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author | Adrian Prantl <aprantl@apple.com> | 2014-04-25 00:38:40 +0000 |
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committer | Adrian Prantl <aprantl@apple.com> | 2014-04-25 00:38:40 +0000 |
commit | 50e7ba14ca8ec3a3f4bd6ca0b15dfacfda58ec06 (patch) | |
tree | 218e2a352e9633521687e77f7df0bdadeb4ab5b7 /lib/CodeGen/CodeGenPrepare.cpp | |
parent | ab6ab3c33363452bc53c119dc36ad650f6c267d7 (diff) | |
download | llvm-50e7ba14ca8ec3a3f4bd6ca0b15dfacfda58ec06.tar.gz llvm-50e7ba14ca8ec3a3f4bd6ca0b15dfacfda58ec06.tar.bz2 llvm-50e7ba14ca8ec3a3f4bd6ca0b15dfacfda58ec06.tar.xz |
This reapplies r207130 with an additional testcase+and a missing check for
AllocaInst that was missing in one location.
Debug info for optimized code: Support variables that are on the stack and
described by DBG_VALUEs during their lifetime.
Previously, when a variable was at a FrameIndex for any part of its
lifetime, this would shadow all other DBG_VALUEs and only a single
fbreg location would be emitted, which in fact is only valid for a small
range and not the entire lexical scope of the variable. The included
dbg-value-const-byref testcase demonstrates this.
This patch fixes this by
Local
- emitting dbg.value intrinsics for allocas that are passed by reference
- dropping all dbg.declares (they are now fully lowered to dbg.values)
SelectionDAG
- renamed constructors for SDDbgValue for better readability.
- fix UserValue::match() to handle indirect values correctly
- not inserting an MMI table entries for dbg.values that describe allocas.
- lowering dbg.values that describe allocas into *indirect* DBG_VALUEs.
CodeGenPrepare
- leaving dbg.values for an alloca were they are (see comment)
Other
- regenerated/updated instcombine.ll testcase and included source
rdar://problem/16679879
http://reviews.llvm.org/D3374
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207165 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/CodeGenPrepare.cpp')
-rw-r--r-- | lib/CodeGen/CodeGenPrepare.cpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/lib/CodeGen/CodeGenPrepare.cpp b/lib/CodeGen/CodeGenPrepare.cpp index 85734f715c..875615c4c3 100644 --- a/lib/CodeGen/CodeGenPrepare.cpp +++ b/lib/CodeGen/CodeGenPrepare.cpp @@ -3470,7 +3470,12 @@ bool CodeGenPrepare::PlaceDbgValues(Function &F) { for (BasicBlock::iterator BI = I->begin(), BE = I->end(); BI != BE;) { Instruction *Insn = BI; ++BI; DbgValueInst *DVI = dyn_cast<DbgValueInst>(Insn); - if (!DVI) { + // Leave dbg.values that refer to an alloca alone. These + // instrinsics describe the address of a variable (= the alloca) + // being taken. They should not be moved next to the alloca + // (and to the beginning of the scope), but rather stay close to + // where said address is used. + if (!DVI || (DVI->getValue() && isa<AllocaInst>(DVI->getValue()))) { PrevNonDbgInst = Insn; continue; } |