From 00622952ce10e762a48f281f970cbfe73cf55ea8 Mon Sep 17 00:00:00 2001 From: Devang Patel Date: Wed, 17 Sep 2008 17:53:47 +0000 Subject: [PATCH] Do not ignore iv uses outside the loop. This one slipped through cracks very well. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56284 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopIndexSplit.cpp | 22 +++++- .../LoopIndexSplit/2008-05-19-IndVar.ll | 3 +- .../LoopIndexSplit/2008-09-17-IVUse.ll | 78 +++++++++++++++++++ .../LoopIndexSplit/OneIterLoop3-2007-08-17.ll | 3 +- 4 files changed, 101 insertions(+), 5 deletions(-) create mode 100644 test/Transforms/LoopIndexSplit/2008-09-17-IVUse.ll diff --git a/lib/Transforms/Scalar/LoopIndexSplit.cpp b/lib/Transforms/Scalar/LoopIndexSplit.cpp index d8a1eb68aa3..8cafe7424d0 100644 --- a/lib/Transforms/Scalar/LoopIndexSplit.cpp +++ b/lib/Transforms/Scalar/LoopIndexSplit.cpp @@ -111,6 +111,10 @@ namespace { /// instruction then loop body is executed only for one iteration. In /// such case eliminate loop structure surrounding this loop body. For bool processOneIterationLoop(SplitInfo &SD); + + /// isOneIterationLoop - Return true if split condition is EQ and + /// the IV is not used outside the loop. + bool isOneIterationLoop(ICmpInst *CI); void updateLoopBounds(ICmpInst *CI); /// updateLoopIterationSpace - Current loop body is covered by an AND @@ -248,7 +252,7 @@ bool LoopIndexSplit::runOnLoop(Loop *IncomingLoop, LPPassManager &LPM_Ref) { SI = SplitData.erase(Delete_SI); } } - else if (CI && CI->getPredicate() == ICmpInst::ICMP_EQ) { + else if (isOneIterationLoop(CI)) { Changed = processOneIterationLoop(SD); if (Changed) { ++NumIndexSplit; @@ -276,6 +280,22 @@ bool LoopIndexSplit::runOnLoop(Loop *IncomingLoop, LPPassManager &LPM_Ref) { return Changed; } +/// isOneIterationLoop - Return true if split condition is EQ and +/// the IV is not used outside the loop. +bool LoopIndexSplit::isOneIterationLoop(ICmpInst *CI) { + if (!CI) + return false; + if (CI->getPredicate() != ICmpInst::ICMP_EQ) + return false; + + Value *Incr = IndVar->getIncomingValueForBlock(L->getLoopLatch()); + for (Value::use_iterator UI = Incr->use_begin(), E = Incr->use_end(); + UI != E; ++UI) + if (!L->contains(cast(*UI)->getParent())) + return false; + + return true; +} /// Return true if V is a induction variable or induction variable's /// increment for loop L. void LoopIndexSplit::findIndVar(Value *V, Loop *L) { diff --git a/test/Transforms/LoopIndexSplit/2008-05-19-IndVar.ll b/test/Transforms/LoopIndexSplit/2008-05-19-IndVar.ll index c4678b47ac4..5809918acff 100644 --- a/test/Transforms/LoopIndexSplit/2008-05-19-IndVar.ll +++ b/test/Transforms/LoopIndexSplit/2008-05-19-IndVar.ll @@ -1,5 +1,4 @@ -; RUN: llvm-as < %s | opt -loop-index-split | llvm-dis | grep tmp8 | count 3 -; count 3 = increment + phi + store +; RUN: llvm-as < %s | opt -loop-index-split -stats -disable-output | not grep "loop-index-split" ;PR2294 @g_2 = external global i16 ; [#uses=4] @g_5 = external global i32 ; [#uses=1] diff --git a/test/Transforms/LoopIndexSplit/2008-09-17-IVUse.ll b/test/Transforms/LoopIndexSplit/2008-09-17-IVUse.ll new file mode 100644 index 00000000000..a7a7cc23fef --- /dev/null +++ b/test/Transforms/LoopIndexSplit/2008-09-17-IVUse.ll @@ -0,0 +1,78 @@ +; RUN: llvm-as < %s | opt -loop-index-split -stats -disable-output | not grep "loop-index-split" +; PR 2791 +@g_40 = common global i32 0 ; [#uses=1] +@g_192 = common global i32 0 ; [#uses=2] +@"\01LC" = internal constant [4 x i8] c"%d\0A\00" ; <[4 x i8]*> [#uses=1] + +define void @func_29() nounwind { +entry: + %0 = load i32* @g_40, align 4 ; [#uses=1] + %1 = icmp eq i32 %0, 0 ; [#uses=1] + %g_192.promoted = load i32* @g_192 ; [#uses=0] + br i1 %1, label %entry.split.us, label %entry.split + +entry.split.us: ; preds = %entry + br label %bb.us + +bb.us: ; preds = %bb5.us, %entry.split.us + %i.0.reg2mem.0.us = phi i32 [ 0, %entry.split.us ], [ %3, %bb5.us ] ; [#uses=2] + %2 = icmp eq i32 %i.0.reg2mem.0.us, 0 ; [#uses=1] + br i1 %2, label %bb1.us, label %bb5.us + +bb5.us: ; preds = %bb1.us, %bb4.us, %bb.us + %iftmp.0.0.us = phi i32 [ 0, %bb4.us ], [ 1, %bb.us ], [ 1, %bb1.us ] ; [#uses=1] + %3 = add i32 %i.0.reg2mem.0.us, 1 ; [#uses=3] + %4 = icmp ult i32 %3, 10 ; [#uses=1] + br i1 %4, label %bb.us, label %bb8.us + +bb4.us: ; preds = %bb1.us + br label %bb5.us + +bb1.us: ; preds = %bb.us + br i1 true, label %bb4.us, label %bb5.us + +bb8.us: ; preds = %bb5.us + %iftmp.0.0.lcssa.us = phi i32 [ %iftmp.0.0.us, %bb5.us ] ; [#uses=1] + %.lcssa.us = phi i32 [ %3, %bb5.us ] ; [#uses=1] + br label %bb8.split + +entry.split: ; preds = %entry + br label %bb + +bb: ; preds = %bb5, %entry.split + %i.0.reg2mem.0 = phi i32 [ 0, %entry.split ], [ %6, %bb5 ] ; [#uses=2] + %5 = icmp eq i32 %i.0.reg2mem.0, 0 ; [#uses=1] + br i1 %5, label %bb1, label %bb5 + +bb1: ; preds = %bb + br i1 false, label %bb4, label %bb5 + +bb4: ; preds = %bb1 + br label %bb5 + +bb5: ; preds = %bb1, %bb, %bb4 + %iftmp.0.0 = phi i32 [ 0, %bb4 ], [ 1, %bb ], [ 1, %bb1 ] ; [#uses=1] + %6 = add i32 %i.0.reg2mem.0, 1 ; [#uses=3] + %7 = icmp ult i32 %6, 10 ; [#uses=1] + br i1 %7, label %bb, label %bb8 + +bb8: ; preds = %bb5 + %iftmp.0.0.lcssa = phi i32 [ %iftmp.0.0, %bb5 ] ; [#uses=1] + %.lcssa = phi i32 [ %6, %bb5 ] ; [#uses=1] + br label %bb8.split + +bb8.split: ; preds = %bb8.us, %bb8 + %iftmp.0.0.lcssa.us-lcssa = phi i32 [ %iftmp.0.0.lcssa, %bb8 ], [ %iftmp.0.0.lcssa.us, %bb8.us ] ; [#uses=1] + %.lcssa.us-lcssa = phi i32 [ %.lcssa, %bb8 ], [ %.lcssa.us, %bb8.us ] ; [#uses=1] + store i32 %iftmp.0.0.lcssa.us-lcssa, i32* @g_192 + %8 = tail call i32 (i8*, ...)* @printf( i8* getelementptr ([4 x i8]* @"\01LC", i32 0, i32 0), i32 %.lcssa.us-lcssa ) nounwind ; [#uses=0] + ret void +} + +declare i32 @printf(i8*, ...) nounwind + +define i32 @main() nounwind { +entry: + call void @func_29( ) nounwind + ret i32 0 +} diff --git a/test/Transforms/LoopIndexSplit/OneIterLoop3-2007-08-17.ll b/test/Transforms/LoopIndexSplit/OneIterLoop3-2007-08-17.ll index 9ca8923a6fa..bf568e57f24 100644 --- a/test/Transforms/LoopIndexSplit/OneIterLoop3-2007-08-17.ll +++ b/test/Transforms/LoopIndexSplit/OneIterLoop3-2007-08-17.ll @@ -1,6 +1,5 @@ ; Loop is elimianted. Save last value assignments, including induction variable. -; RUN: llvm-as < %s | opt -loop-index-split -disable-output -stats |& \ -; RUN: grep "loop-index-split" | count 1 +; RUN: llvm-as < %s | opt -loop-index-split -disable-output -stats | not grep "loop-index-split" declare i32 @foo(i32) declare i32 @bar(i32, i32) -- 2.34.1