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llvm-mirror/test/Transforms/IndVarSimplify/no-iv-rewrite.ll
Philip Reames 23f506e253 [LoopPred] Selectively disable to preserve test cases
I'm about to enable the new loop predication transform by default.  It has the effect of completely destroying many read only loops - which happen to be a super common idiom in our test cases.  So as to preserve test coverage of other transforms, disable the new transform where it would cause sharp test coverage regressions.

(This is semantically part of the enabling commit.  It's committed separate to ease revert if the actual flag flip gets reverted.)
2019-11-06 15:41:57 -08:00

398 lines
9.4 KiB
LLVM

; RUN: opt < %s -indvars -S -indvars-predicate-loops=0 | FileCheck %s
;
; Make sure that indvars isn't inserting canonical IVs.
; This is kinda hard to do until linear function test replacement is removed.
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"
define i32 @sum(i32* %arr, i32 %n) nounwind {
entry:
%precond = icmp slt i32 0, %n
br i1 %precond, label %ph, label %return
ph:
br label %loop
; CHECK: loop:
;
; We should only have 2 IVs.
; CHECK: phi
; CHECK: phi
; CHECK-NOT: phi
;
; sext should be eliminated while preserving gep inboundsness.
; CHECK-NOT: sext
; CHECK: getelementptr inbounds
; CHECK: exit:
loop:
%i.02 = phi i32 [ 0, %ph ], [ %iinc, %loop ]
%s.01 = phi i32 [ 0, %ph ], [ %sinc, %loop ]
%ofs = sext i32 %i.02 to i64
%adr = getelementptr inbounds i32, i32* %arr, i64 %ofs
%val = load i32, i32* %adr
%sinc = add nsw i32 %s.01, %val
%iinc = add nsw i32 %i.02, 1
%cond = icmp slt i32 %iinc, %n
br i1 %cond, label %loop, label %exit
exit:
%s.lcssa = phi i32 [ %sinc, %loop ]
br label %return
return:
%s.0.lcssa = phi i32 [ %s.lcssa, %exit ], [ 0, %entry ]
ret i32 %s.0.lcssa
}
define i64 @suml(i32* %arr, i32 %n) nounwind {
entry:
%precond = icmp slt i32 0, %n
br i1 %precond, label %ph, label %return
ph:
br label %loop
; CHECK: loop:
;
; We should only have 2 IVs.
; CHECK: phi
; CHECK: phi
; CHECK-NOT: phi
;
; %ofs sext should be eliminated while preserving gep inboundsness.
; CHECK-NOT: sext
; CHECK: getelementptr inbounds
; %vall sext should obviously not be eliminated
; CHECK: sext
; CHECK: exit:
loop:
%i.02 = phi i32 [ 0, %ph ], [ %iinc, %loop ]
%s.01 = phi i64 [ 0, %ph ], [ %sinc, %loop ]
%ofs = sext i32 %i.02 to i64
%adr = getelementptr inbounds i32, i32* %arr, i64 %ofs
%val = load i32, i32* %adr
%vall = sext i32 %val to i64
%sinc = add nsw i64 %s.01, %vall
%iinc = add nsw i32 %i.02, 1
%cond = icmp slt i32 %iinc, %n
br i1 %cond, label %loop, label %exit
exit:
%s.lcssa = phi i64 [ %sinc, %loop ]
br label %return
return:
%s.0.lcssa = phi i64 [ %s.lcssa, %exit ], [ 0, %entry ]
ret i64 %s.0.lcssa
}
define void @outofbounds(i32* %first, i32* %last, i32 %idx) nounwind {
%precond = icmp ne i32* %first, %last
br i1 %precond, label %ph, label %return
; CHECK: ph:
; It's not indvars' job to perform LICM on %ofs
; CHECK-NOT: sext
ph:
br label %loop
; CHECK: loop:
;
; Preserve exactly one pointer type IV.
; CHECK: phi i32*
; CHECK-NOT: phi
;
; Don't create any extra adds.
; CHECK-NOT: add
;
; Preserve gep inboundsness, and don't factor it.
; CHECK: getelementptr inbounds i32, i32* %ptriv, i32 1
; CHECK-NOT: add
; CHECK: exit:
loop:
%ptriv = phi i32* [ %first, %ph ], [ %ptrpost, %loop ]
%ofs = sext i32 %idx to i64
%adr = getelementptr inbounds i32, i32* %ptriv, i64 %ofs
store i32 3, i32* %adr
%ptrpost = getelementptr inbounds i32, i32* %ptriv, i32 1
%cond = icmp ne i32* %ptrpost, %last
br i1 %cond, label %loop, label %exit
exit:
br label %return
return:
ret void
}
%structI = type { i32 }
define void @bitcastiv(i32 %start, i32 %limit, i32 %step, %structI* %base)
nounwind
{
entry:
br label %loop
; CHECK: loop:
;
; Preserve casts
; CHECK: phi i32
; CHECK: bitcast
; CHECK: getelementptr
; CHECK: exit:
loop:
%iv = phi i32 [%start, %entry], [%next, %loop]
%p = phi %structI* [%base, %entry], [%pinc, %loop]
%adr = getelementptr %structI, %structI* %p, i32 0, i32 0
store i32 3, i32* %adr
%pp = bitcast %structI* %p to i32*
store i32 4, i32* %pp
%pinc = getelementptr %structI, %structI* %p, i32 1
%next = add i32 %iv, 1
%cond = icmp ne i32 %next, %limit
br i1 %cond, label %loop, label %exit
exit:
ret void
}
define void @maxvisitor(i32 %limit, i32* %base) nounwind {
entry:
br label %loop
; Test inserting a truncate at a phi use.
;
; CHECK: loop:
; CHECK: phi i64
; CHECK: trunc
; CHECK: exit:
loop:
%idx = phi i32 [ 0, %entry ], [ %idx.next, %loop.inc ]
%max = phi i32 [ 0, %entry ], [ %max.next, %loop.inc ]
%idxprom = sext i32 %idx to i64
%adr = getelementptr inbounds i32, i32* %base, i64 %idxprom
%val = load i32, i32* %adr
%cmp19 = icmp sgt i32 %val, %max
br i1 %cmp19, label %if.then, label %if.else
if.then:
br label %loop.inc
if.else:
br label %loop.inc
loop.inc:
%max.next = phi i32 [ %idx, %if.then ], [ %max, %if.else ]
%idx.next = add nsw i32 %idx, 1
%cmp = icmp slt i32 %idx.next, %limit
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define void @identityphi(i32 %limit) nounwind {
entry:
br label %loop
; Test an edge case of removing an identity phi that directly feeds
; back to the loop iv.
;
; CHECK: loop:
; CHECK-NOT: phi
; CHECK: exit:
loop:
%iv = phi i32 [ 0, %entry], [ %iv.next, %control ]
br i1 undef, label %if.then, label %control
if.then:
br label %control
control:
%iv.next = phi i32 [ %iv, %loop ], [ undef, %if.then ]
%cmp = icmp slt i32 %iv.next, %limit
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
define i64 @cloneOr(i32 %limit, i64* %base) nounwind {
entry:
; ensure that the loop can't overflow
%halfLim = ashr i32 %limit, 2
br label %loop
; Test cloning an or, which is not an OverflowBinaryOperator.
;
; CHECK: sext
; CHECK: loop:
; CHECK: phi i64
; CHECK-NOT: sext
; CHECK: or i64
; CHECK: exit:
loop:
%iv = phi i32 [ 0, %entry], [ %iv.next, %loop ]
%t1 = sext i32 %iv to i64
%adr = getelementptr i64, i64* %base, i64 %t1
%val = load i64, i64* %adr
%t2 = or i32 %iv, 1
%t3 = sext i32 %t2 to i64
%iv.next = add i32 %iv, 2
%cmp = icmp slt i32 %iv.next, %halfLim
br i1 %cmp, label %loop, label %exit
exit:
%result = and i64 %val, %t3
ret i64 %result
}
; The i induction variable looks like a wrap-around, but it really is just
; a simple affine IV. Make sure that indvars simplifies through.
define i32 @indirectRecurrence() nounwind {
entry:
br label %loop
; ReplaceLoopExitValue should fold the return value to constant 9.
; CHECK: loop:
; CHECK: phi i32
; CHECK: ret i32 9
loop:
%j.0 = phi i32 [ 1, %entry ], [ %j.next, %cond_true ]
%i.0 = phi i32 [ 0, %entry ], [ %j.0, %cond_true ]
%tmp = icmp ne i32 %j.0, 10
br i1 %tmp, label %cond_true, label %return
cond_true:
%j.next = add i32 %j.0, 1
br label %loop
return:
ret i32 %i.0
}
; Eliminate the congruent phis j, k, and l.
; Eliminate the redundant IV increments k.next and l.next.
; Two phis should remain, one starting at %init, and one at %init1.
; Two increments should remain, one by %step and one by %step1.
; CHECK: loop:
; CHECK: phi i32
; CHECK: phi i32
; CHECK-NOT: phi
; CHECK: add i32
; CHECK: add i32
; CHECK: add i32
; CHECK-NOT: add
; CHECK: return:
;
; Five live-outs should remain.
; CHECK: lcssa = phi
; CHECK: lcssa = phi
; CHECK: lcssa = phi
; CHECK: lcssa = phi
; CHECK: lcssa = phi
; CHECK-NOT: phi
; CHECK: ret
define i32 @isomorphic(i32 %init, i32 %step, i32 %lim) nounwind {
entry:
%step1 = add i32 %step, 1
%init1 = add i32 %init, %step1
%l.0 = sub i32 %init1, %step1
br label %loop
loop:
%ii = phi i32 [ %init1, %entry ], [ %ii.next, %loop ]
%i = phi i32 [ %init, %entry ], [ %ii, %loop ]
%j = phi i32 [ %init, %entry ], [ %j.next, %loop ]
%k = phi i32 [ %init1, %entry ], [ %k.next, %loop ]
%l = phi i32 [ %l.0, %entry ], [ %l.next, %loop ]
%ii.next = add i32 %ii, %step1
%j.next = add i32 %j, %step1
%k.next = add i32 %k, %step1
%l.step = add i32 %l, %step
%l.next = add i32 %l.step, 1
%cmp = icmp ne i32 %ii.next, %lim
br i1 %cmp, label %loop, label %return
return:
%sum1 = add i32 %i, %j.next
%sum2 = add i32 %sum1, %k.next
%sum3 = add i32 %sum1, %l.step
%sum4 = add i32 %sum1, %l.next
ret i32 %sum4
}
; Test a GEP IV that is derived from another GEP IV by a nop gep that
; lowers the type without changing the expression.
%structIF = type { i32, float }
define void @congruentgepiv(%structIF* %base) nounwind uwtable ssp {
entry:
%first = getelementptr inbounds %structIF, %structIF* %base, i64 0, i32 0
br label %loop
; CHECK: loop:
; CHECK: phi %structIF*
; CHECK-NOT: phi
; CHECK: getelementptr inbounds
; CHECK-NOT: getelementptr
; CHECK: exit:
loop:
%ptr.iv = phi %structIF* [ %ptr.inc, %latch ], [ %base, %entry ]
%next = phi i32* [ %next.inc, %latch ], [ %first, %entry ]
store i32 4, i32* %next
br i1 undef, label %latch, label %exit
latch: ; preds = %for.inc50.i
%ptr.inc = getelementptr inbounds %structIF, %structIF* %ptr.iv, i64 1
%next.inc = getelementptr inbounds %structIF, %structIF* %ptr.inc, i64 0, i32 0
br label %loop
exit:
ret void
}
declare void @use32(i32 %x)
declare void @use64(i64 %x)
; Test a widened IV that is used by a phi on different paths within the loop.
;
; CHECK: for.body:
; CHECK: phi i64
; CHECK: trunc i64
; CHECK: if.then:
; CHECK: for.inc:
; CHECK: phi i32
; CHECK: for.end:
define void @phiUsesTrunc() nounwind {
entry:
br i1 undef, label %for.body, label %for.end
for.body:
%iv = phi i32 [ %inc, %for.inc ], [ 1, %entry ]
br i1 undef, label %if.then, label %if.else
if.then:
br i1 undef, label %if.then33, label %for.inc
if.then33:
br label %for.inc
if.else:
br i1 undef, label %if.then97, label %for.inc
if.then97:
%idxprom100 = sext i32 %iv to i64
call void @use64(i64 %idxprom100)
br label %for.inc
for.inc:
%kmin.1 = phi i32 [ %iv, %if.then33 ], [ 0, %if.then ], [ %iv, %if.then97 ], [ 0, %if.else ]
call void @use32(i32 %kmin.1)
%inc = add nsw i32 %iv, 1
br i1 undef, label %for.body, label %for.end
for.end:
ret void
}