caio/clang-p2996
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
ef2cdfe393d01cd4935c806387ac912b5a2c8ced
clang-p2996/llvm/test/Transforms/LoopVectorize/X86/pr23997.ll
Florian Hahn 23c2f2e6b2 [LV] Mark increment of main vector loop induction variable as NUW. 
This patch marks the induction increment of the main induction variable
of the vector loop as NUW when not folding the tail.

If the tail is not folded, we know that End - Start >= Step (either
statically or through the minimum iteration checks). We also know that both
Start % Step == 0 and End % Step == 0. We exit the vector loop if %IV +
%Step == %End. Hence we must exit the loop before %IV + %Step unsigned
overflows and we can mark the induction increment as NUW.

This should make SCEV return more precise bounds for the created vector
loops, used by later optimizations, like late unrolling.

At the moment quite a few tests still need to be updated, but before
doing so I'd like to get initial feedback to make sure I am not missing
anything.

Note that this could probably be further improved by using information
from the original IV.

Attempt of modeling of the assumption in Alive2:
https://alive2.llvm.org/ce/z/H_DL_g

Part of a set of fixes required for PR50412.

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D103255
2021-06-07 10:47:52 +01:00

108 lines
8.3 KiB
LLVM
Raw Blame History

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S -loop-vectorize -dce -instcombine < %s | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128-ni:1"
target triple = "x86_64-unknown-linux-gnu"
; Ensure that the 'inbounds' is preserved on the GEPs that feed the load and store in the loop.
define void @foo(i8 addrspace(1)* align 8 dereferenceable_or_null(16), i8 addrspace(1)* align 8 dereferenceable_or_null(8), i64) #0 {
; CHECK-LABEL: @foo(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[PREHEADER:%.*]]
; CHECK: preheader:
; CHECK-NEXT: [[DOT10:%.*]] = getelementptr inbounds i8, i8 addrspace(1)* [[TMP0:%.*]], i64 16
; CHECK-NEXT: [[DOT11:%.*]] = bitcast i8 addrspace(1)* [[DOT10]] to i8 addrspace(1)* addrspace(1)*
; CHECK-NEXT: [[DOT12:%.*]] = getelementptr inbounds i8, i8 addrspace(1)* [[TMP1:%.*]], i64 16
; CHECK-NEXT: [[DOT13:%.*]] = bitcast i8 addrspace(1)* [[DOT12]] to i8 addrspace(1)* addrspace(1)*
; CHECK-NEXT: [[UMAX2:%.*]] = call i64 @llvm.umax.i64(i64 [[TMP2:%.*]], i64 1)
; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[UMAX2]], 16
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]]
; CHECK: vector.memcheck:
; CHECK-NEXT: [[UMAX:%.*]] = call i64 @llvm.umax.i64(i64 [[TMP2]], i64 1)
; CHECK-NEXT: [[TMP3:%.*]] = shl i64 [[UMAX]], 3
; CHECK-NEXT: [[TMP4:%.*]] = add i64 [[TMP3]], 16
; CHECK-NEXT: [[SCEVGEP:%.*]] = getelementptr i8, i8 addrspace(1)* [[TMP0]], i64 [[TMP4]]
; CHECK-NEXT: [[SCEVGEP1:%.*]] = getelementptr i8, i8 addrspace(1)* [[TMP1]], i64 [[TMP4]]
; CHECK-NEXT: [[BOUND0:%.*]] = icmp ult i8 addrspace(1)* [[DOT10]], [[SCEVGEP1]]
; CHECK-NEXT: [[BOUND1:%.*]] = icmp ult i8 addrspace(1)* [[DOT12]], [[SCEVGEP]]
; CHECK-NEXT: [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
; CHECK-NEXT: br i1 [[FOUND_CONFLICT]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: [[N_VEC:%.*]] = and i64 [[UMAX2]], -16
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP5:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[DOT13]], i64 [[INDEX]]
; CHECK-NEXT: [[TMP6:%.*]] = bitcast i8 addrspace(1)* addrspace(1)* [[TMP5]] to <4 x i8 addrspace(1)*> addrspace(1)*
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x i8 addrspace(1)*>, <4 x i8 addrspace(1)*> addrspace(1)* [[TMP6]], align 8, !alias.scope !0
; CHECK-NEXT: [[TMP7:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[TMP5]], i64 4
; CHECK-NEXT: [[TMP8:%.*]] = bitcast i8 addrspace(1)* addrspace(1)* [[TMP7]] to <4 x i8 addrspace(1)*> addrspace(1)*
; CHECK-NEXT: [[WIDE_LOAD3:%.*]] = load <4 x i8 addrspace(1)*>, <4 x i8 addrspace(1)*> addrspace(1)* [[TMP8]], align 8, !alias.scope !0
; CHECK-NEXT: [[TMP9:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[TMP5]], i64 8
; CHECK-NEXT: [[TMP10:%.*]] = bitcast i8 addrspace(1)* addrspace(1)* [[TMP9]] to <4 x i8 addrspace(1)*> addrspace(1)*
; CHECK-NEXT: [[WIDE_LOAD4:%.*]] = load <4 x i8 addrspace(1)*>, <4 x i8 addrspace(1)*> addrspace(1)* [[TMP10]], align 8, !alias.scope !0
; CHECK-NEXT: [[TMP11:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[TMP5]], i64 12
; CHECK-NEXT: [[TMP12:%.*]] = bitcast i8 addrspace(1)* addrspace(1)* [[TMP11]] to <4 x i8 addrspace(1)*> addrspace(1)*
; CHECK-NEXT: [[WIDE_LOAD5:%.*]] = load <4 x i8 addrspace(1)*>, <4 x i8 addrspace(1)*> addrspace(1)* [[TMP12]], align 8, !alias.scope !0
; CHECK-NEXT: [[TMP13:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[DOT11]], i64 [[INDEX]]
; CHECK-NEXT: [[TMP14:%.*]] = bitcast i8 addrspace(1)* addrspace(1)* [[TMP13]] to <4 x i8 addrspace(1)*> addrspace(1)*
; CHECK-NEXT: store <4 x i8 addrspace(1)*> [[WIDE_LOAD]], <4 x i8 addrspace(1)*> addrspace(1)* [[TMP14]], align 8, !alias.scope !3, !noalias !0
; CHECK-NEXT: [[TMP15:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[TMP13]], i64 4
; CHECK-NEXT: [[TMP16:%.*]] = bitcast i8 addrspace(1)* addrspace(1)* [[TMP15]] to <4 x i8 addrspace(1)*> addrspace(1)*
; CHECK-NEXT: store <4 x i8 addrspace(1)*> [[WIDE_LOAD3]], <4 x i8 addrspace(1)*> addrspace(1)* [[TMP16]], align 8, !alias.scope !3, !noalias !0
; CHECK-NEXT: [[TMP17:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[TMP13]], i64 8
; CHECK-NEXT: [[TMP18:%.*]] = bitcast i8 addrspace(1)* addrspace(1)* [[TMP17]] to <4 x i8 addrspace(1)*> addrspace(1)*
; CHECK-NEXT: store <4 x i8 addrspace(1)*> [[WIDE_LOAD4]], <4 x i8 addrspace(1)*> addrspace(1)* [[TMP18]], align 8, !alias.scope !3, !noalias !0
; CHECK-NEXT: [[TMP19:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[TMP13]], i64 12
; CHECK-NEXT: [[TMP20:%.*]] = bitcast i8 addrspace(1)* addrspace(1)* [[TMP19]] to <4 x i8 addrspace(1)*> addrspace(1)*
; CHECK-NEXT: store <4 x i8 addrspace(1)*> [[WIDE_LOAD5]], <4 x i8 addrspace(1)*> addrspace(1)* [[TMP20]], align 8, !alias.scope !3, !noalias !0
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 16
; CHECK-NEXT: [[TMP21:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
; CHECK-NEXT: br i1 [[TMP21]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], [[LOOP5:!llvm.loop !.*]]
; CHECK: middle.block:
; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 [[UMAX2]], [[N_VEC]]
; CHECK-NEXT: br i1 [[CMP_N]], label [[LOOPEXIT:%.*]], label [[SCALAR_PH]]
; CHECK: scalar.ph:
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[PREHEADER]] ], [ 0, [[VECTOR_MEMCHECK]] ]
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[INDVARS_IV3:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[INDVARS_IV_NEXT4:%.*]], [[LOOP]] ]
; CHECK-NEXT: [[DOT18:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[DOT13]], i64 [[INDVARS_IV3]]
; CHECK-NEXT: [[V:%.*]] = load i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[DOT18]], align 8
; CHECK-NEXT: [[DOT20:%.*]] = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* [[DOT11]], i64 [[INDVARS_IV3]]
; CHECK-NEXT: store i8 addrspace(1)* [[V]], i8 addrspace(1)* addrspace(1)* [[DOT20]], align 8
; CHECK-NEXT: [[INDVARS_IV_NEXT4]] = add nuw nsw i64 [[INDVARS_IV3]], 1
; CHECK-NEXT: [[DOT21:%.*]] = icmp ult i64 [[INDVARS_IV_NEXT4]], [[TMP2]]
; CHECK-NEXT: br i1 [[DOT21]], label [[LOOP]], label [[LOOPEXIT]], [[LOOP7:!llvm.loop !.*]]
; CHECK: loopexit:
; CHECK-NEXT: ret void
;
entry:
br label %preheader
preheader: ; preds = %4
%.10 = getelementptr inbounds i8, i8 addrspace(1)* %0, i64 16
%.11 = bitcast i8 addrspace(1)* %.10 to i8 addrspace(1)* addrspace(1)*
%.12 = getelementptr inbounds i8, i8 addrspace(1)* %1, i64 16
%.13 = bitcast i8 addrspace(1)* %.12 to i8 addrspace(1)* addrspace(1)*
br label %loop
loop:
%indvars.iv3 = phi i64 [ 0, %preheader ], [ %indvars.iv.next4, %loop ]
%.18 = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* %.13, i64 %indvars.iv3
%v = load i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* %.18, align 8
%.20 = getelementptr inbounds i8 addrspace(1)*, i8 addrspace(1)* addrspace(1)* %.11, i64 %indvars.iv3
store i8 addrspace(1)* %v, i8 addrspace(1)* addrspace(1)* %.20, align 8
%indvars.iv.next4 = add nuw nsw i64 %indvars.iv3, 1
%.21 = icmp ult i64 %indvars.iv.next4, %2
br i1 %.21, label %loop, label %loopexit
loopexit:
ret void
}
attributes #0 = { uwtable "target-cpu"="skylake" "target-features"="+sse2,+cx16,+sahf,-tbm,-avx512ifma,-sha,-gfni,-fma4,-vpclmulqdq,+prfchw,+bmi2,-cldemote,+fsgsbase,+xsavec,+popcnt,+aes,-avx512bitalg,+xsaves,-avx512er,-avx512vnni,-avx512vpopcntdq,-clwb,-avx512f,-clzero,-pku,+mmx,-lwp,-rdpid,-xop,+rdseed,-waitpkg,-sse4a,-avx512bw,+clflushopt,+xsave,-avx512vbmi2,-avx512vl,-avx512cd,+avx,-vaes,+rtm,+fma,+bmi,+rdrnd,-mwaitx,+sse4.1,+sse4.2,+avx2,-wbnoinvd,+sse,+lzcnt,+pclmul,-prefetchwt1,+f16c,+ssse3,+sgx,-shstk,+cmov,-avx512vbmi,+movbe,+xsaveopt,-avx512dq,+adx,-avx512pf,+sse3" }
!0 = !{i32 0, i32 2147483646}
!1 = !{}
Reference in New Issue View Git Blame Copy Permalink