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author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-08-02 18:45:54 +0000 |
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committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-08-02 18:45:54 +0000 |
commit | 79a20ce6f0d6c1041a5031aca41b50a1e58b1d4b (patch) | |
tree | 38970feb1da9ccf60caa5b586c081edcaf54a67d /lib/CodeGen/MachineTraceMetrics.h | |
parent | af2662606745bdebaa2cb43096274ce3d33b665f (diff) | |
download | llvm-79a20ce6f0d6c1041a5031aca41b50a1e58b1d4b.tar.gz llvm-79a20ce6f0d6c1041a5031aca41b50a1e58b1d4b.tar.bz2 llvm-79a20ce6f0d6c1041a5031aca41b50a1e58b1d4b.tar.xz |
Compute the critical path length through a trace.
Whenever both instruction depths and instruction heights are known in a
block, it is possible to compute the length of the critical path as
max(depth+height) over the instructions in the block.
The stored live-in lists make it possible to accurately compute the
length of a critical path that bypasses the current (small) block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161197 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/MachineTraceMetrics.h')
-rw-r--r-- | lib/CodeGen/MachineTraceMetrics.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/CodeGen/MachineTraceMetrics.h b/lib/CodeGen/MachineTraceMetrics.h index b0edfeb7bd..33c2d95988 100644 --- a/lib/CodeGen/MachineTraceMetrics.h +++ b/lib/CodeGen/MachineTraceMetrics.h @@ -174,6 +174,11 @@ public: /// Instruction heights have been computed. This implies hasValidHeight(). bool HasValidInstrHeights; + /// Critical path length. This is the number of cycles in the longest data + /// dependency chain through the trace. This is only valid when both + /// HasValidInstrDepths and HasValidInstrHeights are set. + unsigned CriticalPath; + /// Live-in registers. These registers are defined above the current block /// and used by this block or a block below it. /// This does not include PHI uses in the current block, but it does @@ -224,6 +229,7 @@ public: void computeTrace(const MachineBasicBlock*); void computeDepthResources(const MachineBasicBlock*); void computeHeightResources(const MachineBasicBlock*); + unsigned computeCrossBlockCriticalPath(const TraceBlockInfo&); void computeInstrDepths(const MachineBasicBlock*); void computeInstrHeights(const MachineBasicBlock*); void addLiveIns(const MachineInstr *DefMI, |