caio/clang-p2996
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
8564e2fea559c58fecab3c7c01acf498bbe7820a
clang-p2996/llvm/test/Transforms/PhaseOrdering/X86/vdiv.ll
Florian Hahn b7315ffc3c [LAA,LV] Add initial support for pointer-diff memory checks. 
This patch adds initial support for a pointer diff based runtime check
scheme for vectorization. This scheme requires fewer computations and
checks than the existing full overlap checking, if it is applicable.

The main idea is to only check if source and sink of a dependency are
far enough apart so the accesses won't overlap in the vector loop. To do
so, it is sufficient to compute the difference and compare it to the
`VF * UF * AccessSize`. It is sufficient to check
`(Sink - Src) <u VF * UF * AccessSize` to rule out a backwards
dependence in the vector loop with the given VF and UF. If Src >=u Sink,
there is not dependence preventing vectorization, hence the overflow
should not matter and using the ULT should be sufficient.

Note that the initial version is restricted in multiple ways:

1. Pointers must only either be read or written, by a single
   instruction (this allows re-constructing source/sink for
   dependences with the available information)
 2. Source and sink pointers must be add-recs, with matching steps
 3. The step must be a constant.
 3. abs(step) == AccessSize.

Most of those restrictions can be relaxed in the future.

See https://github.com/llvm/llvm-project/issues/53590.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D119078
2022-05-16 15:27:22 +01:00

185 lines
13 KiB
LLVM
Raw Blame History

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -O3 -S | FileCheck %s
; RUN: opt < %s -passes="default<O3>" -S | FileCheck %s
; Test that IR is optimal after vectorization/unrolling/CSE/canonicalization.
; In particular, there should be no fdivs inside loops because that is expensive.
; TODO: There is a CSE opportunity to reduce the hoisted fdivs after vectorization/unrolling.
; PR46115 - https://llvm.org/PR46115
target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.15.0"
define void @vdiv(double* %x, double* %y, double %a, i32 %N) #0 {
; CHECK-LABEL: @vdiv(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP1:%.*]] = icmp sgt i32 [[N:%.*]], 0
; CHECK-NEXT: br i1 [[CMP1]], label [[FOR_BODY_PREHEADER:%.*]], label [[FOR_END:%.*]]
; CHECK: for.body.preheader:
; CHECK-NEXT: [[X4:%.*]] = ptrtoint double* [[X:%.*]] to i64
; CHECK-NEXT: [[Y5:%.*]] = ptrtoint double* [[Y:%.*]] to i64
; CHECK-NEXT: [[WIDE_TRIP_COUNT:%.*]] = zext i32 [[N]] to i64
; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i32 [[N]], 16
; CHECK-NEXT: [[TMP0:%.*]] = sub i64 [[X4]], [[Y5]]
; CHECK-NEXT: [[DIFF_CHECK:%.*]] = icmp ult i64 [[TMP0]], 128
; CHECK-NEXT: [[OR_COND:%.*]] = select i1 [[MIN_ITERS_CHECK]], i1 true, i1 [[DIFF_CHECK]]
; CHECK-NEXT: br i1 [[OR_COND]], label [[FOR_BODY_PREHEADER15:%.*]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: [[N_VEC:%.*]] = and i64 [[WIDE_TRIP_COUNT]], 4294967280
; CHECK-NEXT: [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x double> poison, double [[A:%.*]], i64 0
; CHECK-NEXT: [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x double> [[BROADCAST_SPLATINSERT]], <4 x double> poison, <4 x i32> zeroinitializer
; CHECK-NEXT: [[BROADCAST_SPLATINSERT12:%.*]] = insertelement <4 x double> poison, double [[A]], i64 0
; CHECK-NEXT: [[BROADCAST_SPLAT13:%.*]] = shufflevector <4 x double> [[BROADCAST_SPLATINSERT12]], <4 x double> poison, <4 x i32> zeroinitializer
; CHECK-NEXT: [[BROADCAST_SPLATINSERT14:%.*]] = insertelement <4 x double> poison, double [[A]], i64 0
; CHECK-NEXT: [[BROADCAST_SPLAT15:%.*]] = shufflevector <4 x double> [[BROADCAST_SPLATINSERT14]], <4 x double> poison, <4 x i32> zeroinitializer
; CHECK-NEXT: [[BROADCAST_SPLATINSERT16:%.*]] = insertelement <4 x double> poison, double [[A]], i64 0
; CHECK-NEXT: [[BROADCAST_SPLAT17:%.*]] = shufflevector <4 x double> [[BROADCAST_SPLATINSERT16]], <4 x double> poison, <4 x i32> zeroinitializer
; CHECK-NEXT: [[TMP0:%.*]] = fdiv fast <4 x double> <double 1.000000e+00, double 1.000000e+00, double 1.000000e+00, double 1.000000e+00>, [[BROADCAST_SPLAT]]
; CHECK-NEXT: [[TMP1:%.*]] = fdiv fast <4 x double> <double 1.000000e+00, double 1.000000e+00, double 1.000000e+00, double 1.000000e+00>, [[BROADCAST_SPLAT13]]
; CHECK-NEXT: [[TMP2:%.*]] = fdiv fast <4 x double> <double 1.000000e+00, double 1.000000e+00, double 1.000000e+00, double 1.000000e+00>, [[BROADCAST_SPLAT15]]
; CHECK-NEXT: [[TMP3:%.*]] = fdiv fast <4 x double> <double 1.000000e+00, double 1.000000e+00, double 1.000000e+00, double 1.000000e+00>, [[BROADCAST_SPLAT17]]
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP4:%.*]] = getelementptr inbounds double, double* [[Y]], i64 [[INDEX]]
; CHECK-NEXT: [[TMP5:%.*]] = bitcast double* [[TMP4]] to <4 x double>*
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x double>, <4 x double>* [[TMP5]], align 8, !tbaa [[TBAA3:![0-9]+]]
; CHECK-NEXT: [[TMP6:%.*]] = getelementptr inbounds double, double* [[TMP4]], i64 4
; CHECK-NEXT: [[TMP7:%.*]] = bitcast double* [[TMP6]] to <4 x double>*
; CHECK-NEXT: [[WIDE_LOAD9:%.*]] = load <4 x double>, <4 x double>* [[TMP7]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP8:%.*]] = getelementptr inbounds double, double* [[TMP4]], i64 8
; CHECK-NEXT: [[TMP9:%.*]] = bitcast double* [[TMP8]] to <4 x double>*
; CHECK-NEXT: [[WIDE_LOAD10:%.*]] = load <4 x double>, <4 x double>* [[TMP9]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP10:%.*]] = getelementptr inbounds double, double* [[TMP4]], i64 12
; CHECK-NEXT: [[TMP11:%.*]] = bitcast double* [[TMP10]] to <4 x double>*
; CHECK-NEXT: [[WIDE_LOAD11:%.*]] = load <4 x double>, <4 x double>* [[TMP11]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP12:%.*]] = fmul fast <4 x double> [[WIDE_LOAD]], [[TMP0]]
; CHECK-NEXT: [[TMP13:%.*]] = fmul fast <4 x double> [[WIDE_LOAD9]], [[TMP1]]
; CHECK-NEXT: [[TMP14:%.*]] = fmul fast <4 x double> [[WIDE_LOAD10]], [[TMP2]]
; CHECK-NEXT: [[TMP15:%.*]] = fmul fast <4 x double> [[WIDE_LOAD11]], [[TMP3]]
; CHECK-NEXT: [[TMP16:%.*]] = getelementptr inbounds double, double* [[X]], i64 [[INDEX]]
; CHECK-NEXT: [[TMP17:%.*]] = bitcast double* [[TMP16]] to <4 x double>*
; CHECK-NEXT: store <4 x double> [[TMP12]], <4 x double>* [[TMP17]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP18:%.*]] = getelementptr inbounds double, double* [[TMP16]], i64 4
; CHECK-NEXT: [[TMP19:%.*]] = bitcast double* [[TMP18]] to <4 x double>*
; CHECK-NEXT: store <4 x double> [[TMP13]], <4 x double>* [[TMP19]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP20:%.*]] = getelementptr inbounds double, double* [[TMP16]], i64 8
; CHECK-NEXT: [[TMP21:%.*]] = bitcast double* [[TMP20]] to <4 x double>*
; CHECK-NEXT: store <4 x double> [[TMP14]], <4 x double>* [[TMP21]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP22:%.*]] = getelementptr inbounds double, double* [[TMP16]], i64 12
; CHECK-NEXT: [[TMP23:%.*]] = bitcast double* [[TMP22]] to <4 x double>*
; CHECK-NEXT: store <4 x double> [[TMP15]], <4 x double>* [[TMP23]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 16
; CHECK-NEXT: [[TMP24:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
; CHECK-NEXT: br i1 [[TMP24]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP12:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 [[N_VEC]], [[WIDE_TRIP_COUNT]]
; CHECK-NEXT: br i1 [[CMP_N]], label [[FOR_END]], label [[FOR_BODY_PREHEADER15]]
; CHECK: for.body.preheader15:
; CHECK-NEXT: [[INDVARS_IV_PH:%.*]] = phi i64 [ 0, [[FOR_BODY_PREHEADER]] ], [ [[N_VEC]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: [[TMP25:%.*]] = xor i64 [[INDVARS_IV_PH]], -1
; CHECK-NEXT: [[TMP26:%.*]] = add nsw i64 [[TMP25]], [[WIDE_TRIP_COUNT]]
; CHECK-NEXT: [[XTRAITER:%.*]] = and i64 [[WIDE_TRIP_COUNT]], 3
; CHECK-NEXT: [[LCMP_MOD_NOT:%.*]] = icmp eq i64 [[XTRAITER]], 0
; CHECK-NEXT: br i1 [[LCMP_MOD_NOT]], label [[FOR_BODY_PROL_LOOPEXIT:%.*]], label [[FOR_BODY_PROL_PREHEADER:%.*]]
; CHECK: for.body.prol.preheader:
; CHECK-NEXT: [[TMP27:%.*]] = fdiv fast double 1.000000e+00, [[A]]
; CHECK-NEXT: br label [[FOR_BODY_PROL:%.*]]
; CHECK: for.body.prol:
; CHECK-NEXT: [[INDVARS_IV_PROL:%.*]] = phi i64 [ [[INDVARS_IV_NEXT_PROL:%.*]], [[FOR_BODY_PROL]] ], [ [[INDVARS_IV_PH]], [[FOR_BODY_PROL_PREHEADER]] ]
; CHECK-NEXT: [[PROL_ITER:%.*]] = phi i64 [ [[PROL_ITER_NEXT:%.*]], [[FOR_BODY_PROL]] ], [ 0, [[FOR_BODY_PROL_PREHEADER]] ]
; CHECK-NEXT: [[ARRAYIDX_PROL:%.*]] = getelementptr inbounds double, double* [[Y]], i64 [[INDVARS_IV_PROL]]
; CHECK-NEXT: [[T0_PROL:%.*]] = load double, double* [[ARRAYIDX_PROL]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP28:%.*]] = fmul fast double [[T0_PROL]], [[TMP27]]
; CHECK-NEXT: [[ARRAYIDX2_PROL:%.*]] = getelementptr inbounds double, double* [[X]], i64 [[INDVARS_IV_PROL]]
; CHECK-NEXT: store double [[TMP28]], double* [[ARRAYIDX2_PROL]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[INDVARS_IV_NEXT_PROL]] = add nuw nsw i64 [[INDVARS_IV_PROL]], 1
; CHECK-NEXT: [[PROL_ITER_NEXT]] = add i64 [[PROL_ITER]], 1
; CHECK-NEXT: [[PROL_ITER_CMP_NOT:%.*]] = icmp eq i64 [[PROL_ITER_NEXT]], [[XTRAITER]]
; CHECK-NEXT: br i1 [[PROL_ITER_CMP_NOT]], label [[FOR_BODY_PROL_LOOPEXIT]], label [[FOR_BODY_PROL]], !llvm.loop [[LOOP14:![0-9]+]]
; CHECK: for.body.prol.loopexit:
; CHECK-NEXT: [[INDVARS_IV_UNR:%.*]] = phi i64 [ [[INDVARS_IV_PH]], [[FOR_BODY_PREHEADER15]] ], [ [[INDVARS_IV_NEXT_PROL]], [[FOR_BODY_PROL]] ]
; CHECK-NEXT: [[TMP29:%.*]] = icmp ult i64 [[TMP26]], 3
; CHECK-NEXT: br i1 [[TMP29]], label [[FOR_END]], label [[FOR_BODY_PREHEADER18_NEW:%.*]]
; CHECK: for.body.preheader15.new:
; CHECK-NEXT: [[TMP30:%.*]] = fdiv fast double 1.000000e+00, [[A]]
; CHECK-NEXT: [[TMP31:%.*]] = fdiv fast double 1.000000e+00, [[A]]
; CHECK-NEXT: [[TMP32:%.*]] = fdiv fast double 1.000000e+00, [[A]]
; CHECK-NEXT: [[TMP33:%.*]] = fdiv fast double 1.000000e+00, [[A]]
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_UNR]], [[FOR_BODY_PREHEADER18_NEW]] ], [ [[INDVARS_IV_NEXT_3:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds double, double* [[Y]], i64 [[INDVARS_IV]]
; CHECK-NEXT: [[T0:%.*]] = load double, double* [[ARRAYIDX]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP34:%.*]] = fmul fast double [[T0]], [[TMP30]]
; CHECK-NEXT: [[ARRAYIDX2:%.*]] = getelementptr inbounds double, double* [[X]], i64 [[INDVARS_IV]]
; CHECK-NEXT: store double [[TMP34]], double* [[ARRAYIDX2]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[INDVARS_IV_NEXT:%.*]] = add nuw nsw i64 [[INDVARS_IV]], 1
; CHECK-NEXT: [[ARRAYIDX_1:%.*]] = getelementptr inbounds double, double* [[Y]], i64 [[INDVARS_IV_NEXT]]
; CHECK-NEXT: [[T0_1:%.*]] = load double, double* [[ARRAYIDX_1]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP35:%.*]] = fmul fast double [[T0_1]], [[TMP31]]
; CHECK-NEXT: [[ARRAYIDX2_1:%.*]] = getelementptr inbounds double, double* [[X]], i64 [[INDVARS_IV_NEXT]]
; CHECK-NEXT: store double [[TMP35]], double* [[ARRAYIDX2_1]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[INDVARS_IV_NEXT_1:%.*]] = add nuw nsw i64 [[INDVARS_IV]], 2
; CHECK-NEXT: [[ARRAYIDX_2:%.*]] = getelementptr inbounds double, double* [[Y]], i64 [[INDVARS_IV_NEXT_1]]
; CHECK-NEXT: [[T0_2:%.*]] = load double, double* [[ARRAYIDX_2]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP36:%.*]] = fmul fast double [[T0_2]], [[TMP32]]
; CHECK-NEXT: [[ARRAYIDX2_2:%.*]] = getelementptr inbounds double, double* [[X]], i64 [[INDVARS_IV_NEXT_1]]
; CHECK-NEXT: store double [[TMP36]], double* [[ARRAYIDX2_2]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[INDVARS_IV_NEXT_2:%.*]] = add nuw nsw i64 [[INDVARS_IV]], 3
; CHECK-NEXT: [[ARRAYIDX_3:%.*]] = getelementptr inbounds double, double* [[Y]], i64 [[INDVARS_IV_NEXT_2]]
; CHECK-NEXT: [[T0_3:%.*]] = load double, double* [[ARRAYIDX_3]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[TMP37:%.*]] = fmul fast double [[T0_3]], [[TMP33]]
; CHECK-NEXT: [[ARRAYIDX2_3:%.*]] = getelementptr inbounds double, double* [[X]], i64 [[INDVARS_IV_NEXT_2]]
; CHECK-NEXT: store double [[TMP37]], double* [[ARRAYIDX2_3]], align 8, !tbaa [[TBAA3]]
; CHECK-NEXT: [[INDVARS_IV_NEXT_3]] = add nuw nsw i64 [[INDVARS_IV]], 4
; CHECK-NEXT: [[EXITCOND_NOT_3:%.*]] = icmp eq i64 [[INDVARS_IV_NEXT_3]], [[WIDE_TRIP_COUNT]]
; CHECK-NEXT: br i1 [[EXITCOND_NOT_3]], label [[FOR_END]], label [[FOR_BODY]], !llvm.loop [[LOOP16:![0-9]+]]
; CHECK: for.end:
; CHECK-NEXT: ret void
;
entry:
%div = fdiv fast double 1.0, %a
br label %for.cond
for.cond:
%n.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]
%cmp = icmp slt i32 %n.0, %N
br i1 %cmp, label %for.body, label %for.cond.cleanup
for.cond.cleanup:
br label %for.end
for.body:
%idxprom = sext i32 %n.0 to i64
%arrayidx = getelementptr inbounds double, double* %y, i64 %idxprom
%t0 = load double, double* %arrayidx, align 8, !tbaa !3
%mul = fmul fast double %t0, %div
%idxprom1 = sext i32 %n.0 to i64
%arrayidx2 = getelementptr inbounds double, double* %x, i64 %idxprom1
store double %mul, double* %arrayidx2, align 8, !tbaa !3
br label %for.inc
for.inc:
%inc = add nsw i32 %n.0, 1
br label %for.cond
for.end:
ret void
}
attributes #0 = { nounwind ssp uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="true" "no-jump-tables"="false" "no-nans-fp-math"="true" "no-signed-zeros-fp-math"="true" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="skylake-avx512" "target-features"="+adx,+aes,+avx,+avx2,+avx512bw,+avx512cd,+avx512dq,+avx512f,+avx512vl,+bmi,+bmi2,+clflushopt,+clwb,+cx16,+cx8,+f16c,+fma,+fsgsbase,+fxsr,+invpcid,+lzcnt,+mmx,+movbe,+pclmul,+pku,+popcnt,+prfchw,+rdrnd,+rdseed,+sahf,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87,+xsave,+xsavec,+xsaveopt,+xsaves" "unsafe-fp-math"="true" "use-soft-float"="false" }
!llvm.module.flags = !{!0, !1}
!llvm.ident = !{!2}
!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 7, !"PIC Level", i32 2}
!2 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project.git 45ebe38ffc40bb7221fc587bfb4481cf7f53ebbc)"}
!3 = !{!4, !4, i64 0}
!4 = !{!"double", !5, i64 0}
!5 = !{!"omnipotent char", !6, i64 0}
!6 = !{!"Simple C/C++ TBAA"}
Reference in New Issue View Git Blame Copy Permalink