diff options
author | Anton Korobeynikov <asl@math.spbu.ru> | 2008-06-29 17:57:03 +0000 |
---|---|---|
committer | Anton Korobeynikov <asl@math.spbu.ru> | 2008-06-29 17:57:03 +0000 |
commit | 6d116bc7ced56a820d33b0dd35ee36af8a810eab (patch) | |
tree | b9d056c655001ef42c66a3395d01233d2a499537 /lib/Analysis/ValueTracking.cpp | |
parent | 28a2b54580b28be10c536def7f49b5599adf3631 (diff) |
Revert (52748 and friends):
Move GetConstantStringInfo to lib/Analysis. Remove
string output routine from Constant. Update all
callers. Change debug intrinsic api slightly to
accomodate move of routine, these now return values
instead of strings.
This unbreaks llvm-gcc bootstrap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52884 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/ValueTracking.cpp')
-rw-r--r-- | lib/Analysis/ValueTracking.cpp | 100 |
1 files changed, 0 insertions, 100 deletions
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp index e7e291fb92..32a77e6f46 100644 --- a/lib/Analysis/ValueTracking.cpp +++ b/lib/Analysis/ValueTracking.cpp @@ -15,7 +15,6 @@ #include "llvm/Analysis/ValueTracking.h" #include "llvm/Constants.h" #include "llvm/Instructions.h" -#include "llvm/GlobalVariable.h" #include "llvm/IntrinsicInst.h" #include "llvm/Target/TargetData.h" #include "llvm/Support/GetElementPtrTypeIterator.h" @@ -931,102 +930,3 @@ Value *llvm::FindInsertedValue(Value *V, const unsigned *idx_begin, // or load instruction) return 0; } - -/// GetConstantStringInfo - This function computes the length of a -/// null-terminated C string pointed to by V. If successful, it returns true -/// and returns the string in Str. If unsuccessful, it returns false. -bool llvm::GetConstantStringInfo(Value *V, std::string &Str, uint64_t Offset, - bool StopAtNul) { - // If V is NULL then return false; - if (V == NULL) return false; - - // Look through bitcast instructions. - if (BitCastInst *BCI = dyn_cast<BitCastInst>(V)) - return GetConstantStringInfo(BCI->getOperand(0), Str, Offset, StopAtNul); - - // If the value is not a GEP instruction nor a constant expression with a - // GEP instruction, then return false because ConstantArray can't occur - // any other way - User *GEP = 0; - if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(V)) { - GEP = GEPI; - } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) { - if (CE->getOpcode() == Instruction::BitCast) - return GetConstantStringInfo(CE->getOperand(0), Str, Offset, StopAtNul); - if (CE->getOpcode() != Instruction::GetElementPtr) - return false; - GEP = CE; - } - - if (GEP) { - // Make sure the GEP has exactly three arguments. - if (GEP->getNumOperands() != 3) - return false; - - // Make sure the index-ee is a pointer to array of i8. - const PointerType *PT = cast<PointerType>(GEP->getOperand(0)->getType()); - const ArrayType *AT = dyn_cast<ArrayType>(PT->getElementType()); - if (AT == 0 || AT->getElementType() != Type::Int8Ty) - return false; - - // Check to make sure that the first operand of the GEP is an integer and - // has value 0 so that we are sure we're indexing into the initializer. - ConstantInt *FirstIdx = dyn_cast<ConstantInt>(GEP->getOperand(1)); - if (FirstIdx == 0 || !FirstIdx->isZero()) - return false; - - // If the second index isn't a ConstantInt, then this is a variable index - // into the array. If this occurs, we can't say anything meaningful about - // the string. - uint64_t StartIdx = 0; - if (ConstantInt *CI = dyn_cast<ConstantInt>(GEP->getOperand(2))) - StartIdx = CI->getZExtValue(); - else - return false; - return GetConstantStringInfo(GEP->getOperand(0), Str, StartIdx+Offset, - StopAtNul); - } - - // The GEP instruction, constant or instruction, must reference a global - // variable that is a constant and is initialized. The referenced constant - // initializer is the array that we'll use for optimization. - GlobalVariable* GV = dyn_cast<GlobalVariable>(V); - if (!GV || !GV->isConstant() || !GV->hasInitializer()) - return false; - Constant *GlobalInit = GV->getInitializer(); - - // Handle the ConstantAggregateZero case - if (isa<ConstantAggregateZero>(GlobalInit)) { - // This is a degenerate case. The initializer is constant zero so the - // length of the string must be zero. - Str.clear(); - return true; - } - - // Must be a Constant Array - ConstantArray *Array = dyn_cast<ConstantArray>(GlobalInit); - if (Array == 0 || Array->getType()->getElementType() != Type::Int8Ty) - return false; - - // Get the number of elements in the array - uint64_t NumElts = Array->getType()->getNumElements(); - - if (Offset > NumElts) - return false; - - // Traverse the constant array from 'Offset' which is the place the GEP refers - // to in the array. - Str.reserve(NumElts-Offset); - for (unsigned i = Offset; i != NumElts; ++i) { - Constant *Elt = Array->getOperand(i); - ConstantInt *CI = dyn_cast<ConstantInt>(Elt); - if (!CI) // This array isn't suitable, non-int initializer. - return false; - if (StopAtNul && CI->isZero()) - return true; // we found end of string, success! - Str += (char)CI->getZExtValue(); - } - - // The array isn't null terminated, but maybe this is a memcpy, not a strcpy. - return true; -} |