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llvm-project/llvm/test/Transforms/IndVarSimplify/lftr-reuse.ll
Florian Hahn dce77a3579
[IndVars] Preserve flags of narrow IV inc if replacing with wider inc. (#80446) 
We are replacing a narrow IV increment with a wider one. If the original
(narrow) increment did not wrap, the wider one should not wrap either.
Set the flags to be the union of both wide increment and original
increment; this ensures we preserve flags SCEV could infer for the wider
increment.

Fixes https://github.com/llvm/llvm-project/issues/71517.
2024-02-10 18:11:17 +00:00

334 lines
13 KiB
LLVM
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=indvars -S -indvars-predicate-loops=0 | FileCheck %s
; Make sure that indvars can perform LFTR without a canonical IV.
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
; Perform LFTR using the original pointer-type IV.
declare void @use(double %x)
; for(char* p = base; p < base + n; ++p) {
; *p = p-base;
; }
define void @ptriv(ptr %base, i32 %n) nounwind {
; CHECK-LABEL: @ptriv(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[IDX_EXT:%.*]] = sext i32 [[N:%.*]] to i64
; CHECK-NEXT: [[ADD_PTR:%.*]] = getelementptr inbounds i8, ptr [[BASE:%.*]], i64 [[IDX_EXT]]
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult ptr [[BASE]], [[ADD_PTR]]
; CHECK-NEXT: br i1 [[CMP1]], label [[FOR_BODY_PREHEADER:%.*]], label [[FOR_END:%.*]]
; CHECK: for.body.preheader:
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: [[P_02:%.*]] = phi ptr [ [[INCDEC_PTR:%.*]], [[FOR_BODY]] ], [ [[BASE]], [[FOR_BODY_PREHEADER]] ]
; CHECK-NEXT: [[SUB_PTR_LHS_CAST:%.*]] = ptrtoint ptr [[P_02]] to i64
; CHECK-NEXT: [[SUB_PTR_RHS_CAST:%.*]] = ptrtoint ptr [[BASE]] to i64
; CHECK-NEXT: [[SUB_PTR_SUB:%.*]] = sub i64 [[SUB_PTR_LHS_CAST]], [[SUB_PTR_RHS_CAST]]
; CHECK-NEXT: [[CONV:%.*]] = trunc i64 [[SUB_PTR_SUB]] to i8
; CHECK-NEXT: store i8 [[CONV]], ptr [[P_02]], align 1
; CHECK-NEXT: [[INCDEC_PTR]] = getelementptr inbounds i8, ptr [[P_02]], i32 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne ptr [[INCDEC_PTR]], [[ADD_PTR]]
; CHECK-NEXT: br i1 [[EXITCOND]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]]
; CHECK: for.end.loopexit:
; CHECK-NEXT: br label [[FOR_END]]
; CHECK: for.end:
; CHECK-NEXT: ret void
;
entry:
%idx.ext = sext i32 %n to i64
%add.ptr = getelementptr inbounds i8, ptr %base, i64 %idx.ext
%cmp1 = icmp ult ptr %base, %add.ptr
br i1 %cmp1, label %for.body, label %for.end
for.body:
%p.02 = phi ptr [ %base, %entry ], [ %incdec.ptr, %for.body ]
; cruft to make the IV useful
%sub.ptr.lhs.cast = ptrtoint ptr %p.02 to i64
%sub.ptr.rhs.cast = ptrtoint ptr %base to i64
%sub.ptr.sub = sub i64 %sub.ptr.lhs.cast, %sub.ptr.rhs.cast
%conv = trunc i64 %sub.ptr.sub to i8
store i8 %conv, ptr %p.02
%incdec.ptr = getelementptr inbounds i8, ptr %p.02, i32 1
%cmp = icmp ult ptr %incdec.ptr, %add.ptr
br i1 %cmp, label %for.body, label %for.end
for.end:
ret void
}
; This test checks that SCEVExpander can handle an outer loop that has been
; simplified, and as a result the inner loop's exit test will be rewritten.
define void @expandOuterRecurrence(i32 %arg) nounwind {
; CHECK-LABEL: @expandOuterRecurrence(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[SUB1:%.*]] = sub nsw i32 [[ARG:%.*]], 1
; CHECK-NEXT: [[CMP1:%.*]] = icmp slt i32 0, [[SUB1]]
; CHECK-NEXT: br i1 [[CMP1]], label [[OUTER_PREHEADER:%.*]], label [[EXIT:%.*]]
; CHECK: outer.preheader:
; CHECK-NEXT: br label [[OUTER:%.*]]
; CHECK: outer:
; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i32 [ [[SUB1]], [[OUTER_PREHEADER]] ], [ [[INDVARS_IV_NEXT:%.*]], [[OUTER_INC:%.*]] ]
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[I_INC:%.*]], [[OUTER_INC]] ], [ 0, [[OUTER_PREHEADER]] ]
; CHECK-NEXT: [[SUB2:%.*]] = sub nsw i32 [[ARG]], [[I]]
; CHECK-NEXT: [[SUB3:%.*]] = sub nsw i32 [[SUB2]], 1
; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 0, [[SUB3]]
; CHECK-NEXT: br i1 [[CMP2]], label [[INNER_PH:%.*]], label [[OUTER_INC]]
; CHECK: inner.ph:
; CHECK-NEXT: br label [[INNER:%.*]]
; CHECK: inner:
; CHECK-NEXT: [[J:%.*]] = phi i32 [ 0, [[INNER_PH]] ], [ [[J_INC:%.*]], [[INNER]] ]
; CHECK-NEXT: [[J_INC]] = add nuw nsw i32 [[J]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[J_INC]], [[INDVARS_IV]]
; CHECK-NEXT: br i1 [[EXITCOND]], label [[INNER]], label [[OUTER_INC_LOOPEXIT:%.*]]
; CHECK: outer.inc.loopexit:
; CHECK-NEXT: br label [[OUTER_INC]]
; CHECK: outer.inc:
; CHECK-NEXT: [[I_INC]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add i32 [[INDVARS_IV]], -1
; CHECK-NEXT: [[EXITCOND1:%.*]] = icmp ne i32 [[I_INC]], [[SUB1]]
; CHECK-NEXT: br i1 [[EXITCOND1]], label [[OUTER]], label [[EXIT_LOOPEXIT:%.*]]
; CHECK: exit.loopexit:
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
%sub1 = sub nsw i32 %arg, 1
%cmp1 = icmp slt i32 0, %sub1
br i1 %cmp1, label %outer, label %exit
outer:
%i = phi i32 [ 0, %entry ], [ %i.inc, %outer.inc ]
%sub2 = sub nsw i32 %arg, %i
%sub3 = sub nsw i32 %sub2, 1
%cmp2 = icmp slt i32 0, %sub3
br i1 %cmp2, label %inner.ph, label %outer.inc
inner.ph:
br label %inner
inner:
%j = phi i32 [ 0, %inner.ph ], [ %j.inc, %inner ]
%j.inc = add nsw i32 %j, 1
%cmp3 = icmp slt i32 %j.inc, %sub3
br i1 %cmp3, label %inner, label %outer.inc
outer.inc:
%i.inc = add nsw i32 %i, 1
%cmp4 = icmp slt i32 %i.inc, %sub1
br i1 %cmp4, label %outer, label %exit
exit:
ret void
}
; Force SCEVExpander to look for an existing well-formed phi.
; Perform LFTR without generating extra preheader code.
; TODO: Recover regression after not strengthening AddRec flags during
; get[Sign,Zero]ExtendExpr for INDVARS_IV_NEXT.
define void @guardedloop(ptr %matrix, ptr %vector,
;
; CHECK-LABEL: @guardedloop(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 1, [[IROW:%.*]]
; CHECK-NEXT: br i1 [[CMP]], label [[LOOP_PREHEADER:%.*]], label [[RETURN:%.*]]
; CHECK: loop.preheader:
; CHECK-NEXT: [[TMP0:%.*]] = sext i32 [[ILEAD:%.*]] to i64
; CHECK-NEXT: [[WIDE_TRIP_COUNT:%.*]] = zext i32 [[IROW]] to i64
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[INDVARS_IV2:%.*]] = phi i64 [ 0, [[LOOP_PREHEADER]] ], [ [[INDVARS_IV_NEXT3:%.*]], [[LOOP]] ]
; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ 0, [[LOOP_PREHEADER]] ], [ [[INDVARS_IV_NEXT:%.*]], [[LOOP]] ]
; CHECK-NEXT: [[TMP1:%.*]] = add nsw i64 [[INDVARS_IV]], [[INDVARS_IV2]]
; CHECK-NEXT: [[MATRIXP:%.*]] = getelementptr inbounds [0 x double], ptr [[MATRIX:%.*]], i32 0, i64 [[TMP1]]
; CHECK-NEXT: [[V1:%.*]] = load double, ptr [[MATRIXP]], align 8
; CHECK-NEXT: call void @use(double [[V1]])
; CHECK-NEXT: [[VECTORP:%.*]] = getelementptr inbounds [0 x double], ptr [[VECTOR:%.*]], i32 0, i64 [[INDVARS_IV2]]
; CHECK-NEXT: [[V2:%.*]] = load double, ptr [[VECTORP]], align 8
; CHECK-NEXT: call void @use(double [[V2]])
; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nsw i64 [[INDVARS_IV]], [[TMP0]]
; CHECK-NEXT: [[INDVARS_IV_NEXT3]] = add nuw nsw i64 [[INDVARS_IV2]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDVARS_IV_NEXT3]], [[WIDE_TRIP_COUNT]]
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[RETURN_LOOPEXIT:%.*]]
; CHECK: return.loopexit:
; CHECK-NEXT: br label [[RETURN]]
; CHECK: return:
; CHECK-NEXT: ret void
;
i32 %irow, i32 %ilead) nounwind {
entry:
%cmp = icmp slt i32 1, %irow
br i1 %cmp, label %loop, label %return
loop:
%rowidx = phi i32 [ 0, %entry ], [ %row.inc, %loop ]
%i = phi i32 [ 0, %entry ], [ %i.inc, %loop ]
%diagidx = add nsw i32 %rowidx, %i
%diagidxw = sext i32 %diagidx to i64
%matrixp = getelementptr inbounds [0 x double], ptr %matrix, i32 0, i64 %diagidxw
%v1 = load double, ptr %matrixp
call void @use(double %v1)
%iw = sext i32 %i to i64
%vectorp = getelementptr inbounds [0 x double], ptr %vector, i32 0, i64 %iw
%v2 = load double, ptr %vectorp
call void @use(double %v2)
%row.inc = add nsw i32 %rowidx, %ilead
%i.inc = add nsw i32 %i, 1
%cmp196 = icmp slt i32 %i.inc, %irow
br i1 %cmp196, label %loop, label %return
return:
ret void
}
; Avoid generating extra code to materialize a trip count. Skip LFTR.
define void @unguardedloop(ptr %matrix, ptr %vector,
;
; CHECK-LABEL: @unguardedloop(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[SMAX:%.*]] = call i32 @llvm.smax.i32(i32 [[IROW:%.*]], i32 1)
; CHECK-NEXT: [[WIDE_TRIP_COUNT:%.*]] = zext i32 [[SMAX]] to i64
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[INDVARS_IV2:%.*]] = phi i64 [ [[INDVARS_IV_NEXT3:%.*]], [[LOOP]] ], [ 0, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[INDVARS_IV_NEXT3]] = add nuw nsw i64 [[INDVARS_IV2]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDVARS_IV_NEXT3]], [[WIDE_TRIP_COUNT]]
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[RETURN:%.*]]
; CHECK: return:
; CHECK-NEXT: ret void
;
i32 %irow, i32 %ilead) nounwind {
entry:
br label %loop
loop:
%rowidx = phi i32 [ 0, %entry ], [ %row.inc, %loop ]
%i = phi i32 [ 0, %entry ], [ %i.inc, %loop ]
%diagidx = add nsw i32 %rowidx, %i
%diagidxw = sext i32 %diagidx to i64
%matrixp = getelementptr inbounds [0 x double], ptr %matrix, i32 0, i64 %diagidxw
%v1 = load double, ptr %matrixp
%iw = sext i32 %i to i64
%vectorp = getelementptr inbounds [0 x double], ptr %vector, i32 0, i64 %iw
%v2 = load double, ptr %vectorp
%row.inc = add nsw i32 %rowidx, %ilead
%i.inc = add nsw i32 %i, 1
%cmp196 = icmp slt i32 %i.inc, %irow
br i1 %cmp196, label %loop, label %return
return:
ret void
}
; Remove %i which is only used by the exit test.
; Verify that SCEV can still compute a backedge count from the sign
; extended %n, used for pointer comparison by LFTR.
;
; TODO: Fix for PR13371 currently makes this impossible. See
; IndVarSimplify.cpp hasConcreteDef(). We may want to change to undef rules.
define void @geplftr(ptr %base, i32 %x, i32 %y, i32 %n) nounwind {
; CHECK-LABEL: @geplftr(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[X_EXT:%.*]] = sext i32 [[X:%.*]] to i64
; CHECK-NEXT: [[ADD_PTR:%.*]] = getelementptr inbounds i8, ptr [[BASE:%.*]], i64 [[X_EXT]]
; CHECK-NEXT: [[Y_EXT:%.*]] = sext i32 [[Y:%.*]] to i64
; CHECK-NEXT: [[ADD_PTR10:%.*]] = getelementptr inbounds i8, ptr [[ADD_PTR]], i64 [[Y_EXT]]
; CHECK-NEXT: [[LIM:%.*]] = add i32 [[X]], [[N:%.*]]
; CHECK-NEXT: [[CMP_PH:%.*]] = icmp ult i32 [[X]], [[LIM]]
; CHECK-NEXT: br i1 [[CMP_PH]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
; CHECK: loop.preheader:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[INC:%.*]], [[LOOP]] ], [ [[X]], [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[APTR:%.*]] = phi ptr [ [[INCDEC_PTR:%.*]], [[LOOP]] ], [ [[ADD_PTR10]], [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[INCDEC_PTR]] = getelementptr inbounds i8, ptr [[APTR]], i32 1
; CHECK-NEXT: store i8 3, ptr [[APTR]], align 1
; CHECK-NEXT: [[INC]] = add nuw i32 [[I]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i32 [[INC]], [[LIM]]
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
; CHECK: exit.loopexit:
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
%x.ext = sext i32 %x to i64
%add.ptr = getelementptr inbounds i8, ptr %base, i64 %x.ext
%y.ext = sext i32 %y to i64
%add.ptr10 = getelementptr inbounds i8, ptr %add.ptr, i64 %y.ext
%lim = add i32 %x, %n
%cmp.ph = icmp ult i32 %x, %lim
br i1 %cmp.ph, label %loop, label %exit
loop:
%i = phi i32 [ %x, %entry ], [ %inc, %loop ]
%aptr = phi ptr [ %add.ptr10, %entry ], [ %incdec.ptr, %loop ]
%incdec.ptr = getelementptr inbounds i8, ptr %aptr, i32 1
store i8 3, ptr %aptr
%inc = add i32 %i, 1
%cmp = icmp ult i32 %inc, %lim
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
; Exercise backedge taken count verification with a never-taken loop.
define void @nevertaken() nounwind uwtable ssp {
; CHECK-LABEL: @nevertaken(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: br i1 false, label [[LOOP]], label [[EXIT:%.*]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
br label %loop
loop:
%i = phi i32 [ 0, %entry ], [ %inc, %loop ]
%inc = add nsw i32 %i, 1
%cmp = icmp sle i32 %inc, 0
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
; Test LFTR on an IV whose recurrence start is a non-unit pointer type.
define void @aryptriv(ptr %base, i32 %n) nounwind {
; CHECK-LABEL: @aryptriv(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[IVEND:%.*]] = getelementptr inbounds [256 x i8], ptr [[BASE:%.*]], i32 0, i32 [[N:%.*]]
; CHECK-NEXT: [[CMP_PH:%.*]] = icmp ult ptr [[BASE]], [[IVEND]]
; CHECK-NEXT: br i1 [[CMP_PH]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
; CHECK: loop.preheader:
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[APTR:%.*]] = phi ptr [ [[INCDEC_PTR:%.*]], [[LOOP]] ], [ [[BASE]], [[LOOP_PREHEADER]] ]
; CHECK-NEXT: [[INCDEC_PTR]] = getelementptr inbounds i8, ptr [[APTR]], i32 1
; CHECK-NEXT: store i8 3, ptr [[APTR]], align 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne ptr [[INCDEC_PTR]], [[IVEND]]
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
; CHECK: exit.loopexit:
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
%ivend = getelementptr inbounds [256 x i8], ptr %base, i32 0, i32 %n
%cmp.ph = icmp ult ptr %base, %ivend
br i1 %cmp.ph, label %loop, label %exit
loop:
%aptr = phi ptr [ %base, %entry ], [ %incdec.ptr, %loop ]
%incdec.ptr = getelementptr inbounds i8, ptr %aptr, i32 1
store i8 3, ptr %aptr
%cmp = icmp ult ptr %incdec.ptr, %ivend
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
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