[llvm-commits] [llvm] r161463 - in /llvm/trunk: include/llvm/CodeGen/MachineBasicBlock.h include/llvm/CodeGen/MachineBranchProbabilityInfo.h lib/CodeGen/MachineBasicBlock.cpp lib/CodeGen/MachineBranchProbabilityInfo.cpp
Jakob Stoklund Olesen
stoklund at 2pi.dk
Tue Aug 7 19:18:55 PDT 2012
I can't share the test case, but any giant switch should do the trick.
it should be a trivial fix, I'm not sure why it failed.
On Aug 7, 2012, at 7:01 PM, Chandler Carruth <chandlerc at google.com> wrote:
> Can you send me a test case for the quadratic behavior? I'm happy to help with fixing it
>
> On Aug 7, 2012 6:12 PM, "Jakob Stoklund Olesen" <stoklund at 2pi.dk> wrote:
> Author: stoklund
> Date: Tue Aug 7 20:10:31 2012
> New Revision: 161463
>
> URL: http://llvm.org/viewvc/llvm-project?rev=161463&view=rev
> Log:
> Revert "Fix a quadratic algorithm in MachineBranchProbabilityInfo."
>
> It caused an assertion failure when compiling consumer-typeset.
>
> Modified:
> llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h
> llvm/trunk/include/llvm/CodeGen/MachineBranchProbabilityInfo.h
> llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp
> llvm/trunk/lib/CodeGen/MachineBranchProbabilityInfo.cpp
>
> Modified: llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h?rev=161463&r1=161462&r2=161463&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h (original)
> +++ llvm/trunk/include/llvm/CodeGen/MachineBasicBlock.h Tue Aug 7 20:10:31 2012
> @@ -572,7 +572,7 @@
> /// getSuccWeight - Return weight of the edge from this block to MBB. This
> /// method should NOT be called directly, but by using getEdgeWeight method
> /// from MachineBranchProbabilityInfo class.
> - uint32_t getSuccWeight(const_succ_iterator Succ) const;
> + uint32_t getSuccWeight(const MachineBasicBlock *succ) const;
>
>
> // Methods used to maintain doubly linked list of blocks...
>
> Modified: llvm/trunk/include/llvm/CodeGen/MachineBranchProbabilityInfo.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineBranchProbabilityInfo.h?rev=161463&r1=161462&r2=161463&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/CodeGen/MachineBranchProbabilityInfo.h (original)
> +++ llvm/trunk/include/llvm/CodeGen/MachineBranchProbabilityInfo.h Tue Aug 7 20:10:31 2012
> @@ -16,12 +16,14 @@
> #define LLVM_CODEGEN_MACHINEBRANCHPROBABILITYINFO_H
>
> #include "llvm/Pass.h"
> -#include "llvm/CodeGen/MachineBasicBlock.h"
> #include "llvm/Support/BranchProbability.h"
> #include <climits>
>
> namespace llvm {
>
> +class raw_ostream;
> +class MachineBasicBlock;
> +
> class MachineBranchProbabilityInfo : public ImmutablePass {
> virtual void anchor();
>
> @@ -50,11 +52,6 @@
> uint32_t getEdgeWeight(const MachineBasicBlock *Src,
> const MachineBasicBlock *Dst) const;
>
> - // Same thing, but using a const_succ_iterator from Src. This is faster when
> - // the iterator is already available.
> - uint32_t getEdgeWeight(const MachineBasicBlock *Src,
> - MachineBasicBlock::const_succ_iterator Dst) const;
> -
> // Get sum of the block successors' weights, potentially scaling them to fit
> // within 32-bits. If scaling is required, sets Scale based on the necessary
> // adjustment. Any edge weights used with the sum should be divided by Scale.
>
> Modified: llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp?rev=161463&r1=161462&r2=161463&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp (original)
> +++ llvm/trunk/lib/CodeGen/MachineBasicBlock.cpp Tue Aug 7 20:10:31 2012
> @@ -912,11 +912,12 @@
>
> /// getSuccWeight - Return weight of the edge from this block to MBB.
> ///
> -uint32_t MachineBasicBlock::getSuccWeight(const_succ_iterator Succ) const {
> +uint32_t MachineBasicBlock::getSuccWeight(const MachineBasicBlock *succ) const {
> if (Weights.empty())
> return 0;
>
> - return *getWeightIterator(Succ);
> + const_succ_iterator I = std::find(Successors.begin(), Successors.end(), succ);
> + return *getWeightIterator(I);
> }
>
> /// getWeightIterator - Return wight iterator corresonding to the I successor
>
> Modified: llvm/trunk/lib/CodeGen/MachineBranchProbabilityInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineBranchProbabilityInfo.cpp?rev=161463&r1=161462&r2=161463&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/MachineBranchProbabilityInfo.cpp (original)
> +++ llvm/trunk/lib/CodeGen/MachineBranchProbabilityInfo.cpp Tue Aug 7 20:10:31 2012
> @@ -38,7 +38,7 @@
> Scale = 1;
> for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
> E = MBB->succ_end(); I != E; ++I) {
> - uint32_t Weight = getEdgeWeight(MBB, I);
> + uint32_t Weight = getEdgeWeight(MBB, *I);
> Sum += Weight;
> }
>
> @@ -53,30 +53,22 @@
> Sum = 0;
> for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
> E = MBB->succ_end(); I != E; ++I) {
> - uint32_t Weight = getEdgeWeight(MBB, I);
> + uint32_t Weight = getEdgeWeight(MBB, *I);
> Sum += Weight / Scale;
> }
> assert(Sum <= UINT32_MAX);
> return Sum;
> }
>
> -uint32_t MachineBranchProbabilityInfo::
> -getEdgeWeight(const MachineBasicBlock *Src,
> - MachineBasicBlock::const_succ_iterator Dst) const {
> +uint32_t
> +MachineBranchProbabilityInfo::getEdgeWeight(const MachineBasicBlock *Src,
> + const MachineBasicBlock *Dst) const {
> uint32_t Weight = Src->getSuccWeight(Dst);
> if (!Weight)
> return DEFAULT_WEIGHT;
> return Weight;
> }
>
> -uint32_t MachineBranchProbabilityInfo::
> -getEdgeWeight(const MachineBasicBlock *Src,
> - const MachineBasicBlock *Dst) const {
> - // This is a linear search. Try to use the const_succ_iterator version when
> - // possible.
> - return getEdgeWeight(Src, std::find(Src->succ_begin(), Src->succ_end(), Dst));
> -}
> -
> bool MachineBranchProbabilityInfo::isEdgeHot(MachineBasicBlock *Src,
> MachineBasicBlock *Dst) const {
> // Hot probability is at least 4/5 = 80%
> @@ -90,7 +82,7 @@
> MachineBasicBlock *MaxSucc = 0;
> for (MachineBasicBlock::const_succ_iterator I = MBB->succ_begin(),
> E = MBB->succ_end(); I != E; ++I) {
> - uint32_t Weight = getEdgeWeight(MBB, I);
> + uint32_t Weight = getEdgeWeight(MBB, *I);
> if (Weight > MaxWeight) {
> MaxWeight = Weight;
> MaxSucc = *I;
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20120807/4ff9dc96/attachment.html>
More information about the llvm-commits
mailing list