From 9caa8f7ba7b74bce41dc37b4e9ac61096c65683e Mon Sep 17 00:00:00 2001 From: Hal Finkel Date: Tue, 16 Jul 2013 17:10:55 +0000 Subject: [PATCH] When the inliner merges allocas, it must keep the larger alignment For safety, the inliner cannot decrease the allignment on an alloca when merging it with another. I've included two variants of the test case for this: one with DataLayout available, and one without. When DataLayout is not available, if only one of the allocas uses the default alignment (getAlignment() == 0), then they cannot be safely merged. llvm-svn: 186425 --- llvm/lib/Transforms/IPO/Inliner.cpp | 18 ++++- .../Transforms/Inline/alloca-merge-align-nodl.ll | 93 +++++++++++++++++++++ llvm/test/Transforms/Inline/alloca-merge-align.ll | 94 ++++++++++++++++++++++ 3 files changed, 203 insertions(+), 2 deletions(-) create mode 100644 llvm/test/Transforms/Inline/alloca-merge-align-nodl.ll create mode 100644 llvm/test/Transforms/Inline/alloca-merge-align.ll diff --git a/llvm/lib/Transforms/IPO/Inliner.cpp b/llvm/lib/Transforms/IPO/Inliner.cpp index 663ddb7..f72121d 100644 --- a/llvm/lib/Transforms/IPO/Inliner.cpp +++ b/llvm/lib/Transforms/IPO/Inliner.cpp @@ -116,7 +116,8 @@ static void AdjustCallerSSPLevel(Function *Caller, Function *Callee) { /// any new allocas to the set if not possible. static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, InlinedArrayAllocasTy &InlinedArrayAllocas, - int InlineHistory, bool InsertLifetime) { + int InlineHistory, bool InsertLifetime, + const DataLayout *TD) { Function *Callee = CS.getCalledFunction(); Function *Caller = CS.getCaller(); @@ -189,6 +190,14 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, bool MergedAwayAlloca = false; for (unsigned i = 0, e = AllocasForType.size(); i != e; ++i) { AllocaInst *AvailableAlloca = AllocasForType[i]; + + unsigned Align1 = AI->getAlignment(), + Align2 = AvailableAlloca->getAlignment(); + // If we don't have data layout information, and only one alloca is using + // the target default, then we can't safely merge them because we can't + // pick the greater alignment. + if (!TD && (!Align1 || !Align2) && Align1 != Align2) + continue; // The available alloca has to be in the right function, not in some other // function in this SCC. @@ -206,6 +215,11 @@ static bool InlineCallIfPossible(CallSite CS, InlineFunctionInfo &IFI, << *AvailableAlloca << '\n'); AI->replaceAllUsesWith(AvailableAlloca); + + if (Align1 > Align2 || (!Align1 && TD && + TD->getABITypeAlignment(AI->getAllocatedType()) > Align2)) + AvailableAlloca->setAlignment(Align1); + AI->eraseFromParent(); MergedAwayAlloca = true; ++NumMergedAllocas; @@ -482,7 +496,7 @@ bool Inliner::runOnSCC(CallGraphSCC &SCC) { // Attempt to inline the function. if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas, - InlineHistoryID, InsertLifetime)) + InlineHistoryID, InsertLifetime, TD)) continue; ++NumInlined; diff --git a/llvm/test/Transforms/Inline/alloca-merge-align-nodl.ll b/llvm/test/Transforms/Inline/alloca-merge-align-nodl.ll new file mode 100644 index 0000000..203f52b --- /dev/null +++ b/llvm/test/Transforms/Inline/alloca-merge-align-nodl.ll @@ -0,0 +1,93 @@ +; RUN: opt < %s -inline -S | FileCheck %s +; This variant of the test has no data layout information. +target triple = "powerpc64-unknown-linux-gnu" + +%struct.s = type { i32, i32 } + +define void @foo(%struct.s* byval nocapture readonly %a) { +entry: + %x = alloca [2 x i32], align 4 + %a1 = getelementptr inbounds %struct.s* %a, i64 0, i32 0 + %0 = load i32* %a1, align 4, !tbaa !0 + %arrayidx = getelementptr inbounds [2 x i32]* %x, i64 0, i64 0 + store i32 %0, i32* %arrayidx, align 4, !tbaa !0 + %b = getelementptr inbounds %struct.s* %a, i64 0, i32 1 + %1 = load i32* %b, align 4, !tbaa !0 + %arrayidx2 = getelementptr inbounds [2 x i32]* %x, i64 0, i64 1 + store i32 %1, i32* %arrayidx2, align 4, !tbaa !0 + call void @bar(i32* %arrayidx) #2 + ret void +} + +define void @foo0(%struct.s* byval nocapture readonly %a) { +entry: + %x = alloca [2 x i32] + %a1 = getelementptr inbounds %struct.s* %a, i64 0, i32 0 + %0 = load i32* %a1, align 4, !tbaa !0 + %arrayidx = getelementptr inbounds [2 x i32]* %x, i64 0, i64 0 + store i32 %0, i32* %arrayidx, align 4, !tbaa !0 + %b = getelementptr inbounds %struct.s* %a, i64 0, i32 1 + %1 = load i32* %b, align 4, !tbaa !0 + %arrayidx2 = getelementptr inbounds [2 x i32]* %x, i64 0, i64 1 + store i32 %1, i32* %arrayidx2, align 4, !tbaa !0 + call void @bar(i32* %arrayidx) #2 + ret void +} + +declare void @bar(i32*) #1 + +define void @goo(%struct.s* byval nocapture readonly %a) { +entry: + %x = alloca [2 x i32], align 32 + %a1 = getelementptr inbounds %struct.s* %a, i64 0, i32 0 + %0 = load i32* %a1, align 4, !tbaa !0 + %arrayidx = getelementptr inbounds [2 x i32]* %x, i64 0, i64 0 + store i32 %0, i32* %arrayidx, align 32, !tbaa !0 + %b = getelementptr inbounds %struct.s* %a, i64 0, i32 1 + %1 = load i32* %b, align 4, !tbaa !0 + %arrayidx2 = getelementptr inbounds [2 x i32]* %x, i64 0, i64 1 + store i32 %1, i32* %arrayidx2, align 4, !tbaa !0 + call void @bar(i32* %arrayidx) #2 + ret void +} + +; CHECK-LABEL: @main +; CHECK: alloca [2 x i32], align 32 +; CHECK-NOT: alloca [2 x i32] +; CHECK: ret i32 0 + +define signext i32 @main() { +entry: + %a = alloca i64, align 8 + %tmpcast = bitcast i64* %a to %struct.s* + store i64 0, i64* %a, align 8 + %a1 = bitcast i64* %a to i32* + store i32 1, i32* %a1, align 8, !tbaa !0 + call void @foo(%struct.s* byval %tmpcast) + store i32 2, i32* %a1, align 8, !tbaa !0 + call void @goo(%struct.s* byval %tmpcast) + ret i32 0 +} + +; CHECK-LABEL: @test0 +; CHECK: alloca [2 x i32], align 32 +; CHECK: alloca [2 x i32] +; CHECK: ret i32 0 + +define signext i32 @test0() { +entry: + %a = alloca i64, align 8 + %tmpcast = bitcast i64* %a to %struct.s* + store i64 0, i64* %a, align 8 + %a1 = bitcast i64* %a to i32* + store i32 1, i32* %a1, align 8, !tbaa !0 + call void @foo0(%struct.s* byval %tmpcast) + store i32 2, i32* %a1, align 8, !tbaa !0 + call void @goo(%struct.s* byval %tmpcast) + ret i32 0 +} + +!0 = metadata !{metadata !"int", metadata !1} +!1 = metadata !{metadata !"omnipotent char", metadata !2} +!2 = metadata !{metadata !"Simple C/C++ TBAA"} + diff --git a/llvm/test/Transforms/Inline/alloca-merge-align.ll b/llvm/test/Transforms/Inline/alloca-merge-align.ll new file mode 100644 index 0000000..de4707d --- /dev/null +++ b/llvm/test/Transforms/Inline/alloca-merge-align.ll @@ -0,0 +1,94 @@ +; RUN: opt < %s -inline -S | FileCheck %s + +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-f128:128:128-v128:128:128-n32:64" +target triple = "powerpc64-unknown-linux-gnu" + +%struct.s = type { i32, i32 } + +define void @foo(%struct.s* byval nocapture readonly %a) { +entry: + %x = alloca [2 x i32], align 4 + %a1 = getelementptr inbounds %struct.s* %a, i64 0, i32 0 + %0 = load i32* %a1, align 4, !tbaa !0 + %arrayidx = getelementptr inbounds [2 x i32]* %x, i64 0, i64 0 + store i32 %0, i32* %arrayidx, align 4, !tbaa !0 + %b = getelementptr inbounds %struct.s* %a, i64 0, i32 1 + %1 = load i32* %b, align 4, !tbaa !0 + %arrayidx2 = getelementptr inbounds [2 x i32]* %x, i64 0, i64 1 + store i32 %1, i32* %arrayidx2, align 4, !tbaa !0 + call void @bar(i32* %arrayidx) #2 + ret void +} + +define void @foo0(%struct.s* byval nocapture readonly %a) { +entry: + %x = alloca [2 x i32] + %a1 = getelementptr inbounds %struct.s* %a, i64 0, i32 0 + %0 = load i32* %a1, align 4, !tbaa !0 + %arrayidx = getelementptr inbounds [2 x i32]* %x, i64 0, i64 0 + store i32 %0, i32* %arrayidx, align 4, !tbaa !0 + %b = getelementptr inbounds %struct.s* %a, i64 0, i32 1 + %1 = load i32* %b, align 4, !tbaa !0 + %arrayidx2 = getelementptr inbounds [2 x i32]* %x, i64 0, i64 1 + store i32 %1, i32* %arrayidx2, align 4, !tbaa !0 + call void @bar(i32* %arrayidx) #2 + ret void +} + +declare void @bar(i32*) #1 + +define void @goo(%struct.s* byval nocapture readonly %a) { +entry: + %x = alloca [2 x i32], align 32 + %a1 = getelementptr inbounds %struct.s* %a, i64 0, i32 0 + %0 = load i32* %a1, align 4, !tbaa !0 + %arrayidx = getelementptr inbounds [2 x i32]* %x, i64 0, i64 0 + store i32 %0, i32* %arrayidx, align 32, !tbaa !0 + %b = getelementptr inbounds %struct.s* %a, i64 0, i32 1 + %1 = load i32* %b, align 4, !tbaa !0 + %arrayidx2 = getelementptr inbounds [2 x i32]* %x, i64 0, i64 1 + store i32 %1, i32* %arrayidx2, align 4, !tbaa !0 + call void @bar(i32* %arrayidx) #2 + ret void +} + +; CHECK-LABEL: @main +; CHECK: alloca [2 x i32], align 32 +; CHECK-NOT: alloca [2 x i32] +; CHECK: ret i32 0 + +define signext i32 @main() { +entry: + %a = alloca i64, align 8 + %tmpcast = bitcast i64* %a to %struct.s* + store i64 0, i64* %a, align 8 + %a1 = bitcast i64* %a to i32* + store i32 1, i32* %a1, align 8, !tbaa !0 + call void @foo(%struct.s* byval %tmpcast) + store i32 2, i32* %a1, align 8, !tbaa !0 + call void @goo(%struct.s* byval %tmpcast) + ret i32 0 +} + +; CHECK-LABEL: @test0 +; CHECK: alloca [2 x i32], align 32 +; CHECK-NOT: alloca [2 x i32] +; CHECK: ret i32 0 + +define signext i32 @test0() { +entry: + %a = alloca i64, align 8 + %tmpcast = bitcast i64* %a to %struct.s* + store i64 0, i64* %a, align 8 + %a1 = bitcast i64* %a to i32* + store i32 1, i32* %a1, align 8, !tbaa !0 + call void @foo0(%struct.s* byval %tmpcast) + store i32 2, i32* %a1, align 8, !tbaa !0 + call void @goo(%struct.s* byval %tmpcast) + ret i32 0 +} + +!0 = metadata !{metadata !"int", metadata !1} +!1 = metadata !{metadata !"omnipotent char", metadata !2} +!2 = metadata !{metadata !"Simple C/C++ TBAA"} + -- 2.7.4