoted
6566+
// during type legalization.
6567+
APInt Divisor = C->getAPIntValue().trunc(EltBits);
65676568
SignedDivisionByConstantInfo magics = SignedDivisionByConstantInfo::get(Divisor);
65686569
int NumeratorFactor = 0;
65696570
int ShiftMask = -1;
@@ -6593,7 +6594,8 @@ SDValue TargetLowering::BuildSDIV(SDNode *N, SelectionDAG &DAG,
65936594
SDValue N1 = N->getOperand(1);
65946595

65956596
// Collect the shifts / magic values from each element.
6596-
if (!ISD::matchUnaryPredicate(N1, BuildSDIVPattern))
6597+
if (!ISD::matchUnaryPredicate(N1, BuildSDIVPattern, /*AllowUndefs=*/false,
6598+
/*AllowTruncation=*/true))
65976599
return SDValue();
65986600

65996601
SDValue MagicFactor, Factor, Shift, ShiftMask;

‎llvm/test/CodeGen/AArch64/rem-by-const.ll‎

Lines changed: 17 additions & 72 deletions
Original file line numberDiff line numberDiff line change
@@ -893,46 +893,15 @@ define <4 x i8> @sv4i8_7(<4 x i8> %d, <4 x i8> %e) {
893893
; CHECK-SD-LABEL: sv4i8_7:
894894
; CHECK-SD: // %bb.0: // %entry
895895
; CHECK-SD-NEXT: shl v0.4h, v0.4h, #8
896-
; CHECK-SD-NEXT: mov x8, #-56173 // =0xffffffffffff2493
897-
; CHECK-SD-NEXT: movk x8, #37449, lsl #16
896+
; CHECK-SD-NEXT: mov w8, #18725 // =0x4925
897+
; CHECK-SD-NEXT: movi v2.4h, #7
898+
; CHECK-SD-NEXT: dup v1.4h, w8
898899
; CHECK-SD-NEXT: sshr v0.4h, v0.4h, #8
899-
; CHECK-SD-NEXT: smov x10, v0.h[0]
900-
; CHECK-SD-NEXT: smov x9, v0.h[1]
901-
; CHECK-SD-NEXT: smov w12, v0.h[0]
902-
; CHECK-SD-NEXT: smov w11, v0.h[1]
903-
; CHECK-SD-NEXT: smov x13, v0.h[2]
904-
; CHECK-SD-NEXT: smov w14, v0.h[2]
905-
; CHECK-SD-NEXT: smov x17, v0.h[3]
906-
; CHECK-SD-NEXT: smull x10, w10, w8
907-
; CHECK-SD-NEXT: smull x9, w9, w8
908-
; CHECK-SD-NEXT: smull x13, w13, w8
909-
; CHECK-SD-NEXT: add x10, x12, x10, lsr #32
910-
; CHECK-SD-NEXT: smull x8, w17, w8
911-
; CHECK-SD-NEXT: add x9, x11, x9, lsr #32
912-
; CHECK-SD-NEXT: asr w16, w10, #2
913-
; CHECK-SD-NEXT: add x13, x14, x13, lsr #32
914-
; CHECK-SD-NEXT: asr w15, w9, #2
915-
; CHECK-SD-NEXT: add w10, w16, w10, lsr #31
916-
; CHECK-SD-NEXT: asr w16, w13, #2
917-
; CHECK-SD-NEXT: add w9, w15, w9, lsr #31
918-
; CHECK-SD-NEXT: smov w15, v0.h[3]
919-
; CHECK-SD-NEXT: sub w10, w10, w10, lsl #3
920-
; CHECK-SD-NEXT: sub w9, w9, w9, lsl #3
921-
; CHECK-SD-NEXT: add w10, w12, w10
922-
; CHECK-SD-NEXT: fmov s0, w10
923-
; CHECK-SD-NEXT: add w9, w11, w9
924-
; CHECK-SD-NEXT: add w10, w16, w13, lsr #31
925-
; CHECK-SD-NEXT: add x8, x15, x8, lsr #32
926-
; CHECK-SD-NEXT: mov v0.h[1], w9
927-
; CHECK-SD-NEXT: sub w9, w10, w10, lsl #3
928-
; CHECK-SD-NEXT: asr w10, w8, #2
929-
; CHECK-SD-NEXT: add w9, w14, w9
930-
; CHECK-SD-NEXT: add w8, w10, w8, lsr #31
931-
; CHECK-SD-NEXT: mov v0.h[2], w9
932-
; CHECK-SD-NEXT: sub w8, w8, w8, lsl #3
933-
; CHECK-SD-NEXT: add w8, w15, w8
934-
; CHECK-SD-NEXT: mov v0.h[3], w8
935-
; CHECK-SD-NEXT: // kill: def $d0 killed $d0 killed $q0
900+
; CHECK-SD-NEXT: smull v1.4s, v0.4h, v1.4h
901+
; CHECK-SD-NEXT: sshr v1.4s, v1.4s, #17
902+
; CHECK-SD-NEXT: xtn v1.4h, v1.4s
903+
; CHECK-SD-NEXT: usra v1.4h, v1.4h, #15
904+
; CHECK-SD-NEXT: mls v0.4h, v1.4h, v2.4h
936905
; CHECK-SD-NEXT: ret
937906
;
938907
; CHECK-GI-LABEL: sv4i8_7:
@@ -978,39 +947,15 @@ define <4 x i8> @sv4i8_100(<4 x i8> %d, <4 x i8> %e) {
978947
; CHECK-SD-LABEL: sv4i8_100:
979948
; CHECK-SD: // %bb.0: // %entry
980949
; CHECK-SD-NEXT: shl v0.4h, v0.4h, #8
981-
; CHECK-SD-NEXT: mov w8, #34079 // =0x851f
982-
; CHECK-SD-NEXT: mov w14, #100 // =0x64
983-
; CHECK-SD-NEXT: movk w8, #20971, lsl #16
984-
; CHECK-SD-NEXT: sshr v1.4h, v0.4h, #8
985-
; CHECK-SD-NEXT: smov x9, v1.h[0]
986-
; CHECK-SD-NEXT: smov x10, v1.h[1]
987-
; CHECK-SD-NEXT: smov x11, v1.h[2]
988-
; CHECK-SD-NEXT: smov w12, v1.h[0]
989-
; CHECK-SD-NEXT: smov x13, v1.h[3]
990-
; CHECK-SD-NEXT: smov w15, v1.h[1]
991-
; CHECK-SD-NEXT: smull x9, w9, w8
992-
; CHECK-SD-NEXT: smull x10, w10, w8
993-
; CHECK-SD-NEXT: smull x11, w11, w8
994-
; CHECK-SD-NEXT: asr x9, x9, #37
995-
; CHECK-SD-NEXT: smull x8, w13, w8
996-
; CHECK-SD-NEXT: asr x10, x10, #37
997-
; CHECK-SD-NEXT: add w9, w9, w9, lsr #31
998-
; CHECK-SD-NEXT: asr x11, x11, #37
999-
; CHECK-SD-NEXT: add w10, w10, w10, lsr #31
1000-
; CHECK-SD-NEXT: asr x8, x8, #37
1001-
; CHECK-SD-NEXT: msub w9, w9, w14, w12
1002-
; CHECK-SD-NEXT: msub w10, w10, w14, w15
1003-
; CHECK-SD-NEXT: add w8, w8, w8, lsr #31
1004-
; CHECK-SD-NEXT: fmov s0, w9
1005-
; CHECK-SD-NEXT: add w9, w11, w11, lsr #31
1006-
; CHECK-SD-NEXT: smov w11, v1.h[2]
1007-
; CHECK-SD-NEXT: msub w9, w9, w14, w11
1008-
; CHECK-SD-NEXT: mov v0.h[1], w10
1009-
; CHECK-SD-NEXT: smov w10, v1.h[3]
1010-
; CHECK-SD-NEXT: msub w8, w8, w14, w10
1011-
; CHECK-SD-NEXT: mov v0.h[2], w9
1012-
; CHECK-SD-NEXT: mov v0.h[3], w8
1013-
; CHECK-SD-NEXT: // kill: def $d0 killed $d0 killed $q0
950+
; CHECK-SD-NEXT: mov w8, #5243 // =0x147b
951+
; CHECK-SD-NEXT: movi v2.4h, #100
952+
; CHECK-SD-NEXT: dup v1.4h, w8
953+
; CHECK-SD-NEXT: sshr v0.4h, v0.4h, #8
954+
; CHECK-SD-NEXT: smull v1.4s, v0.4h, v1.4h
955+
; CHECK-SD-NEXT: sshr v1.4s, v1.4s, #19
956+
; CHECK-SD-NEXT: xtn v1.4h, v1.4s
957+
; CHECK-SD-NEXT: usra v1.4h, v1.4h, #15
958+
; CHECK-SD-NEXT: mls v0.4h, v1.4h, v2.4h
1014959
; CHECK-SD-NEXT: ret
1015960
;
1016961
; CHECK-GI-LABEL: sv4i8_100:

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