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Make FunctionAttrs TBAA-aware. 

llvm-svn: 118417
This commit is contained in:
Dan Gohman 2010-11-08 17:12:04 +00:00
parent 601c94b309
commit 2cd1fd4a82
2 changed files with 61 additions and 12 deletions
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36
llvm/lib/Transforms/IPO/FunctionAttrs.cpp
View File

@ -23,6 +23,7 @@
#include "llvm/CallGraphSCCPass.h"
#include "llvm/GlobalVariable.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/LLVMContext.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Analysis/CaptureTracking.h"
@ -140,10 +141,14 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) {
for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
CI != CE; ++CI) {
Value *Arg = *CI;
if (Arg->getType()->isPointerTy() &&
!AA->pointsToConstantMemory(Arg, /*OrLocal=*/true))
// Writes memory. Just give up.
return false;
if (Arg->getType()->isPointerTy()) {
AliasAnalysis::Location Loc(Arg,
AliasAnalysis::UnknownSize,
I->getMetadata(LLVMContext::MD_tbaa));
if (!AA->pointsToConstantMemory(Arg, /*OrLocal=*/true))
// Writes memory. Just give up.
return false;
}
}
// Only reads and writes local memory.
continue;
@ -153,16 +158,23 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) {
}
} else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
// Ignore non-volatile loads from local memory.
if (!LI->isVolatile() &&
AA->pointsToConstantMemory(LI->getPointerOperand(),
/*OrLocal=*/true))
continue;
if (!LI->isVolatile()) {
AliasAnalysis::Location Loc(LI->getPointerOperand(),
AA->getTypeStoreSize(LI->getType()),
LI->getMetadata(LLVMContext::MD_tbaa));
if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true))
continue;
}
} else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
// Ignore non-volatile stores to local memory.
if (!SI->isVolatile() &&
AA->pointsToConstantMemory(SI->getPointerOperand(),
/*OrLocal=*/true))
continue;
if (!SI->isVolatile()) {
const Type *StoredType = SI->getValueOperand()->getType();
AliasAnalysis::Location Loc(SI->getPointerOperand(),
AA->getTypeStoreSize(StoredType),
SI->getMetadata(LLVMContext::MD_tbaa));
if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true))
continue;
}
}
// Any remaining instructions need to be taken seriously! Check if they

37
llvm/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll Normal file
View File

@ -0,0 +1,37 @@
; RUN: opt < %s -enable-tbaa -tbaa -basicaa -functionattrs -S | FileCheck %s
; FunctionAttrs should make use of TBAA.
; CHECK: define void @test0_yes(i32* nocapture %p) nounwind readnone {
define void @test0_yes(i32* %p) nounwind {
store i32 0, i32* %p, !tbaa !1
ret void
}
; CHECK: define void @test0_no(i32* nocapture %p) nounwind {
define void @test0_no(i32* %p) nounwind {
store i32 0, i32* %p, !tbaa !2
ret void
}
; CHECK: define void @test1_yes(i32* %p) nounwind readonly {
define void @test1_yes(i32* %p) nounwind {
call void @callee(i32* %p), !tbaa !1
ret void
}
; CHECK: define void @test1_no(i32* %p) nounwind {
define void @test1_no(i32* %p) nounwind {
call void @callee(i32* %p), !tbaa !2
ret void
}
declare void @callee(i32* %p) nounwind
; Root note.
!0 = metadata !{ }
; Invariant memory.
!1 = metadata !{ metadata !"foo", metadata !0, i1 1 }
; Not invariant memory.
!2 = metadata !{ metadata !"foo", metadata !0, i1 0 }