[llvm-commits] [llvm] r68093 - in /llvm/trunk: lib/CodeGen/PreAllocSplitting.cpp test/CodeGen/X86/pre-split4.ll
Owen Anderson
resistor at mac.com
Tue Mar 31 01:27:10 PDT 2009
Author: resistor
Date: Tue Mar 31 03:27:09 2009
New Revision: 68093
URL: http://llvm.org/viewvc/llvm-project?rev=68093&view=rev
Log:
Remove the "fast" cases for spill and restore point determination, as these were subtlely wrong in obscure cases. Patch the testcase
to account for this change.
Modified:
llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
llvm/trunk/test/CodeGen/X86/pre-split4.ll
Modified: llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp?rev=68093&r1=68092&r2=68093&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp (original)
+++ llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp Tue Mar 31 03:27:09 2009
@@ -232,68 +232,38 @@
unsigned &SpillIndex) {
MachineBasicBlock::iterator Pt = MBB->begin();
- // Go top down if RefsInMBB is empty.
- if (RefsInMBB.empty() && !DefMI) {
- MachineBasicBlock::iterator MII = MBB->begin();
- MachineBasicBlock::iterator EndPt = MI;
-
- if (MII == EndPt) return Pt;
-
- do {
- ++MII;
- unsigned Index = LIs->getInstructionIndex(MII);
- unsigned Gap = LIs->findGapBeforeInstr(Index);
-
- // We can't insert the spill between the barrier (a call), and its
- // corresponding call frame setup/teardown.
- if (prior(MII)->getOpcode() == TRI->getCallFrameSetupOpcode()) {
- bool reachedBarrier = false;
- do {
- if (MII == EndPt) {
- reachedBarrier = true;
- break;
- }
- ++MII;
- } while (MII->getOpcode() != TRI->getCallFrameDestroyOpcode());
-
- if (reachedBarrier) break;
- } else if (Gap) {
- Pt = MII;
- SpillIndex = Gap;
- break;
- }
- } while (MII != EndPt);
- } else {
- MachineBasicBlock::iterator MII = MI;
- MachineBasicBlock::iterator EndPt = DefMI
- ? MachineBasicBlock::iterator(DefMI) : MBB->begin();
+ MachineBasicBlock::iterator MII = MI;
+ MachineBasicBlock::iterator EndPt = DefMI
+ ? MachineBasicBlock::iterator(DefMI) : MBB->begin();
- while (MII != EndPt && !RefsInMBB.count(MII)) {
- unsigned Index = LIs->getInstructionIndex(MII);
-
- // We can't insert the spill between the barrier (a call), and its
- // corresponding call frame setup.
- if (prior(MII)->getOpcode() == TRI->getCallFrameSetupOpcode()) {
+ while (MII != EndPt && !RefsInMBB.count(MII) &&
+ MII->getOpcode() != TRI->getCallFrameSetupOpcode())
+ --MII;
+ if (MII == EndPt || RefsInMBB.count(MII)) return Pt;
+
+ while (MII != EndPt && !RefsInMBB.count(MII)) {
+ unsigned Index = LIs->getInstructionIndex(MII);
+
+ // We can't insert the spill between the barrier (a call), and its
+ // corresponding call frame setup.
+ if (MII->getOpcode() == TRI->getCallFrameDestroyOpcode()) {
+ while (MII->getOpcode() != TRI->getCallFrameSetupOpcode()) {
--MII;
- continue;
- } if (MII->getOpcode() == TRI->getCallFrameDestroyOpcode()) {
- bool reachedBarrier = false;
- while (MII->getOpcode() != TRI->getCallFrameSetupOpcode()) {
- --MII;
- if (MII == EndPt) {
- reachedBarrier = true;
- break;
- }
+ if (MII == EndPt) {
+ return Pt;
}
-
- if (reachedBarrier) break;
- else continue;
- } else if (LIs->hasGapBeforeInstr(Index)) {
- Pt = MII;
- SpillIndex = LIs->findGapBeforeInstr(Index, true);
}
- --MII;
+ continue;
+ } else if (LIs->hasGapBeforeInstr(Index)) {
+ Pt = MII;
+ SpillIndex = LIs->findGapBeforeInstr(Index, true);
}
+
+ if (RefsInMBB.count(MII))
+ return Pt;
+
+
+ --MII;
}
return Pt;
@@ -311,81 +281,44 @@
// FIXME: Allow spill to be inserted to the beginning of the mbb. Update mbb
// begin index accordingly.
MachineBasicBlock::iterator Pt = MBB->end();
- unsigned EndIdx = LIs->getMBBEndIdx(MBB);
+ MachineBasicBlock::iterator EndPt = MBB->getFirstTerminator();
- // Go bottom up if RefsInMBB is empty and the end of the mbb isn't beyond
- // the last index in the live range.
- if (RefsInMBB.empty() && LastIdx >= EndIdx) {
- MachineBasicBlock::iterator MII = MBB->getFirstTerminator();
- MachineBasicBlock::iterator EndPt = MI;
-
- if (MII == EndPt) return Pt;
-
- --MII;
- do {
- unsigned Index = LIs->getInstructionIndex(MII);
- unsigned Gap = LIs->findGapBeforeInstr(Index);
-
- // We can't insert a restore between the barrier (a call) and its
- // corresponding call frame teardown.
- if (MII->getOpcode() == TRI->getCallFrameDestroyOpcode()) {
- bool reachedBarrier = false;
- while (MII->getOpcode() != TRI->getCallFrameSetupOpcode()) {
- --MII;
- if (MII == EndPt) {
- reachedBarrier = true;
- break;
- }
- }
-
- if (reachedBarrier) break;
- else continue;
- } else if (Gap) {
- Pt = MII;
- RestoreIndex = Gap;
- break;
- }
-
- --MII;
- } while (MII != EndPt);
- } else {
- MachineBasicBlock::iterator MII = MI;
- MII = ++MII;
-
- // FIXME: Limit the number of instructions to examine to reduce
- // compile time?
- while (MII != MBB->getFirstTerminator()) {
- unsigned Index = LIs->getInstructionIndex(MII);
- if (Index > LastIdx)
- break;
- unsigned Gap = LIs->findGapBeforeInstr(Index);
+ // We start at the call, so walk forward until we find the call frame teardown
+ // since we can't insert restores before that. Bail if we encounter a use
+ // during this time.
+ MachineBasicBlock::iterator MII = MI;
+ if (MII == EndPt) return Pt;
+
+ while (MII != EndPt && !RefsInMBB.count(MII) &&
+ MII->getOpcode() != TRI->getCallFrameDestroyOpcode())
+ ++MII;
+ if (MII == EndPt || RefsInMBB.count(MII)) return Pt;
+ ++MII;
+
+ // FIXME: Limit the number of instructions to examine to reduce
+ // compile time?
+ while (MII != EndPt) {
+ unsigned Index = LIs->getInstructionIndex(MII);
+ if (Index > LastIdx)
+ break;
+ unsigned Gap = LIs->findGapBeforeInstr(Index);
- // We can't insert a restore between the barrier (a call) and its
- // corresponding call frame teardown.
- if (MII->getOpcode() == TRI->getCallFrameDestroyOpcode()) {
+ // We can't insert a restore between the barrier (a call) and its
+ // corresponding call frame teardown.
+ if (MII->getOpcode() == TRI->getCallFrameSetupOpcode()) {
+ do {
+ if (MII == EndPt || RefsInMBB.count(MII)) return Pt;
++MII;
- continue;
- } else if (prior(MII)->getOpcode() == TRI->getCallFrameSetupOpcode()) {
- bool reachedBarrier = false;
- do {
- if (MII == MBB->getFirstTerminator() || RefsInMBB.count(MII)) {
- reachedBarrier = true;
- break;
- }
-
- ++MII;
- } while (MII->getOpcode() != TRI->getCallFrameDestroyOpcode());
-
- if (reachedBarrier) break;
- } else if (Gap) {
- Pt = MII;
- RestoreIndex = Gap;
- }
-
- if (RefsInMBB.count(MII))
- break;
- ++MII;
+ } while (MII->getOpcode() != TRI->getCallFrameDestroyOpcode());
+ } else if (Gap) {
+ Pt = MII;
+ RestoreIndex = Gap;
}
+
+ if (RefsInMBB.count(MII))
+ return Pt;
+
+ ++MII;
}
return Pt;
Modified: llvm/trunk/test/CodeGen/X86/pre-split4.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pre-split4.ll?rev=68093&r1=68092&r2=68093&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/pre-split4.ll (original)
+++ llvm/trunk/test/CodeGen/X86/pre-split4.ll Tue Mar 31 03:27:09 2009
@@ -1,5 +1,5 @@
; RUN: llvm-as < %s | llc -march=x86 -mattr=+sse2 -pre-alloc-split -stats |& \
-; RUN: grep {pre-alloc-split} | grep {Number of intervals split} | grep 4
+; RUN: grep {pre-alloc-split} | grep {Number of intervals split} | grep 2
define i32 @main(i32 %argc, i8** %argv) nounwind {
entry:
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