[PATCH] D21405: [PGO] IRPGO pre-cleanup pass changes

[David Li via llvm-commits]

davidxl added inline comments.

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Comment at: lib/Transforms/IPO/PassManagerBuilder.cpp:238
@@ +237,3 @@
+        computePreInlineThresholdFromOptLevels(OptLevel, SizeLevel)));
+    MPM.add(createEarlyCSEPass());      // Catch trivial redundancies
+    MPM.add(createJumpThreadingPass()); // Thread jumps.
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A more effective cleanup should probably include SROA + EarlyCSE

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Comment at: lib/Transforms/IPO/PassManagerBuilder.cpp:239
@@ +238,3 @@
+    MPM.add(createEarlyCSEPass());      // Catch trivial redundancies
+    MPM.add(createJumpThreadingPass()); // Thread jumps.
+    MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
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I doubt JumpThreading pass will make any difference here. Can you experiment removing it?

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Comment at: lib/Transforms/IPO/PassManagerBuilder.cpp:240
@@ +239,3 @@
+    MPM.add(createJumpThreadingPass()); // Thread jumps.
+    MPM.add(createCorrelatedValuePropagationPass()); // Propagate conditionals
+    MPM.add(createCFGSimplificationPass());          // Merge & remove BBs
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Experimenting removing this pass too?

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Comment at: lib/Transforms/IPO/PassManagerBuilder.cpp:242
@@ +241,3 @@
+    MPM.add(createCFGSimplificationPass());          // Merge & remove BBs
+    MPM.add(createInstructionCombiningPass());       // Combine silly seq's
+    MPM.add(createGVNPass(DisableGVNLoadPRE));       // Remove redundancies
----------------
CFG simplification and inst combine look ok

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Comment at: lib/Transforms/IPO/PassManagerBuilder.cpp:243
@@ +242,3 @@
+    MPM.add(createInstructionCombiningPass());       // Combine silly seq's
+    MPM.add(createGVNPass(DisableGVNLoadPRE));       // Remove redundancies
+    addExtensionsToPM(EP_Peephole, MPM);
----------------
Remove GVN pass?


http://reviews.llvm.org/D21405