Files
clang-p2996/llvm/test/Transforms/LoopVectorize/X86/pr35432.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

200 lines
11 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -loop-vectorize -mtriple=x86_64-unknown-linux-gnu -S < %s | FileCheck %s
; The test checks that there is no assert caused by issue described in PR35432
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
@a = common local_unnamed_addr global [192 x [192 x i32]] zeroinitializer, align 16
; Function Attrs: nounwind uwtable
define i32 @main() local_unnamed_addr #0 {
; CHECK-LABEL: @main(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[I:%.*]] = alloca i32, align 4
; CHECK-NEXT: [[S:%.*]] = alloca i16, align 2
; CHECK-NEXT: [[TMP0:%.*]] = bitcast i32* [[I]] to i8*
; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull [[TMP0]])
; CHECK-NEXT: store i32 0, i32* [[I]], align 4
; CHECK-NEXT: [[TMP1:%.*]] = bitcast i16* [[S]] to i8*
; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 2, i8* nonnull [[TMP1]])
; CHECK-NEXT: [[CALL:%.*]] = call i32 (i32*, ...) bitcast (i32 (...)* @goo to i32 (i32*, ...)*)(i32* nonnull [[I]])
; CHECK-NEXT: [[TMP2:%.*]] = load i32, i32* [[I]], align 4
; CHECK-NEXT: [[STOREMERGE6:%.*]] = trunc i32 [[TMP2]] to i16
; CHECK-NEXT: store i16 [[STOREMERGE6]], i16* [[S]], align 2
; CHECK-NEXT: [[CONV17:%.*]] = and i32 [[TMP2]], 65472
; CHECK-NEXT: [[CMP8:%.*]] = icmp eq i32 [[CONV17]], 0
; CHECK-NEXT: br i1 [[CMP8]], label [[FOR_BODY_LR_PH:%.*]], label [[FOR_END12:%.*]]
; CHECK: for.body.lr.ph:
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: [[STOREMERGE_IN9:%.*]] = phi i32 [ [[TMP2]], [[FOR_BODY_LR_PH]] ], [ [[ADD:%.*]], [[FOR_INC9:%.*]] ]
; CHECK-NEXT: [[CONV52:%.*]] = and i32 [[STOREMERGE_IN9]], 255
; CHECK-NEXT: [[CMP63:%.*]] = icmp ult i32 [[TMP2]], [[CONV52]]
; CHECK-NEXT: br i1 [[CMP63]], label [[FOR_BODY8_LR_PH:%.*]], label [[FOR_INC9]]
; CHECK: for.body8.lr.ph:
; CHECK-NEXT: [[CONV3:%.*]] = trunc i32 [[STOREMERGE_IN9]] to i8
; CHECK-NEXT: [[DOTPROMOTED:%.*]] = load i32, i32* getelementptr inbounds ([192 x [192 x i32]], [192 x [192 x i32]]* @a, i64 0, i64 0, i64 0), align 16
; CHECK-NEXT: [[TMP3:%.*]] = add i8 [[CONV3]], -1
; CHECK-NEXT: [[TMP4:%.*]] = zext i8 [[TMP3]] to i32
; CHECK-NEXT: [[TMP5:%.*]] = add i32 [[TMP4]], 1
; CHECK-NEXT: [[UMIN1:%.*]] = call i32 @llvm.umin.i32(i32 [[TMP2]], i32 [[TMP4]])
; CHECK-NEXT: [[TMP6:%.*]] = sub i32 [[TMP5]], [[UMIN1]]
; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i32 [[TMP6]], 8
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
; CHECK: vector.scevcheck:
; CHECK-NEXT: [[TMP7:%.*]] = add i8 [[CONV3]], -1
; CHECK-NEXT: [[TMP8:%.*]] = zext i8 [[TMP7]] to i32
; CHECK-NEXT: [[UMIN:%.*]] = call i32 @llvm.umin.i32(i32 [[TMP2]], i32 [[TMP8]])
; CHECK-NEXT: [[TMP9:%.*]] = sub i32 [[TMP8]], [[UMIN]]
; CHECK-NEXT: [[TMP10:%.*]] = trunc i32 [[TMP9]] to i8
; CHECK-NEXT: [[MUL:%.*]] = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 1, i8 [[TMP10]])
; CHECK-NEXT: [[MUL_RESULT:%.*]] = extractvalue { i8, i1 } [[MUL]], 0
; CHECK-NEXT: [[MUL_OVERFLOW:%.*]] = extractvalue { i8, i1 } [[MUL]], 1
; CHECK-NEXT: [[TMP11:%.*]] = add i8 [[TMP7]], [[MUL_RESULT]]
; CHECK-NEXT: [[TMP12:%.*]] = sub i8 [[TMP7]], [[MUL_RESULT]]
; CHECK-NEXT: [[TMP13:%.*]] = icmp ugt i8 [[TMP12]], [[TMP7]]
; CHECK-NEXT: [[TMP14:%.*]] = icmp ult i8 [[TMP11]], [[TMP7]]
; CHECK-NEXT: [[TMP15:%.*]] = select i1 true, i1 [[TMP13]], i1 [[TMP14]]
; CHECK-NEXT: [[TMP16:%.*]] = icmp ugt i32 [[TMP9]], 255
; CHECK-NEXT: [[TMP17:%.*]] = or i1 [[TMP15]], [[TMP16]]
; CHECK-NEXT: [[TMP18:%.*]] = or i1 [[TMP17]], [[MUL_OVERFLOW]]
; CHECK-NEXT: [[TMP19:%.*]] = or i1 false, [[TMP18]]
; CHECK-NEXT: br i1 [[TMP19]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i32 [[TMP6]], 8
; CHECK-NEXT: [[N_VEC:%.*]] = sub i32 [[TMP6]], [[N_MOD_VF]]
; CHECK-NEXT: [[CAST_CRD:%.*]] = trunc i32 [[N_VEC]] to i8
; CHECK-NEXT: [[IND_END:%.*]] = sub i8 [[CONV3]], [[CAST_CRD]]
; CHECK-NEXT: [[TMP20:%.*]] = insertelement <4 x i32> zeroinitializer, i32 [[DOTPROMOTED]], i32 0
; 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> [ [[TMP20]], [[VECTOR_PH]] ], [ [[TMP24:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI2:%.*]] = phi <4 x i32> [ zeroinitializer, [[VECTOR_PH]] ], [ [[TMP25:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP21:%.*]] = trunc i32 [[INDEX]] to i8
; CHECK-NEXT: [[OFFSET_IDX:%.*]] = sub i8 [[CONV3]], [[TMP21]]
; CHECK-NEXT: [[TMP22:%.*]] = add i8 [[OFFSET_IDX]], 0
; CHECK-NEXT: [[TMP23:%.*]] = add i8 [[OFFSET_IDX]], -4
; CHECK-NEXT: [[TMP24]] = add <4 x i32> [[VEC_PHI]], <i32 1, i32 1, i32 1, i32 1>
; CHECK-NEXT: [[TMP25]] = add <4 x i32> [[VEC_PHI2]], <i32 1, i32 1, i32 1, i32 1>
; CHECK-NEXT: [[TMP26:%.*]] = add i8 [[TMP22]], -1
; CHECK-NEXT: [[TMP27:%.*]] = add i8 [[TMP23]], -1
; CHECK-NEXT: [[TMP28:%.*]] = zext i8 [[TMP26]] to i32
; CHECK-NEXT: [[TMP29:%.*]] = zext i8 [[TMP27]] to i32
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 8
; CHECK-NEXT: [[TMP30:%.*]] = icmp eq i32 [[INDEX_NEXT]], [[N_VEC]]
; CHECK-NEXT: br i1 [[TMP30]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], [[LOOP0:!llvm.loop !.*]]
; CHECK: middle.block:
; CHECK-NEXT: [[BIN_RDX:%.*]] = add <4 x i32> [[TMP25]], [[TMP24]]
; CHECK-NEXT: [[TMP31:%.*]] = call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> [[BIN_RDX]])
; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i32 [[TMP6]], [[N_VEC]]
; CHECK-NEXT: br i1 [[CMP_N]], label [[FOR_COND4_FOR_INC9_CRIT_EDGE:%.*]], label [[SCALAR_PH]]
; CHECK: scalar.ph:
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i8 [ [[IND_END]], [[MIDDLE_BLOCK]] ], [ [[CONV3]], [[FOR_BODY8_LR_PH]] ], [ [[CONV3]], [[VECTOR_SCEVCHECK]] ]
; CHECK-NEXT: [[BC_MERGE_RDX:%.*]] = phi i32 [ [[DOTPROMOTED]], [[FOR_BODY8_LR_PH]] ], [ [[DOTPROMOTED]], [[VECTOR_SCEVCHECK]] ], [ [[TMP31]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: br label [[FOR_BODY8:%.*]]
; CHECK: for.body8:
; CHECK-NEXT: [[INC5:%.*]] = phi i32 [ [[BC_MERGE_RDX]], [[SCALAR_PH]] ], [ [[INC:%.*]], [[FOR_BODY8]] ]
; CHECK-NEXT: [[C_04:%.*]] = phi i8 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[DEC:%.*]], [[FOR_BODY8]] ]
; CHECK-NEXT: [[INC]] = add i32 [[INC5]], 1
; CHECK-NEXT: [[DEC]] = add i8 [[C_04]], -1
; CHECK-NEXT: [[CONV5:%.*]] = zext i8 [[DEC]] to i32
; CHECK-NEXT: [[CMP6:%.*]] = icmp ult i32 [[TMP2]], [[CONV5]]
; CHECK-NEXT: br i1 [[CMP6]], label [[FOR_BODY8]], label [[FOR_COND4_FOR_INC9_CRIT_EDGE]], [[LOOP2:!llvm.loop !.*]]
; CHECK: for.cond4.for.inc9_crit_edge:
; CHECK-NEXT: [[INC_LCSSA:%.*]] = phi i32 [ [[INC]], [[FOR_BODY8]] ], [ [[TMP31]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: store i32 [[INC_LCSSA]], i32* getelementptr inbounds ([192 x [192 x i32]], [192 x [192 x i32]]* @a, i64 0, i64 0, i64 0), align 16
; CHECK-NEXT: br label [[FOR_INC9]]
; CHECK: for.inc9:
; CHECK-NEXT: [[CONV10:%.*]] = and i32 [[STOREMERGE_IN9]], 65535
; CHECK-NEXT: [[ADD]] = add nuw nsw i32 [[CONV10]], 1
; CHECK-NEXT: [[CONV1:%.*]] = and i32 [[ADD]], 65472
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[CONV1]], 0
; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[FOR_COND_FOR_END12_CRIT_EDGE:%.*]]
; CHECK: for.cond.for.end12_crit_edge:
; CHECK-NEXT: [[ADD_LCSSA:%.*]] = phi i32 [ [[ADD]], [[FOR_INC9]] ]
; CHECK-NEXT: [[STOREMERGE:%.*]] = trunc i32 [[ADD_LCSSA]] to i16
; CHECK-NEXT: store i16 [[STOREMERGE]], i16* [[S]], align 2
; CHECK-NEXT: br label [[FOR_END12]]
; CHECK: for.end12:
; CHECK-NEXT: [[CALL13:%.*]] = call i32 (i16*, ...) bitcast (i32 (...)* @foo to i32 (i16*, ...)*)(i16* nonnull [[S]])
; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 2, i8* nonnull [[TMP1]])
; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull [[TMP0]])
; CHECK-NEXT: ret i32 0
;
entry:
%i = alloca i32, align 4
%s = alloca i16, align 2
%0 = bitcast i32* %i to i8*
call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %0) #3
store i32 0, i32* %i, align 4
%1 = bitcast i16* %s to i8*
call void @llvm.lifetime.start.p0i8(i64 2, i8* nonnull %1) #3
%call = call i32 (i32*, ...) bitcast (i32 (...)* @goo to i32 (i32*, ...)*)(i32* nonnull %i) #3
%2 = load i32, i32* %i, align 4
%storemerge6 = trunc i32 %2 to i16
store i16 %storemerge6, i16* %s, align 2
%conv17 = and i32 %2, 65472
%cmp8 = icmp eq i32 %conv17, 0
br i1 %cmp8, label %for.body.lr.ph, label %for.end12
for.body.lr.ph: ; preds = %entry
br label %for.body
for.body: ; preds = %for.body.lr.ph, %for.inc9
%storemerge.in9 = phi i32 [ %2, %for.body.lr.ph ], [ %add, %for.inc9 ]
%conv52 = and i32 %storemerge.in9, 255
%cmp63 = icmp ult i32 %2, %conv52
br i1 %cmp63, label %for.body8.lr.ph, label %for.inc9
for.body8.lr.ph: ; preds = %for.body
%conv3 = trunc i32 %storemerge.in9 to i8
%.promoted = load i32, i32* getelementptr inbounds ([192 x [192 x i32]], [192 x [192 x i32]]* @a, i64 0, i64 0, i64 0), align 16
br label %for.body8
for.body8: ; preds = %for.body8.lr.ph, %for.body8
%inc5 = phi i32 [ %.promoted, %for.body8.lr.ph ], [ %inc, %for.body8 ]
%c.04 = phi i8 [ %conv3, %for.body8.lr.ph ], [ %dec, %for.body8 ]
%inc = add i32 %inc5, 1
%dec = add i8 %c.04, -1
%conv5 = zext i8 %dec to i32
%cmp6 = icmp ult i32 %2, %conv5
br i1 %cmp6, label %for.body8, label %for.cond4.for.inc9_crit_edge
for.cond4.for.inc9_crit_edge: ; preds = %for.body8
%inc.lcssa = phi i32 [ %inc, %for.body8 ]
store i32 %inc.lcssa, i32* getelementptr inbounds ([192 x [192 x i32]], [192 x [192 x i32]]* @a, i64 0, i64 0, i64 0), align 16
br label %for.inc9
for.inc9: ; preds = %for.cond4.for.inc9_crit_edge, %for.body
%conv10 = and i32 %storemerge.in9, 65535
%add = add nuw nsw i32 %conv10, 1
%conv1 = and i32 %add, 65472
%cmp = icmp eq i32 %conv1, 0
br i1 %cmp, label %for.body, label %for.cond.for.end12_crit_edge
for.cond.for.end12_crit_edge: ; preds = %for.inc9
%add.lcssa = phi i32 [ %add, %for.inc9 ]
%storemerge = trunc i32 %add.lcssa to i16
store i16 %storemerge, i16* %s, align 2
br label %for.end12
for.end12: ; preds = %for.cond.for.end12_crit_edge, %entry
%call13 = call i32 (i16*, ...) bitcast (i32 (...)* @foo to i32 (i16*, ...)*)(i16* nonnull %s) #3
call void @llvm.lifetime.end.p0i8(i64 2, i8* nonnull %1) #3
call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %0) #3
ret i32 0
}
; Function Attrs: argmemonly nounwind
declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) #1
declare i32 @goo(...) local_unnamed_addr #2
declare i32 @foo(...) local_unnamed_addr #2
; Function Attrs: argmemonly nounwind
declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) #1