[cfe-commits] r66707 - /cfe/trunk/lib/CodeGen/CGObjCMac.cpp
Fariborz Jahanian
fjahanian at apple.com
Wed Mar 11 13:59:06 PDT 2009
Author: fjahanian
Date: Wed Mar 11 15:59:05 2009
New Revision: 66707
URL: http://llvm.org/viewvc/llvm-project?rev=66707&view=rev
Log:
More of objc2's ivar layout bitmap (Next: specific).
Work in progress.
Modified:
cfe/trunk/lib/CodeGen/CGObjCMac.cpp
Modified: cfe/trunk/lib/CodeGen/CGObjCMac.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGObjCMac.cpp?rev=66707&r1=66706&r2=66707&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGObjCMac.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGObjCMac.cpp Wed Mar 11 15:59:05 2009
@@ -307,6 +307,8 @@
};
class CGObjCCommonMac : public CodeGen::CGObjCRuntime {
+public:
+ // FIXME - accessibility
class GC_IVAR {
public:
unsigned int ivar_bytepos;
@@ -314,13 +316,22 @@
GC_IVAR() : ivar_bytepos(0), ivar_size(0) {}
};
+ class SKIP_SCAN {
+ public:
+ unsigned int skip;
+ unsigned int scan;
+ SKIP_SCAN() : skip(0), scan(0) {}
+ };
+
protected:
CodeGen::CodeGenModule &CGM;
// FIXME! May not be needing this after all.
unsigned ObjCABI;
- llvm::SmallVector<GC_IVAR, 8> SkipIvars;
- llvm::SmallVector<GC_IVAR, 8> IvarsInfo;
+ // gc ivar layout bitmap calculation helper caches.
+ llvm::SmallVector<GC_IVAR, 16> SkipIvars;
+ llvm::SmallVector<GC_IVAR, 16> IvarsInfo;
+ llvm::SmallVector<SKIP_SCAN, 32> SkipScanIvars;
/// LazySymbols - Symbols to generate a lazy reference for. See
/// DefinedSymbols and FinishModule().
@@ -410,7 +421,8 @@
///
llvm::Constant *BuildIvarLayout(const llvm::StructLayout *Layout,
ObjCImplementationDecl *OI,
- bool ForStrongLayout);
+ bool ForStrongLayout,
+ const ObjCCommonTypesHelper &ObjCTypes);
void BuildAggrIvarLayout(const llvm::StructLayout *Layout,
const RecordDecl *RD,
@@ -2624,6 +2636,19 @@
return;
}
+static int
+IvarBytePosCompare (const void *a, const void *b)
+{
+ unsigned int sa = ((CGObjCCommonMac::GC_IVAR *)a)->ivar_bytepos;
+ unsigned int sb = ((CGObjCCommonMac::GC_IVAR *)b)->ivar_bytepos;
+
+ if (sa < sb)
+ return -1;
+ if (sa > sb)
+ return 1;
+ return 0;
+}
+
/// BuildIvarLayout - Builds ivar layout bitmap for the class
/// implementation for the __strong or __weak case.
/// The layout map displays which words in ivar list must be skipped
@@ -2641,21 +2666,159 @@
/// - __weak anything
///
llvm::Constant *CGObjCCommonMac::BuildIvarLayout(
- const llvm::StructLayout *Layout,
- ObjCImplementationDecl *OMD,
- bool ForStrongLayout) {
- int iIndex = -1;
- int iSkIndex = -1;
+ const llvm::StructLayout *Layout,
+ ObjCImplementationDecl *OMD,
+ bool ForStrongLayout,
+ const ObjCCommonTypesHelper &ObjCTypes) {
+ int Index = -1;
+ int SkIndex = -1;
bool hasUnion = false;
+ int SkipScan;
+ unsigned int WordsToScan, WordsToSkip;
std::vector<FieldDecl*> RecFields;
ObjCInterfaceDecl *OI = OMD->getClassInterface();
CGM.getContext().CollectObjCIvars(OI, RecFields);
if (RecFields.empty())
- return 0;
+ return llvm::Constant::getNullValue(ObjCTypes.Int8PtrTy);
+
BuildAggrIvarLayout (Layout, 0, RecFields, 0, ForStrongLayout,
- iIndex, iSkIndex, hasUnion);
- return 0;
+ Index, SkIndex, hasUnion);
+ if (Index == -1)
+ return llvm::Constant::getNullValue(ObjCTypes.Int8PtrTy);
+
+ // Sort on byte position in case we encounterred a union nested in
+ // the ivar list.
+ if (hasUnion && Index > 0)
+ // FIXME - Is this correct?
+ qsort(&IvarsInfo[0], Index+1, sizeof(GC_IVAR), IvarBytePosCompare);
+ if (hasUnion && SkIndex > 0)
+ qsort(&SkipIvars[0], Index+1, sizeof(GC_IVAR), IvarBytePosCompare);
+
+ // Build the string of skip/scan nibbles
+ SkipScan = -1;
+ unsigned int WordSize =
+ CGM.getTypes().getTargetData().getTypePaddedSize(ObjCTypes.Int8PtrTy);
+ if (IvarsInfo[0].ivar_bytepos == 0) {
+ WordsToSkip = 0;
+ WordsToScan = IvarsInfo[0].ivar_size;
+ }
+ else {
+ WordsToSkip = IvarsInfo[0].ivar_bytepos/WordSize;
+ WordsToScan = IvarsInfo[0].ivar_size;
+ }
+ for (int i=1; i <= Index; i++)
+ {
+ unsigned int TailPrevGCObjC =
+ IvarsInfo[i-1].ivar_bytepos + IvarsInfo[i-1].ivar_size * WordSize;
+ if (IvarsInfo[i].ivar_bytepos == TailPrevGCObjC)
+ {
+ // consecutive 'scanned' object pointers.
+ WordsToScan += IvarsInfo[i].ivar_size;
+ }
+ else
+ {
+ // Skip over 'gc'able object pointer which lay over each other.
+ if (TailPrevGCObjC > IvarsInfo[i].ivar_bytepos)
+ continue;
+ // Must skip over 1 or more words. We save current skip/scan values
+ // and start a new pair.
+ SkipScanIvars[++SkipScan].skip = WordsToSkip;
+ SkipScanIvars[SkipScan].scan = WordsToScan;
+ // Skip the hole.
+ SkipScanIvars[++SkipScan].skip =
+ (IvarsInfo[i].ivar_bytepos - TailPrevGCObjC) / WordSize;
+ SkipScanIvars[SkipScan].scan = 0;
+ WordsToSkip = 0;
+ WordsToScan = IvarsInfo[i].ivar_size;
+ }
+ }
+ if (WordsToScan > 0)
+ {
+ SkipScanIvars[++SkipScan].skip = WordsToSkip;
+ SkipScanIvars[SkipScan].scan = WordsToScan;
+ }
+
+ bool BytesSkipped = false;
+ if (SkIndex >= 0)
+ {
+ int LastByteSkipped =
+ SkipIvars[SkIndex].ivar_bytepos + SkipIvars[SkIndex].ivar_size;
+ int LastByteScanned =
+ IvarsInfo[Index].ivar_bytepos + IvarsInfo[Index].ivar_size * WordSize;
+ BytesSkipped = (LastByteSkipped > LastByteScanned);
+ // Compute number of bytes to skip at the tail end of the last ivar scanned.
+ if (BytesSkipped)
+ {
+ unsigned int TotalWords = (LastByteSkipped + (WordSize -1)) / WordSize;
+ SkipScanIvars[++SkipScan].skip = TotalWords - (LastByteScanned/WordSize);
+ SkipScanIvars[SkipScan].scan = 0;
+ }
+ }
+ // Mini optimization of nibbles such that an 0xM0 followed by 0x0N is produced
+ // as 0xMN.
+ for (int i = 0; i <= SkipScan; i++)
+ {
+ if ((i < SkipScan) && SkipScanIvars[i].skip && SkipScanIvars[i].scan == 0
+ && SkipScanIvars[i+1].skip == 0 && SkipScanIvars[i+1].scan) {
+ // 0xM0 followed by 0x0N detected.
+ SkipScanIvars[i].scan = SkipScanIvars[i+1].scan;
+ for (int j = i+1; j < SkipScan; j++)
+ SkipScanIvars[j] = SkipScanIvars[j+1];
+ --SkipScan;
+ }
+ }
+
+ // Generate the string.
+ std::string BitMap;
+ for (int i = 0; i <= SkipScan; i++)
+ {
+ unsigned char byte;
+ unsigned int skip_small = SkipScanIvars[i].skip % 0xf;
+ unsigned int scan_small = SkipScanIvars[i].scan % 0xf;
+ unsigned int skip_big = SkipScanIvars[i].skip / 0xf;
+ unsigned int scan_big = SkipScanIvars[i].scan / 0xf;
+
+ if (skip_small > 0 || skip_big > 0)
+ BytesSkipped = true;
+ // first skip big.
+ for (unsigned int ix = 0; ix < skip_big; ix++)
+ BitMap += (unsigned char)(0xf0);
+
+ // next (skip small, scan)
+ if (skip_small)
+ {
+ byte = skip_small << 4;
+ if (scan_big > 0)
+ {
+ byte |= 0xf;
+ --scan_big;
+ }
+ else if (scan_small)
+ {
+ byte |= scan_small;
+ scan_small = 0;
+ }
+ BitMap += byte;
+ }
+ // next scan big
+ for (unsigned int ix = 0; ix < scan_big; ix++)
+ BitMap += (unsigned char)(0x0f);
+ // last scan small
+ if (scan_small)
+ {
+ byte = scan_small;
+ BitMap += byte;
+ }
+ }
+ // null terminate string.
+ // BitMap += (unsigned char)0;
+ // if ivar_layout bitmap is all 1 bits (nothing skipped) then use NULL as
+ // final layout.
+ if (ForStrongLayout && !BytesSkipped)
+ return llvm::Constant::getNullValue(ObjCTypes.Int8PtrTy);
+
+ return llvm::ConstantArray::get(BitMap);
}
llvm::Constant *CGObjCCommonMac::GetMethodVarName(Selector Sel) {
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