[llvm-commits] [llvm] r148288 - in /llvm/trunk: lib/Transforms/Scalar/LoopStrengthReduce.cpp test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll
Andrew Trick
atrick at apple.com
Mon Jan 16 22:45:52 PST 2012
Author: atrick
Date: Tue Jan 17 00:45:52 2012
New Revision: 148288
URL: http://llvm.org/viewvc/llvm-project?rev=148288&view=rev
Log:
LSR fix: broaden the check for loop preheaders.
It's becoming clear that LoopSimplify needs to unconditionally create loop preheaders. But that is a bigger fix. For now, continuing to hack LSR.
Fixes rdar://10701050 "Cannot split an edge from an IndirectBrInst" assert.
Added:
llvm/trunk/test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp?rev=148288&r1=148287&r2=148288&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp Tue Jan 17 00:45:52 2012
@@ -4518,11 +4518,19 @@
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;
Added: llvm/trunk/test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll?rev=148288&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll (added)
+++ llvm/trunk/test/Transforms/LoopStrengthReduce/2012-01-16-nopreheader.ll Tue Jan 17 00:45:52 2012
@@ -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
+}
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