[PATCH] D124703: [memprof] Don't instrument PGO and other compiler inserted variables
Teresa Johnson via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Mon May 2 12:18:10 PDT 2022
This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGa0b5af46a2a0: [memprof] Don't instrument PGO and other compiler inserted variables (authored by tejohnson).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D124703/new/
https://reviews.llvm.org/D124703
Files:
llvm/lib/Transforms/Instrumentation/MemProfiler.cpp
llvm/test/Instrumentation/HeapProfiler/skip-compiler-inserted.ll
Index: llvm/test/Instrumentation/HeapProfiler/skip-compiler-inserted.ll
===================================================================
--- /dev/null
+++ llvm/test/Instrumentation/HeapProfiler/skip-compiler-inserted.ll
@@ -0,0 +1,47 @@
+;; Test that we don't instrument loads to PGO counters or other
+;; compiler inserted variables.
+;
+; RUN: opt < %s -passes='function(memprof),module(memprof-module)' -S | FileCheck --check-prefixes=CHECK %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-unknown-linux-gnu"
+
+$__profc__Z3foov = comdat nodeduplicate
+ at __profc__Z3foov = private global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", comdat, align 8
+ at __llvm_gcov_ctr = internal global [1 x i64] zeroinitializer
+
+define void @_Z3foov(i32* %a) {
+entry:
+ ;; Load that should get instrumentation.
+ %tmp1 = load i32, i32* %a, align 4
+ ;; PGO counter update
+ %pgocount = load i64, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3foov, i64 0, i64 0), align 8
+ %0 = add i64 %pgocount, 1
+ store i64 %0, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3foov, i64 0, i64 0), align 8
+ ;; Gcov counter update
+ %gcovcount = load i64, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__llvm_gcov_ctr, i64 0, i64 0), align 8
+ %1 = add i64 %gcovcount, 1
+ store i64 %1, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__llvm_gcov_ctr, i64 0, i64 0), align 8
+ ret void
+}
+
+;; We should only add memory profile instrumentation for the first load.
+; CHECK: define void @_Z3foov
+; CHECK-NEXT: entry:
+; CHECK-NEXT: %0 = load i64, i64* @__memprof_shadow_memory_dynamic_address, align 8
+; CHECK-NEXT: %1 = ptrtoint i32* %a to i64
+; CHECK-NEXT: %2 = and i64 %1, -64
+; CHECK-NEXT: %3 = lshr i64 %2, 3
+; CHECK-NEXT: %4 = add i64 %3, %0
+; CHECK-NEXT: %5 = inttoptr i64 %4 to i64*
+; CHECK-NEXT: %6 = load i64, i64* %5, align 8
+; CHECK-NEXT: %7 = add i64 %6, 1
+; CHECK-NEXT: store i64 %7, i64* %5, align 8
+; CHECK-NEXT: %tmp1 = load i32, i32* %a, align 4
+; CHECK-NEXT: %pgocount = load i64, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3foov, i64 0, i64 0)
+; CHECK-NEXT: %8 = add i64 %pgocount, 1
+; CHECK-NEXT: store i64 %8, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__profc__Z3foov, i64 0, i64 0)
+; CHECK-NEXT: %gcovcount = load i64, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__llvm_gcov_ctr, i64 0, i64 0)
+; CHECK-NEXT: %9 = add i64 %gcovcount, 1
+; CHECK-NEXT: store i64 %9, i64* getelementptr inbounds ([1 x i64], [1 x i64]* @__llvm_gcov_ctr, i64 0, i64 0)
+; CHECK-NEXT: ret void
Index: llvm/lib/Transforms/Instrumentation/MemProfiler.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/MemProfiler.cpp
+++ llvm/lib/Transforms/Instrumentation/MemProfiler.cpp
@@ -32,6 +32,7 @@
#include "llvm/IR/Value.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
+#include "llvm/ProfileData/InstrProf.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
@@ -408,6 +409,25 @@
if (Access.Addr->isSwiftError())
return None;
+ // Peel off GEPs and BitCasts.
+ auto *Addr = Access.Addr->stripInBoundsOffsets();
+
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
+ // Do not instrument PGO counter updates.
+ if (GV->hasSection()) {
+ StringRef SectionName = GV->getSection();
+ // Check if the global is in the PGO counters section.
+ auto OF = Triple(I->getModule()->getTargetTriple()).getObjectFormat();
+ if (SectionName.endswith(
+ getInstrProfSectionName(IPSK_cnts, OF, /*AddSegmentInfo=*/false)))
+ return None;
+ }
+
+ // Do not instrument accesses to LLVM internal variables.
+ if (GV->getName().startswith("__llvm"))
+ return None;
+ }
+
const DataLayout &DL = I->getModule()->getDataLayout();
Access.TypeSize = DL.getTypeStoreSizeInBits(Access.AccessTy);
return Access;
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