Files
clang-p2996/llvm/test/Transforms/LoopVectorize/pr45259.ll
Eli Friedman 8f3d16905d [ScalarEvolution] Ensure backedge-taken counts are not pointers.
A backedge-taken count doesn't refer to memory; returning a pointer type
is nonsense. So make sure we always return an integer.

The obvious way to do this would be to just convert the operands of the
icmp to integers, but that doesn't quite work out at the moment:
isLoopEntryGuardedByCond currently gets confused by ptrtoint operations.
So we perform the ptrtoint conversion late for lt/gt operations.

The test changes are mostly innocuous. The most interesting changes are
more complex SCEV expressions of the form "(-1 * (ptrtoint i8* %ptr to
i64)) + %ptr)". This is expected: we can't fold this to zero because we
need to preserve the pointer base.

The call to isLoopEntryGuardedByCond in howFarToZero is less precise
because of ptrtoint operations; this shows up in the function
pr46786_c26_char in ptrtoint.ll. Fixing it here would require more
complex refactoring.  It should eventually be fixed by future
improvements to isImpliedCond.

See https://bugs.llvm.org/show_bug.cgi?id=46786 for context.

Differential Revision: https://reviews.llvm.org/D103656
2021-06-21 16:24:16 -07:00

108 lines
5.6 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -S -loop-vectorize -force-vector-width=4 -force-vector-interleave=1 | FileCheck %s
; Check that we can vectorize this loop without crashing.
define i8 @widget(i8* %arr, i8 %t9) {
; CHECK-LABEL: @widget(
; CHECK-NEXT: bb:
; CHECK-NEXT: [[ARR2:%.*]] = ptrtoint i8* [[ARR:%.*]] to i64
; CHECK-NEXT: br label [[BB6:%.*]]
; CHECK: bb6:
; CHECK-NEXT: [[T1_0:%.*]] = phi i8* [ [[ARR]], [[BB:%.*]] ], [ null, [[BB6]] ]
; CHECK-NEXT: [[C:%.*]] = call i1 @cond()
; CHECK-NEXT: br i1 [[C]], label [[FOR_PREHEADER:%.*]], label [[BB6]]
; CHECK: for.preheader:
; CHECK-NEXT: [[T1_0_LCSSA:%.*]] = phi i8* [ [[T1_0]], [[BB6]] ]
; CHECK-NEXT: [[T1_0_LCSSA1:%.*]] = ptrtoint i8* [[T1_0_LCSSA]] to i64
; CHECK-NEXT: [[TMP0:%.*]] = trunc i64 [[T1_0_LCSSA1]] to i32
; CHECK-NEXT: [[TMP1:%.*]] = trunc i64 [[ARR2]] to i32
; CHECK-NEXT: [[TMP2:%.*]] = sub i32 [[TMP0]], [[TMP1]]
; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i32 [[TMP2]], 4
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
; CHECK: vector.scevcheck:
; CHECK-NEXT: [[TMP3:%.*]] = add i64 [[T1_0_LCSSA1]], -1
; CHECK-NEXT: [[TMP4:%.*]] = sub i64 [[TMP3]], [[ARR2]]
; CHECK-NEXT: [[TMP5:%.*]] = trunc i64 [[TMP4]] to i8
; CHECK-NEXT: [[MUL:%.*]] = call { i8, i1 } @llvm.umul.with.overflow.i8(i8 1, i8 [[TMP5]])
; CHECK-NEXT: [[MUL_RESULT:%.*]] = extractvalue { i8, i1 } [[MUL]], 0
; CHECK-NEXT: [[MUL_OVERFLOW:%.*]] = extractvalue { i8, i1 } [[MUL]], 1
; CHECK-NEXT: [[TMP6:%.*]] = add i8 1, [[MUL_RESULT]]
; CHECK-NEXT: [[TMP7:%.*]] = sub i8 1, [[MUL_RESULT]]
; CHECK-NEXT: [[TMP8:%.*]] = icmp sgt i8 [[TMP7]], 1
; CHECK-NEXT: [[TMP9:%.*]] = icmp slt i8 [[TMP6]], 1
; CHECK-NEXT: [[TMP10:%.*]] = select i1 false, i1 [[TMP8]], i1 [[TMP9]]
; CHECK-NEXT: [[TMP11:%.*]] = icmp ugt i64 [[TMP4]], 255
; CHECK-NEXT: [[TMP12:%.*]] = or i1 [[TMP10]], [[TMP11]]
; CHECK-NEXT: [[TMP13:%.*]] = or i1 [[TMP12]], [[MUL_OVERFLOW]]
; CHECK-NEXT: [[TMP14:%.*]] = or i1 false, [[TMP13]]
; CHECK-NEXT: br i1 [[TMP14]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i32 [[TMP2]], 4
; CHECK-NEXT: [[N_VEC:%.*]] = sub i32 [[TMP2]], [[N_MOD_VF]]
; CHECK-NEXT: [[IND_END:%.*]] = trunc i32 [[N_VEC]] to i8
; CHECK-NEXT: [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x i8> poison, i8 [[T9:%.*]], i32 0
; CHECK-NEXT: [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x i8> [[BROADCAST_SPLATINSERT]], <4 x i8> poison, <4 x i32> zeroinitializer
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_IND:%.*]] = phi <4 x i8> [ <i8 0, i8 1, i8 2, i8 3>, [[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP15:%.*]] = add <4 x i8> [[VEC_IND]], <i8 1, i8 1, i8 1, i8 1>
; CHECK-NEXT: [[TMP16:%.*]] = extractelement <4 x i8> [[TMP15]], i32 0
; CHECK-NEXT: [[TMP17:%.*]] = getelementptr inbounds i8, i8* [[ARR]], i8 [[TMP16]]
; CHECK-NEXT: [[TMP18:%.*]] = icmp slt <4 x i8> [[TMP15]], [[BROADCAST_SPLAT]]
; CHECK-NEXT: [[TMP19:%.*]] = zext <4 x i1> [[TMP18]] to <4 x i8>
; CHECK-NEXT: [[TMP20:%.*]] = getelementptr inbounds i8, i8* [[TMP17]], i32 0
; CHECK-NEXT: [[TMP21:%.*]] = bitcast i8* [[TMP20]] to <4 x i8>*
; CHECK-NEXT: store <4 x i8> [[TMP19]], <4 x i8>* [[TMP21]], align 1
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 4
; CHECK-NEXT: [[VEC_IND_NEXT]] = add <4 x i8> [[VEC_IND]], <i8 4, i8 4, i8 4, i8 4>
; CHECK-NEXT: [[TMP22:%.*]] = icmp eq i32 [[INDEX_NEXT]], [[N_VEC]]
; CHECK-NEXT: br i1 [[TMP22]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i32 [[TMP2]], [[N_VEC]]
; CHECK-NEXT: br i1 [[CMP_N]], label [[FOR_EXIT:%.*]], label [[SCALAR_PH]]
; CHECK: scalar.ph:
; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i8 [ [[IND_END]], [[MIDDLE_BLOCK]] ], [ 0, [[FOR_PREHEADER]] ], [ 0, [[VECTOR_SCEVCHECK]] ]
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], [[FOR_BODY]] ], [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ]
; CHECK-NEXT: [[IV_NEXT]] = add i8 [[IV]], 1
; CHECK-NEXT: [[PTR:%.*]] = getelementptr inbounds i8, i8* [[ARR]], i8 [[IV_NEXT]]
; CHECK-NEXT: [[T3_I:%.*]] = icmp slt i8 [[IV_NEXT]], [[T9]]
; CHECK-NEXT: [[T3_I8:%.*]] = zext i1 [[T3_I]] to i8
; CHECK-NEXT: store i8 [[T3_I8]], i8* [[PTR]], align 1
; CHECK-NEXT: [[EC:%.*]] = icmp eq i8* [[T1_0_LCSSA]], [[PTR]]
; CHECK-NEXT: br i1 [[EC]], label [[FOR_EXIT]], label [[FOR_BODY]], !llvm.loop [[LOOP2:![0-9]+]]
; CHECK: for.exit:
; CHECK-NEXT: [[IV_NEXT_LCSSA:%.*]] = phi i8 [ [[IV_NEXT]], [[FOR_BODY]] ], [ [[IND_END]], [[MIDDLE_BLOCK]] ]
; CHECK-NEXT: ret i8 [[IV_NEXT_LCSSA]]
;
bb:
br label %bb6
bb6:
%t1.0 = phi i8* [ %arr, %bb ], [ null, %bb6 ]
%c = call i1 @cond()
br i1 %c, label %for.preheader, label %bb6
for.preheader:
br label %for.body
for.body:
%iv = phi i8 [ %iv.next, %for.body ], [ 0, %for.preheader ]
%iv.next = add i8 %iv, 1
%ptr = getelementptr inbounds i8, i8* %arr, i8 %iv.next
%t3.i = icmp slt i8 %iv.next, %t9
%t3.i8 = zext i1 %t3.i to i8
store i8 %t3.i8, i8* %ptr
%ec = icmp eq i8* %t1.0, %ptr
br i1 %ec, label %for.exit, label %for.body
for.exit:
%iv.next.lcssa = phi i8 [ %iv.next, %for.body ]
ret i8 %iv.next.lcssa
}
declare i1 @cond()