Florian Hahn 86813aa786
[VPlan] Add dedicated user for resume phi with epilogue vectorization.
Epilogue vectorization currently relies on the resume phi for the
canonical induction being always available, which is why VPPhi are
considered to have side-effects, to prevent their removal.

This patch adds a new ResumeForEpilogue opcode to mark the resume phi as
used for epilogue vectorization. This allows treating VPPhis in general
as not having side-effects, enabling removal of unused VPPhis.
2025-08-10 21:21:16 +01:00

122 lines
6.0 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -force-vector-width=4 -force-vector-interleave=1 -passes=loop-vectorize -S %s | FileCheck %s
target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
define i32 @test(i64 %N, i32 %x) {
; CHECK-LABEL: @test(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[EXTRA_ITER:%.*]] = and i64 [[N:%.*]], 7
; CHECK-NEXT: br label [[CHECK:%.*]]
; CHECK: check:
; CHECK-NEXT: [[EXTRA_ITER_CHECK:%.*]] = icmp eq i64 [[EXTRA_ITER]], 0
; CHECK-NEXT: br i1 [[EXTRA_ITER_CHECK]], label [[EXIT:%.*]], label [[LOOP_PREHEADER:%.*]]
; CHECK: loop.preheader:
; CHECK-NEXT: br i1 false, label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: [[N_RND_UP:%.*]] = add i64 [[EXTRA_ITER]], 3
; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i64 [[N_RND_UP]], 4
; CHECK-NEXT: [[N_VEC:%.*]] = sub i64 [[N_RND_UP]], [[N_MOD_VF]]
; CHECK-NEXT: [[TRIP_COUNT_MINUS_1:%.*]] = sub i64 [[EXTRA_ITER]], 1
; CHECK-NEXT: [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x i64> poison, i64 [[TRIP_COUNT_MINUS_1]], i64 0
; CHECK-NEXT: [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x i64> [[BROADCAST_SPLATINSERT]], <4 x i64> poison, <4 x i32> zeroinitializer
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi <4 x i32> [ zeroinitializer, [[VECTOR_PH]] ], [ [[TMP2:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[BROADCAST_SPLATINSERT1:%.*]] = insertelement <4 x i64> poison, i64 [[INDEX]], i64 0
; CHECK-NEXT: [[BROADCAST_SPLAT2:%.*]] = shufflevector <4 x i64> [[BROADCAST_SPLATINSERT1]], <4 x i64> poison, <4 x i32> zeroinitializer
; CHECK-NEXT: [[VEC_IV:%.*]] = add <4 x i64> [[BROADCAST_SPLAT2]], <i64 0, i64 1, i64 2, i64 3>
; CHECK-NEXT: [[TMP0:%.*]] = icmp ule <4 x i64> [[VEC_IV]], [[BROADCAST_SPLAT]]
; CHECK-NEXT: [[TMP1:%.*]] = icmp sgt <4 x i32> [[VEC_PHI]], splat (i32 10)
; CHECK-NEXT: [[TMP2]] = select <4 x i1> [[TMP1]], <4 x i32> [[VEC_PHI]], <4 x i32> splat (i32 10)
; CHECK-NEXT: [[TMP3:%.*]] = select <4 x i1> [[TMP0]], <4 x i32> [[TMP2]], <4 x i32> [[VEC_PHI]]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT: [[TMP4:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
; CHECK-NEXT: br i1 [[TMP4]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[TMP5:%.*]] = call i32 @llvm.vector.reduce.smax.v4i32(<4 x i32> [[TMP3]])
; CHECK-NEXT: br label [[EXIT_LOOPEXIT:%.*]]
; CHECK: scalar.ph:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[NEXT:%.*]] = phi i32 [ [[SEL:%.*]], [[LOOP]] ], [ 0, [[SCALAR_PH]] ]
; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[IV_NEXT:%.*]], [[LOOP]] ], [ [[EXTRA_ITER]], [[SCALAR_PH]] ]
; CHECK-NEXT: [[SEL_COND:%.*]] = icmp sgt i32 [[NEXT]], 10
; CHECK-NEXT: [[SEL]] = select i1 [[SEL_COND]], i32 [[NEXT]], i32 10
; CHECK-NEXT: [[IV_NEXT]] = add nsw i64 [[IV]], -1
; CHECK-NEXT: [[EC:%.*]] = icmp eq i64 [[IV_NEXT]], 0
; CHECK-NEXT: br i1 [[EC]], label [[EXIT_LOOPEXIT]], label [[LOOP]], !llvm.loop [[LOOP3:![0-9]+]]
; CHECK: exit.loopexit:
; CHECK-NEXT: [[SEL_LCSSA:%.*]] = phi i32 [ [[SEL]], [[LOOP]] ], [ [[TMP5]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: [[RESULT:%.*]] = phi i32 [ 0, [[CHECK]] ], [ [[SEL_LCSSA]], [[EXIT_LOOPEXIT]] ]
; CHECK-NEXT: ret i32 [[RESULT]]
;
entry:
%extra.iter = and i64 %N, 7
br label %check
check:
%extra.iter.check = icmp eq i64 %extra.iter, 0
br i1 %extra.iter.check, label %exit, label %loop
loop:
%next = phi i32 [ %sel, %loop ], [ 0, %check ]
%iv = phi i64 [ %iv.next, %loop ], [ %extra.iter, %check ]
%sel.cond = icmp sgt i32 %next, 10
%sel = select i1 %sel.cond, i32 %next, i32 10
%iv.next = add nsw i64 %iv, -1
%ec = icmp eq i64 %iv.next, 0
br i1 %ec, label %exit, label %loop
exit:
%result = phi i32 [ %sel, %loop], [ 0, %check ]
ret i32 %result
}
define i32 @pr66895_tail_fold_reduction_exit_inst_gets_simplified(i32 %n) {
; CHECK-LABEL: @pr66895_tail_fold_reduction_exit_inst_gets_simplified(
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 false, label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi <4 x i32> [ <i32 0, i32 1, i32 1, i32 1>, [[VECTOR_PH]] ], [ [[VEC_PHI]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 4
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[INDEX_NEXT]], 16
; CHECK-NEXT: br i1 [[TMP2]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP4:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[TMP3:%.*]] = call i32 @llvm.vector.reduce.mul.v4i32(<4 x i32> [[VEC_PHI]])
; CHECK-NEXT: br label [[EXIT:%.*]]
; CHECK: scalar.ph:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 12, [[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], [[LOOP]] ]
; CHECK-NEXT: [[RED:%.*]] = phi i32 [ 0, [[SCALAR_PH]] ], [ [[RED_NEXT:%.*]], [[LOOP]] ]
; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], -1
; CHECK-NEXT: [[RED_NEXT]] = mul i32 [[RED]], 1
; CHECK-NEXT: [[EC:%.*]] = icmp eq i32 [[IV]], 0
; CHECK-NEXT: br i1 [[EC]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP5:![0-9]+]]
; CHECK: exit:
; CHECK-NEXT: [[RED_LCSSA:%.*]] = phi i32 [ [[RED_NEXT]], [[LOOP]] ], [ [[TMP3]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: ret i32 [[RED_LCSSA]]
;
entry:
br label %loop
loop:
%iv = phi i32 [ 12, %entry ], [ %iv.next, %loop ]
%red = phi i32 [ 0, %entry ], [ %red.next, %loop ]
%iv.next = add i32 %iv, -1
%red.next = mul i32 %red, 1
%ec = icmp eq i32 %iv, 0
br i1 %ec, label %exit, label %loop
exit:
%red.lcssa = phi i32 [ %red.next, %loop ]
ret i32 %red.lcssa
}