diff options
| -rw-r--r-- | lib/Transforms/Scalar/LoopStrengthReduce.cpp | 18 | ||||
| -rw-r--r-- | test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll | 113 |
2 files changed, 126 insertions, 5 deletions
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 85f1389..baf5669 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -4518,11 +4518,19 @@ LSRInstance::LSRInstance(const TargetLowering *tli, Loop *l, Pass *P) if (!L->isLoopSimplifyForm()) return; - // All outer loops must have preheaders, or SCEVExpander may not be able to - // materialize an AddRecExpr whose Start is an outer AddRecExpr. - for (const Loop *OuterLoop = L; (OuterLoop = OuterLoop->getParentLoop());) { - if (!OuterLoop->getLoopPreheader()) - return; + // All dominating loops must have preheaders, or SCEVExpander may not be able + // to materialize an AddRecExpr whose Start is an outer AddRecExpr. + // + // FIXME: This is a little absurd. I think LoopSimplify should be taught + // to create a preheader under any circumstance. + for (DomTreeNode *Rung = DT.getNode(L->getLoopPreheader()); + Rung; Rung = Rung->getIDom()) { + BasicBlock *BB = Rung->getBlock(); + const Loop *DomLoop = LI.getLoopFor(BB); + if (DomLoop && DomLoop->getHeader() == BB) { + if (!DomLoop->getLoopPreheader()) + return; + } } // If there's no interesting work to be done, bail early. if (IU.empty()) return; diff --git a/test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll b/test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll new file mode 100644 index 0000000..3036a7e --- /dev/null +++ b/test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll @@ -0,0 +1,113 @@ +; RUN: opt -loop-reduce -S < %s | FileCheck %s +; +; <rdar://10701050> "Cannot split an edge from an IndirectBrInst" assert. + +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" +target triple = "x86_64-apple-darwin10.0.0" + +; while.cond197 is a dominates the simplified loop while.cond238 but +; has no with no preheader. +; +; CHECK: @nopreheader +; CHECK: %while.cond238 +; CHECK: phi i64 +; CHECK-NOT: phi +; CHECK: indirectbr +define void @nopreheader(i8* %end) nounwind { +entry: + br label %while.cond179 + +while.cond179: ; preds = %if.end434, %if.end369, %if.end277, %if.end165 + %s.1 = phi i8* [ undef, %if.end434 ], [ %incdec.ptr356, %if.end348 ], [ undef, %entry ] + indirectbr i8* undef, [label %land.rhs184, label %while.end453] + +land.rhs184: ; preds = %while.cond179 + indirectbr i8* undef, [label %while.end453, label %while.cond197] + +while.cond197: ; preds = %land.rhs202, %land.rhs184 + %0 = phi i64 [ %indvar.next11, %land.rhs202 ], [ 0, %land.rhs184 ] + indirectbr i8* undef, [label %land.rhs202, label %while.end215] + +land.rhs202: ; preds = %while.cond197 + %indvar.next11 = add i64 %0, 1 + indirectbr i8* undef, [label %while.end215, label %while.cond197] + +while.end215: ; preds = %land.rhs202, %while.cond197 + indirectbr i8* undef, [label %PREMATURE, label %if.end221] + +if.end221: ; preds = %while.end215 + indirectbr i8* undef, [label %while.cond238.preheader, label %lor.lhs.false227] + +lor.lhs.false227: ; preds = %if.end221 + indirectbr i8* undef, [label %while.cond238.preheader, label %if.else] + +while.cond238.preheader: ; preds = %lor.lhs.false227, %if.end221 + %tmp16 = add i64 %0, 2 + indirectbr i8* undef, [label %while.cond238] + +while.cond238: ; preds = %land.rhs243, %while.cond238.preheader + %1 = phi i64 [ %indvar.next15, %land.rhs243 ], [ 0, %while.cond238.preheader ] + %tmp36 = add i64 %tmp16, %1 + %s.3 = getelementptr i8* %s.1, i64 %tmp36 + %cmp241 = icmp ult i8* %s.3, %end + indirectbr i8* undef, [label %land.rhs243, label %while.end256] + +land.rhs243: ; preds = %while.cond238 + %indvar.next15 = add i64 %1, 1 + indirectbr i8* undef, [label %while.end256, label %while.cond238] + +while.end256: ; preds = %land.rhs243, %while.cond238 + indirectbr i8* undef, [label %PREMATURE] + +if.else: ; preds = %lor.lhs.false227 + indirectbr i8* undef, [label %if.then297, label %if.else386] + +if.then297: ; preds = %if.else + indirectbr i8* undef, [label %PREMATURE, label %if.end307] + +if.end307: ; preds = %if.then297 + indirectbr i8* undef, [label %if.end314, label %FAIL] + +if.end314: ; preds = %if.end307 + indirectbr i8* undef, [label %if.end340] + +if.end340: ; preds = %while.end334 + indirectbr i8* undef, [label %PREMATURE, label %if.end348] + +if.end348: ; preds = %if.end340 + %incdec.ptr356 = getelementptr inbounds i8* undef, i64 2 + indirectbr i8* undef, [label %while.cond179] + +if.else386: ; preds = %if.else + indirectbr i8* undef, [label %while.end453, label %if.end434] + +if.end434: ; preds = %if.then428, %if.end421 + indirectbr i8* undef, [label %while.cond179] + +while.end453: ; preds = %if.else386, %land.rhs184, %while.cond179 + indirectbr i8* undef, [label %PREMATURE, label %if.end459] + +if.end459: ; preds = %while.end453 + indirectbr i8* undef, [label %if.then465, label %FAIL] + +if.then465: ; preds = %if.end459 + indirectbr i8* undef, [label %return, label %if.then479] + +if.then479: ; preds = %if.then465 + indirectbr i8* undef, [label %return] + +FAIL: ; preds = %if.end459, %if.end307, %land.lhs.true142, %land.lhs.true131, %while.end + indirectbr i8* undef, [label %DECL_FAIL] + +PREMATURE: ; preds = %while.end453, %while.end415, %if.end340, %while.end334, %if.then297, %while.end256, %while.end215 + indirectbr i8* undef, [label %return, label %if.then495] + +if.then495: ; preds = %PREMATURE + indirectbr i8* undef, [label %return] + +DECL_FAIL: ; preds = %if.then488, %FAIL, %land.lhs.true99, %lor.lhs.false, %if.end83, %if.then39, %if.end + indirectbr i8* undef, [label %return] + +return: ; preds = %if.then512, %if.end504, %DECL_FAIL, %if.then495, %PREMATURE, %if.then479, %if.then465, %if.then69, %if.end52, %if.end19, %if.then + ret void +} |