PGO: Add IR-based PGO.

ldc-developers · Dec 28, 2017 · c60bf81 · c60bf81
1 parent 7cf6565
commit c60bf81
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Showing 3 changed files with 85 additions and 2 deletions.
diff --git a/driver/cl_options_instrumentation.cpp b/driver/cl_options_instrumentation.cpp
@@ -78,7 +78,20 @@ void initializeInstrumentationOptionsFromCmdline() {
     pgoMode = PGO_ASTBasedUse;
     initFromPathString(global.params.datafileInstrProf, ASTPGOInstrUseFile);
   }
+#if LDC_LLVM_VER >= 309
+  else if (IRPGOInstrGenFile.getNumOccurrences() > 0) {
+    pgoMode = PGO_IRBasedInstr;
+    if (IRPGOInstrGenFile.empty()) {
+      global.params.datafileInstrProf = "default_%m.profraw";
+    } else {
+      initFromPathString(global.params.datafileInstrProf, IRPGOInstrGenFile);
+    }
+  } else if (!IRPGOInstrUseFile.empty()) {
+    pgoMode = PGO_IRBasedUse;
+    initFromPathString(global.params.datafileInstrProf, IRPGOInstrUseFile);
+  }
 #endif
+#endif // LDC_WITH_PGO
 }
 
 } // namespace opts
diff --git a/gen/optimizer.cpp b/gen/optimizer.cpp
@@ -201,7 +201,8 @@ static void addSanitizerCoveragePass(const PassManagerBuilder &Builder,
 }
 
 // Adds PGO instrumentation generation and use passes.
-static void addPGOPasses(legacy::PassManagerBase &mpm, unsigned optLevel) {
+static void addPGOPasses(PassManagerBuilder &builder,
+                         legacy::PassManagerBase &mpm, unsigned optLevel) {
 #if LDC_WITH_PGO
   if (opts::isInstrumentingForASTBasedPGO()) {
     InstrProfOptions options;
@@ -222,7 +223,17 @@ static void addPGOPasses(legacy::PassManagerBase &mpm, unsigned optLevel) {
     }
 #endif
   }
+#if LDC_LLVM_VER >= 309
+  else if (opts::isInstrumentingForIRBasedPGO()) {
+#if LDC_LLVM_VER >= 600
+    builder.EnablePGOInstrGen = true;
+#endif
+    builder.PGOInstrGen = global.params.datafileInstrProf;
+  } else if (opts::isUsingIRBasedPGOProfile()) {
+    builder.PGOInstrUse = global.params.datafileInstrProf;
+  }
 #endif
+#endif // LDC_WITH_PGO
 }
 
 /**
@@ -324,7 +335,7 @@ static void addOptimizationPasses(legacy::PassManagerBase &mpm,
   builder.addExtension(PassManagerBuilder::EP_OptimizerLast,
                        addStripExternalsPass);
 
-  addPGOPasses(mpm, optLevel);
+  addPGOPasses(builder, mpm, optLevel);
 
   builder.populateFunctionPassManager(fpm);
   builder.populateModulePassManager(mpm);

diff --git a/tests/PGO/irbased_indirect_calls.d b/tests/PGO/irbased_indirect_calls.d
@@ -0,0 +1,59 @@
+// Test instrumentation of indirect calls
+
+// REQUIRES: atleast_llvm309
+
+// RUN: %ldc -O3 -fprofile-generate=%t.profraw -run %s  \
+// RUN:   &&  %profdata merge %t.profraw -o %t.profdata \
+// RUN:   &&  %ldc -O3 -c -output-ll -of=%t.use.ll -fprofile-use=%t.profdata %s \
+// RUN:   &&  FileCheck %s -check-prefix=PROFUSE < %t.use.ll
+
+import ldc.attributes : weak;
+
+extern (C)
+{ // simplify name mangling for simpler string matching
+
+    @weak // disable reasoning about this function
+    void hot()
+    {
+    }
+
+    void luke()
+    {
+    }
+
+    void cold()
+    {
+    }
+
+    void function() foo;
+
+    @weak // disable reasoning about this function
+    void select_func(int i)
+    {
+        if (i < 1700)
+            foo = &hot;
+        else if (i < 1990)
+            foo = &luke;
+        else
+            foo = &cold;
+    }
+
+} // extern C
+
+// PROFUSE-LABEL: @_Dmain(
+int main()
+{
+    for (int i; i < 2000; ++i)
+    {
+        select_func(i);
+
+        // PROFUSE:  [[REG1:%[0-9]+]] = load void ()*, void ()** @foo
+        // PROFUSE:  [[REG2:%[0-9]+]] = icmp eq void ()* [[REG1]], @hot
+        // PROFUSE:  call void @hot()
+        // PROFUSE:  call void [[REG1]]()
+
+        foo();
+    }
+
+    return 0;
+}