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| author | Stephen Lin <stephenwlin@gmail.com> | 2013-04-23 16:31:56 +0000 |
|---|---|---|
| committer | Stephen Lin <stephenwlin@gmail.com> | 2013-04-23 16:31:56 +0000 |
| commit | 13aba14eb5c643234f5d756b94f30afb28f8cd5d (patch) | |
| tree | 73921fe363e92a6502e09a8ba7b1a19c27259a10 /lib/CodeGen/Analysis.cpp | |
| parent | 120cf5743b03d67d9f26ae05c2b79d98cc05f79d (diff) | |
Add some constraints to use of 'returned':
1) Disallow 'returned' on parameter that is also 'sret' (no sensible semantics, as far as I can tell).
2) Conservatively disallow tail calls through 'returned' parameters that also are 'zext' or 'sext' (for consistency with treatment of other zero-extending and sign-extending operations in tail call position detection...can be revised later to handle situations that can be determined to be safe).
This is a new attribute that is not yet used, so there is no impact.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180118 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/Analysis.cpp')
| -rw-r--r-- | lib/CodeGen/Analysis.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/CodeGen/Analysis.cpp b/lib/CodeGen/Analysis.cpp index 4731af5089..e2b2067b0c 100644 --- a/lib/CodeGen/Analysis.cpp +++ b/lib/CodeGen/Analysis.cpp @@ -269,6 +269,8 @@ static bool sameNoopInput(const Value *V1, const Value *V2, i != e; ++i) { unsigned attrInd = i - I->op_begin() + 1; if (cast<CallInst>(I)->paramHasAttr(attrInd, Attribute::Returned) && + !cast<CallInst>(I)->paramHasAttr(attrInd, Attribute::ZExt) && + !cast<CallInst>(I)->paramHasAttr(attrInd, Attribute::SExt) && isNoopBitcast((*i)->getType(), I->getType(), TLI)) { NoopInput = *i; break; @@ -282,6 +284,8 @@ static bool sameNoopInput(const Value *V1, const Value *V2, i != e; ++i) { unsigned attrInd = i - I->op_begin() + 1; if (cast<InvokeInst>(I)->paramHasAttr(attrInd, Attribute::Returned) && + !cast<InvokeInst>(I)->paramHasAttr(attrInd, Attribute::ZExt) && + !cast<InvokeInst>(I)->paramHasAttr(attrInd, Attribute::SExt) && isNoopBitcast((*i)->getType(), I->getType(), TLI)) { NoopInput = *i; break; |