From 1851db6b0f9ef1b85d14b24eb9f838748396352f Mon Sep 17 00:00:00 2001 From: Devang Patel Date: Thu, 5 Feb 2009 19:15:39 +0000 Subject: [PATCH] Ignore dbg intrinsics while propagating conditional expression info. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63876 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Transforms/Utils/Local.h | 8 ++++ lib/Transforms/Scalar/CondPropagate.cpp | 4 +- lib/Transforms/Utils/Local.cpp | 17 +++++++++ lib/Transforms/Utils/SimplifyCFG.cpp | 14 ------- test/Transforms/CondProp/basictest-dbg.ll | 45 +++++++++++++++++++++++ 5 files changed, 72 insertions(+), 16 deletions(-) create mode 100644 test/Transforms/CondProp/basictest-dbg.ll diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h index 35d2c0ce7e0..2032d548714 100644 --- a/include/llvm/Transforms/Utils/Local.h +++ b/include/llvm/Transforms/Utils/Local.h @@ -39,6 +39,14 @@ template class SmallVectorImpl; /// bool ConstantFoldTerminator(BasicBlock *BB); +//===----------------------------------------------------------------------===// +// CFG Simplification +// + +/// isTerminatorFirstRelevantInsn - Return true if Term is very first +/// instruction ignoring Phi nodes and dbg intrinsics. +bool isTerminatorFirstRelevantInsn(BasicBlock *BB, Instruction *Term); + //===----------------------------------------------------------------------===// // Local dead code elimination. // diff --git a/lib/Transforms/Scalar/CondPropagate.cpp b/lib/Transforms/Scalar/CondPropagate.cpp index f68fb292e4a..1b755171c31 100644 --- a/lib/Transforms/Scalar/CondPropagate.cpp +++ b/lib/Transforms/Scalar/CondPropagate.cpp @@ -137,7 +137,7 @@ void CondProp::SimplifyPredecessors(BranchInst *BI) { if (!PN->hasOneUse()) return; BasicBlock *BB = BI->getParent(); - if (&*BB->begin() != PN || &*next(BB->begin()) != BI) + if (!isTerminatorFirstRelevantInsn (BB, BI)) return; // Ok, we have this really simple case, walk the PHI operands, looking for @@ -171,7 +171,7 @@ void CondProp::SimplifyPredecessors(SwitchInst *SI) { if (!PN->hasOneUse()) return; BasicBlock *BB = SI->getParent(); - if (&*BB->begin() != PN || &*next(BB->begin()) != SI) + if (!isTerminatorFirstRelevantInsn (BB, SI)) return; bool RemovedPreds = false; diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index c22485342e0..aa6efe80b32 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -148,6 +148,23 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB) { return false; } +//===----------------------------------------------------------------------===// +// CFG Simplification +// + +/// isTerminatorFirstRelevantInsn - Return true if Term is very first +/// instruction ignoring Phi nodes and dbg intrinsics. +bool llvm::isTerminatorFirstRelevantInsn(BasicBlock *BB, Instruction *Term) { + BasicBlock::iterator BBI = Term; + while (BBI != BB->begin()) { + --BBI; + if (!isa(BBI)) + break; + } + if (isa(BBI) || &*BBI == Term) + return true; + return false; +} //===----------------------------------------------------------------------===// // Local dead code elimination... diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp index d9c4b69e6de..0248d3d0ca0 100644 --- a/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1330,20 +1330,6 @@ static bool FoldTwoEntryPHINode(PHINode *PN) { return true; } -/// isTerminatorFirstRelevantInsn - Return true if Term is very first -/// instruction ignoring Phi nodes and dbg intrinsics. -static bool isTerminatorFirstRelevantInsn(BasicBlock *BB, Instruction *Term) { - BasicBlock::iterator BBI = Term; - while (BBI != BB->begin()) { - --BBI; - if (!isa(BBI)) - break; - } - if (isa(BBI) || &*BBI == Term) - return true; - return false; -} - /// SimplifyCondBranchToTwoReturns - If we found a conditional branch that goes /// to two returning blocks, try to merge them together into one return, /// introducing a select if the return values disagree. diff --git a/test/Transforms/CondProp/basictest-dbg.ll b/test/Transforms/CondProp/basictest-dbg.ll new file mode 100644 index 00000000000..d8a680b8984 --- /dev/null +++ b/test/Transforms/CondProp/basictest-dbg.ll @@ -0,0 +1,45 @@ +; RUN: llvm-as < %s | opt -condprop | llvm-dis | \ +; RUN: not grep {br label} + + %llvm.dbg.anchor.type = type { i32, i32 } + %llvm.dbg.compile_unit.type = type { i32, { }*, i32, i8*, i8*, i8*, i1, i1, i8* } + +@llvm.dbg.compile_units = linkonce constant %llvm.dbg.anchor.type { i32 458752, i32 17 }, section "llvm.metadata" ; + +@.str = internal constant [4 x i8] c"a.c\00", section "llvm.metadata" ; <[4 x i8]*> [#uses=1] +@.str1 = internal constant [6 x i8] c"/tmp/\00", section "llvm.metadata" ; <[6 x i8]*> [#uses=1] +@.str2 = internal constant [55 x i8] c"4.2.1 (Based on Apple Inc. build 5636) (LLVM build 00)\00", section "llvm.metadata" ; <[55 x i8]*> [#uses=1] +@llvm.dbg.compile_unit = internal constant %llvm.dbg.compile_unit.type { i32 458769, { }* bitcast (%llvm.dbg.anchor.type* @llvm.dbg.compile_units to { }*), i32 1, i8* getelementptr ([4 x i8]* @.str, i32 0, i32 0), i8* getelementptr ([6 x i8]* @.str1, i32 0, i32 0), i8* getelementptr ([55 x i8]* @.str2, i32 0, i32 0), i1 true, i1 false, i8* null }, section "llvm.metadata" ; <%llvm.dbg.compile_unit.type*> [#uses=1] + +declare void @llvm.dbg.stoppoint(i32, i32, { }*) nounwind + + +define i32 @test(i1 %C) { + br i1 %C, label %T1, label %F1 + +T1: ; preds = %0 +call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*)) + br label %Cont + +F1: ; preds = %0 +call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*)) + br label %Cont + +Cont: ; preds = %F1, %T1 + %C2 = phi i1 [ false, %F1 ], [ true, %T1 ] ; [#uses=1] +call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*)) + br i1 %C2, label %T2, label %F2 + +T2: ; preds = %Cont +call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*)) + call void @bar( ) +call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*)) + ret i32 17 + +F2: ; preds = %Cont +call void @llvm.dbg.stoppoint(i32 5, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*)) + ret i32 1 +} + +declare void @bar() + -- 2.34.1