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-rw-r--r--llvm/lib/IR/DebugInfoMetadata.cpp43
-rw-r--r--llvm/lib/Target/X86/X86OptimizeLEAs.cpp55
-rw-r--r--llvm/lib/Transforms/Utils/Local.cpp53
3 files changed, 97 insertions, 54 deletions
diff --git a/llvm/lib/IR/DebugInfoMetadata.cpp b/llvm/lib/IR/DebugInfoMetadata.cpp
index 3db9a3de92e..92f485323d5 100644
--- a/llvm/lib/IR/DebugInfoMetadata.cpp
+++ b/llvm/lib/IR/DebugInfoMetadata.cpp
@@ -15,6 +15,7 @@
#include "LLVMContextImpl.h"
#include "MetadataImpl.h"
#include "llvm/ADT/StringSwitch.h"
+#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/Function.h"
using namespace llvm;
@@ -660,6 +661,48 @@ DIExpression::getFragmentInfo(expr_op_iterator Start, expr_op_iterator End) {
return None;
}
+void DIExpression::appendOffset(SmallVectorImpl<uint64_t> &Ops,
+ int64_t Offset) {
+ if (Offset > 0) {
+ Ops.push_back(dwarf::DW_OP_plus);
+ Ops.push_back(Offset);
+ } else if (Offset < 0) {
+ Ops.push_back(dwarf::DW_OP_minus);
+ Ops.push_back(-Offset);
+ }
+}
+
+DIExpression *
+DIExpression::prependDIExpr(DIBuilder &Builder, DIExpression *DIExpr,
+ bool Deref, int64_t Offset,
+ bool StackValue) {
+ if (!Deref && !Offset && !StackValue)
+ return DIExpr;
+
+ SmallVector<uint64_t, 8> Ops;
+ appendOffset(Ops, Offset);
+ if (Deref)
+ Ops.push_back(dwarf::DW_OP_deref);
+ if (DIExpr)
+ for (auto Op : DIExpr->expr_ops()) {
+ // A DW_OP_stack_value comes at the end, but before a DW_OP_LLVM_fragment.
+ if (StackValue) {
+ if (Op.getOp() == dwarf::DW_OP_stack_value)
+ StackValue = false;
+ else if (Op.getOp() == dwarf::DW_OP_LLVM_fragment) {
+ Ops.push_back(dwarf::DW_OP_stack_value);
+ StackValue = false;
+ }
+ }
+ Ops.push_back(Op.getOp());
+ for (unsigned I = 0; I < Op.getNumArgs(); ++I)
+ Ops.push_back(Op.getArg(I));
+ }
+ if (StackValue)
+ Ops.push_back(dwarf::DW_OP_stack_value);
+ return Builder.createExpression(Ops);
+}
+
bool DIExpression::isConstant() const {
// Recognize DW_OP_constu C DW_OP_stack_value (DW_OP_LLVM_fragment Len Ofs)?.
if (getNumElements() != 3 && getNumElements() != 6)
diff --git a/llvm/lib/Target/X86/X86OptimizeLEAs.cpp b/llvm/lib/Target/X86/X86OptimizeLEAs.cpp
index debb192732e..28c0757b2b6 100644
--- a/llvm/lib/Target/X86/X86OptimizeLEAs.cpp
+++ b/llvm/lib/Target/X86/X86OptimizeLEAs.cpp
@@ -27,6 +27,8 @@
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
+#include "llvm/IR/DebugInfoMetadata.h"
+#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
@@ -221,6 +223,8 @@ public:
StringRef getPassName() const override { return "X86 LEA Optimize"; }
+ bool doInitialization(Module &M) override;
+
/// \brief Loop over all of the basic blocks, replacing address
/// calculations in load and store instructions, if it's already
/// been calculated by LEA. Also, remove redundant LEAs.
@@ -262,6 +266,12 @@ private:
/// \brief Removes redundant address calculations.
bool removeRedundantAddrCalc(MemOpMap &LEAs);
+ /// Replace debug value MI with a new debug value instruction using register
+ /// VReg with an appropriate offset and DIExpression to incorporate the
+ /// address displacement AddrDispShift. Return new debug value instruction.
+ MachineInstr *replaceDebugValue(MachineInstr &MI, unsigned VReg,
+ int64_t AddrDispShift);
+
/// \brief Removes LEAs which calculate similar addresses.
bool removeRedundantLEAs(MemOpMap &LEAs);
@@ -270,6 +280,7 @@ private:
MachineRegisterInfo *MRI;
const X86InstrInfo *TII;
const X86RegisterInfo *TRI;
+ Module *TheModule;
static char ID;
};
@@ -532,6 +543,26 @@ bool OptimizeLEAPass::removeRedundantAddrCalc(MemOpMap &LEAs) {
return Changed;
}
+MachineInstr *OptimizeLEAPass::replaceDebugValue(MachineInstr &MI,
+ unsigned VReg,
+ int64_t AddrDispShift) {
+ DIExpression *Expr = const_cast<DIExpression *>(MI.getDebugExpression());
+
+ if (AddrDispShift != 0) {
+ DIBuilder DIB(*TheModule);
+ Expr = DIExpression::prependDIExpr(DIB, Expr, false, AddrDispShift, true);
+ }
+
+ // Replace DBG_VALUE instruction with modified version.
+ MachineBasicBlock *MBB = MI.getParent();
+ DebugLoc DL = MI.getDebugLoc();
+ bool IsIndirect = MI.isIndirectDebugValue();
+ int64_t Offset = IsIndirect ? MI.getOperand(1).getImm() : 0;
+ const MDNode *Var = MI.getDebugVariable();
+ return BuildMI(*MBB, MBB->erase(&MI), DL, TII->get(TargetOpcode::DBG_VALUE),
+ IsIndirect, VReg, Offset, Var, Expr);
+}
+
// Try to find similar LEAs in the list and replace one with another.
bool OptimizeLEAPass::removeRedundantLEAs(MemOpMap &LEAs) {
bool Changed = false;
@@ -563,13 +594,21 @@ bool OptimizeLEAPass::removeRedundantLEAs(MemOpMap &LEAs) {
// Loop over all uses of the Last LEA and update their operands. Note
// that the correctness of this has already been checked in the
// isReplaceable function.
+ unsigned FirstVReg = First.getOperand(0).getReg();
unsigned LastVReg = Last.getOperand(0).getReg();
- for (auto UI = MRI->use_nodbg_begin(LastVReg),
- UE = MRI->use_nodbg_end();
+ for (auto UI = MRI->use_begin(LastVReg), UE = MRI->use_end();
UI != UE;) {
MachineOperand &MO = *UI++;
MachineInstr &MI = *MO.getParent();
+ if (MI.isDebugValue()) {
+ // Replace DBG_VALUE instruction with modified version using the
+ // register from the replacing LEA and the address displacement
+ // between the LEA instructions.
+ replaceDebugValue(MI, FirstVReg, AddrDispShift);
+ continue;
+ }
+
// Get the number of the first memory operand.
const MCInstrDesc &Desc = MI.getDesc();
int MemOpNo =
@@ -577,7 +616,7 @@ bool OptimizeLEAPass::removeRedundantLEAs(MemOpMap &LEAs) {
X86II::getOperandBias(Desc);
// Update address base.
- MO.setReg(First.getOperand(0).getReg());
+ MO.setReg(FirstVReg);
// Update address disp.
MachineOperand &Op = MI.getOperand(MemOpNo + X86::AddrDisp);
@@ -587,11 +626,8 @@ bool OptimizeLEAPass::removeRedundantLEAs(MemOpMap &LEAs) {
Op.setOffset(Op.getOffset() + AddrDispShift);
}
- // Mark debug values referring to Last LEA as undefined.
- MRI->markUsesInDebugValueAsUndef(LastVReg);
-
// Since we can possibly extend register lifetime, clear kill flags.
- MRI->clearKillFlags(First.getOperand(0).getReg());
+ MRI->clearKillFlags(FirstVReg);
++NumRedundantLEAs;
DEBUG(dbgs() << "OptimizeLEAs: Remove redundant LEA: "; Last.dump(););
@@ -614,6 +650,11 @@ bool OptimizeLEAPass::removeRedundantLEAs(MemOpMap &LEAs) {
return Changed;
}
+bool OptimizeLEAPass::doInitialization(Module &M) {
+ TheModule = &M;
+ return false;
+}
+
bool OptimizeLEAPass::runOnMachineFunction(MachineFunction &MF) {
bool Changed = false;
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index d3002c5fb75..1b643c53fe6 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1259,50 +1259,8 @@ void llvm::findDbgValues(SmallVectorImpl<DbgValueInst *> &DbgValues, Value *V) {
DbgValues.push_back(DVI);
}
-static void appendOffset(SmallVectorImpl<uint64_t> &Ops, int64_t Offset) {
- if (Offset > 0) {
- Ops.push_back(dwarf::DW_OP_plus);
- Ops.push_back(Offset);
- } else if (Offset < 0) {
- Ops.push_back(dwarf::DW_OP_minus);
- Ops.push_back(-Offset);
- }
-}
-
enum { WithStackValue = true };
-/// Prepend \p DIExpr with a deref and offset operation and optionally turn it
-/// into a stack value.
-static DIExpression *prependDIExpr(DIBuilder &Builder, DIExpression *DIExpr,
- bool Deref, int64_t Offset = 0,
- bool StackValue = false) {
- if (!Deref && !Offset && !StackValue)
- return DIExpr;
-
- SmallVector<uint64_t, 8> Ops;
- appendOffset(Ops, Offset);
- if (Deref)
- Ops.push_back(dwarf::DW_OP_deref);
- if (DIExpr)
- for (auto Op : DIExpr->expr_ops()) {
- // A DW_OP_stack_value comes at the end, but before a DW_OP_LLVM_fragment.
- if (StackValue) {
- if (Op.getOp() == dwarf::DW_OP_stack_value)
- StackValue = false;
- else if (Op.getOp() == dwarf::DW_OP_LLVM_fragment) {
- Ops.push_back(dwarf::DW_OP_stack_value);
- StackValue = false;
- }
- }
- Ops.push_back(Op.getOp());
- for (unsigned I = 0; I < Op.getNumArgs(); ++I)
- Ops.push_back(Op.getArg(I));
- }
- if (StackValue)
- Ops.push_back(dwarf::DW_OP_stack_value);
- return Builder.createExpression(Ops);
-}
-
bool llvm::replaceDbgDeclare(Value *Address, Value *NewAddress,
Instruction *InsertBefore, DIBuilder &Builder,
bool Deref, int Offset) {
@@ -1314,7 +1272,7 @@ bool llvm::replaceDbgDeclare(Value *Address, Value *NewAddress,
auto *DIExpr = DDI->getExpression();
assert(DIVar && "Missing variable");
- DIExpr = prependDIExpr(Builder, DIExpr, Deref, Offset);
+ DIExpr = DIExpression::prependDIExpr(Builder, DIExpr, Deref, Offset);
// Insert llvm.dbg.declare immediately after the original alloca, and remove
// old llvm.dbg.declare.
@@ -1348,7 +1306,7 @@ static void replaceOneDbgValueForAlloca(DbgValueInst *DVI, Value *NewAddress,
if (Offset) {
SmallVector<uint64_t, 4> Ops;
Ops.push_back(dwarf::DW_OP_deref);
- appendOffset(Ops, Offset);
+ DIExpression::appendOffset(Ops, Offset);
Ops.append(DIExpr->elements_begin() + 1, DIExpr->elements_end());
DIExpr = Builder.createExpression(Ops);
}
@@ -1398,8 +1356,9 @@ void llvm::salvageDebugInfo(Instruction &I) {
auto *DIExpr = DVI->getExpression();
DIBuilder DIB(M, /*AllowUnresolved*/ false);
// GEP offsets are i32 and thus always fit into an int64_t.
- DIExpr = prependDIExpr(DIB, DIExpr, NoDeref, Offset.getSExtValue(),
- WithStackValue);
+ DIExpr = DIExpression::prependDIExpr(DIB, DIExpr, NoDeref,
+ Offset.getSExtValue(),
+ WithStackValue);
DVI->setOperand(0, MDWrap(I.getOperand(0)));
DVI->setOperand(3, MetadataAsValue::get(I.getContext(), DIExpr));
DEBUG(dbgs() << "SALVAGE: " << *DVI << '\n');
@@ -1411,7 +1370,7 @@ void llvm::salvageDebugInfo(Instruction &I) {
// Rewrite the load into DW_OP_deref.
auto *DIExpr = DVI->getExpression();
DIBuilder DIB(M, /*AllowUnresolved*/ false);
- DIExpr = prependDIExpr(DIB, DIExpr, WithDeref);
+ DIExpr = DIExpression::prependDIExpr(DIB, DIExpr, WithDeref);
DVI->setOperand(0, MDWrap(I.getOperand(0)));
DVI->setOperand(3, MetadataAsValue::get(I.getContext(), DIExpr));
DEBUG(dbgs() << "SALVAGE: " << *DVI << '\n');
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