LoopVectorize: Cache edge masks created during if-conversion

Otherwise, we end up with an exponential IR blowup.
Fixes PR16472.

llvm-svn: 185097
This commit is contained in:
Arnold Schwaighofer 2013-06-27 20:31:06 +00:00
parent ecff07c897
commit 38de7cd464
2 changed files with 258 additions and 0 deletions

View File

@ -175,6 +175,11 @@ private:
/// originated from one scalar instruction.
typedef SmallVector<Value*, 2> VectorParts;
// When we if-convert we need create edge masks. We have to cache values so
// that we don't end up with exponential recursion/IR.
typedef DenseMap<std::pair<BasicBlock*, BasicBlock*>,
VectorParts> EdgeMaskCache;
/// Add code that checks at runtime if the accessed arrays overlap.
/// Returns the comparator value or NULL if no check is needed.
Instruction *addRuntimeCheck(LoopVectorizationLegality *Legal,
@ -318,6 +323,7 @@ private:
Value *ExtendedIdx;
/// Maps scalars to widened vectors.
ValueMap WidenMap;
EdgeMaskCache MaskCache;
};
/// \brief Check if conditionally executed loads are hoistable.
@ -2166,6 +2172,12 @@ InnerLoopVectorizer::createEdgeMask(BasicBlock *Src, BasicBlock *Dst) {
assert(std::find(pred_begin(Dst), pred_end(Dst), Src) != pred_end(Dst) &&
"Invalid edge");
// Look for cached value.
std::pair<BasicBlock*, BasicBlock*> Edge(Src, Dst);
EdgeMaskCache::iterator ECEntryIt = MaskCache.find(Edge);
if (ECEntryIt != MaskCache.end())
return ECEntryIt->second;
VectorParts SrcMask = createBlockInMask(Src);
// The terminator has to be a branch inst!
@ -2181,9 +2193,12 @@ InnerLoopVectorizer::createEdgeMask(BasicBlock *Src, BasicBlock *Dst) {
for (unsigned part = 0; part < UF; ++part)
EdgeMask[part] = Builder.CreateAnd(EdgeMask[part], SrcMask[part]);
MaskCache[Edge] = EdgeMask;
return EdgeMask;
}
MaskCache[Edge] = SrcMask;
return SrcMask;
}

View File

@ -0,0 +1,243 @@
; RUN: opt -S -loop-vectorize < %s | FileCheck %s
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-S128"
target triple = "x86_64-apple-macosx10.9.0"
@a = global i32* null, align 8
@b = global i32* null, align 8
@c = global i32* null, align 8
; Don't create an exponetial IR for the edge masks needed when if-converting
; this code.
; PR16472
; CHECK-NOT: %6000000 =
define void @_Z3fn4i(i32 %p1) {
entry:
%cmp88 = icmp sgt i32 %p1, 0
br i1 %cmp88, label %for.body.lr.ph, label %for.end
for.body.lr.ph:
%0 = load i32** @b, align 8 %1 = load i32** @a, align 8 %2 = load i32** @c, align 8 br label %for.body
for.body:
%indvars.iv = phi i64 [ 0, %for.body.lr.ph ], [ %indvars.iv.next, %_ZL3fn3ii.exit58 ]
%arrayidx = getelementptr inbounds i32* %0, i64 %indvars.iv
%3 = load i32* %arrayidx, align 4 %4 = trunc i64 %indvars.iv to i32
%and.i = and i32 %4, 1
%tobool.i.i = icmp eq i32 %and.i, 0
br i1 %tobool.i.i, label %if.end.i, label %if.then.i
if.then.i:
%and.i.i = lshr i32 %3, 2
%and.lobit.i.i = and i32 %and.i.i, 1
%5 = xor i32 %and.lobit.i.i, 1
%or.i.i = or i32 %5, %3
%cmp.i = icmp sgt i32 %or.i.i, 0
%conv.i = zext i1 %cmp.i to i32
br label %if.end.i
if.end.i:
%tobool.i87 = phi i1 [ true, %if.then.i ], [ false, %for.body ]
%p1.addr.0.i = phi i32 [ %conv.i, %if.then.i ], [ %3, %for.body ]
%6 = trunc i64 %indvars.iv to i32
%and1.i = and i32 %6, 7
%tobool2.i = icmp eq i32 %and1.i, 0
br i1 %tobool2.i, label %if.end7.i, label %if.then3.i
if.then3.i:
%p1.addr.0.lobit.i = lshr i32 %p1.addr.0.i, 31
%and6.i = and i32 %p1.addr.0.i, 1
%or.i = or i32 %p1.addr.0.lobit.i, %and6.i
br label %if.end7.i
if.end7.i:
%p1.addr.1.i = phi i32 [ %or.i, %if.then3.i ], [ %p1.addr.0.i, %if.end.i ]
br i1 %tobool.i87, label %if.then10.i, label %if.end13.i
if.then10.i:
%cmp11.i = icmp sgt i32 %p1.addr.1.i, 0
%conv12.i = zext i1 %cmp11.i to i32
br label %if.end13.i
if.end13.i:
%p1.addr.2.i = phi i32 [ %conv12.i, %if.then10.i ], [ %p1.addr.1.i, %if.end7.i ]
br i1 %tobool.i.i, label %_Z3fn2iii.exit, label %if.then16.i
if.then16.i:
%and17.i = lshr i32 %p1.addr.2.i, 3
%and17.lobit.i = and i32 %and17.i, 1
br label %_Z3fn2iii.exit
_Z3fn2iii.exit:
%p1.addr.3.i = phi i32 [ %and17.lobit.i, %if.then16.i ], [ %p1.addr.2.i, %if.end13.i ]
%7 = trunc i64 %indvars.iv to i32
%shr.i = ashr i32 %7, 1
%and.i18.i = and i32 %shr.i, 1
%tobool.i19.i = icmp ne i32 %and.i18.i, 0
br i1 %tobool.i19.i, label %if.then.i20.i, label %if.end.i.i
if.then.i20.i:
%cmp.i.i = icmp sgt i32 %p1.addr.3.i, 0
%conv.i.i = zext i1 %cmp.i.i to i32
br label %if.end.i.i
if.end.i.i:
%p1.addr.0.i21.i = phi i32 [ %conv.i.i, %if.then.i20.i ], [ %p1.addr.3.i, %_Z3fn2iii.exit ]
%and1.i.i = and i32 %shr.i, 7
%tobool2.i.i = icmp eq i32 %and1.i.i, 0
br i1 %tobool2.i.i, label %if.end7.i.i, label %if.then3.i.i
if.then3.i.i:
%p1.addr.0.lobit.i.i = lshr i32 %p1.addr.0.i21.i, 31
%and6.i.i = and i32 %p1.addr.0.i21.i, 1
%or.i22.i = or i32 %p1.addr.0.lobit.i.i, %and6.i.i
br label %if.end7.i.i
if.end7.i.i:
%p1.addr.1.i.i = phi i32 [ %or.i22.i, %if.then3.i.i ], [ %p1.addr.0.i21.i, %if.end.i.i ]
br i1 %tobool.i19.i, label %if.then10.i.i, label %if.end13.i.i
if.then10.i.i:
%cmp11.i.i = icmp sgt i32 %p1.addr.1.i.i, 0
%conv12.i.i = zext i1 %cmp11.i.i to i32
br label %if.end13.i.i
if.end13.i.i:
%p1.addr.2.i.i = phi i32 [ %conv12.i.i, %if.then10.i.i ], [ %p1.addr.1.i.i, %if.end7.i.i ]
%and14.i.i = and i32 %shr.i, 5
%tobool15.i.i = icmp eq i32 %and14.i.i, 0
br i1 %tobool15.i.i, label %_Z3fn2iii.exit.i, label %if.then16.i.i
if.then16.i.i:
%and17.i.i = lshr i32 %p1.addr.2.i.i, 3
%and17.lobit.i.i = and i32 %and17.i.i, 1
br label %_Z3fn2iii.exit.i
_Z3fn2iii.exit.i:
%p1.addr.3.i.i = phi i32 [ %and17.lobit.i.i, %if.then16.i.i ], [ %p1.addr.2.i.i, %if.end13.i.i ]
%8 = trunc i64 %indvars.iv to i32
%tobool.i11.i = icmp eq i32 %8, 0
br i1 %tobool.i11.i, label %_ZL3fn3ii.exit, label %if.then.i15.i
if.then.i15.i:
%and.i12.i = lshr i32 %p1.addr.3.i.i, 2
%and.lobit.i13.i = and i32 %and.i12.i, 1
%9 = xor i32 %and.lobit.i13.i, 1
%or.i14.i = or i32 %9, %p1.addr.3.i.i
br label %_ZL3fn3ii.exit
_ZL3fn3ii.exit:
%p1.addr.0.i16.i = phi i32 [ %or.i14.i, %if.then.i15.i ], [ %p1.addr.3.i.i, %_Z3fn2iii.exit.i ]
%arrayidx2 = getelementptr inbounds i32* %1, i64 %indvars.iv
store i32 %p1.addr.0.i16.i, i32* %arrayidx2, align 4 %arrayidx4 = getelementptr inbounds i32* %0, i64 %indvars.iv
%10 = load i32* %arrayidx4, align 4 br i1 %tobool.i.i, label %_Z3fn1ii.exit.i26, label %if.then.i.i21
if.then.i.i21:
%and.i.i18 = lshr i32 %10, 2
%and.lobit.i.i19 = and i32 %and.i.i18, 1
%11 = xor i32 %and.lobit.i.i19, 1
%or.i.i20 = or i32 %11, %10
br label %_Z3fn1ii.exit.i26
_Z3fn1ii.exit.i26:
%p1.addr.0.i.i22 = phi i32 [ %or.i.i20, %if.then.i.i21 ], [ %10, %_ZL3fn3ii.exit ]
br i1 %tobool.i87, label %if.then.i63, label %if.end.i67
if.then.i63:
%cmp.i61 = icmp sgt i32 %p1.addr.0.i.i22, 0
%conv.i62 = zext i1 %cmp.i61 to i32
br label %if.end.i67
if.end.i67:
%p1.addr.0.i64 = phi i32 [ %conv.i62, %if.then.i63 ], [ %p1.addr.0.i.i22, %_Z3fn1ii.exit.i26 ]
br i1 %tobool2.i, label %if.end7.i73, label %if.then3.i71
if.then3.i71:
%p1.addr.0.lobit.i68 = lshr i32 %p1.addr.0.i64, 31
%and6.i69 = and i32 %p1.addr.0.i64, 1
%or.i70 = or i32 %p1.addr.0.lobit.i68, %and6.i69
br label %if.end7.i73
if.end7.i73:
%p1.addr.1.i72 = phi i32 [ %or.i70, %if.then3.i71 ], [ %p1.addr.0.i64, %if.end.i67 ]
br i1 %tobool.i87, label %if.then10.i76, label %if.end13.i80
if.then10.i76:
%cmp11.i74 = icmp sgt i32 %p1.addr.1.i72, 0
%conv12.i75 = zext i1 %cmp11.i74 to i32
br label %if.end13.i80
if.end13.i80:
%p1.addr.2.i77 = phi i32 [ %conv12.i75, %if.then10.i76 ], [ %p1.addr.1.i72, %if.end7.i73 ]
br i1 %tobool.i.i, label %_Z3fn2iii.exit85, label %if.then16.i83
if.then16.i83:
%and17.i81 = lshr i32 %p1.addr.2.i77, 3
%and17.lobit.i82 = and i32 %and17.i81, 1
br label %_Z3fn2iii.exit85
_Z3fn2iii.exit85:
%p1.addr.3.i84 = phi i32 [ %and17.lobit.i82, %if.then16.i83 ], [ %p1.addr.2.i77, %if.end13.i80 ]
br i1 %tobool.i19.i, label %if.then.i20.i29, label %if.end.i.i33
if.then.i20.i29:
%cmp.i.i27 = icmp sgt i32 %p1.addr.3.i84, 0
%conv.i.i28 = zext i1 %cmp.i.i27 to i32
br label %if.end.i.i33
if.end.i.i33:
%p1.addr.0.i21.i30 = phi i32 [ %conv.i.i28, %if.then.i20.i29 ], [ %p1.addr.3.i84, %_Z3fn2iii.exit85 ]
br i1 %tobool2.i.i, label %if.end7.i.i39, label %if.then3.i.i37
if.then3.i.i37:
%p1.addr.0.lobit.i.i34 = lshr i32 %p1.addr.0.i21.i30, 31
%and6.i.i35 = and i32 %p1.addr.0.i21.i30, 1
%or.i22.i36 = or i32 %p1.addr.0.lobit.i.i34, %and6.i.i35
br label %if.end7.i.i39
if.end7.i.i39:
%p1.addr.1.i.i38 = phi i32 [ %or.i22.i36, %if.then3.i.i37 ], [ %p1.addr.0.i21.i30, %if.end.i.i33 ]
br i1 %tobool.i19.i, label %if.then10.i.i42, label %if.end13.i.i46
if.then10.i.i42:
%cmp11.i.i40 = icmp sgt i32 %p1.addr.1.i.i38, 0
%conv12.i.i41 = zext i1 %cmp11.i.i40 to i32
br label %if.end13.i.i46
if.end13.i.i46:
%p1.addr.2.i.i43 = phi i32 [ %conv12.i.i41, %if.then10.i.i42 ], [ %p1.addr.1.i.i38, %if.end7.i.i39 ]
br i1 %tobool15.i.i, label %_Z3fn2iii.exit.i52, label %if.then16.i.i49
if.then16.i.i49:
%and17.i.i47 = lshr i32 %p1.addr.2.i.i43, 3
%and17.lobit.i.i48 = and i32 %and17.i.i47, 1
br label %_Z3fn2iii.exit.i52
_Z3fn2iii.exit.i52:
%p1.addr.3.i.i50 = phi i32 [ %and17.lobit.i.i48, %if.then16.i.i49 ], [ %p1.addr.2.i.i43, %if.end13.i.i46 ]
br i1 %tobool.i11.i, label %_ZL3fn3ii.exit58, label %if.then.i15.i56
if.then.i15.i56:
%and.i12.i53 = lshr i32 %p1.addr.3.i.i50, 2
%and.lobit.i13.i54 = and i32 %and.i12.i53, 1
%12 = xor i32 %and.lobit.i13.i54, 1
%or.i14.i55 = or i32 %12, %p1.addr.3.i.i50
br label %_ZL3fn3ii.exit58
_ZL3fn3ii.exit58:
%p1.addr.0.i16.i57 = phi i32 [ %or.i14.i55, %if.then.i15.i56 ], [ %p1.addr.3.i.i50, %_Z3fn2iii.exit.i52 ]
%arrayidx7 = getelementptr inbounds i32* %2, i64 %indvars.iv
store i32 %p1.addr.0.i16.i57, i32* %arrayidx7, align 4 %indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp ne i32 %lftr.wideiv, %p1
br i1 %exitcond, label %for.body, label %for.cond.for.end_crit_edge
for.cond.for.end_crit_edge:
br label %for.end
for.end:
ret void
}