diff options
| -rw-r--r-- | llvm/lib/Transforms/IPO/FunctionAttrs.cpp | 33 | ||||
| -rw-r--r-- | llvm/test/Transforms/FunctionAttrs/writeonly.ll | 30 |
2 files changed, 52 insertions, 11 deletions
diff --git a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp index 5ccd8bc4b0f..0e923a717e6 100644 --- a/llvm/lib/Transforms/IPO/FunctionAttrs.cpp +++ b/llvm/lib/Transforms/IPO/FunctionAttrs.cpp @@ -664,6 +664,25 @@ static bool addArgumentAttrsFromCallsites(Function &F) { return Changed; } +static bool addReadAttr(Argument *A, Attribute::AttrKind R) { + assert((R == Attribute::ReadOnly || R == Attribute::ReadNone) + && "Must be a Read attribute."); + assert(A && "Argument must not be null."); + + // If the argument already has the attribute, nothing needs to be done. + if (A->hasAttribute(R)) + return false; + + // Otherwise, remove potentially conflicting attribute, add the new one, + // and update statistics. + A->removeAttr(Attribute::WriteOnly); + A->removeAttr(Attribute::ReadOnly); + A->removeAttr(Attribute::ReadNone); + A->addAttr(R); + R == Attribute::ReadOnly ? ++NumReadOnlyArg : ++NumReadNoneArg; + return true; +} + /// Deduce nocapture attributes for the SCC. static bool addArgumentAttrs(const SCCNodeSet &SCCNodes) { bool Changed = false; @@ -732,11 +751,8 @@ static bool addArgumentAttrs(const SCCNodeSet &SCCNodes) { SmallPtrSet<Argument *, 8> Self; Self.insert(&*A); Attribute::AttrKind R = determinePointerReadAttrs(&*A, Self); - if (R != Attribute::None) { - A->addAttr(R); - Changed = true; - R == Attribute::ReadOnly ? ++NumReadOnlyArg : ++NumReadNoneArg; - } + if (R != Attribute::None) + Changed = addReadAttr(A, R); } } } @@ -833,12 +849,7 @@ static bool addArgumentAttrs(const SCCNodeSet &SCCNodes) { if (ReadAttr != Attribute::None) { for (unsigned i = 0, e = ArgumentSCC.size(); i != e; ++i) { Argument *A = ArgumentSCC[i]->Definition; - // Clear out existing readonly/readnone attributes - A->removeAttr(Attribute::ReadOnly); - A->removeAttr(Attribute::ReadNone); - A->addAttr(ReadAttr); - ReadAttr == Attribute::ReadOnly ? ++NumReadOnlyArg : ++NumReadNoneArg; - Changed = true; + Changed = addReadAttr(A, ReadAttr); } } } diff --git a/llvm/test/Transforms/FunctionAttrs/writeonly.ll b/llvm/test/Transforms/FunctionAttrs/writeonly.ll new file mode 100644 index 00000000000..6514cd9d106 --- /dev/null +++ b/llvm/test/Transforms/FunctionAttrs/writeonly.ll @@ -0,0 +1,30 @@ +; RUN: opt < %s -functionattrs -S | FileCheck %s +; RUN: opt < %s -passes=function-attrs -S | FileCheck %s + +; CHECK: define void @nouses-argworn-funrn(i32* nocapture readnone %.aaa) #0 { +define void @nouses-argworn-funrn(i32* writeonly %.aaa) { +nouses-argworn-funrn_entry: + ret void +} + +; CHECK: define void @nouses-argworn-funro(i32* nocapture readnone %.aaa, i32* nocapture readonly %.bbb) #1 { +define void @nouses-argworn-funro(i32* writeonly %.aaa, i32* %.bbb) { +nouses-argworn-funro_entry: + %val = load i32 , i32* %.bbb + ret void +} + +%_type_of_d-ccc = type <{ i8*, i8, i8, i8, i8 }> + +@d-ccc = internal global %_type_of_d-ccc <{ i8* null, i8 1, i8 13, i8 0, i8 -127 }>, align 8 + +; CHECK: define void @nouses-argworn-funwo(i32* nocapture readnone %.aaa) #2 { +define void @nouses-argworn-funwo(i32* writeonly %.aaa) { +nouses-argworn-funwo_entry: + store i8 0, i8* getelementptr inbounds (%_type_of_d-ccc, %_type_of_d-ccc* @d-ccc, i32 0, i32 3) + ret void +} + +; CHECK: attributes #0 = { {{.*}} readnone } +; CHECK: attributes #1 = { {{.*}} readonly } +; CHECK: attributes #2 = { {{.*}} writeonly } |
