From 94cfb281c31748162b621b2c7a54a892be4472ce Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sat, 31 Jan 2009 07:04:22 +0000 Subject: [PATCH] make sure to set Changed=true when instcombine hacks on the code, not doing so prevents it from properly iterating and prevents it from deleting the entire body of dce-iterate.ll llvm-svn: 63476 --- .../Scalar/InstructionCombining.cpp | 14 +++++++---- .../Transforms/InstCombine/dce-iterate.ll | 24 +++++++++++++++++++ 2 files changed, 33 insertions(+), 5 deletions(-) create mode 100644 llvm/test/Transforms/InstCombine/dce-iterate.ll diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp index 7f7592840a4d..6c571511e7cc 100644 --- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp @@ -12356,6 +12356,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { if (!I->use_empty()) I->replaceAllUsesWith(UndefValue::get(I->getType())); I->eraseFromParent(); + Changed = true; } } } @@ -12375,6 +12376,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { I->eraseFromParent(); RemoveFromWorkList(I); + Changed = true; continue; } @@ -12389,17 +12391,19 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { ++NumConstProp; I->eraseFromParent(); RemoveFromWorkList(I); + Changed = true; continue; } if (TD && I->getType()->getTypeID() == Type::VoidTyID) { // See if we can constant fold its operands. - for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) { - if (ConstantExpr *CE = dyn_cast(i)) { + for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) + if (ConstantExpr *CE = dyn_cast(i)) if (Constant *NewC = ConstantFoldConstantExpression(CE, TD)) - i->set(NewC); - } - } + if (NewC != CE) { + i->set(NewC); + Changed = true; + } } // See if we can trivially sink this instruction to a successor basic block. diff --git a/llvm/test/Transforms/InstCombine/dce-iterate.ll b/llvm/test/Transforms/InstCombine/dce-iterate.ll new file mode 100644 index 000000000000..e222970df6d8 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/dce-iterate.ll @@ -0,0 +1,24 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep {ret double .sy} + +define internal double @ScaleObjectAdd(double %sx, double %sy, double %sz) nounwind { +entry: + %sx34 = bitcast double %sx to i64 ; [#uses=1] + %sx3435 = zext i64 %sx34 to i960 ; [#uses=1] + %sy22 = bitcast double %sy to i64 ; [#uses=1] + %sy2223 = zext i64 %sy22 to i960 ; [#uses=1] + %sy222324 = shl i960 %sy2223, 320 ; [#uses=1] + %sy222324.ins = or i960 %sx3435, %sy222324 ; [#uses=1] + %sz10 = bitcast double %sz to i64 ; [#uses=1] + %sz1011 = zext i64 %sz10 to i960 ; [#uses=1] + %sz101112 = shl i960 %sz1011, 640 ; [#uses=1] + %sz101112.ins = or i960 %sy222324.ins, %sz101112 + + %a = trunc i960 %sz101112.ins to i64 ; [#uses=1] + %b = bitcast i64 %a to double ; [#uses=1] + %c = lshr i960 %sz101112.ins, 320 ; [#uses=1] + %d = trunc i960 %c to i64 ; [#uses=1] + %e = bitcast i64 %d to double ; [#uses=1] + %f = add double %b, %e + + ret double %e +}