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author | Gerolf Hoflehner <ghoflehner@apple.com> | 2014-04-17 00:21:52 +0000 |
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committer | Gerolf Hoflehner <ghoflehner@apple.com> | 2014-04-17 00:21:52 +0000 |
commit | d6312bbbbd7739c8bfd8cc1ddad7662b1c6ee158 (patch) | |
tree | 537b7157c9c541f592812566704d12cc0113b2ce | |
parent | 0fa7dc4762d6fe0ab811f86e5d2c87231f2abcfe (diff) | |
download | llvm-d6312bbbbd7739c8bfd8cc1ddad7662b1c6ee158.tar.gz llvm-d6312bbbbd7739c8bfd8cc1ddad7662b1c6ee158.tar.bz2 llvm-d6312bbbbd7739c8bfd8cc1ddad7662b1c6ee158.tar.xz |
Inline a function when the always_inline attribute
is set even when it contains a indirect branch.
The attribute overrules correctness concerns
like the escape of a local block address.
This is for rdar://16501761
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206429 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Analysis/IPA/InlineCost.cpp | 10 | ||||
-rw-r--r-- | test/Transforms/Inline/always-inline-attribute.ll | 26 | ||||
-rw-r--r-- | test/Transforms/Inline/always-inline.ll | 2 |
3 files changed, 35 insertions, 3 deletions
diff --git a/lib/Analysis/IPA/InlineCost.cpp b/lib/Analysis/IPA/InlineCost.cpp index a803f8c3bf..683637f5b7 100644 --- a/lib/Analysis/IPA/InlineCost.cpp +++ b/lib/Analysis/IPA/InlineCost.cpp @@ -1300,8 +1300,14 @@ bool InlineCostAnalysis::isInlineViable(Function &F) { F.getAttributes().hasAttribute(AttributeSet::FunctionIndex, Attribute::ReturnsTwice); for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) { - // Disallow inlining of functions which contain an indirect branch. - if (isa<IndirectBrInst>(BI->getTerminator())) + // Disallow inlining of functions which contain an indirect branch, + // unless the always_inline attribute is set. + // The attribute serves as a assertion that no local address + // like a block label can escpape the function. + // Revisit enabling inlining for functions with indirect branches + // when a more sophisticated espape/points-to analysis becomes available. + if (isa<IndirectBrInst>(BI->getTerminator()) && + !F.hasFnAttribute(Attribute::AlwaysInline)) return false; for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE; diff --git a/test/Transforms/Inline/always-inline-attribute.ll b/test/Transforms/Inline/always-inline-attribute.ll new file mode 100644 index 0000000000..c146122e16 --- /dev/null +++ b/test/Transforms/Inline/always-inline-attribute.ll @@ -0,0 +1,26 @@ +; RUN: opt < %s -O3 -S | FileCheck %s +@gv = external global i32 + +define i32 @main() nounwind { +; CHECK-NOT: call i32 @foo + %1 = load i32* @gv, align 4 + %2 = tail call i32 @foo(i32 %1) + unreachable +} + +define internal i32 @foo(i32) alwaysinline { + br label %2 + +; <label>:2 ; preds = %8, %1 + %3 = phi i32 [ %0, %1 ], [ %10, %8 ] + %4 = phi i8* [ blockaddress(@foo, %2), %1 ], [ %6, %8 ] + %5 = icmp eq i32 %3, 1 + %6 = select i1 %5, i8* blockaddress(@foo, %8), i8* %4 + %7 = add nsw i32 %3, -1 + br label %8 + +; <label>:8 ; preds = %8, %2 + %9 = phi i32 [ %7, %2 ], [ %10, %8 ] + %10 = add nsw i32 %9, -1 + indirectbr i8* %6, [label %2, label %8] +} diff --git a/test/Transforms/Inline/always-inline.ll b/test/Transforms/Inline/always-inline.ll index a8703b8987..832e000eac 100644 --- a/test/Transforms/Inline/always-inline.ll +++ b/test/Transforms/Inline/always-inline.ll @@ -78,7 +78,7 @@ entry: ret i32 %add } -define i32 @inner5(i8* %addr) alwaysinline { +define i32 @inner5(i8* %addr) { entry: indirectbr i8* %addr, [ label %one, label %two ] |