[llvm] r321961 - [CodeExtractor] Use subset of function attributes for extracted function.
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Sun Jan 7 03:22:25 PST 2018
Author: fhahn
Date: Sun Jan 7 03:22:25 2018
New Revision: 321961
URL: http://llvm.org/viewvc/llvm-project?rev=321961&view=rev
Log:
[CodeExtractor] Use subset of function attributes for extracted function.
In addition to target-dependent attributes, we can also preserve a
white-listed subset of target independent function attributes. The white-list
excludes problematic attributes, most prominently:
* attributes related to memory accesses, as alloca instructions
could be moved in/out of the extracted block
* control-flow dependent attributes, like no_return or thunk, as the
relerelevant instructions might or might not get extracted.
Thanks @efriedma and @aemerson for providing a set of attributes that cannot be
propagated.
Reviewers: efriedma, davidxl, davide, silvas
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D41334
Added:
llvm/trunk/test/Transforms/CodeExtractor/PartialInlineAttributes.ll
Modified:
llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp
Modified: llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp?rev=321961&r1=321960&r2=321961&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/CodeExtractor.cpp Sun Jan 7 03:22:25 2018
@@ -620,16 +620,86 @@ Function *CodeExtractor::constructFuncti
if (oldFunction->hasUWTable())
newFunction->setHasUWTable();
- // Inherit all of the target dependent attributes.
+ // Inherit all of the target dependent attributes and white-listed
+ // target independent attributes.
// (e.g. If the extracted region contains a call to an x86.sse
// instruction we need to make sure that the extracted region has the
// "target-features" attribute allowing it to be lowered.
// FIXME: This should be changed to check to see if a specific
// attribute can not be inherited.
- AttrBuilder AB(oldFunction->getAttributes().getFnAttributes());
- for (const auto &Attr : AB.td_attrs())
- newFunction->addFnAttr(Attr.first, Attr.second);
+ for (const auto &Attr : oldFunction->getAttributes().getFnAttributes()) {
+ if (Attr.isStringAttribute()) {
+ if (Attr.getKindAsString() == "thunk")
+ continue;
+ } else
+ switch (Attr.getKindAsEnum()) {
+ // Those attributes cannot be propagated safely. Explicitly list them
+ // here so we get a warning if new attributes are added. This list also
+ // includes non-function attributes.
+ case Attribute::Alignment:
+ case Attribute::AllocSize:
+ case Attribute::ArgMemOnly:
+ case Attribute::Builtin:
+ case Attribute::ByVal:
+ case Attribute::Convergent:
+ case Attribute::Dereferenceable:
+ case Attribute::DereferenceableOrNull:
+ case Attribute::InAlloca:
+ case Attribute::InReg:
+ case Attribute::InaccessibleMemOnly:
+ case Attribute::InaccessibleMemOrArgMemOnly:
+ case Attribute::JumpTable:
+ case Attribute::Naked:
+ case Attribute::Nest:
+ case Attribute::NoAlias:
+ case Attribute::NoBuiltin:
+ case Attribute::NoCapture:
+ case Attribute::NoReturn:
+ case Attribute::None:
+ case Attribute::NonNull:
+ case Attribute::ReadNone:
+ case Attribute::ReadOnly:
+ case Attribute::Returned:
+ case Attribute::ReturnsTwice:
+ case Attribute::SExt:
+ case Attribute::Speculatable:
+ case Attribute::StackAlignment:
+ case Attribute::StructRet:
+ case Attribute::SwiftError:
+ case Attribute::SwiftSelf:
+ case Attribute::WriteOnly:
+ case Attribute::ZExt:
+ case Attribute::EndAttrKinds:
+ continue;
+ // Those attributes should be safe to propagate to the extracted function.
+ case Attribute::AlwaysInline:
+ case Attribute::Cold:
+ case Attribute::NoRecurse:
+ case Attribute::InlineHint:
+ case Attribute::MinSize:
+ case Attribute::NoDuplicate:
+ case Attribute::NoImplicitFloat:
+ case Attribute::NoInline:
+ case Attribute::NonLazyBind:
+ case Attribute::NoRedZone:
+ case Attribute::NoUnwind:
+ case Attribute::OptimizeNone:
+ case Attribute::OptimizeForSize:
+ case Attribute::SafeStack:
+ case Attribute::SanitizeAddress:
+ case Attribute::SanitizeMemory:
+ case Attribute::SanitizeThread:
+ case Attribute::SanitizeHWAddress:
+ case Attribute::StackProtect:
+ case Attribute::StackProtectReq:
+ case Attribute::StackProtectStrong:
+ case Attribute::StrictFP:
+ case Attribute::UWTable:
+ break;
+ }
+ newFunction->addFnAttr(Attr);
+ }
newFunction->getBasicBlockList().push_back(newRootNode);
// Create an iterator to name all of the arguments we inserted.
Added: llvm/trunk/test/Transforms/CodeExtractor/PartialInlineAttributes.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/CodeExtractor/PartialInlineAttributes.ll?rev=321961&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/CodeExtractor/PartialInlineAttributes.ll (added)
+++ llvm/trunk/test/Transforms/CodeExtractor/PartialInlineAttributes.ll Sun Jan 7 03:22:25 2018
@@ -0,0 +1,85 @@
+; RUN: opt < %s -S -partial-inliner -skip-partial-inlining-cost-analysis=true | FileCheck %s
+
+
+define i32 @callee_most(i32 %v) unnamed_addr #0 #1 {
+entry:
+ %cmp = icmp sgt i32 %v, 2000
+ br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+ br label %if.then2
+
+if.then2:
+ %sub = sub i32 %v, 10
+ br label %if.end
+
+if.end:
+ %v2 = phi i32 [ %v, %entry ], [ %sub, %if.then2 ]
+ %add = add nsw i32 %v2, 200
+ ret i32 %add
+}
+
+define i32 @callee_noinline(i32 %v) optnone noinline {
+entry:
+ %cmp = icmp sgt i32 %v, 2000
+ br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+ br label %if.then2
+
+if.then2:
+ %sub = sub i32 %v, 10
+ br label %if.end
+
+if.end:
+ %v2 = phi i32 [ %v, %entry ], [ %sub, %if.then2 ]
+ %add = add nsw i32 %v2, 200
+ ret i32 %add
+}
+
+define i32 @callee_writeonly(i32 %v) writeonly {
+entry:
+ %cmp = icmp sgt i32 %v, 2000
+ br i1 %cmp, label %if.then, label %if.end
+
+if.then:
+ br label %if.then2
+
+if.then2:
+ %sub = sub i32 %v, 10
+ br label %if.end
+
+if.end:
+ %v2 = phi i32 [ %v, %entry ], [ %sub, %if.then2 ]
+ %add = add nsw i32 %v2, 200
+ ret i32 %add
+}
+; CHECK-LABEL: @caller
+; CHECK: call void @callee_most.2_if.then(i32 %v
+; CHECK: call i32 @callee_noinline(i32 %v)
+; CHECK: call void @callee_writeonly.1_if.then(i32 %v
+define i32 @caller(i32 %v) {
+entry:
+ %c1 = call i32 @callee_most(i32 %v)
+ %c2 = call i32 @callee_noinline(i32 %v)
+ %c3 = call i32 @callee_writeonly(i32 %v)
+ ret i32 %c3
+}
+
+; CHECK: define internal void @callee_writeonly.1_if.then(i32 %v, i32* %sub.out) {
+; CHECK: define internal void @callee_most.2_if.then(i32 %v, i32* %sub.out) [[FN_ATTRS:#[0-9]+]]
+
+; attributes to preserve
+attributes #0 = {
+ inlinehint minsize noduplicate noimplicitfloat norecurse noredzone nounwind
+ nonlazybind optsize safestack sanitize_address sanitize_hwaddress sanitize_memory
+ sanitize_thread ssp sspreq sspstrong strictfp uwtable "foo"="bar"
+ "patchable-function"="prologue-short-redirect" "probe-stack"="_foo_guard" "stack-probe-size"="4096" }
+
+; CHECK: attributes [[FN_ATTRS]] = { inlinehint minsize noduplicate noimplicitfloat norecurse noredzone nounwind nonlazybind optsize safestack sanitize_address sanitize_hwaddress sanitize_memory sanitize_thread ssp sspreq sspstrong strictfp uwtable "foo"="bar" "patchable-function"="prologue-short-redirect" "probe-stack"="_foo_guard" "stack-probe-size"="4096" }
+
+; attributes to drop
+attributes #1 = {
+ alignstack=16 convergent inaccessiblememonly inaccessiblemem_or_argmemonly naked
+ noreturn readonly argmemonly returns_twice speculatable "thunk"
+}
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