[llvm-commits] CVS: llvm/lib/CodeGen/LiveIntervalAnalysis.cpp VirtRegMap.cpp

[Evan Cheng]

Hi Dan,

Is this necessary? ARM is already doing this by marking trivially re- 
materializable instructions with let isReMaterializable = 1.

Evan

On Jun 14, 2007, at 1:51 PM, Dan Gohman wrote:

>
>
> Changes in directory llvm/lib/CodeGen:
>
> LiveIntervalAnalysis.cpp updated: 1.246 -> 1.247
> VirtRegMap.cpp updated: 1.111 -> 1.112
> ---
> Log message:
>
> Add a target hook to allow loads from constant pools to be  
> rematerialized, and an
> implementation for x86.
>
>
> ---
> Diffs of the changes:  (+6 -3)
>
>  LiveIntervalAnalysis.cpp |    6 ++++--
>  VirtRegMap.cpp           |    3 ++-
>  2 files changed, 6 insertions(+), 3 deletions(-)
>
>
> Index: llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
> diff -u llvm/lib/CodeGen/LiveIntervalAnalysis.cpp:1.246 llvm/lib/ 
> CodeGen/LiveIntervalAnalysis.cpp:1.247
> --- llvm/lib/CodeGen/LiveIntervalAnalysis.cpp:1.246	Fri Jun  8  
> 12:18:56 2007
> +++ llvm/lib/CodeGen/LiveIntervalAnalysis.cpp	Thu Jun 14 15:50:44 2007
> @@ -336,12 +336,14 @@
>    // time we see a vreg.
>    if (interval.empty()) {
>      // Remember if the definition can be rematerialized. All  
> load's from fixed
> -    // stack slots are re-materializable.
> +    // stack slots are re-materializable. The target may permit  
> other loads to
> +    // be re-materialized as well.
>      int FrameIdx = 0;
>      if (vi.DefInst &&
>          (tii_->isReMaterializable(vi.DefInst->getOpcode()) ||
>           (tii_->isLoadFromStackSlot(vi.DefInst, FrameIdx) &&
> -          mf_->getFrameInfo()->isFixedObjectIndex(FrameIdx))))
> +          mf_->getFrameInfo()->isFixedObjectIndex(FrameIdx)) ||
> +         tii_->isOtherReMaterializableLoad(vi.DefInst)))
>        interval.remat = vi.DefInst;
>
>      // Get the Idx of the defining instructions.
>
>
> Index: llvm/lib/CodeGen/VirtRegMap.cpp
> diff -u llvm/lib/CodeGen/VirtRegMap.cpp:1.111 llvm/lib/CodeGen/ 
> VirtRegMap.cpp:1.112
> --- llvm/lib/CodeGen/VirtRegMap.cpp:1.111	Thu Apr 26 13:59:33 2007
> +++ llvm/lib/CodeGen/VirtRegMap.cpp	Thu Jun 14 15:50:44 2007
> @@ -664,7 +664,8 @@
>      // If this instruction is being rematerialized, just remove it!
>      int FrameIdx;
>      if ((TID->Flags & M_REMATERIALIZIBLE) ||
> -        TII->isLoadFromStackSlot(&MI, FrameIdx)) {
> +        TII->isLoadFromStackSlot(&MI, FrameIdx) ||
> +        TII->isOtherReMaterializableLoad(&MI)) {
>        bool Remove = true;
>        for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
>          MachineOperand &MO = MI.getOperand(i);
>
>
>
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