Changes in directory llvm/lib/CodeGen:
PrologEpilogInserter.cpp updated: 1.76 -> 1.77
---
Log message:
If target decides to create an emergency spill slot, make sure it's closest to
SP or frame pointer.
---
Diffs of the changes: (+56 -7)
PrologEpilogInserter.cpp | 63 +++++++++++++++++++++++++++++++++++++++++------
1 files changed, 56 insertions(+), 7 deletions(-)
Index: llvm/lib/CodeGen/PrologEpilogInserter.cpp
diff -u llvm/lib/CodeGen/PrologEpilogInserter.cpp:1.76
llvm/lib/CodeGen/PrologEpilogInserter.cpp:1.77
--- llvm/lib/CodeGen/PrologEpilogInserter.cpp:1.76 Thu Mar 1 04:23:33 2007
+++ llvm/lib/CodeGen/PrologEpilogInserter.cpp Tue Mar 6 04:02:38 2007
@@ -39,6 +39,9 @@
/// frame indexes with appropriate references.
///
bool runOnMachineFunction(MachineFunction &Fn) {
+ const MRegisterInfo *MRI = Fn.getTarget().getRegisterInfo();
+ RS = MRI->requiresRegisterScavenging(Fn) ? new RegScavenger() : NULL;
+
// Get MachineModuleInfo so that we can track the construction of the
// frame.
if (MachineModuleInfo *MMI = getAnalysisToUpdate<MachineModuleInfo>()) {
@@ -47,8 +50,7 @@
// Allow the target machine to make some adjustments to the function
// e.g. UsedPhysRegs before calculateCalleeSavedRegisters.
- Fn.getTarget().getRegisterInfo()
- ->processFunctionBeforeCalleeSavedScan(Fn);
+ MRI->processFunctionBeforeCalleeSavedScan(Fn, RS);
// Scan the function for modified callee saved registers and insert spill
// code for any callee saved registers that are modified. Also calculate
@@ -78,10 +80,13 @@
//
replaceFrameIndices(Fn);
+ delete RS;
return true;
}
private:
+ RegScavenger *RS;
+
// MinCSFrameIndex, MaxCSFrameIndex - Keeps the range of callee saved
// stack frame indexes.
unsigned MinCSFrameIndex, MaxCSFrameIndex;
@@ -363,11 +368,37 @@
}
}
+ // Make sure the special register scavenging spill slot is closest to the
+ // frame pointer if a frame pointer is required.
+ const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
+ if (RS && RegInfo->hasFP(Fn)) {
+ int SFI = RS->getScavengingFrameIndex();
+ if (SFI >= 0) {
+ // If stack grows down, we need to add size of find the lowest
+ // address of the object.
+ if (StackGrowsDown)
+ Offset += FFI->getObjectSize(SFI);
+
+ unsigned Align = FFI->getObjectAlignment(SFI);
+ // Adjust to alignment boundary
+ Offset = (Offset+Align-1)/Align*Align;
+
+ if (StackGrowsDown) {
+ FFI->setObjectOffset(SFI, -Offset); // Set the computed offset
+ } else {
+ FFI->setObjectOffset(SFI, Offset);
+ Offset += FFI->getObjectSize(SFI);
+ }
+ }
+ }
+
// Then assign frame offsets to stack objects that are not used to spill
// callee saved registers.
for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
continue;
+ if (RS && (int)i == RS->getScavengingFrameIndex())
+ continue;
// If stack grows down, we need to add size of find the lowest
// address of the object.
@@ -389,10 +420,32 @@
}
}
+ // Make sure the special register scavenging spill slot is closest to the
+ // stack pointer.
+ if (RS) {
+ int SFI = RS->getScavengingFrameIndex();
+ if (SFI >= 0) {
+ // If stack grows down, we need to add size of find the lowest
+ // address of the object.
+ if (StackGrowsDown)
+ Offset += FFI->getObjectSize(SFI);
+
+ unsigned Align = FFI->getObjectAlignment(SFI);
+ // Adjust to alignment boundary
+ Offset = (Offset+Align-1)/Align*Align;
+
+ if (StackGrowsDown) {
+ FFI->setObjectOffset(SFI, -Offset); // Set the computed offset
+ } else {
+ FFI->setObjectOffset(SFI, Offset);
+ Offset += FFI->getObjectSize(SFI);
+ }
+ }
+ }
+
// Round up the size to a multiple of the alignment, but only if there are
// calls or alloca's in the function. This ensures that any calls to
// subroutines have their stack frames suitable aligned.
- const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
if (!RegInfo->targetHandlesStackFrameRounding() &&
(FFI->hasCalls() || FFI->hasVarSizedObjects())) {
// When we have no frame pointer, we reserve argument space for call sites
@@ -442,7 +495,6 @@
const TargetMachine &TM = Fn.getTarget();
assert(TM.getRegisterInfo() && "TM::getRegisterInfo() must be implemented!");
const MRegisterInfo &MRI = *TM.getRegisterInfo();
- RegScavenger *RS=MRI.requiresRegisterScavenging(Fn) ? new
RegScavenger():NULL;
for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB)
{
if (RS) RS->enterBasicBlock(BB);
@@ -458,7 +510,4 @@
if (RS) RS->forward(I);
}
}
-
- delete RS;
}
-
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