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author | Adrian Prantl <aprantl@apple.com> | 2014-04-25 17:01:00 +0000 |
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committer | Adrian Prantl <aprantl@apple.com> | 2014-04-25 17:01:00 +0000 |
commit | 7e96d883473efa300aee116dd2451cc1f9ef9214 (patch) | |
tree | 35ad097230ecc2b0ec3c7ed37956c5476bb64944 /lib/Transforms/Utils | |
parent | e1cd93134fc2629b4be907c75bb5c7b4dd9b4657 (diff) | |
download | llvm-7e96d883473efa300aee116dd2451cc1f9ef9214.tar.gz llvm-7e96d883473efa300aee116dd2451cc1f9ef9214.tar.bz2 llvm-7e96d883473efa300aee116dd2451cc1f9ef9214.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@207235 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Utils')
-rw-r--r-- | lib/Transforms/Utils/Local.cpp | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index b3fc3dd6bb..a55971ea45 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -1051,20 +1051,26 @@ bool llvm::LowerDbgDeclare(Function &F) { AllocaInst *AI = dyn_cast_or_null<AllocaInst>(DDI->getAddress()); // If this is an alloca for a scalar variable, insert a dbg.value // at each load and store to the alloca and erase the dbg.declare. + // The dbg.values allow tracking a variable even if it is not + // stored on the stack, while the dbg.declare can only describe + // the stack slot (and at a lexical-scope granularity). Later + // passes will attempt to elide the stack slot. if (AI && !AI->isArrayAllocation()) { - - // We only remove the dbg.declare intrinsic if all uses are - // converted to dbg.value intrinsics. - bool RemoveDDI = true; for (User *U : AI->users()) if (StoreInst *SI = dyn_cast<StoreInst>(U)) ConvertDebugDeclareToDebugValue(DDI, SI, DIB); else if (LoadInst *LI = dyn_cast<LoadInst>(U)) ConvertDebugDeclareToDebugValue(DDI, LI, DIB); - else - RemoveDDI = false; - if (RemoveDDI) - DDI->eraseFromParent(); + else if (Instruction *I = dyn_cast<Instruction>(U)) { + // This is a call by-value or some other instruction that + // takes a pointer to the variable. Insert a *value* + // intrinsic that describes the alloca. + auto DbgVal = + DIB.insertDbgValueIntrinsic(AI, 0, + DIVariable(DDI->getVariable()), I); + DbgVal->setDebugLoc(I->getDebugLoc()); + } + DDI->eraseFromParent(); } } return true; |