6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-04-06 09:44:39 +00:00
Code Issues Projects Releases Wiki Activity

Remove unused function.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52749 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eric Christopher 2008-06-26 01:19:35 +00:00
parent 0d2b0aba42
commit 872a738775
1 changed files with 1 additions and 82 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

83
lib/Transforms/Scalar/SimplifyLibCalls.cpp
View File

@ -23,6 +23,7 @@
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/Support/IRBuilder.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Target/TargetData.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/StringMap.h"
@ -229,88 +230,6 @@ void LibCallOptimization::EmitFWrite(Value *Ptr, Value *Size, Value *File,
// Helper Functions
//===----------------------------------------------------------------------===//
/// 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.
static bool GetConstantStringInfo(Value *V, std::string &Str) {
// Look bitcast instructions.
if (BitCastInst *BCI = dyn_cast<BitCastInst>(V))
return GetConstantStringInfo(BCI->getOperand(0), Str);
// 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::GetElementPtr)
return false;
GEP = CE;
} else {
return false;
}
// Make sure the GEP has exactly three arguments.
if (GEP->getNumOperands() != 3)
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.
if (ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(1))) {
if (!Idx->isZero())
return false;
} else
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;
// 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>(GEP->getOperand(0));
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();
// Traverse the constant array from StartIdx (derived above) which is
// the place the GEP refers to in the array.
for (unsigned i = StartIdx; 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 (CI->isZero())
return true; // we found end of string, success!
Str += (char)CI->getZExtValue();
}
return false; // The array isn't null terminated.
}
/// GetStringLengthH - If we can compute the length of the string pointed to by
/// the specified pointer, return 'len+1'. If we can't, return 0.
static uint64_t GetStringLengthH(Value *V, SmallPtrSet<PHINode*, 32> &PHIs) {