[llvm] r216947 - [FastISel] Provide the option to skip target-independent instruction selection. NFC.
Juergen Ributzka
juergen at apple.com
Tue Sep 2 14:07:45 PDT 2014
Author: ributzka
Date: Tue Sep 2 16:07:44 2014
New Revision: 216947
URL: http://llvm.org/viewvc/llvm-project?rev=216947&view=rev
Log:
[FastISel] Provide the option to skip target-independent instruction selection. NFC.
This allows the target to disable target-independent instruction selection and
jump directly into the target-dependent instruction selection code.
This can be beneficial for targets, such as AArch64, which could emit much
better code, but never got a chance to do so, because the target-independent
instruction selector was able to find an instruction sequence.
Modified:
llvm/trunk/include/llvm/CodeGen/FastISel.h
llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp
Modified: llvm/trunk/include/llvm/CodeGen/FastISel.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/FastISel.h?rev=216947&r1=216946&r2=216947&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/FastISel.h (original)
+++ llvm/trunk/include/llvm/CodeGen/FastISel.h Tue Sep 2 16:07:44 2014
@@ -202,6 +202,7 @@ protected:
const TargetLowering &TLI;
const TargetRegisterInfo &TRI;
const TargetLibraryInfo *LibInfo;
+ bool SkipTargetIndependentISel;
/// The position of the last instruction for materializing constants for use
/// in the current block. It resets to EmitStartPt when it makes sense (for
@@ -307,8 +308,9 @@ public:
virtual ~FastISel();
protected:
- explicit FastISel(FunctionLoweringInfo &funcInfo,
- const TargetLibraryInfo *libInfo);
+ explicit FastISel(FunctionLoweringInfo &FuncInfo,
+ const TargetLibraryInfo *LibInfo,
+ bool SkipTargetIndependentISel = false);
/// This method is called by target-independent code when the normal FastISel
/// process fails to select an instruction. This gives targets a chance to
@@ -545,7 +547,6 @@ protected:
}
}
-private:
bool SelectBinaryOp(const User *I, unsigned ISDOpcode);
bool SelectFNeg(const User *I);
@@ -566,6 +567,7 @@ private:
bool SelectInsertValue(const User *I);
+private:
/// \brief Handle PHI nodes in successor blocks.
///
/// Emit code to ensure constants are copied into registers when needed.
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp?rev=216947&r1=216946&r2=216947&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp Tue Sep 2 16:07:44 2014
@@ -1344,8 +1344,24 @@ FastISel::SelectInstruction(const Instru
}
// First, try doing target-independent selection.
- if (SelectOperator(I, I->getOpcode())) {
- ++NumFastIselSuccessIndependent;
+ if (!SkipTargetIndependentISel) {
+ if (SelectOperator(I, I->getOpcode())) {
+ ++NumFastIselSuccessIndependent;
+ DbgLoc = DebugLoc();
+ return true;
+ }
+ // Remove dead code. However, ignore call instructions since we've flushed
+ // the local value map and recomputed the insert point.
+ if (!isa<CallInst>(I)) {
+ recomputeInsertPt();
+ if (SavedInsertPt != FuncInfo.InsertPt)
+ removeDeadCode(FuncInfo.InsertPt, SavedInsertPt);
+ }
+ SavedInsertPt = FuncInfo.InsertPt;
+ }
+ // Next, try calling the target to attempt to handle the instruction.
+ if (TargetSelectInstruction(I)) {
+ ++NumFastIselSuccessTarget;
DbgLoc = DebugLoc();
return true;
}
@@ -1357,18 +1373,6 @@ FastISel::SelectInstruction(const Instru
removeDeadCode(FuncInfo.InsertPt, SavedInsertPt);
}
- // Next, try calling the target to attempt to handle the instruction.
- SavedInsertPt = FuncInfo.InsertPt;
- if (TargetSelectInstruction(I)) {
- ++NumFastIselSuccessTarget;
- DbgLoc = DebugLoc();
- return true;
- }
- // Check for dead code and remove as necessary.
- recomputeInsertPt();
- if (SavedInsertPt != FuncInfo.InsertPt)
- removeDeadCode(FuncInfo.InsertPt, SavedInsertPt);
-
DbgLoc = DebugLoc();
// Undo phi node updates, because they will be added again by SelectionDAG.
if (isa<TerminatorInst>(I))
@@ -1603,14 +1607,16 @@ FastISel::SelectOperator(const User *I,
}
}
-FastISel::FastISel(FunctionLoweringInfo &funcInfo,
- const TargetLibraryInfo *libInfo)
- : FuncInfo(funcInfo), MF(funcInfo.MF), MRI(FuncInfo.MF->getRegInfo()),
+FastISel::FastISel(FunctionLoweringInfo &FuncInfo,
+ const TargetLibraryInfo *LibInfo,
+ bool SkipTargetIndependentISel)
+ : FuncInfo(FuncInfo), MF(FuncInfo.MF), MRI(FuncInfo.MF->getRegInfo()),
MFI(*FuncInfo.MF->getFrameInfo()), MCP(*FuncInfo.MF->getConstantPool()),
TM(FuncInfo.MF->getTarget()), DL(*TM.getSubtargetImpl()->getDataLayout()),
TII(*TM.getSubtargetImpl()->getInstrInfo()),
TLI(*TM.getSubtargetImpl()->getTargetLowering()),
- TRI(*TM.getSubtargetImpl()->getRegisterInfo()), LibInfo(libInfo) {}
+ TRI(*TM.getSubtargetImpl()->getRegisterInfo()), LibInfo(LibInfo),
+ SkipTargetIndependentISel(SkipTargetIndependentISel) {}
FastISel::~FastISel() {}
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