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author | Evan Cheng <evan.cheng@apple.com> | 2008-10-28 00:47:49 +0000 |
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committer | Evan Cheng <evan.cheng@apple.com> | 2008-10-28 00:47:49 +0000 |
commit | f62ce370a48e1621af7934e668c215b8109cddb7 (patch) | |
tree | dd23fbfca63b2a9f71c96c6d5b8de65636580b40 | |
parent | e649778b555465fd25811daef98f6ddbc9efd378 (diff) | |
download | external_llvm-f62ce370a48e1621af7934e668c215b8109cddb7.zip external_llvm-f62ce370a48e1621af7934e668c215b8109cddb7.tar.gz external_llvm-f62ce370a48e1621af7934e668c215b8109cddb7.tar.bz2 |
Avoid putting a split past the end of the live range; always shrink wrap live interval in the barrier mbb.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58309 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/CodeGen/PreAllocSplitting.cpp | 31 | ||||
-rw-r--r-- | test/CodeGen/X86/pre-split8.ll | 35 | ||||
-rw-r--r-- | test/CodeGen/X86/pre-split9.ll | 38 |
3 files changed, 93 insertions, 11 deletions
diff --git a/lib/CodeGen/PreAllocSplitting.cpp b/lib/CodeGen/PreAllocSplitting.cpp index f3a3ac3..5c1c223 100644 --- a/lib/CodeGen/PreAllocSplitting.cpp +++ b/lib/CodeGen/PreAllocSplitting.cpp @@ -109,7 +109,7 @@ namespace { 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 @@ PreAllocSplitting::findSpillPoint(MachineBasicBlock *MBB, MachineInstr *MI, /// 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 @@ PreAllocSplitting::findRestorePoint(MachineBasicBlock *MBB, MachineInstr *MI, } 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 @@ PreAllocSplitting::ShrinkWrapLiveInterval(VNInfo *ValNo, MachineBasicBlock *MBB, // 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 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) { // 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; diff --git a/test/CodeGen/X86/pre-split8.ll b/test/CodeGen/X86/pre-split8.ll new file mode 100644 index 0000000..eb6d49f --- /dev/null +++ b/test/CodeGen/X86/pre-split8.ll @@ -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 + +@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 +} diff --git a/test/CodeGen/X86/pre-split9.ll b/test/CodeGen/X86/pre-split9.ll new file mode 100644 index 0000000..bfafe85 --- /dev/null +++ b/test/CodeGen/X86/pre-split9.ll @@ -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 + +@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 +} |