Add a quick and dirty "loop aligner pass". x86 uses it to align its loops to 16-byte boundaries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47703 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/AsmPrinter.h b/include/llvm/CodeGen/AsmPrinter.h
index 6607afe..462c401 100644
--- a/include/llvm/CodeGen/AsmPrinter.h
+++ b/include/llvm/CodeGen/AsmPrinter.h
@@ -78,6 +78,10 @@
/// CurrentSection - The current section we are emitting to. This is
/// controlled and used by the SwitchSection method.
std::string CurrentSection;
+
+ /// IsInTextSection - True if the current section we are emitting to is a
+ /// text section.
+ bool IsInTextSection;
protected:
AsmPrinter(std::ostream &o, TargetMachine &TM, const TargetAsmInfo *T);
@@ -269,9 +273,7 @@
/// an explicit alignment requested, it will unconditionally override the
/// alignment request. However, if ForcedAlignBits is specified, this value
/// has final say: the ultimate alignment will be the max of ForcedAlignBits
- /// and the alignment computed with NumBits and the global. If UseFillExpr
- /// is true, it also emits an optional second value FillValue which the
- /// assembler uses to fill gaps to match alignment.
+ /// and the alignment computed with NumBits and the global
///
/// The algorithm is:
/// Align = NumBits;
@@ -279,8 +281,7 @@
/// Align = std::max(Align, ForcedAlignBits);
///
void EmitAlignment(unsigned NumBits, const GlobalValue *GV = 0,
- unsigned ForcedAlignBits = 0, bool UseFillExpr = false,
- unsigned FillValue = 0) const;
+ unsigned ForcedAlignBits = 0) const;
/// printLabel - This method prints a local label used by debug and
/// exception handling tables.
@@ -317,6 +318,7 @@
/// printBasicBlockLabel - This method prints the label for the specified
/// MachineBasicBlock
virtual void printBasicBlockLabel(const MachineBasicBlock *MBB,
+ bool printAlign = false,
bool printColon = false,
bool printComment = true) const;
diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index d2b1d5f..66de06d 100644
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -75,6 +75,10 @@
/// LiveIns - Keep track of the physical registers that are livein of
/// the basicblock.
std::vector<unsigned> LiveIns;
+
+ /// Alignment - Alignment of the basic block. Zero if the basic block does
+ /// not need to be aligned.
+ unsigned Alignment;
/// IsLandingPad - Indicate that this basic block is entered via an
/// exception handler.
@@ -82,7 +86,8 @@
public:
explicit MachineBasicBlock(const BasicBlock *bb = 0)
- : Prev(0), Next(0), BB(bb), Number(-1), xParent(0), IsLandingPad(false) {
+ : Prev(0), Next(0), BB(bb), Number(-1), xParent(0),
+ Alignment(0), IsLandingPad(false) {
Insts.parent = this;
}
@@ -181,6 +186,14 @@
const_livein_iterator livein_end() const { return LiveIns.end(); }
bool livein_empty() const { return LiveIns.empty(); }
+ /// getAlignment - Return alignment of the basic block.
+ ///
+ unsigned getAlignment() const { return Alignment; }
+
+ /// setAlignment - Set alignment of the basic block.
+ ///
+ void setAlignment(unsigned Align) { Alignment = Align; }
+
/// isLandingPad - Returns true if the block is a landing pad. That is
/// this basic block is entered via an exception handler.
bool isLandingPad() const { return IsLandingPad; }
diff --git a/include/llvm/CodeGen/MachineFrameInfo.h b/include/llvm/CodeGen/MachineFrameInfo.h
index 3a04325..4cc9073 100644
--- a/include/llvm/CodeGen/MachineFrameInfo.h
+++ b/include/llvm/CodeGen/MachineFrameInfo.h
@@ -204,7 +204,7 @@
}
/// getObjectAlignment - Return the alignment of the specified stack object...
- int getObjectAlignment(int ObjectIdx) const {
+ unsigned getObjectAlignment(int ObjectIdx) const {
assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
"Invalid Object Idx!");
return Objects[ObjectIdx+NumFixedObjects].Alignment;
diff --git a/include/llvm/CodeGen/Passes.h b/include/llvm/CodeGen/Passes.h
index be7857c..5218f7a 100644
--- a/include/llvm/CodeGen/Passes.h
+++ b/include/llvm/CodeGen/Passes.h
@@ -129,6 +129,10 @@
/// IfConverter Pass - This pass performs machine code if conversion.
FunctionPass *createIfConverterPass();
+ /// LoopAligner Pass - This pass aligns loop headers to target specific
+ /// alignment boundary.
+ FunctionPass *createLoopAlignerPass();
+
/// DebugLabelFoldingPass - This pass prunes out redundant debug labels. This
/// allows a debug emitter to determine if the range of two labels is empty,
/// by seeing if the labels map to the same reduced label.
diff --git a/include/llvm/Target/TargetAsmInfo.h b/include/llvm/Target/TargetAsmInfo.h
index 8597e40..f1d29ac 100644
--- a/include/llvm/Target/TargetAsmInfo.h
+++ b/include/llvm/Target/TargetAsmInfo.h
@@ -164,6 +164,10 @@
/// boundary.
bool AlignmentIsInBytes; // Defaults to true
+ /// TextAlignFillValue - If non-zero, this is used to fill the executable
+ /// space created as the result of a alignment directive.
+ unsigned TextAlignFillValue;
+
//===--- Section Switching Directives ---------------------------------===//
/// SwitchToSectionDirective - This is the directive used when we want to
@@ -503,6 +507,9 @@
bool getAlignmentIsInBytes() const {
return AlignmentIsInBytes;
}
+ unsigned getTextAlignFillValue() const {
+ return TextAlignFillValue;
+ }
const char *getSwitchToSectionDirective() const {
return SwitchToSectionDirective;
}
diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h
index b010a69..4f04ce3 100644
--- a/include/llvm/Target/TargetLowering.h
+++ b/include/llvm/Target/TargetLowering.h
@@ -548,17 +548,23 @@
/// getIfCvtBlockLimit - returns the target specific if-conversion block size
/// limit. Any block whose size is greater should not be predicated.
- virtual unsigned getIfCvtBlockSizeLimit() const {
+ unsigned getIfCvtBlockSizeLimit() const {
return IfCvtBlockSizeLimit;
}
/// getIfCvtDupBlockLimit - returns the target specific size limit for a
/// block to be considered for duplication. Any block whose size is greater
/// should not be duplicated to facilitate its predication.
- virtual unsigned getIfCvtDupBlockSizeLimit() const {
+ unsigned getIfCvtDupBlockSizeLimit() const {
return IfCvtDupBlockSizeLimit;
}
+ /// getPrefLoopAlignment - return the preferred loop alignment.
+ ///
+ unsigned getPrefLoopAlignment() const {
+ return PrefLoopAlignment;
+ }
+
/// getPreIndexedAddressParts - returns true by value, base pointer and
/// offset pointer and addressing mode by reference if the node's address
/// can be legally represented as pre-indexed load / store address.
@@ -583,7 +589,7 @@
/// jumptable.
virtual SDOperand getPICJumpTableRelocBase(SDOperand Table,
SelectionDAG &DAG) const;
-
+
//===--------------------------------------------------------------------===//
// TargetLowering Optimization Methods
//
@@ -890,6 +896,12 @@
void setIfCvtDupBlockSizeLimit(unsigned Limit) {
IfCvtDupBlockSizeLimit = Limit;
}
+
+ /// setPrefLoopAlignment - Set the target's preferred loop alignment. Default
+ /// alignment is zero, it means the target does not care about loop alignment.
+ void setPrefLoopAlignment(unsigned Align) {
+ PrefLoopAlignment = Align;
+ }
public:
@@ -1276,6 +1288,10 @@
/// duplicated during if-conversion.
unsigned IfCvtDupBlockSizeLimit;
+ /// PrefLoopAlignment - The perferred loop alignment.
+ ///
+ unsigned PrefLoopAlignment;
+
/// StackPointerRegisterToSaveRestore - If set to a physical register, this
/// specifies the register that llvm.savestack/llvm.restorestack should save
/// and restore.