[llvm-commits] [llvm] r58309 - in /llvm/trunk: lib/CodeGen/PreAllocSplitting.cpp test/CodeGen/X86/pre-split8.ll test/CodeGen/X86/pre-split9.ll
Evan Cheng
evan.cheng at apple.com
Mon Oct 27 17:47:50 PDT 2008
Author: evancheng
Date: Mon Oct 27 19:47:49 2008
New Revision: 58309
URL: http://llvm.org/viewvc/llvm-project?rev=58309&view=rev
Log:
Avoid putting a split past the end of the live range; always shrink wrap live interval in the barrier mbb.
Added:
llvm/trunk/test/CodeGen/X86/pre-split8.ll
llvm/trunk/test/CodeGen/X86/pre-split9.ll
Modified:
llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
Modified: llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp?rev=58309&r1=58308&r2=58309&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp (original)
+++ llvm/trunk/lib/CodeGen/PreAllocSplitting.cpp Mon Oct 27 19:47:49 2008
@@ -109,7 +109,7 @@
SmallPtrSet<MachineInstr*, 4>&, unsigned&);
MachineBasicBlock::iterator
- findRestorePoint(MachineBasicBlock*, MachineInstr*,
+ findRestorePoint(MachineBasicBlock*, MachineInstr*, unsigned,
SmallPtrSet<MachineInstr*, 4>&, unsigned&);
void RecordSplit(unsigned, unsigned, unsigned, int);
@@ -203,12 +203,15 @@
/// found.
MachineBasicBlock::iterator
PreAllocSplitting::findRestorePoint(MachineBasicBlock *MBB, MachineInstr *MI,
+ unsigned LastIdx,
SmallPtrSet<MachineInstr*, 4> &RefsInMBB,
unsigned &RestoreIndex) {
MachineBasicBlock::iterator Pt = MBB->end();
+ unsigned EndIdx = LIs->getMBBEndIdx(MBB);
- // Go bottom up if RefsInMBB is empty.
- if (RefsInMBB.empty()) {
+ // 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->end();
MachineBasicBlock::iterator EndPt = MI;
do {
@@ -224,8 +227,12 @@
} else {
MachineBasicBlock::iterator MII = MI;
MII = ++MII;
+ // FIXME: Limit the number of instructions to examine to reduce
+ // compile time?
while (MII != MBB->end()) {
unsigned Index = LIs->getInstructionIndex(MII);
+ if (Index > LastIdx)
+ break;
unsigned Gap = LIs->findGapBeforeInstr(Index);
if (Gap) {
Pt = MII;
@@ -438,13 +445,15 @@
// If live interval is live in another successor path, then we can't process
// this block. But we may able to do so after all the successors have been
// processed.
- for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
- SE = MBB->succ_end(); SI != SE; ++SI) {
- MachineBasicBlock *SMBB = *SI;
- if (SMBB == SuccMBB)
- continue;
- if (CurrLI->liveAt(LIs->getMBBStartIdx(SMBB)))
- return;
+ if (MBB != BarrierMBB) {
+ for (MachineBasicBlock::succ_iterator SI = MBB->succ_begin(),
+ SE = MBB->succ_end(); SI != SE; ++SI) {
+ MachineBasicBlock *SMBB = *SI;
+ if (SMBB == SuccMBB)
+ continue;
+ if (CurrLI->liveAt(LIs->getMBBStartIdx(SMBB)))
+ return;
+ }
}
Visited.insert(MBB);
@@ -536,7 +545,7 @@
// Find a point to restore the value after the barrier.
unsigned RestoreIndex;
MachineBasicBlock::iterator RestorePt =
- findRestorePoint(BarrierMBB, Barrier, RefsInMBB, RestoreIndex);
+ findRestorePoint(BarrierMBB, Barrier, LR->end, RefsInMBB, RestoreIndex);
if (RestorePt == BarrierMBB->end())
return false;
Added: llvm/trunk/test/CodeGen/X86/pre-split8.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pre-split8.ll?rev=58309&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/pre-split8.ll (added)
+++ llvm/trunk/test/CodeGen/X86/pre-split8.ll Mon Oct 27 19:47:49 2008
@@ -0,0 +1,35 @@
+; RUN: llvm-as < %s | llc -march=x86 -mattr=+sse2 -pre-alloc-split -stats |& \
+; RUN: grep {pre-alloc-split} | grep {Number of intervals split} | grep 1
+
+ at current_surfaces.b = external global i1 ; <i1*> [#uses=1]
+
+declare double @asin(double) nounwind readonly
+
+declare double @tan(double) nounwind readonly
+
+define fastcc void @trace_line(i32 %line) nounwind {
+entry:
+ %.b3 = load i1* @current_surfaces.b ; <i1> [#uses=1]
+ br i1 %.b3, label %bb, label %return
+
+bb: ; preds = %bb9.i, %entry
+ %.rle4 = phi double [ %7, %bb9.i ], [ 0.000000e+00, %entry ] ; <double> [#uses=1]
+ %0 = load double* null, align 8 ; <double> [#uses=3]
+ %1 = fcmp une double %0, 0.000000e+00 ; <i1> [#uses=1]
+ br i1 %1, label %bb9.i, label %bb13.i
+
+bb9.i: ; preds = %bb
+ %2 = sub double %.rle4, %0 ; <double> [#uses=0]
+ %3 = tail call double @asin(double 0.000000e+00) nounwind readonly ; <double> [#uses=0]
+ %4 = mul double 0.000000e+00, %0 ; <double> [#uses=1]
+ %5 = tail call double @tan(double 0.000000e+00) nounwind readonly ; <double> [#uses=0]
+ %6 = mul double %4, 0.000000e+00 ; <double> [#uses=1]
+ %7 = add double %6, 0.000000e+00 ; <double> [#uses=1]
+ br i1 false, label %return, label %bb
+
+bb13.i: ; preds = %bb
+ unreachable
+
+return: ; preds = %bb9.i, %entry
+ ret void
+}
Added: llvm/trunk/test/CodeGen/X86/pre-split9.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pre-split9.ll?rev=58309&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/pre-split9.ll (added)
+++ llvm/trunk/test/CodeGen/X86/pre-split9.ll Mon Oct 27 19:47:49 2008
@@ -0,0 +1,38 @@
+; RUN: llvm-as < %s | llc -march=x86 -mattr=+sse2 -pre-alloc-split -stats |& \
+; RUN: grep {pre-alloc-split} | grep {Number of intervals split} | grep 1
+
+ at current_surfaces.b = external global i1 ; <i1*> [#uses=1]
+
+declare double @sin(double) nounwind readonly
+
+declare double @asin(double) nounwind readonly
+
+declare double @tan(double) nounwind readonly
+
+define fastcc void @trace_line(i32 %line) nounwind {
+entry:
+ %.b3 = load i1* @current_surfaces.b ; <i1> [#uses=1]
+ br i1 %.b3, label %bb, label %return
+
+bb: ; preds = %bb9.i, %entry
+ %.rle4 = phi double [ %8, %bb9.i ], [ 0.000000e+00, %entry ] ; <double> [#uses=1]
+ %0 = load double* null, align 8 ; <double> [#uses=3]
+ %1 = fcmp une double %0, 0.000000e+00 ; <i1> [#uses=1]
+ br i1 %1, label %bb9.i, label %bb13.i
+
+bb9.i: ; preds = %bb
+ %2 = sub double %.rle4, %0 ; <double> [#uses=0]
+ %3 = tail call double @asin(double 0.000000e+00) nounwind readonly ; <double> [#uses=0]
+ %4 = tail call double @sin(double 0.000000e+00) nounwind readonly ; <double> [#uses=1]
+ %5 = mul double %4, %0 ; <double> [#uses=1]
+ %6 = tail call double @tan(double 0.000000e+00) nounwind readonly ; <double> [#uses=0]
+ %7 = mul double %5, 0.000000e+00 ; <double> [#uses=1]
+ %8 = add double %7, 0.000000e+00 ; <double> [#uses=1]
+ br i1 false, label %return, label %bb
+
+bb13.i: ; preds = %bb
+ unreachable
+
+return: ; preds = %bb9.i, %entry
+ ret void
+}
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