llvm-project/llvm/test/Transforms/LoopVectorize/scalable-first-order-recurrence.ll
Florian Hahn a5891fa4d2
[VPlan] Initial modeling of VF * UF as VPValue. (#74761)
This patch starts initial modeling of VF * UF in VPlan.
Initially, introduce a dedicated VFxUF VPValue, which is then
populated during VPlan::prepareToExecute. Initially, the VF * UF
applies only to the main vector loop region. Once we extend the
scope of VPlan in the future, we may want to associate different VFxUFs
with different vector loop regions (e.g. the epilogue vector loop)

This allows explicitly parameterizing recipes that rely on the
VF * UF, like the canonical induction increment. At the moment, this
mainly helps to avoid generating some duplicated calls to vscale with
scalable vectors. It should also allow using EVL as induction increments
explicitly in D99750. Referring to VF * UF is also needed in other
places that we plan to migrate to VPlan, like the minimum trip count
check during skeleton creation.

The first version creates the value for VF * UF directly in
prepareToExecute to limit the scope of the patch. A follow-on patch will
model VF * UF computation explicitly in VPlan using recipes.

Moved from Phabricator (https://reviews.llvm.org/D157322)
2023-12-08 18:30:30 +00:00

272 lines
13 KiB
LLVM

; RUN: opt -passes=loop-vectorize -scalable-vectorization=on -force-vector-width=4 -force-vector-interleave=1 -force-target-supports-scalable-vectors=true -S < %s | FileCheck %s --check-prefix=CHECK-VF4UF1
; RUN: opt -passes=loop-vectorize -scalable-vectorization=on -force-vector-width=4 -force-vector-interleave=2 -force-target-supports-scalable-vectors=true -S < %s | FileCheck %s --check-prefix=CHECK-VF4UF2
; void recurrence_1(int *a, int *b, int n) {
; for(int i = 0; i < n; i++)
; b[i] = a[i] + a[i - 1]
; }
;
define i32 @recurrence_1(ptr nocapture readonly %a, ptr nocapture %b, i32 %n) {
; CHECK-VF4UF1-LABEL: @recurrence_1
; CHECK-VF4UF1: for.preheader
; CHECK-VF4UF1: %[[SUB_1:.*]] = add i32 %n, -1
; CHECK-VF4UF1: %[[ZEXT:.*]] = zext i32 %[[SUB_1]] to i64
; CHECK-VF4UF1: %[[ADD:.*]] = add nuw nsw i64 %[[ZEXT]], 1
; CHECK-VF4UF1: vector.ph:
; CHECK-VF4UF1: %[[VSCALE1:.*]] = call i32 @llvm.vscale.i32()
; CHECK-VF4UF1: %[[MUL1:.*]] = mul i32 %[[VSCALE1]], 4
; CHECK-VF4UF1: %[[SUB1:.*]] = sub i32 %[[MUL1]], 1
; CHECK-VF4UF1: %[[VEC_RECUR_INIT:.*]] = insertelement <vscale x 4 x i32> poison, i32 %pre_load, i32 %[[SUB1]]
; CHECK-VF4UF1: vector.body:
; CHECK-VF4UF1: %[[INDEX:.*]] = phi i64 [ 0, %vector.ph ], [ %[[NEXT_IDX:.*]], %vector.body ]
; CHECK-VF4UF1: %[[VEC_RECUR:.*]] = phi <vscale x 4 x i32> [ %[[VEC_RECUR_INIT]], %vector.ph ], [ %[[LOAD:.*]], %vector.body ]
; CHECK-VF4UF1: %[[LOAD]] = load <vscale x 4 x i32>, ptr
; CHECK-VF4UF1: %[[SPLICE:.*]] = call <vscale x 4 x i32> @llvm.experimental.vector.splice.nxv4i32(<vscale x 4 x i32> %[[VEC_RECUR]], <vscale x 4 x i32> %[[LOAD]], i32 -1)
; CHECK-VF4UF1: middle.block:
; CHECK-VF4UF1: %[[VSCALE2:.*]] = call i32 @llvm.vscale.i32()
; CHECK-VF4UF1: %[[MUL2:.*]] = mul i32 %[[VSCALE2]], 4
; CHECK-VF4UF1: %[[SUB2:.*]] = sub i32 %[[MUL2]], 1
; CHECK-VF4UF1: %[[VEC_RECUR_EXT:.*]] = extractelement <vscale x 4 x i32> %[[LOAD]], i32 %[[SUB2]]
; CHECK-VF4UF1: %[[SUB3:.*]] = sub i32 %[[MUL2]], 2
; CHECK-VF4UF1: %[[VEC_RECUR_FOR_PHI:.*]] = extractelement <vscale x 4 x i32> %[[LOAD]], i32 %[[SUB3]]
entry:
br label %for.preheader
for.preheader:
%pre_load = load i32, ptr %a
br label %scalar.body
scalar.body:
%0 = phi i32 [ %pre_load, %for.preheader ], [ %1, %scalar.body ]
%indvars.iv = phi i64 [ 0, %for.preheader ], [ %indvars.iv.next, %scalar.body ]
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%arrayidx32 = getelementptr inbounds i32, ptr %a, i64 %indvars.iv.next
%1 = load i32, ptr %arrayidx32
%arrayidx34 = getelementptr inbounds i32, ptr %b, i64 %indvars.iv
%add35 = add i32 %1, %0
store i32 %add35, ptr %arrayidx34
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, %n
br i1 %exitcond, label %for.exit, label %scalar.body, !llvm.loop !0
for.exit:
ret i32 %0
}
; int recurrence_2(int *a, int n) {
; int minmax;
; for (int i = 0; i < n; ++i)
; minmax = min(minmax, max(a[i] - a[i-1], 0));
; return minmax;
; }
;
define i32 @recurrence_2(ptr nocapture readonly %a, i32 %n) {
; CHECK-VF4UF1-LABEL: @recurrence_2
; CHECK-VF4UF1: vector.ph:
; CHECK-VF4UF1: %[[VSCALE1:.*]] = call i32 @llvm.vscale.i32()
; CHECK-VF4UF1: %[[MUL1:.*]] = mul i32 %[[VSCALE1]], 4
; CHECK-VF4UF1: %[[SUB1:.*]] = sub i32 %[[MUL1]], 1
; CHECK-VF4UF1: %[[VEC_RECUR_INIT:.*]] = insertelement <vscale x 4 x i32> poison, i32 %.pre, i32 %[[SUB1]]
; CHECK-VF4UF1: vector.body:
; CHECK-VF4UF1: %[[VEC_RECUR:.*]] = phi <vscale x 4 x i32> [ %[[VEC_RECUR_INIT]], %vector.ph ], [ %[[LOAD:.*]], %vector.body ]
; CHECK-VF4UF1: %[[LOAD]] = load <vscale x 4 x i32>, ptr
; CHECK-VF4UF1: %[[REVERSE:.*]] = call <vscale x 4 x i32> @llvm.experimental.vector.splice.nxv4i32(<vscale x 4 x i32> %[[VEC_RECUR]], <vscale x 4 x i32> %[[LOAD]], i32 -1)
; CHECK-VF4UF1: middle.block:
; CHECK-VF4UF1: %[[VSCALE2:.*]] = call i32 @llvm.vscale.i32()
; CHECK-VF4UF1: %[[MUL2:.*]] = mul i32 %[[VSCALE2]], 4
; CHECK-VF4UF1: %[[SUB2:.*]] = sub i32 %[[MUL2]], 1
; CHECK-VF4UF1: %[[VEC_RECUR_EXT:.*]] = extractelement <vscale x 4 x i32> %[[LOAD]], i32 %[[SUB2]]
entry:
%cmp27 = icmp sgt i32 %n, 0
br i1 %cmp27, label %for.preheader, label %for.cond.cleanup
for.preheader:
%arrayidx2.phi.trans.insert = getelementptr inbounds i32, ptr %a, i64 -1
%.pre = load i32, ptr %arrayidx2.phi.trans.insert, align 4
br label %scalar.body
for.cond.cleanup.loopexit:
%minmax.0.cond.lcssa = phi i32 [ %minmax.0.cond, %scalar.body ]
br label %for.cond.cleanup
for.cond.cleanup:
%minmax.0.lcssa = phi i32 [ undef, %entry ], [ %minmax.0.cond.lcssa, %for.cond.cleanup.loopexit ]
ret i32 %minmax.0.lcssa
scalar.body:
%0 = phi i32 [ %.pre, %for.preheader ], [ %1, %scalar.body ]
%indvars.iv = phi i64 [ 0, %for.preheader ], [ %indvars.iv.next, %scalar.body ]
%minmax.028 = phi i32 [ undef, %for.preheader ], [ %minmax.0.cond, %scalar.body ]
%arrayidx = getelementptr inbounds i32, ptr %a, i64 %indvars.iv
%1 = load i32, ptr %arrayidx, align 4
%sub3 = sub nsw i32 %1, %0
%cmp4 = icmp sgt i32 %sub3, 0
%cond = select i1 %cmp4, i32 %sub3, i32 0
%cmp5 = icmp slt i32 %minmax.028, %cond
%minmax.0.cond = select i1 %cmp5, i32 %minmax.028, i32 %cond
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, %n
br i1 %exitcond, label %for.cond.cleanup.loopexit, label %scalar.body, !llvm.loop !0
}
define void @recurrence_3(ptr nocapture readonly %a, ptr nocapture %b, i32 %n, float %f, i16 %p) {
; CHECK-VF4UF1: vector.ph:
; CHECK-VF4UF1: %[[VSCALE1:.*]] = call i32 @llvm.vscale.i32()
; CHECK-VF4UF1: %[[MUL1:.*]] = mul i32 %[[VSCALE1]], 4
; CHECK-VF4UF1: %[[SUB1:.*]] = sub i32 %[[MUL1]], 1
; CHECK-VF4UF1: %vector.recur.init = insertelement <vscale x 4 x i16> poison, i16 %0, i32 %[[SUB1]]
; CHECK-VF4UF1: vector.body:
; CHECK-VF4UF1: %vector.recur = phi <vscale x 4 x i16> [ %vector.recur.init, %vector.ph ], [ %[[L1:.*]], %vector.body ]
; CHECK-VF4UF1: %[[L1]] = load <vscale x 4 x i16>, ptr
; CHECK-VF4UF1: %[[SPLICE:.*]] = call <vscale x 4 x i16> @llvm.experimental.vector.splice.nxv4i16(<vscale x 4 x i16> %vector.recur, <vscale x 4 x i16> %[[L1]], i32 -1)
; Check also that the casts were not moved needlessly.
; CHECK-VF4UF1: sitofp <vscale x 4 x i16> %[[L1]] to <vscale x 4 x double>
; CHECK-VF4UF1: sitofp <vscale x 4 x i16> %[[SPLICE]] to <vscale x 4 x double>
; CHECK-VF4UF1: middle.block:
; CHECK-VF4UF1: %[[VSCALE2:.*]] = call i32 @llvm.vscale.i32()
; CHECK-VF4UF1: %[[MUL2:.*]] = mul i32 %[[VSCALE2]], 4
; CHECK-VF4UF1: %[[SUB2:.*]] = sub i32 %[[MUL2]], 1
; CHECK-VF4UF1: %vector.recur.extract = extractelement <vscale x 4 x i16> %[[L1]], i32 %[[SUB2]]
entry:
%0 = load i16, ptr %a, align 2
%conv = sitofp i16 %0 to double
%conv1 = fpext float %f to double
%conv2 = sitofp i16 %p to double
%mul = fmul fast double %conv2, %conv1
%sub = fsub fast double %conv, %mul
store double %sub, ptr %b, align 8
%cmp25 = icmp sgt i32 %n, 1
br i1 %cmp25, label %for.preheader, label %for.end
for.preheader:
br label %scalar.body
scalar.body:
%1 = phi i16 [ %0, %for.preheader ], [ %2, %scalar.body ]
%iv = phi i64 [ %iv.next, %scalar.body ], [ 1, %for.preheader ]
%arrayidx5 = getelementptr inbounds i16, ptr %a, i64 %iv
%2 = load i16, ptr %arrayidx5, align 2
%conv6 = sitofp i16 %2 to double
%conv11 = sitofp i16 %1 to double
%mul12 = fmul fast double %conv11, %conv1
%sub13 = fsub fast double %conv6, %mul12
%arrayidx15 = getelementptr inbounds double, ptr %b, i64 %iv
store double %sub13, ptr %arrayidx15, align 8
%iv.next = add nuw nsw i64 %iv, 1
%lftr.wideiv = trunc i64 %iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, %n
br i1 %exitcond, label %for.end.loopexit, label %scalar.body, !llvm.loop !0
for.end.loopexit:
br label %for.end
for.end:
ret void
}
define i64 @constant_folded_previous_value() {
; CHECK-VF4UF2-LABEL: @constant_folded_previous_value
; CHECK-VF4UF2: vector.body
; CHECK-VF4UF2: %[[VECTOR_RECUR:.*]] = phi <vscale x 4 x i64> [ %vector.recur.init, %vector.ph ], [ shufflevector (<vscale x 4 x i64> insertelement (<vscale x 4 x i64> poison, i64 1, i64 0), <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer), %vector.body ]
; CHECK-VF4UF2: %[[SPLICE1:.*]] = call <vscale x 4 x i64> @llvm.experimental.vector.splice.nxv4i64(<vscale x 4 x i64> %vector.recur, <vscale x 4 x i64> shufflevector (<vscale x 4 x i64> insertelement (<vscale x 4 x i64> poison, i64 1, i64 0), <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer), i32 -1)
; CHECK-VF4UF2: %[[SPLICE2:.*]] = call <vscale x 4 x i64> @llvm.experimental.vector.splice.nxv4i64(<vscale x 4 x i64> shufflevector (<vscale x 4 x i64> insertelement (<vscale x 4 x i64> poison, i64 1, i64 0), <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer), <vscale x 4 x i64> shufflevector (<vscale x 4 x i64> insertelement (<vscale x 4 x i64> poison, i64 1, i64 0), <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer), i32 -1)
; CHECK-VF4UF2: br i1 {{.*}}, label %middle.block, label %vector.body
entry:
br label %scalar.body
scalar.body:
%i = phi i64 [ 0, %entry ], [ %i.next, %scalar.body ]
%tmp2 = phi i64 [ 0, %entry ], [ %tmp3, %scalar.body ]
%tmp3 = add i64 0, 1
%i.next = add nuw nsw i64 %i, 1
%cond = icmp eq i64 %i.next, undef
br i1 %cond, label %for.end, label %scalar.body, !llvm.loop !0
for.end:
ret i64 %tmp2
}
; We vectorize this first order recurrence, by generating two
; extracts for the phi `val.phi` - one at the last index and
; another at the second last index. We need these 2 extracts because
; the first order recurrence phi is used outside the loop, so we require the phi
; itself and not its update (addx).
define i32 @extract_second_last_iteration(ptr %cval, i32 %x) {
; CHECK-VF4UF2-LABEL: @extract_second_last_iteration
; CHECK-VF4UF2: vector.ph
; CHECK-VF4UF2: call i32 @llvm.vscale.i32()
; CHECK-VF4UF2: call i32 @llvm.vscale.i32()
; CHECK-VF4UF2: call i32 @llvm.vscale.i32()
; CHECK-VF4UF2: %[[VSCALE1:.*]] = call i32 @llvm.vscale.i32()
; CHECK-VF4UF2: %[[MUL1:.*]] = mul i32 %[[VSCALE1]], 4
; CHECK-VF4UF2: %[[SUB1:.*]] = sub i32 %[[MUL1]], 1
; CHECK-VF4UF2: %[[VEC_RECUR_INIT:.*]] = insertelement <vscale x 4 x i32> poison, i32 0, i32 %[[SUB1]]
; CHECK-VF4UF2: %[[SPLAT_INS1:.*]] = insertelement <vscale x 4 x i32> poison, i32 %x, i64 0
; CHECK-VF4UF2: %[[SPLAT1:.*]] = shufflevector <vscale x 4 x i32> %[[SPLAT_INS1]], <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer
; ; CHECK-VF4UF2: vector.body
; CHECK-VF4UF2: %[[VEC_RECUR:.*]] = phi <vscale x 4 x i32> [ %[[VEC_RECUR_INIT]], %vector.ph ], [ %[[ADD2:.*]], %vector.body ]
; CHECK-VF4UF2: %[[ADD1:.*]] = add <vscale x 4 x i32> %{{.*}}, %[[SPLAT1]]
; CHECK-VF4UF2: %[[ADD2]] = add <vscale x 4 x i32> %{{.*}}, %[[SPLAT1]]
; CHECK-VF4UF2: middle.block
; CHECK-VF4UF2: %[[VSCALE2:.*]] = call i32 @llvm.vscale.i32()
; CHECK-VF4UF2: %[[MUL2:.*]] = mul i32 %[[VSCALE2]], 4
; CHECK-VF4UF2: %[[SUB2:.*]] = sub i32 %[[MUL2]], 1
; CHECK-VF4UF2: %vector.recur.extract = extractelement <vscale x 4 x i32> %[[ADD2]], i32 %[[SUB2]]
; CHECK-VF4UF2: %[[SUB3:.*]] = sub i32 %[[MUL2]], 2
; CHECK-VF4UF2: %vector.recur.extract.for.phi = extractelement <vscale x 4 x i32> %[[ADD2]], i32 %[[SUB3]]
entry:
br label %for.body
for.body:
%inc.phi = phi i32 [ 0, %entry ], [ %inc, %for.body ]
%val.phi = phi i32 [ 0, %entry ], [ %addx, %for.body ]
%inc = add i32 %inc.phi, 1
%bc = zext i32 %inc.phi to i64
%addx = add i32 %inc.phi, %x
%cmp = icmp eq i32 %inc.phi, 95
br i1 %cmp, label %for.end, label %for.body, !llvm.loop !0
for.end:
ret i32 %val.phi
}
; void sink_after(short *a, int n, int *b) {
; for(int i = 0; i < n; i++)
; b[i] = (aptr a[i + 1]);
; }
; Check that the sext sank after the load in the vector loop.
define void @sink_after(ptr %a, ptr %b, i64 %n) {
; CHECK-VF4UF1-LABEL: @sink_after
; CHECK-VF4UF1: vector.body
; CHECK-VF4UF1: %[[VEC_RECUR:.*]] = phi <vscale x 4 x i16> [ %vector.recur.init, %vector.ph ], [ %[[LOAD:.*]], %vector.body ]
; CHECK-VF4UF1: %[[LOAD]] = load <vscale x 4 x i16>, ptr
; CHECK-VF4UF1-NEXT: %[[SPLICE:.*]] = call <vscale x 4 x i16> @llvm.experimental.vector.splice.nxv4i16(<vscale x 4 x i16> %[[VEC_RECUR]], <vscale x 4 x i16> %[[LOAD]], i32 -1)
; CHECK-VF4UF1-NEXT: sext <vscale x 4 x i16> %[[SPLICE]] to <vscale x 4 x i32>
; CHECK-VF4UF1-NEXT: sext <vscale x 4 x i16> %[[LOAD]] to <vscale x 4 x i32>
entry:
%.pre = load i16, ptr %a
br label %for.body
for.body:
%0 = phi i16 [ %.pre, %entry ], [ %1, %for.body ]
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%conv = sext i16 %0 to i32
%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
%arrayidx2 = getelementptr inbounds i16, ptr %a, i64 %indvars.iv.next
%1 = load i16, ptr %arrayidx2
%conv3 = sext i16 %1 to i32
%mul = mul nsw i32 %conv3, %conv
%arrayidx5 = getelementptr inbounds i32, ptr %b, i64 %indvars.iv
store i32 %mul, ptr %arrayidx5
%exitcond = icmp eq i64 %indvars.iv.next, %n
br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !0
for.end:
ret void
}
!0 = distinct !{!0, !1}
!1 = !{!"llvm.loop.vectorize.scalable.enable", i1 true}